NAVY DEPARTMENT
OFFICE OF NAVAL. RECORDS AND LIBRARY
HISTORICAL SECTION
Publication Number 2
THE NORTHERN BARRAGE AND
OTHER MINING ACTIVITIES
Published under the direction of
The Hon. JOSEPHUS DANIELS, Secretary of the Navy
WASHINGTON
GOVERNMENT PRINTING OFFICE
1920
REAR ADMIRAL JOSEPH STRAUSS, U. S. NAVY,
Commander of the American mining operations in the North Sea during the World War.
e- ncivvv neaxfr &v\r
NAVY DEPARTMENT
OFFICE OF NAVAL RECORDS AND LIBRARY
HISTORICAL SECTION
Publication Number 2
THE NORTHERN BARRAGE AND
OTHER MINING ACTIVITIES
Published under the direction of
The Hon. JOSEPHUS DANIELS, Secretary of the Navy
WASHINGTON
GOVERNMENT PRINTING OFFICE
1920
\ LIBRARY
j MAR 2 5 1968
' UNIVERSITY OF THE PACIFIC 5
THE NORTHERN BARRAGE AND OTHER MINING
ACTIVITIES.
ERRATA
Page 1E5, after paragraph 2 add: The follow-
ing submarines were sunk in the N&rthern Mine
Barrage:
Area Submarine Date
B U-92 September 9, 1918
B U-10E September — (Probable)
A U-156 September 25, 1918
B UB-104 September 19, 1913
B UB-127 September — (Probable)
A UB-123 October 19, 1918
Sources: The Submarine Warfare by
Micholscn and British Submarine Losses Re-
turn 1919.
Pago 124, paragraph 3, 1st lino: change last
word to ono. 5th lino: striko out sentence begin-
ning "Tho other, tho UB-22,otc."
Pago 125, paragraph 1, 4th lino: change U-123
t<? read UB-123*
WASHINGTON : fcOVERNMBNT FEINTING OFFICfc I 1921
THE NORTHERN BARRAGE AND OTHER MINING
ACTIVITIES.
Publication No. 2, Historical Section, Navy Department.
ERRATA.
t age 48, line 14: After the word "dimensions" strike out "34"
and insert 33.
vacing page 80, photographs: In captions for photographs of
U. S. S. Baltimore and U. S. S. San Francisco, strike out "North
Atlantic Fleet" and insert U. S. Mine Force.
Page 87, line 8 : After the word " miles " insert the word in.
Page 105, line 4: Strike out the word "proceed" and insert the
word proceeded.
Page 140, line 43 : Strike out the word " has," and after the word
"issued" insert (Up to July 18, 1919).
NOTE: These Mine Warnings to Mariners are still being issued.
Up to February 3, 1921, 413 have been received by the Hydrographic
Office of the Navy Department.
Page 141, line 2 : After the word " date " insert period.
Page 141, lines 2, 3, and 4 : Strike out the words " and are pub-
xislied herewith in explanation of the policy that was to be carried
***' t " and insert in lieu thereof The explanation of the policy to ~be
u *ried out is illustrated in the two charts of a later date which ac-
company this publication.
34744—21
WASHINGTON : GOVERNMENT PRINTING OFFIC* : l»2i
TABLE OF CONTENTS.
Page.
List of illustrations 5
Preface 7
CHAPTER I.
The conception and inception of the northern barrage project 9
CHAPTER II?
British consideration 01 project 29
CHAPTER III.
American consideration and adoption of project 35
CHAPTER IV.
Status of barrage project on November 1, 1917 - 38
CHAPTER V.
Coordination of preparations 40
CHAPTER VI.
Design of the mine 42
CHAPTER VII.
The manufacturing project 50
CHAPTER VIII.
Mine loading plant, St. Juliens Creek, Va 55
CHAPTER IX.
Assembly and shipment of mine material 58
CHAPTER X.
Overseas mine bases Nos. 17 and 18 61
CHAPTER XI.
Organization of mine squadron and selection of new minelayers 70
CHAPTER XII.
Training the personnel and commissioning the ships of Mine Squadron One. . . 76
CHAPTER XIII.
Completion and sailing of mine squadron 79
3
4 TABLE OF CONTENTS.
CHAPTER XIV.
Page.
Commander Mine Force — Appointment, arrival in Europe, preparations for
commencement of minelaying 86
CHAPTER XV.
Changes in barrage plan 92
CHAPTER XVI.
Mining operations 101
CHAPTER XVII.
Final status of barrage and results obtained 121
CHAPTER XVIII.
*
Contemplated mining operations in the Mediterranean 128
CHARTS IN POCKET.
No. 1. Chart of waters surrounding British Islands. Mined areas and safe channels.
2. Chart of Mediterranean with west coasts of France, Spain, and Portugal. Mined
areas and safe channels.
LIST OF ILLUSTRATIONS.
Rear Admiral Joseph Strauss, U. S. Navy, commander of the American mining
operations in the North Sea, during the World War Frontispiece.
Facing
page-
Admiral Henry T. Mayo, U. S. Navy, commander in chief, U. S. Atlantic Fleet,
and Rear Admiral Joseph Strausj =.. . . 16
Photostatic chart, showing plan of proposed mine barrage between Aberdeen,
Scotland, and Ekersund, Norway 16
Mark VI mine with sinker, fitted with balsa floats for planting in shallow depths . 16
Mark VI mine fitted with D-4 float for planting at lower levels 16
Photostatic chart, showing location of U. S. Mine Bases in Scotland, Base 17 at
Invergordon and Base 18 at Inverness 32
Photostatic chart showing Base No. 18 at Inverness, Scotland 32
Dumb lighter loaded with assembled mines at Base 18, Inverness, Scotland 32
Assembled mines in the ready issue store 32
Tug towing barges to minelayers in the harbor of Inverness, Scotland, Sep-
tember, 1918 48
A fleet of mines, North Sea 48
Handling mine cases. Trucking mine spheres from the bulk stores to the
assembly sheds 48
U. S. S. Shawmut, minelayer in the North Sea, camouflaged 48
U. S. S. Aroostook, minelayer, camouflaged 64
U. S. S. Black Hawk, flagship of Commander U. S. Mine Force, and force
repair ship, camouflaged. Inverness, Scotland 64
Commanding officers of U. S. Minelaying Force on board the San Francisco .... 64
Photostatic chart, showing organization of U. S. Mine Force 64
Photostatic chart, North Sea barrage, showing first proposed location after shift-
ing barrage from Aberdeen-Ekersund line 80
U. S. S. Baltimore of Mine Squadron 1, North Atlantic Fleet 80
Bringing mine lighters alongside the U. S. S. San Francisco, of Mine Squadron 1,
North Atlantic Fleet, Inverness Firth 80
Photostatic chart, showing British mine field, laid by U. S. S. Baltimore,
April 13 to May 2, 1918 80
U. S. Squadron in planting formation in the North Sea 96
Minelaying fleet proceeding to sea on a minelaying expedition 96
Minelaying fleet, North Sea, proceeding to sea 96
Squadron 1, starting on a minelaying " excursion " 96
Smoke screen made by destroyers to protect minelaying fleet 112
Minelayer, laying a mine barrage, protected by the guns of an accompanying
battleship 112
Photostatic chart of North Sea barrage, showing positions of lines and depths of
all American and British mines, and vertical projection showing relative
density of mines 112
Photostatic chart, vertical projection, showing the growth of the North Sea
barrage 112
Summary of U. S. mining operations in the North Sea barrage 121
5
6 LIST OP ILLUSTBATION8.
Facing
Members of the Allied Conference on minelaying in th6 Mediterranean, held
at Malta, August 6 to 9, 1918 128
Photostatic chart, showing the proposed mining operations in the Mediterranean
Sea 128
Photostatic chart, showing the proposed minelaying operations in the Adriatic
Sea 128
Photostatic chart, showing the proposed minelaying in the ^Egean Sea 128
PREFACE.
The mining operations herein described naturally involve two
distinct functions :
(a) The design and manufacture of the mines together with all
the accompanying materials and their transportation to Scotland.
(6) The most difficult and hazardous sea operation of building
the barrage.
The first of these functions was performed by the Bureau of
Ordnance of which Rear Admiral Ralph Earle was the chief.
The second of these operations was conducted by Rear Admiral
Joseph Strauss.
This report is a compilation from the exhaustive report made by
Rear Admiral Strauss, together with that made by Rear Admiral
Ralph Earle, the two with other data being combined by Com-
mander Simon T. Fullinwider, and edited in the historical section of
the Navy Department. .
Referring to the accompanying charts of the mine areas of the
world, it is realized that the first impression is that very little of the
sea was safe in the European waters and the Mediterranean. While
this is more or less true, a careful reading of the meaning of the
various forms of shading will give a more correct idea of the actual
degree of danger that existed.
C. C. MARSH,
Captain, U. S. N. (Ret.),
Officer in Charge, Historical Section, Navy Department.
DECEMBER 12, 1919.
7
THE NORTHERN BARRAGE.
CHAPTER I.
CONCEPTION AND INCEPTION OF THE NORTHERN
BARRAGE1 PROJECT.
The northern barrage was one of the most important naval projects
carried out by the United States during the war. To appreciate the
importance of the barrage as a factor in the prosecution and winning
of the war, one must consider the general military situation as it
existed in April, 1917, when the United States threw her weight
into the scales with the Allies. There was every reason at that time
for a pessimistic view of the situation. The military situation on
the west front was practically a stalemate. The French and British
forces appeared to have a slight advantage over the enemy, having
made small gains here and there; but they plainly had little or no
prospect of obtaining an early military decision. The Italians were
holding their own, but with no prospect of decisive victory.
On the east front the Russians were holding for the tune being, but
there were ominous indications that the newly established revolution-
ary government would be unable to overcome internal dissensions
and that the Russian power might crumble at any time.
In the Balkans the Allies had insufficient force, apparently, to pros-
ecute an offensive campaign; and the growing submarine menace in
the Mediterranean seriously threatened the lines of communication
by which this force was sustained. In fact, there was grave danger,
especially in view of the pro-German attitude of the then Greek Gov-
ernment, that the allied force based on Saloniki would have to be
withdrawn and the entire Balkan Peninsula given up to the Central
Powers. In Asiatic Turkey the British were making slow progress
in Mesopotamia; but it was doubtful whether victory there would
have any material effect on conditions in Europe.
In short, at the tune of the entrance of the United States into the
war, there was no prospect of victory over the Central Powers unless
and until heavy American forces could be sent to Europe to turn the
scale. America was not ready, and could not be expected to create
and equip an adequate army within at least one year, or probably two.
* This barrage was known in the United States as the North Sea barrage; but, since it was termed by the
British the northern, barrage, and since there were other shorter and minor mine barrages planted in the
North Sea by the British, the title northern barrage will be used in this narrative.
0
10 THE NORTHERN BARRAGE.
The sending of an American army to France would necessitate the
safeguarding of the lines of communication across the Atlantic; in
other words, the result of the war was seen to hang upon whether or
not the Allies and the United States could obtain and hold the mastery
of the sea. As in all wars in which maritime nations have been
engaged, sea power was to prove the decisive factor. The British
Fleet and the naval forces of the United States and other associate
powers were supreme on the surface of the sea, and had it not been
for the submarine there would not have been the slightest occasion
for doubt of a quick and satisfactory outcome of the war; but the
surface fleets were, as a matter of fact, almost impotent hi the face
of the submarine menace. The German Government concentrated
early in the war on the development of the submarine and built these
vessels in large numbers, with the purpose, as it turned out, of waging
a ruthless war on shipping and thereby bringing Great Britain and
her Allies to terms. Generally speaking, the German High Seas Fleet
was kept safe at home, while the British Grand Fleet and other
allied heavy naval forces, having no enemy to meet on the high seas,
were compelled to wait at then* well protected bases until the German
Fleet should put to sea. Thus there was little naval activity beyond
the submarine warfare waged by the Germans against merchant
shipping, and the allied anti-submarine campaign.
The Germans embarked on the policy of sinking merchant ships
without warning in December, 1916; and in February, 1917, unre-
stricted submarine warfare on merchant shipping was formally
announced. While the sinking of merchant tonnage had been very
considerable up to this time, it rapidly increased until it reached a
high point in April, 1917, of 800,000 tons a month. The average for
the first six months of that year was 600,000 tons a month, or about
7,000,000 tons a year. It was a plain mathematical deduction that
if this condition were permitted to continue, it would assure a victory
for the Central Powers within a year, since the diminished merchant
fleet of Great Britain and the Allies could not possibly stand this
tremenduous loss and meet the requirements of transportation
necessary to the successful prosecution of the war.
Soon after the United States entered the war it became a settled
policy of our Government to send a large force of troops to reinforce
the French and British on the west front. The increasing sub-
marine menace gravely complicated the problem of transporting our
troops and their supplies, and every known method of hunting out
and destroying submarines was given careful consideration by the
Navy Department. Aside from the possible heavy loss of life, due
to the sinking of American transports by enemy submarines, there was
the moral effect of such sinking to be considered ; it might react most
THE NORTHERN BARRAGE. 11
unfavorably on the morale of the entire American Nation and cor-
respondingly cheer the German public.
It became the general policy of the Navy Department to. employ
every promising means of destroying enemy submarines, and not to
be content to rely on any one means to the exclusion of others. The
means which proved successful and which were developed, in coopera-
tion with our Allies, to the utmost included the following:
(a) Arming of merchant vessels with guns manned by naval gun
crews.
(6) Sending vessels in convoys through the danger zones protected
by destroyers and other suitable naval vessels.
(c) " Hunting groups" of vessels of various types equipped with
"listening apparatus."
(d) Aerial patrol by sea planes and " blimps" armed with depth
bombs.
(e) Arming of destroyers and other suitable craft with an unlim-
ited supply of depth charges.
(/) Mining of waters habitually traversed by enemy submarines.
The first important anti-submarine plan to give encouraging results
was the convoy system, adopted in July, 1917. This plan had the
one serious defect of slowing down shipping, since in a convoy of,
say 20 ort 30 vessels, the speed of the convoy was reduced to that of
the slowest ship; but following the adoption of this plan the average
loss fell to about 450,000 tons a month. The losses were principally
from slow convoys composed of relatively slow-speed cargo vessels.
The losses from fast convoys made up of transports and other craft
having a speed of more than 12 knots were comparatively small; and
the effectiveness of the system was finally demonstrated by the fact
that no troop ships in American convoys were lost during the war.
However, the loss of 450,000 tons of shipping a month, or even a
much smaller loss, would have proved fatal to the allied cause if
permitted to continue; and additional measures were imperatively
necessary.
The allied powers were in a very difficult position and were not
prepared to quickly put into effect adequate measures against the
entirely novel and unexpected form of submarine warfare instituted
by the enemy. So far as the United States was concerned, whatever
offensive or defensive measures were decided upon, the procurement
of the necessary material therefor would take valuable time. In
short, the Navy was not prepared for and could not perform its
proper functions until after adequate numbers, or quantities, of
destroyers, chasers, guns, mines, depth charges, etc., could be built
or manufactured.
Taking the case of mines alone, there were on hand in April, 1917,
approximately 5,000 mines of a type which was comparatively
12 THE NORTHERN BARRAGE.
unsuitable for anti-submarine operations. To show the inadequacy
of this supply, it may be stated that the British were using about
7,000 a month and were endeavoring to increase their output to
10,000 a month. Also, the British had found from their own expe-
rience that the type of mine possessed by the United States (the
Vickers-Elia) was not well suited for the peculiar type of mining in
hand and had changed to a new type — a horn mine resembling the
German and Russian mines.
Not until after the United States entered the war did the British
and other allied Governments furnish us with important military
information; but as soon as we were permitted to avail ourselves of
their war experience the Bureau of Ordnance decided that it would
be desirable to provide at least 100,000 mines and that these must
be of a type more suitable for anti-submarine operations than any
then in existence. In other words, it devolved upon that bureau to
develop a new design of mine and to arrange for its manufacture at
the rate of approximately 1,000 a day, or four and two-tenths times
the production that Great Britain had succeeded in reaching. The
reasoning leading to this decision is given below at some length.
The Bureau of Ordnance, even before the United States entered
the war, had made a close study of the general conditions, particu-
larly with reference to possible measures to be taken to cpunteract
the submarine peril. -The mine section of the Bureau of Ordnance,
as a result of many conferences on this all important subject with
the Chief 2 and Assistant Chief of Bureau and also section chiefs,
suggested the measures that could be taken by the United States in
a memorandum under date of April 15, 1917, a partial copy of which
is appended. This memorandum dwelt upon two principal proposi-
tions : First, the protection of merchant vessels by means of cellular
construction and " blisters"; and second, antisubmarine barrages
inclosing the North Sea and the Adriatic. Obviously, it was impos-
sible to consider seriously any proposition to close German harbors
as long as the enemy had complete control of his own waters. The
next best thing to " closing the holes" was, of course, to close the
North Sea by means of a barrage restricting the operations of enemy
submarines to the North Sea and preventing their getting into the
Atlantic and interfering with the lines of communication between
the United States and Great Britain and France. The proponents
of this plan freely admitted that such a barrage probably could not
be made completely effective, but insisted that even if it were only
partially effective it would win the war.
2 At this time, Rear Admiral Ralph Earle, U. S. Navy, was chief of bureau, Capt. T. A. Kearney
U. S. Navy, the assistant Chief of bureau, and Commander S. P. Fullinwider, U. S. Navy (retired)'
the chief of the mines and net section, while Lieut. Commander T. S. Wilkinson, jr., U. S. Navy, was
chief of the experimental section
THE NORTHERN BARRAGE. 13
The memorandum was written mainly with a view to crystallizing
opinion within the bureau and furnishing a basis for discussion by
officers of the bureau with others concerned in the design and pro-
curement of material for increased naval activities.
Within the Bureau of Ordnance practically all officers who would
be concerned with such a project quite agreed on the principle that
the enemy submarine should be contained by means of such a barrage,
though the type of barrage and its location were for a considerable
period matters of doubt. The concensus of opinion, however, was
that the barrage should extend from the east coast of Scotland to
the Norwegian coast. This, together with a short barrage across
the Dover Straits, would shut off access to the Atlantic, or at least
make the continued operations of enemy submarines exceedingly
hazardous and unprofitable.
The proposal to construct a barrage 250 miles long was so novel
and unprecedented from every practical viewpoint that it was real-
ized at the time that it would be difficult to obtain a prompt decision
without considerable preliminary propaganda within the department.
Tune was regarded as the supreme factor in the situation, as every
day saw the loss of many priceless ships and cargoes.
On April 17 the department cabled to Admiral (then Rear Admiral)
W. S. Sims, in command of United States naval forces in European
waters, directing him to report on the practicability of blockading the
German coast efficiently in order to make the ingress and egress of
submarines practically impossible. He, in answer, stated that this,
of course, had been the object of repeated attempts by the British
navy with all possible means and found unfeasible. Failure to shut in
the submarine by a close blockade, using mines, nets, and patrols
in the Bight and along the Flanders coast, focussed attention of the
department upon plans for the alternative of restricting the enemy to
the North Sea by closing to him the exits through the channel and the
northern end between Scotland and Norway, as proposed by the Bu-
reau of Ordnance. These are outlined in a memorandum of the Office
of Operations dated May 9, 1917, which was to be submitted for the
advice and comment of the British Admiralty with its valuable anti-
submarine experience. It was noted that, in working up any plan,
the whole field of operations was to be considered primarily with a
view to attacking the submarine under water as well as on the surface.
It was stated that the entrances to the North Sea, while very broad
and presenting immense difficulties, came within the bounds of pos-
sibility of control. Estimating the cost of gaining this control and
confining enemy submarines within the North Sea to be $200,000,000,
or perhaps twice that sum, there was no doubt that the United States
would devote whatever amount it was worth if the purpose was to
be accomplished. This was proposed to J>e done by establishing a
14 THE NORTHERN BARRAGE.
barrage of nets, anchored mines, and floating mines, to operate from
35 feet to 200 feet below the surface, which, while safe for surface
craft, would bar a submerged submarine, while patrols could deal with
those running on the surface.
Commenting on this, the Admiralty, who had apparently consid-
ered the United States proposals to particularly advocate the exten-
sive use of nets, replied on May 13 :
From all experience Admiralty considers project of attempting to close exit to
North Sea * * * by method suggested to be quite unpracticable. Project has
previously been considered and abandoned. The difficulty will be appreciated when
total distance, depths, material, and patrols required and distance from base of opera-
tions are considered.
It was the British experience that nets failed in their purpose on
account of the possibility of cutting them; mine nets, when located,
were avoided or run over; all were difficult to maintain in place and
required too many patrol vessels to watch. Mine barrages were not
considered wholly effective unless maintained by patrols at all points.
Considering the use of such a barrage from Norway to Scotland,
patrols could not be properly protected on such a long line, because
the defense would be stretched out in a long and locally weak line,
and therefore subject to enemy raids in sufficient force to break
through the patrol, cut nets, and sweep mines, and so clear a passage
for the submarines. If protected with heavy vessels, these would be
exposed to the German policy of attrition with torpedo attack. In
short, as concluded by Admiral Sims in his report to the department
on May 14, 1917, " Bitter and extensive experience has forced the
abandonment of any serious attempt at blockading such passages."
It is noteworthy that the attitude of the British Admiralty and of
Admiral Sims was not favorable to the further consideration of the
North Sea barrage project; but, notwithstanding this, the proponents
of the project, i. e., the officers of the Navy Bureau of Ordnance,
redoubled their efforts to secure its adoption, feeling that the result
of the war depended upon it more than upon any other possible
measures.
From early in March until the latter part of July, 1917, the mine
section of the Bureau of Ordnance made an intensive study of many
types of barrage, among them the submarine trap and indicator nets
which had been used by the British. Most of the plans considered
were devised within the bureau, but in addition a very large number
of inventions and suggestions from private sources were studied.
Unfortunately, practically all inventions or ideas emanating from
nonprofessional sources were based on incomplete knowledge of fun-
damental conditions and requirements. Their shortcomings may be
expressed briefly by saying that they were based on mill-pond condi-
tions, whereas the waters iji which such a barrage as that under con-
THE NORTHEBN BARRAGE. 15
sideration had to be planted and maintained were subject not only
to very adverse weather conditions, but also to the activities of the
enemy naval forces, which, up to this time, had displayed great
initiative and resourcefulness.
The types of barrage studied were of three principal classes: First,
nets and entanglements; second, nets in combination with mines or
bombs; and third, mines alone. The possibility of employing nets
or entanglements alone was abandoned early, inasmuch as "the
war experience of the British indicated that it was exceedingly
difficult to plant and maintain nets of sufficient weight and strength
to be of any material value, and because of the depth of water in
which the proposed barrage must be laid was quite prohibitive. The
quantity of wire rope required was prohibitive in the time available.
Nets in combination with mines or bombs were open to the same
criticism, with the additional point that such material would be very
difficult and dangerous to handle and the planting would be too slow.
It was finally decided that mines offered the only practicable solution,
and since no mine then in existence, either in America or abroad, was
suitable for the project, mainly owing to the excessive number
required, it became necessary for the bureau to design a mine espe-
cially adapted to the purpose. A discussion of the evolution of the '
mine which was finally adopted will follow. It is only necessary to
say here that the novel principle of the firing gear of the new mine
was discovered in April, 1917, but was not brought to a state of
development warranting its adoption until the latter part of July,
1917.
While from the first the new firing mechanism showed great promise,
the officers responsible for its development felt that it would be unwise
to place too great reliance on it before it had been thoroughly tested
out, and therefore studies of other means of forming a barrage were
continued without cessation up to the day that the new mine was
adopted. As late as July 15, 1917, a memorandum prepared by the
mine 'section was submitted to the Chief of the Bureau of Ordnance
suggesting mines in combination with nets. The idea was to have
a barrage of overlapping light steel wire nets, about 200 feet square,
each net carrying two mines, one attached at the top of the net to be
a mine with a hydrostatic firing mechanism, and a second, attached
to the center of the net, to have a firing mechanism actuated by a
propeller in such manner that a submarine carrying away the net
would tow the mine and explode it after a short distance. The
hydrostatic mine was intended to explode in the event that the sub-
marine submerged it to a certain depth. It is needless to go into
details regarding the construction of this net and the designs of the
mines, since nothing ever came of it. The plan was submitted to a
board, but during the board's consideration of the project information
16 THE NORTHERN BARRAGE.
was received of the latest test of the new mine-firing device, which was
so favorable that further discussion of the plan before it seemed use-
less, and the matter was dropped with the understanding that the
bureau would concentrate on the development of the new mine,
which was thereafter to be known as the Mark VI (up to this time,
during its experimental stage, it had been known as the type "X"
mine).
In the early days of the mine barrage project, very little official
correspondence took place in the matter, principally for the reason
that it was desired to keep the matter a profound secret, since it was
probable that any type of mine produced would sooner or later bring
about methods of counteracting it. It was felt that if information
concerning it could be kept until the material had been produced
and placed in use, the enemy would not have time to devise protective
methods against it.
A decision in the premises favorable to the mine barrage project
was daily becoming more imperative in order to accomplish the
laying of the barrage during the best weather of 1918; and, therefore,
the bureau had prepared by Commander S. P. Fullinwider, U. S.
Navy, chief of the mines and net section, a second memorandum,
dated June 1, 1917, which bearing a strong favorable indorsement
by the Chief of the Naval Bureau of Ordnance, was submitted to the
Chief of Naval Operations, this memorandum recommending certain
projects for the future conduct of the war and laying particular stress
upon the necessity of the northern barrage as being a most promising
offensive operation. In fact, the President had addressed the officers
of the battle fleet and stated that, as it was nigh impossible to destroy
hornets (i. e., German submarines) after they had escaped from
their nests, these hornets must be confined to their nests, or destroyed
before reaching the vast wastes of the ocean.
Realizing that it is difficult to obtain quick action on a novel
scheme of such magnitude as the one under discussion, and especially
in view of the unfavorable attitude shown by the British, the chief
of the mine section, as a representative of the bureau, departed from
the policy of secrecy to the extent of discussing the as yet indefinite
plan with several officers who were in a position to further the scheme,
notably with a member of the general board, with an officer close to
the President, and with representatives of the Office of Naval Opera-
tions. He also discussed the matter with Commander C. D. C.
Bridge, a British officer then officially visiting this country, who was
shortly to return to London. While the type of mine to be used
had not yet been developed, it was important to see to it that the
idea of a northern barrage should be accepted as a sound and indis-
pensable measure to defeat the enemy submarine. The Bureau of
Ordnance, from the first, took the attitude that if the idea of such a
16-1
16-2
MARK VI MINE WITH SINKER, FITTED WITH BALSA FLOATS FOR PLANTING
IN SHALLOW DEPTHS. (Page 42)
16-3.
MARK VI MINE FITTED WITH D-4 FLOAT FOR PLANTING AT LOWER LEVELS.
16_4
THE NORTHERN BARRAGE. 17
barrage were only adopted, the project would be carried through in
some way or other, as the only question then would be merely a
choice of methods and material; and the bureau had no doubt
that the material question could be solved in a satisfactory manner.
It may be added that the measures above referred to bore fruit,
since the project was adopted by the Navy Department without much
loss of time after the Bureau of Ordnance reported that a suitable
mine had been developed. Furthermore, the President's attitude
was known in advance to be favorable; and .the project, when
adopted by the department, was promptly approved by him.
One of the earliest and most enthusiastic proponents of the northern
barrage project was Assistant Secretary of the Navy Franklin D.
Roosevelt, to whom was given a copy of the memorandum of April
15, 1917, and with whom the matter was discussed in a general way.
The Assistant Secretary's keen interest in the matter was very
apparent throughout the early phases of the project; and it is under-
stood that he took up with the Bureau of Yards and Docks the
problem of a net barrage across the North Sea. While the details
of this study are not known, it is assumed that effort along that line
was stopped when it beoame known that the Bureau of Ordnance
had a suitable type of mine, which, of course, was readily accepted
as far preferable to any net plan.
In the month of May, 1917, the Department of Commerce became
interested in a barrage proposed by certain officers of the Coast and
Geodetic Survey; and the Secretary of Commerce took up the matter
with the Navy Department and strongly urged that the two depart-
ments collaborate in designing and putting down such a barrage.
It is needless to go into details regarding its design, and the mere
statement will suffice that it was to be composed of nets in combi-
nation with mines, and that the net was composed in part of insulated
wire, the breaking of which wire by a submarine would fire a mine.
There were several conferences, one of them presided over by the
Secretary of Commerce and attended by Assistant Secretary Roose-
velt, Commander Fullinwider, and Lieut. Commander Castle. The
Bureau of Ordnance was not favorably disposed toward this plan,
because it felt that, even if the necessary quantity of material could
be obtained, which was doubtful, it would be a very difficult project
to carry into execution, and furthermore, that it would be quite
impossible to maintain it in waters such as the North Sea. Plans
were adopted to carry out tests in deep water, but interest in this
plan ceased when Mr. Roosevelt became convinced that the Bureau
of Ordnance had developed a satisfactory mine for a barrage.
The foregoing is mentioned only to show the active and growing
interest at that time in the idea of a barrage. It also became a
favorite problem with inventors. In short, by the time the bureau
181063°— 29 2
18 THE NORTHERN BARRAGE.
had demonstrated to its satisfaction that the new mine would be
effective, the closing of the North Sea was quite recognized in America
as the best possible solution of the anti-submarine problem. It
remained to convert the British naval authorities to this view.
The adoption of any plan for a barrage to close the North Sea
was, of course, dependent upon the suitability and availability of
the material, and so the development of the project was largely the
development of the Mark VI mine. It should be stated in this
connection, however, that the northern barrage would undoubtedly
have been realized whether or not the Mark VI mine had been
adopted for the purpose. There were other designs of mine available
but the Mark VI was deemed the most promising in sight at that tune.
In April, 1917, Mr. Ralph C. Browne, a citizen of Salem, Mass., an
inventor associated with the L. E. Knott Apparatus Co., Cambridge,
Mass., brought, to the department a description of an invention
which he called the " Browne submerged gun." Assistant Secretary
Roosevelt referred him to the Bureau of Ordnance, and the inven-
tion was duly considered by the Chief of Bureau and Commander
Fullinwider and Lieut. Commander T. S. Wilkinson. The inven-
tion in the form offered may be briefly described as follows : A buoy
or float carried as an integral part, a so-called gun or short tube
extending vertically downward. The buoy carried also a copper
wire hanging vertically. A high-explosive shell was carried in the
tube or gun. This shell contained in its base a propelling charge of
slow-burning powder intended to give the projectile a velocity of
about 50 feet per second through the water. The shell was pro-
vided with guides to restrict it to travel along the wire. The float
carried alsd an electrical relay mechanism, all parts so related that
the contact of a submarine or any steel vessel with the pendent wire
would produce a sea-battery current of sufficient energy to actuate
the electric relay, which in turn would ignite the propulsive charge
in the base of the shell and send the shell along the wire into contact
with the submarine, where the shell was expected to burst and
rupture the hull. The design was very ingenious and novel as a
whole; but in its then proposed form it was deemed by the Bureau
to be wholly impracticable for naval use. Commander Fullinwider
saw, however, that the electric principle involved might be applied
to a mine firing device; and, after making a study of the matter
with Capt. S. J. Brown (Math.), United States Navy, and Lieut. Com-
mander Wilkinson, and after reference of such study to the Chief of
Bureau, he suggested to Mr. Browne that he collaborate with the
Bureau in applying the new principle to an antenna mine. This Mr
Browne was loath to do as he felt that his invention would be more
effective than would a mine. After about two weeks' investigation,
including considerable pressure by the Chief of Bureau himself, how-
THE NORTHERN BARRAGE. 19
ever, Mr. Browne agreed that he would defer to the bureau's judg-
ment in the matter and consented to collaborate with the Bureau hi
the development of a mine-firing device based on the use of a sea
battery.
Mr. Browne immediately took up the work, and on June 18, 1917,
a crude model of a mine-firing device was tested with promising
results at the submarine base, New London, Conn. Further tests
were held on July 10; these tests were conducted by the experimental
officer of the Bureau. It was immediately subsequent to these
tests that it was finally decided to adopt the new firing device, and
the Bureau proceeded to design and develop a mine in which this
device could be used.
The Bureau was convinced by the tests that the device, which was
thereafter to be called the K-l device, was correct hi principle, but
realized that hi the short tune available for development and experi-
mentation it could hardly be hoped to obtain reliability in the
mechanical features of the design. However, since it was essential
that mines for the barrage should be ready in large quantities by
the following spring, it was decided to proceed with the manufacture
of the devices and trust to making any necessary modifications after
getting into production, and hi the meantime to proceed with tests,
so far as tests could be conducted without complete mines.
It may be stated here that, although the design of the complete
mine had not yet been decided upon, and could not be completed for
several months, the mine section of the Bureau of Ordnance was
sufficiently assured of the successful development of the mine to
submit tentative plans to the Chief of Bureau; and he took the
responsibility of formally committing the bureau to this method of
closing the North Sea.
On July 18, 1917, the bureau addressed the following letter to the
Chief of Naval Operations announcing the development of a new
type of mine firing gear which would be suitable for mines for a
northern barrage :
Confidential.
JULY 18, 1917.
To: Chief of Naval Operations.
Subject: Submarine mine barriers, material for.
1. The Bureau has developed a new type of mine, at present referred to as Mark VI
(Type X) which it is confidently believed will facilitate the establishment of sub-
marine barriers. The mine is radically different from other mines in its firing gear,
which has been tested out with excellent results and the bureau is now proceeding
with the design of the mine as a whole and expects to complete it within two weeks.
2. The new mine will be as easily planted as the ordinary types of naval defense
mines and therefore the time and the number of vessels required to establish a barrier
will be reduced to a minimum. This mine can be rigged so as to be safe as regards
surface vessels, but effective against craft operating below the surface.
20 THE !N"ORTHERN BARRAGE.
3. The mine will be comparatively simple in design and it is believed that it can
be manufactured at a minimum rate of 1,000 per day, which means that the number
required for about 300 miles of barrier can be produced within about three months
from the beginning of deliveries or within four months from the placing of orders.
4. The Bureau requests that a decision be reached at the earliest practicable moment
as to the desirability of establishing complete barriers to prevent enemy submarines
from gaining access to the Atlantic. The Bureau assumes that such a project is
desirable as no other means of stopping the submarine peril appears to be in prospect,
and, since it is going to take four months to obtain the necessary material, the Bureau
believes that it should be authorized to proceed immediately with arrangements for
procuring the material.
5. Theoretically, only 72,000 mines will be required for 300 miles of barrier, but
100,000 should be provided to allow a reasonable excess for replacements, etc. In
addition, a number, say 25,000, should be provided for our own coast defenses, it is
believed, making a total of 125,000 mines, which, at an estimated cost of $320 each,
gives a total cost of $40,000,000. This estimate is designedly liberal.
6. The Bureau is of the opinion that the design, manufacture, and assembly of the
new mine should be carried out with the utmost secrecy and is taking the necessary
precautions accordingly, since advance information of such a mine would be of the
greatest aid to the enemy in devising means to counteract it.
7. The above estimate as to time is based upon our success in securing the necessary
quantity of T. N. T. or other high explosive.
8. In considering this project the use of high-speed mine-laying vessels, such as
liners and merchantmen, in addition to destroyers and light cruisers, will be required
and such vessels must be provided. The mines can be dropped accurately at any
speed by time devices. The whole barrier should be laid as one operation and be
protected as far as possible. If isolated mines are planted, it is probable that a device
to defeat the mine-firing mechanism will be developed by Germany.
RALPH EARLE.
While awaiting the Department's action, the Bureau proceeded
with the design of the mine, with a view to being prepared at the
earliest possible date to undertake its manufacture.
On July 30, 1917, the Bureau addressed a second communication
to the Chief of Naval Operations, submitting more complete informa-
tion regarding the new mine and proposing an American-British joint
offensive operation in the form of a northern barrage. A copy of
this letter follows :
(N3) MC. JULY 30, 1917.
To: Chief of Naval Operations.
Subject: Proposed British-American joint offensive operations; submarine barriers;
Mark VI mines.
1. In its letter No. 32957 of July 18, 1917, the' bureau announced the development
of a new type of mine that is peculiarly adaptable for use against submarines.
2. The firing mechanism of this mine is based on a very recent discovery in the elec-
trical field, and although there has been little time for development the tests which
have been carried out with an experimental mine by a submarine leaves no doubt in
the bureau 's opinion of the success of this invention.
3. The mine will have the following characteristics:
(a) A spherical mine case carrying a charge of 300 pounds of T. N. T. having a
destructive radius of about 100 feet against a submarine.
THE NORTHERN BARRAGE. 21
(6) The anchor may be either the automatic type, such as that now in use or a
simple mushroom type, depending upon the conditions under which mining operations
shall be carried out.
(c) The firing mechanism comprises an electrical device carried within the mine
case and an antenna of any desired length, the end of which will be supported by a
small buoy as near the surface of the water as may be desired. A second antenna
may be suspended from the mine where the depth of water renders this necessary.
(d) A steel vessel coming in contact with the antenna will fire the mine.
4. The mine has the following advantages over other types:
(a) In depths of less than 100 feet it may be planted on the bottom, where it is least
affected by wave action and current. In this case a buoyant mine is not necessary
or desirable, and it can be made smaller and cheaper than a buoyant mine. In such
circumstances there is no possibility of its getting adrift, and it can not be swept up
in the usual way. It can, however, be fired by a mine sweep.
(6) In depths greater than 100 feet it is proposed to submerge the mine to a depth
of 100 feet, since 100 feet. is about its destructive range against submarines. At this
depth the mine iteelf is entirely protected from wave action and only the light float
or buoy is exposed to such action.
(c) Where conditions permit the antenna may take the form of a net, or the antennae
of adjacent mines may be connected by horizontal wires forming an impassible
barrier.
(d) If a floating mine be desired, this mine may be suspended from a buoy in such
manner as to be harmless to surface craft but deadly to submarines submerged.
(e) It may be used as a towing mine with antennae to give it a very large danger
space.
(/) It can almost entirely replace submarine nets of present types.
(<7) It can be used for mining very deep water more easily than can other types.
5. The mine, with its anchor, antenna, and buoy, will be assembled and launched
as a unit, so that it can be launched at high speed from destroyers if desired.
6. The bureau believes that with this mine it becomes practicable to close the North
Sea, Adriatic, and other exits of enemy submarines, and that it gives us our oppor-
tunity to cooperate in carrying into execution a major offensive operation of a decisive
character. Even if the proposed barriers should prove to be only 50 per cent effective,
the enemy's submarine campaign would surely fail.
7. It is suggested that the North Sea barriers must extend from the coast of Scotland
to Norway and across the English Channel. The proposed line from Scotland to
Norway must, to be at all effective, extend into the territorial waters of Norway,
thereby involving the question of Norway's neutrality. It would seem that if the
German submarine is permitted by Norway to use her territorial waters, it becomes
incumbent upon the Allies to take measures to prevent such use.
8. The proposed mine barrier scheme does not infringe upon the neutrality of
Holland, Denmark, and Sweden, except in the restricted sense that the vessels of
those powers, as well as of Norway, would be required to pass through a gate in the
barriers under the control of the allied forces. In effect, this would amount to the
establishment of additional danger zones to be avoided by neutrals.
9. The bureau understands that the British Admiralty has objected to any barrier
in the North Sea that would interfere with the freedom of the British fleet. It is
suggested that a gate should be left in the barrier at an appropriate place near the
Scotch coast, not only for British naval vessels, but also for neutral merchant vessels.
This gate would be, say, 8 miles long, with mines so planted that their antennae would
not come within 40 feet of the surface at low water. In other words, the subsurface
would be mined against submarines and the surface left open. This gate could be
effectively patroled with a very few vessels and submarines attempting to pass on
the surface could be destroyed.
22 THE ^NORTHERN BARRAGE.
10. If a decision should be reached immediately to proceed with the assembling
of the material for these barriers, it would require approximately six weeks to complete
the designs, place the orders and start production on a large scale. After starting
production mines could be obtained at a minimum rate of 5,000 a week, and if the
project were given the importance due it there is no doubt that the manufacturers
could be depended upon to increase this figure. In this connection it is assumed that
the British Admiralty would be willing to cooperate to the extent of furnishing a
portion, at least, of the mine anchors, but it is believed that we should supply all of
the mines with the exception of the anchors.
11. It would require approximately 72,000 mines to establish barriers around the
North Sea, assuming that the barriers will be composed of four lines of mines, placed
100 feet apart in each line, in other words, a barrier would require a mine for every 25
feet. To this 72,000 should be added at least 28,000 for renewals and as a reserve.
If it should be decided to place the barrier across the Adriatic and to close the Darda-
nelles about 50 miles of barrier, or about 15,000 additional mines would be required.
12. It is estimated that 125,000 mines can be manufactured at a cost of $40,000,000.
13. The bureau has made every effort to keep the discovery and development of this
mine a military secret, and it is believed that this secrecy can be maintained by proper
organization and administration until such time as it becomes necessary to assemble
the completed mines to ship them to Europe. To this end, the various parts of the
mine will be manufactured by different companies and no manufacturer need be
informed as to the characteristics of the mine as a whole. The company which will
manufacture the firing gear has taken such precautions that only three members of the
company will know that the electrical apparatus used in the mine is intended for a
mine.
14.. In view of the importance of keeping this matter a military secret, it is con-
sidered desirable that the British Admiralty should not be informed as to the features
of the mine until the mines shall have been manufactured and shipped. This view
is taken because it is inevitable that information will leak out regarding the design,
if any considerable number of persons should become informed of it, and since it is
proposed to manufacture the mines complete in this country, it would seem unneces-
sary to send any information regarding it abroad and would only invite the possibility
of such a leak.
15. If the enemy should learn of this invention it would be easy for him to evolve a
similar mine which he could use to blockade the British ports. The principle of the
firing mechanism is so simple that only the slightest clue would enable the enemy to
duplicate it.
16. If this project should be carried out, the bureau is of the opinion that its execu-
tion will bring about a general engagement with the German Fleet, which it is supposed
is desirable.
17. The following is a summary of the cooperation deemed necessary to carry out
this plan :
United States:
(a) Provide mines, except anchors.
(6) Send mines to England.
(c) Assist in assembling mines in England.
(d) Provide a number of minelayers.
(e) Assist in laying.
Great Britain:
(a) Provide anchors.
(6) Assemble mines on anchors.
(c) Organize and equip minelaying force.
(d) Lay all mines with United States assistance.
THE NORTHERN BARRAGE. 23
18. In the above it is suggested that Great Britain provide the anchors, for the
reason that about 30,000 tons would be required and that the transportation of this
tonnage should be avoided if possible.
19. Regarding the minelaying part of this project, it is understood that Great
Britain has about 18 regular mine layers and that the United States could probably
furnish 4, giving a total of 22 . not including destroyers. A number of British destroyers
are fitted to carry 80 mines, and probably some of ours could readily be fitted to carry
40 to 80 each, so it is assumed that 40 destroyers may be available. The minelaying
program may then be assumed to be approximately as follows:
(a) Twenty-two minelayers could lay 200 mines per day each. If they take one
day to reload, they would lay an average of 100 per day each.
(6) Forty destroyers could average 50 per day each.
(c) All combined could lay 4,200 per day.
(d) For the Northern barrier about 60,000 mines are required. These, at the rate
of 4,200 per day, could be laid in about 15 days.
(e) For the English Channel barriers, assumed lengths 50 miles, 12,000 mines would
be required. At the rate of 4,200 per day these could be laid in three days. It is
assumed that two barriers each 25 miles long would be required in the channel to
fully protect the Channel crossing.
20. Lacking definite information as to the minelaying facilities in the Mediter-
ranean, but, assuming that 10 vessels could be made available, the Adriatic barrier,
40 miles, could be laid in about one week and the Dardanelles barrier in a shorter time.
21. As the manufacture and assembling of the material will be an immense under-
taking, and as time is precious at this juncture in the war, a decision should be reached
at the earliest moment practicable.
22. If this plan be adopted, it will be necessary to expedite manufacture by giving
this work priority over certain other Government work, particularly in the matter of
obtaining a sufficient supply of T. N. T. This will be made the subject of special
report if the general plan be adopted.
KEARNEY, Acting.
On August 15, 1917, Admiral Mayo, Commander in Chief, Atlantic
Fleet, who was about to proceed to England accompanied by certain
members of his staff, conferred with the Chief of Bureau and officers
of -the mine section regarding the new mine and its value for the
proposed Northern Barrage. This discussion covered not only the
material questions but also matters of strategy and tactics involved
in such an undertaking. The Bureau furnished Admiral Mayo for
his information and for use in discussing the matter with the British
naval authorities a memorandum embodying the ideas of the Bureau
of Ordnance concerning the adaptability of the Mark VI mine for a
barrage. This memorandum is quoted below for the reason that it set
forth with fair accuracy the possibilities and limitations involved in
the use of the new mine and, in connection with the above-quoted
letters to the Chief of Naval Operations, supplied the information
necessary for an intelligent consideration of the Northern Barrage
project.
24 THE NORTHERN BARRAGE.
(D3)MC Confidential.
AUGUST 15, 1917.
MEMORANDUM FOR COMMANDER IN CHIEF, ATLANTIC FLEET.
Subject: Mark VI mine.
Inclosure: (A) Copy of Bu. Ord. letter to Chief of Naval Operations, dated July 30,
1917.
1. The following notes are intended to amplify^and supplement the information
contained in the inclosed letter:
2. From the early stages of submarine warfare trap nets have been used to a con-
siderable extent, but it has been found to be extremely difficult to maintain nets of
sufficient weight and strength to stop submarines, and it has lately become known
that submarines are equipped with cutters which enable them to cut their way
through. Inasmuch as the submarine is free to go to a depth of 200 feet, a heavy trap
net in deep water necessarily becomes a serious problem, not only to manufacture
and plant but also to maintain against the wear and tear due to storms and currents,
etc. The Bureau early became convinced that a trap net designed to offer passive
resistance to submarines is not a sure solution to the problem.
3. Indicator nets of various designs have been studied and much information
regarding foreign types of such nets have been fully considered with the conclusion
that this type of net also is not a satisfactory anti-submarine device. Such nets must
be suspended from surface floats and cables are subjected to extreme conditions of
wear and have a short life. But the principal objection to such a net, when it is not
combined with bombs or mines, is that it merely indicates the presence of a submarine
and that it requires a very large number of patrol vessels to keep a close watch on
the net in order that a vessel may be near at hand to destroy a submarine whose pres-
ence is indicated. With a view to reducing the number of attendant vessels, a radio
buoy has been developed to send out a call automatically in the event of a submarine
fouling an indicator net, but the defect of this scheme is principally that a submarine
has an excellent chance to get clear of such a net by the time a patrol vessel could
arrive on the scene.
4. Nets in combination with mines or bombs are better, on paper at least, than
either the trap nets or the indicator nets; but here again the difficulty of planting and
maintaining such nets on a large scale, for example, the proposed North Sea barrier,
would be prohibitive. The Bureau has examined and carefully considered hundreds
of inventions and suggestions relative to nets of all descriptions, and has come to the
conclusion that the only effective barrier that could be manufactured, planted, and
maintained effectively is one of mines.
5. The German, British, and all other types of mines known to this bureau are
unsuitable for the formation of barriers in deep water, mainly because of the great
number of mines that would be required for any major operation, such as the North
Sea barrier. Since submarines can go with safety to a depth of 200 feet and since the
ordinary mine must be actually struck to be effective, one of the first ideas that
occurred to the bureau was that pendant mines might be used ; that is to say, a number
of small mines at intervals of, say, 25 feet, on a vertical pendant 200 feet long, but this
was not seriously entertained because it is obviously clumsy and such mines would
necessarily have to be supported from the surface by an elaborate system of buoys,
cables, and moorings, and such a system would be difficult to fabricate, plant, and
maintain.
6. It early became evident that what was needed was a mine that would give a
very much larger danger area than any mine in existence, and fortunately the new
firing principle embodied in the Mark VI mine was hit upon and proved on test to
be entirely practicable.
THE NORTHERN BARRAGE. 25
7. By giving the mine a sufficiently heavy charge of high explosive, to disable a
submarine at a distance of 100 feet, and by making the mine effective by mere contact
of a submarine with its antenna 100 feet above and below it, it is apparent that a great
advance has been made possible in antisubmarine mining operations.
8. The mine will be charged with 300 pounds of high explosive, probably T. N. T.
or a combination thereof with some other substance. The British publications on the
subject of depth charges allot a danger radius of 70 feet to a charge of 300 pounds of
amatol (60 per cent T. N. A. and 40 per cent ammonium nitrate). From French
information and from experimental data in possession of the bureau, it is concluded
that the positive destruction area of such a charge is within a radius of 70 feet, but
that within a greater area of a 100-foot radius sufficient damage may be expected to
force the submarine to come to the surface. Accordingly it is considered that the use
of these mines with an antenna 100 feet above the mine and another 100 feet below the
mine will permit the explosion of the mine upon the passage across its vertical plane
in contact with the wires of any submarine within 100 feet above or below the mine.
It will readily be seen that this increases the effective "contact area" in the ratio of
the 200 feet length of the antenna to the 3 feet diameter of the present contact mine
in use by the Allies. In other words, one mine will cover all practicable depths for a
submarine, as it is not probable that submarines will cruise below 200 feet depth.
The "contact area" of the mine may be still further enlarged by transverse antennae
connected to adjacent mines forming a network, but owing to the difficulties of laying
such a barrier in the open sea, it is considered preferable to lay several parallel rows of
unconnected mines.
9. Anchors will be of three different types, viz:
(a) Automatic anchor, similar to present British type, for use where automatic
depth regulation is desired.
(6) Nonautomatic anchor for use in depth of less than 100 feet; fixed length of
anchor cable to hold mine close to bottom where effects of wave action and current
will be minimized.
(c) Modification of (6) nonautomatic anchor for depths exceeding 100 feet, but where
depths are fairly uniform. Length of anchor cable to be set for predetermined depth
to give mine submergence of 100 feet.
10. The third type of anchor (c) is desirable only to save time of manufacture, it
being simpler than an automatic mine, but it would require more time and care to
plant owing to the necessity of knowing the depth fairly accurately. Its principal
use would be in home or controlled waters.
11. In view of the fact that the mine will be at a depth of 100 feet or on the bottom
(in depths less than 100 feet) it will be affected by wave action and the effect of current
will be less than with the usual type of mine, therefore the mine anchor can be lighter
than that of other mines. It is proposed, however, to back the anchor with a small
light anchor (in combination with the plummet or otherwise) to insure holding.
12. All anchors of whatever type will, of course, fit the standard mine track, and all
mines, regardless of type of anchor, will be launched in the same manner.
13. The scheme of mine laying contemplates separating the mines in each line by a
distance of 100 feet, and laying four separate lines, mutually distant 500 yards and what-
ever distance is found necessary for safety and convenience in laying. In this manner
a barrier of practically one mine per 25 feet (since in all probability the several lines
will be staggered with respect to each other) will be created. It is estimated that it
would be well-nigh impossible for a submarine to pass through the four lines without
striking a mine in some one of the lines. This distance apart of 100 feet insures
freedom of the mines from countermining each other.
14. If the upper antenna is made of such length that it reaches the surface, the
passage of surface craft coming in contact with the antenna will fire the mine. This
26 THE NORTHERN BARRAGE.
may be prevented in cases where it is desired to leave "gates" open for the passage
of the fleet by submerging an antenna to a depth of 50 feet. This willprobably
suffice to strike all submarines operating entirely submerged, because it is under-
stood that they cruise usually at a depth of 60 feet in order to avoid fouling the
bottom of surface craft which they can not see. The surface of these gates must, of
course, be thoroughly patrolled in order to prevent the passage of submarines on the
surface, or submerged but with periscope showing. In case, however, of explosion
of one of the mines by a surface vessel, serious damage would unquestionably result
to a merchant vessel. War vessels, however, by reason of their superior strength and
interior subdivision, would be able to stand with comparatively little damage, the
explosion of the mine at a distance.
15. For a barrier to be completely effective against submarines, the entire depth
of water from the surface to 200 feet should be mined; in other words, the buoy of
this mine should reach almost to the surface in order that a submarine on the surface
might be destroyed or seriously damaged. With a barrier of this kind, great care
would be necessary to keep friendly vessels away from the danger zone, and to this
end it would be necessary to put down navigational marks, either vessels or buoys,
to mark the danger zone and to facilitate the work of additional mine planting when
such becomes necessary.
16. The use of a steel sweep metallically connected to the sweeping vessel with a
steel underbody would explode the mines. This presents two advantages:
(a) In case of sweeping by the enemy no mine can be picked up and the construc-
tion thereof examined.
(6) After the war the mines may be readily removed by exploding them. If the
recovery of the mines for stowage and use is desired, however, this can readily be
done by using a parcelled sweep and insuring that the sweep is connected to the
sweeping vessel by means of some nonmetallic joint.
(c) The proposed plan of laying these mines contemplates their use in waters where
enemy sweeping operations could not be carried out without driving off the patrol.
17. The mine is protected from premature firing by two breaks in the electric
circuit. The first of these is closed by the hydrostatic pressure of the water after
the mine is launched. The second is not closed until the contact of the submarine or
other steel vessel with the antenna. The second break is further protected by a mechan-
ical lock not liberated until hydrostatic pressure is applied on the mine on submerg-
ence, and by an electrical ground which is not connected until the mine is in the
water and the buoy and antenna have paid out. The rugged character of this safety
device and its efficiency have been amply demonstrated by tests. Still another
safety device is an "extender" which forces the primer into firing position relative
to the detonator only after submergence of the mine to a predetermined depth.
18. The firing element of the mine is a dry-cell battery completely sealed up.
It is estimated that the life of this battery as thus sealed is at least two years, with
probably much longer life.
19. There are no insulated electrical parts outside the mine case. All electric
circuits within the case are carefully insulated, and in addition they carry such
feeble currents that there is no difficulty to be anticipated from short circuits, grounds,
or defective insulation. The lower antennae wire must be metallically insulated
from contact with the bare metal of the mine case or the mine cable. This can be
accomplished by coating the mine with a nonmetallic bittimastic compound and by
parcelling the anchor or mooring cable. Electrical insulation is not necessary, sim-
ply mechanical insulation to prevent actual contact of the two bare metals.
20. The action of pronounced currents especially where the mine is laid in very
deep water, would be to deflect the mine from the vertical and consequently, since
THE NORTHERN BARRAGE. 27
its mooring rope is of fixed length, to increase the submergence of the mine to some
degree. This difficulty may be overcome by floating spare lengths of antennae on
the surface, so that when by current action the mine is submerged, the spare length
then becomes an additional antenna buoy, now somewhat submerged. The tilting
action on the mine will not prevent the operation of its mechanism. In addition,
the deep submergence of the mine will remove it to a large extent, from influence
by surface currents and wave action, and will subject it only to legitimate deep
currents which do not, in the water in which it is proposed to lay these mines, reach
any high value.
STRATEGICAL AND TACTICAL CONSIDERATIONS.
21. In order to present a fair chance of success, these mines must not be laid as
surprise mines in waters wherein the enemy has control, but must be located at a
distance from enemy bases sufficient to insure absolute control of the waters by the
allied forces. This would then insure the maintenance of an adequate and contin-
uous patrol and the prevention of sweeping operations.
22. In planning for the material required for the North Sea barrier, the line from
Buchan Ness, on the east coast of Scotland, to the coast of Norway was assumed as
a possible line. This line is an extreme example of a barrier because of its length
and the depth of water traversed, though its currents are favorable.
23. It is evident that such a barrier would restrict freedom of action of the British
fleet based on the coast of Scotland, inasmuch as it would not be free to cross the
barrier line at any point except where a "gate" had been established. This gate
could be any width desired, say, 15 or 20 miles, and there could be more than one
gate.
24. Assuming that the North Sea were inclosed by effective barriers, and assuming
that the enemy had 200 submarines in the North Sea and confined thereto, it is to be
expected that the enemy would attempt to trap the allied forces. For example, sup-
pose that a gate 20 miles wide were left in the barrier, near the coast of Scotland, and
that this was the only means by which the allied fleet could pass in and out of the
North Sea. It is to be expected that the enemy might dispose his submarines in
appropriate positions in the neighborhood of such gate, that he would then send his
main fleet into the North Sea to make a demonstration and try to draw the British
and allied forces into an ambush. The important question arises, therefore, as to
whether the British and allied fleets could reasonably expect to cope with such a
situation. It seems reasonable to expect that by means of patrols and sweepers a
large area of sea adjacent to the proposed gate could be kept under control and made
fairly safe- for the fleet. However, denial to the German submarines of access to the
Atlantic would intensify submarine activities in the North Sea. The enemy would
also be likely to attempt to raid and sweep or destroy parts of the barrier. This would
necessitate constant and vigilant patrol by fast, light cruisers and destroyers, and it
is to be expected that this condition would bring on heavy engagements with the
enemy if not a main-fleet action.
27. Further tests are about to be made of a number of mines to demonstrate their
reliability under varying conditions of service, and their safety in handling, but as
the firing gear is the only really novel feature of the mines, and as that has stood every
test yet applied to it, there appears to be no possibility of failure.
28. The manufacture of 10,000 mines for our own service has been started. This
initial lot of 10,000 will prepare manufacturers concerned for production of larger
quantities.
T. A. KEARNEY, Acting.
28 THE NORTHERN BARRAGE.
As will be subsequently seen, the tentative design of the mine had
to be modified as a result of experiments and more mature study of
the project. Notably, the use of a lower antenna was decided to be
impracticable or inadvisable; and the spacing of mines had to be
increased to 300 feet to reduce the danger of countermining. It was
found, too, that the Bureau of Ordnance had been too optimistic in
its forecasts relative to early completion of design and early produc-
tion, due principally to the lack of sufficient experienced personnel
in the early stages of the project.
The foregoing carries the history of the northern barrage to the
point of its formal submission to the British Admiralty by the Navy
Department through Admiral Mayo.
CHAPTER II.
BRITISH CONSIDERATION OF PROJECT.
A British Admiralty "History of Northern Barrage" states that —
Toward the end of August, 1917, Commander (Acting Capt.) Alan M. Yeats-Brown,
D. S. 0., R. N., after having made various proposals during the preceding two months
with regard to anti-submarine measures, produced a paper entitled "Anti-submarine
Mining Proposals." This paper was referred to the plans division. This division
had already been considering these matters for some time, and, after consulting with
Capt. Yeate-Brown on several points which he had brought forward, suggested cer-
tain modifications to the proposals and wrote an appreciation on Capt. Yeats-Brown's
paper. The conclusions arrived at were brought up for discussion at the next allied
naval conference by the First Sea Lord, who, it is believed, had previously discussed
the matter with Admiral Mayo, of United States Navy.
The northern barrage project was taken up at an allied naval con-
ference at London, September 4-5, 1917, attended by Admiral H. T.
Mayo, United States Navy, where, as reported by him on September
8: "The British Admiralty put forward, as an alternative to a close
offensive in German waters, the suggestion that the activity of enemy
submarines might be restricted by the laying of an effective mine-
field or mine-net barrage." The mine-net barrage was considered
impracticable and "as to the proposal to put down a mine barrage
in the northern part of the North Sea, while it could be guarded
against enemy sweepers, certain difficulties exist such as lack of free-
dom of movement of the Grand Fleet, so that a very promising de-
gree of success should be indicated before such an undertaking was
begun." Further, "the conference, after discussion, agreed that the
distant mine barrage could not very well be undertaken until an
adequate supply of mines of satisfactory type was assured."
The British Admiralty history, in reference to the proceedings at
this conference, states:
Admiral Jellicoe put forward the suggestion of laying "an efficient barrage so as to
completely shut in the North Sea."
He computed that 100,000 mines would be required. He remarked (a) "I do not
think we get many German submarines by mines"; (6) "It appears that the result
of our mine fields (in the Bight) is to force the submarines, or a very large proportion,
to go in and out of the German bases through territorial waters or Dutch territorial
waters"; (c) "There is the alternative of laying a mine field in the North Sea in a
position where the enemy sweepers can not reach without running very considerable
risk. In view of our present experience I do not think that would have much more
result than our present policy; but if a mine is produced which is more effective
against submarines than our own mines the matter perhaps becomes somewhat dif-
ferent. * * We get our mines slowly. Our problem is then: Is it better to
put them down as we get them or is it better to wait until we get a very large number
29
30 THE NORTHEKN BARRAGE.
and lay a complete barrage across the North Sea? * * * It is obvious a mine
field so laid would have to be at some considerable distance from German ports,
because it would require to be watched. * * * A great deal depends upon whether
the mine is a satisfactory one. If we get a satisfactory mine, it might be worth while
laying a barrage when we get a sufficient number."
Admiral Mayo approved the idea of a mine barrage involving patrol by the allied
fleet, provided always that we had. confidence in the efficiency of the mine which
would be laid. He thought that this promised really more in the way of results than
the proposed operations in regard to the convoy of ships.
Vice Admiral Sims said, "It must be successful completely or it is not successful
at all. Either the barrage is successful absolutely or it fails absolutely."
Sir Eric Geddes said, "I do not understand from the remarks of the First Sea Lord
that the barrage should take the place of other offensive measures. It is not con-
sidered that the barrage can be sufficiently relied upon to take the place entirely of
other measures for hunting and destroying submarines. ' '
As for Sir Eric Geddes's statement, he was in exact accord with
the American proponents of the project, who, from the first advo-
cated it in addition to other useful antisubmarine measures.
The results of the conference may be summed up as indicating a
favorable attitude in principle toward the northern barrage project
leavened with doubt of its practicability. The reasons for this doubt
are surmised to have been the generally unfortunate experience of
the British in the development and use of mines. At the outbreak
of war in 1914 the British had practically no mines, and, for want of
a better one, adopted the Vickers-Elia type, which soon proved
unreliable and ineffective. This was superseded by one of British
Admiralty design, essentially similar to the Russian and German
horn mines, but with a distinctly British sinker (anchor). This
British horn mine, while perhaps an improvement on the Vickers-
Elia, was not entirely satisfactory, being comparatively dangerous
to hayndle, too susceptible to countermining, unreliable in automatic
depth taking, and not of a type lending itself to rapid and economical
manufacture.
• For some reason, perhaps their own rather slow and unsatisfactory
progress in the development of mines, British officials apparently were
skeptical of the ability of the United States to produce quickly a more
satisfactory type. This attitude first became apparent to the Bureau
of Ordnance on June 2, 1917, when Admiral Sims, in a dispatch to
the department, reported: * * * "the British Admiralty have
concentrated upon the construction of mines to such extent that they
now anticipate that by August the output will reach 10,000 a month.
They consider it unwise from their previous experience with mines
similar to those which we now have on hand to attempt to utilize
our present available supply. They now consider * * * as our
output of a different type mine would not be available in sufficient
time, that we can more profitably concentrate on other work."
An immediate result of the conference was the production on
September 14, 1917, by the Admiralty plans division of a paper for
THE NORTHERN BARRAGE. 31
Admiral Mayo entitled " General Future Policy, Including Future
Mining Policy " with an appendix, "Mine Barrage Across the North
Sea." The following extracts from this paper bearing on the barrage
project are quoted:
The enemy submarine campaign now dominates and overshadows every other consid-
eration, and any increase in the present rate of sinking might bring about an unsatis-
factory peace.
* * * it therefore appears that our future policy must be directed toward a more
concentrated and effective control in the areas between the enemy's ports and our
trade routes.
Some form of barrage corresponding to that which was formerly established by the
battle fleet * * * must be reconstituted in such a form that the enemy submarines
can not venture into it without considerable risk to themselves.
Broadly speaking, four forms of barrage may be considered —
Firstly. A barrage of mines only * * *.
Secondly. A combination of deep mines with surface and aircraft.
Thirdly. Surface and aircraft patrolling a wide belt.
Fourthly. Sealing the submarine exits * * *.
The fourth form of barrage * * is the only radical cure * * * but the
difficulties * * * are so great that it is not recommended to attempt it.
It is therefore proposed to use a combination of the first three.
* * * The enemy submarine would thus be subject when on the surface to attack
of one kind or another from shortly after leaving their bases until they cleared the
Orkney-Shetland-Norway line, in addition to passing through a mine barrage * * *.
The paper also dealt with the protection of the barrage, remarking "* * * with
our fleet based on Rosyth we should be in a position to insure protection even to the
area between the notified area and the Norwegian coast. ' '
The use of neutral waters by enemy submarines was also dealt with. "* * * this
can only be overcome by converting the neutral into an ally or by ourselves preventing
the enemy submarines from using these waters '• *. Should Norway come in
on our side, Stavanger * * * could be used as a base for a fleet or for the light
watching forces, as desired . Should, however, the general situation render it undesira-
ble to include Norway among the Allies, any development of the selective-type mine
would enable us to deal with the passage * * *."
The appendix dealt with the details of the mine barrage which it
was proposed to establish on the Aberdeen-Ekersund line, and was
at that time of such importance to the further consideration of the
project, particularly to the Navy Department, that it is quoted in
full below:
APPENDIX I.
MINE BARRAGE ACROSS THE NORTH SEA.
The object of mining the North Sea is to prevent the enemy submarines from getting
out, but it is most undesirable that any mine barrage should hinder the movements
of our own fleet or lay our coasts open to attack, if it can be avoided.
Before considering the line to be selected, the requirements of an effective mine
barrage will be considered.
The requirements are as follows:
(1) The mine field must be guarded; that is to say, it must either be —
(a) At such a distance from the enemy ports that he can not sweep it; or
(6) We must watch it and drive off any sweeping vessels he sends out.
32 THE NORTHERN BARRAGE.
Obviously (a) is preferable. It is also an advantage to be far enough off the enemy
aircraft bases to prevent interference to our patrols by seaplanes or aeroplanes. Zep-
pelins can be dealt with.-
(2) The mine field should be as far from the enemy ports as other considerations
will permit to enable our patrols to intercept any submarines damaged but not sunk
outright by our mines.
(3) The barrage must consist of both deep mines»and mines near the surface; or, if
deep mines only are used, the barrage must be patrolled in order to force the sub-
marine to dive to the level of the deep mines.
It is also an advantage if the barrage is in such a position that our main fleet can
be based on the enemy side of it, as this will not only give freedom of movement to
our own fleet, but in addition should enable us to intercept any enemy vessels which
endeavor to interfere with our barrage or the vessels patrolling it.
Consideration of the line to be selected. — The line from Aberdeen to Norway is pre-
ferred for the following reasons :
(a) Its great distance from the enemy ports, which will render interference from the
enemy difficult. Thus, every mine laid in this area will continue to be a menace to
the enemy submarines until the end of the war.
(6) The line is shorter than any other, with the exception of the Orkney and Shet-
land-Norway line, which is considered impracticable owing to the depth of water and
the strong tides in the Fair Island Channel.
(c) The Grand Fleet,*if based on Rosyth, is on the enemy side of the line.
(d) Any submarines damaged by mines will have a long way to get home and should
be accounted for by our patrols.
(e) Whether Norway eventually comes in on the side of the Allies or not, -the eastern
end of the line will be far easier to guard than the northern end of the Goodwin-Jut-
land line, which has been suggested.
(/) It would be easier to bring pressure to bear on Norway to induce them to take
steps to prevent submarines passing through their territorial waters than it would in
the case of Denmark with their ever-present fear of invasion.
(<7) The line Aberdeen-Norway deals with submarines using the Baltic exits as well
as with those coming from North Sea port:.
Proposed mining policy. — The principles governing our policy to be —
(a) Never lay a mine which can be swept in such a position that the enemy can
sweep it.
(6) Lay mines which can not be swept as close off the entrance to the enemy harbors
as possible.
The practical application of this policy to take the following form :
(I) Mine the Straits of Dover with deep mines and patrol the mine field to force the
submarines down on to the mines.
(II) Prescribe a mined area on the Aberdeen-Norway line.
(III) Lay deep mines between the notified area and Aberdeen and patrol this line
so as to force the submarines down.
IV. Lay deep mines between the prescribed area and Norway when mines become
available; in the meantime this area to be watched by hydrophone vessels.
V. Mine close in to the German harbors with destructor mines.
The British Navy to be responsible for mining the Straits of Dover and the entrances
to the German rivers.
The American and British Navies to cooperate in mining the Aberdeen-Norway
route.
It is absolutely essential that the whole of the mines laid in the Aberdeen-Norway
barrage should be SD constructed that they automatically become safe should they
break away from their moorings.
Details of the Aberdeen- Norway mine barrage. — Reference: Chart No. 2182 B.
U.S. MINE BASES
IN
SCOTLAND
PHOTOSTATIC CHART. SHOWING LOCATION OF U. S. MINE BASES IN SCOT-
LAND, BASE 17 AT INVERGORDON AND BASE 18 AT INVERNESS.
Fi§. 20
U.S NAVAL BASE N8 IS
INVERNESS, SCOTLAND
PHOTOSTATIC CHART SHOWING BASE 18 AT INVERNESS, SCOTLAND.
(Page 65.)
32-2
32-3
32-4
THE NORTHERN BARRAGE. 33
The total length of the barrage may be taken as 280 miles over the greater part of
which the depth of water is less than 50 fathoms.
To mine any belt of water effectively there should be three lines of mines at each
depth of 5 fathoms (e. g., the vertical distance between lines of mines will be 30 feet).
One line of mines at each depth will be referred to as a " system." Thus the com-
plete barrage will consist of three systems.
It is not considered necessary, however, to lay mines at a greater depth than 200
feet (33 fathoms), as submarines will not willingly go below this depth.
2. The barrage is divided into three parts:
Area A, the notified area. This area has to be made dangerous from the surface
to 200 feet below it.
Area B, area C, deep mines with surface vessels and aircraft patrolling.
The above areas will be considered separately. X
3. Area A:
It is necessary to make this area impassable to submarines whether diving or on
the surface. Three "systems" of mines will be required.* If British mines are used,
each system will have lines of mines at seven different depths, whereas if American
mines are used, each system will only require lines of mines at two different depths.
It is therefore proposed that Americal mines should be used for the area.
The barrage will consist of three systems of lines each, e. g., six lines of mines in all.
Suggested method of laying the mines. — (a) The northern edge of area A would be
mined first in order to restrict the movements of our fleet to the southward as little as
(6) The depth of area A is 56 miles which will allow of the mine field being extended
in a southerly direction without a further notification to neutrals.
(c) It is of great importance, however, to absorb as little of this space as possible on
each occasion of laying mines, and for this purpose three lines of spar buoys will be
laid in area A, as shown on chart 2182 B.
(d) Only one line of buoys will be required for laying the first and second systems,
the third system being laid to the north of the center line of buoys. The presence of
three lines of buoys will confuse the enemy as to the actual position of the mines.
(e) The spar buoys will be laid at intervals of 10 miles and will be numbered so that
the minelayers can ascertain where to commence laying on each occasion.
(/) The operation of laying the mines might be carried out as follows:
Two minelayers to proceed to No. 2 buoy and lay lines A. 1, A. 2, as shown on chart.
These lines would form part of the first system. The lines A. 1 and A. 2 would be 11
miles in length, the first mine being dropped when 2 milesf rom No. 2 buoy.
NOTE. — The object in not laying mines until 2 miles aw-ay from the buoy is twofold:
(1) It enables the buoys to be approached if it is desired to remove them later on.
(2) The buoys will give no information as to the exact position of the ends of the
lines of mines.
On the next occasion the mine layers would proceed well to the eastward of No. 2
buoy, then steer south until they reached the line of buoys, shape course for No. 3
buoy and lay lines A. 1, A. 2.
The second system of mines (lines A. 3, A. 4) would be laid in a similar manner but
to the southward of the line of buoys.
NUMBER OF AMERICAN MINES REQUIRED.
It is assumed mines will be laid 40 yards apart.
First system=Length of the line X number of line X number of mines to the mile.
=(11XH) X2X50.
=12,100.
Complete barrage, three systems= 3x12, 100
=36,300
181063°— 20 3
34 THE NORTHERN BARRAGE.
4. Area B. — The barrage will consist of three systems. Each system will have a
line of mines at each of the five following depths: 65 feet, 95 feet, 125 feet, 155 feet,
185 feet.
It is proposed that the mining of this area should be undertaken by the British.
Each system will require 22,500 mines.
Thereiore complete barrage = three systems.
=67,500 mines.
5. Area C. — It is desirable that American mines should be used for this area as
*he number of sinkers required is thereby reduced considerably. A decision on this
point can only be arrived at when it is known what type of sinker can be used with the
American mine.
NUMBERS REQUIRED.
If American mines-are used:
Complete barrage=three systems=3X2 lines
=6 lines.
Number of mines in each system=length of lineXnumber of linesXnumber of
mines to the mile.
=60X2X50=6,000.
Complete barrage=threesystems=3X6,000=18,000.
If British mines are used:
Complete barrage, three 8ystems=3X5lines
=15 lines.
Number of mines in each system =60X5X50
=15,000.
Complete barrage=45,000.
NOTE. — This number would be considerably reduced if the X attachment is used.
The copy of the above-quoted Appendix I, which was given to
Admiral Mayo for the Navy Department, bore the following notation
on its face: ''Admiralty would be glad to learn whether Navy
Department concurs in the plans as shown."
The Admiralty " History of Northern Barrage" states that "as a
result of this paper, it was decided to proceed with preparations for
laying a barrage on the Aberdeen-Norway line," and adds that
"the date of this decision is not known."
It is important to note that at this period the British Admiralty
was apparently quite in accord with the Navy Department in regard
to major features of the project, but differed with respect to some of
the details. Pending the return of Admiral Mayo to the United
States about the middle of October, the development of the project
was almost at a standstill for want of information as to British inten-
tions, except in the matter of design and manufacture of the new
mines; but the British Admiralty proceeded with the formulation
of policies and plans based on the decision to lay the barrage on the
Aberdeen-Norway line. These activities will be referred to in detail
later.
The location of the proposed barrage, with the proposed area which
should be notified (as it was to contain surface mines as well as deep
mines), together with the suggested arrangement of the mine sys-
tems, is shown in the reproduced chart (fig. 4).
CHAPTER III.
AMERICAN CONSIDERATION AND ADOPTION OF PROJECT.
Upon the return of Admiral Mayo to the United States a conference
was held in the office of the Chief of Naval Operations on October 15,
1917. The following officers were present: Admiral Benson, Admiral
Mayo, Rear Admiral Earle, Capt. F. H. Schofield, Capt. R. R. Bel-
knap, Commander Fullinwider, and Commander King.
. At this conference Admiral Mayo produced for consideration the
above-quoted Appendix I, setting forth the British Admiralty version
of the plan for the proposed barrage. There ensued a general exami-
nation and discussion of the plan; and, the consensus of opinion
being favorable, the Chief of Naval Operations, Admiral Benson,
after consultation with the Secretary of the Navy, then and there
directed the Chief of Bureau of Ordnance to proceed with the pro-
curement of 100,000 Mark VI mines. This action, so far as the
adoption of the project was concerned, was only tentative pending a
careful study of the British version; but it was regarded by the
Bureau of Ordnance as tantamount to a decision to carry out the
project and to provide all necessary material therefor without further
delay.
Following the conference, the planning section of the office of
Naval Operations and representatives of the Bureau of Ordnance con-
ferred informally as to details of the plan, and the papers in the case
were then referred to the general board for consideration.
On October 17, 1917, while the barrage project was under con-
sideration by the general board, the Chief of Naval Staff, British
Admiralty, addressed the following dispatch to the Chief of Naval
Operations:
It will be necessary to increase the number of lines of United States mines in each
system in the North Sea barrage from two to three if there should be any difficulty in
using the lower antennae of United States mines for first supplies. Could you
please state an approximate date when supply of complete mines and sinkers will
begin, stating at what rate the supply will be maintained?
As all British mine layers will be fully engaged in laying British portions of the
barrage will you please say how many United States mine layers will be available
' and the output of United States mines? It is estimated that each ship could
make five mine-laying trips a month. As a base for United States mines and mine-
layers, it is proposed to use Cromarty. The question of facilities for assembling ready
for use, storage, and embarkation is being investigated on the spot. It is suggested
that it is desirable that United States officers should confer with ours on this question
and examine proposed arrangements as to suitability for dealing with United States
mines and sinkers; also to ascertain as to whether our depot system will be suitable
35
36 THE NORTHERN BARRAGE.
for application to United States mines. It is proposed that the necessary assembling
and testing of United States mines and sinkers on receipt and before issue to mine-
layers should be dealt with by depot staffs, provided by you if possible. It is hoped
that you will be able to agree with this. United States officers if sent over can report
numbers required.
I should be much obliged if you would inform me as soon as possible whether you
can supply sinkers for United States mines.
On October 20, on the recommendation of the general board, the
Navy Department cabled Admiral Sims substantially as follows:
The department requests to be informed whether the plan for the placing of a mine
barrage across the North Sea on the Aberdeen-Ekersund line has the approval of the
Admiralty. It is believed that the great experience of the British naval forces in
North Sea operations and their experience in naval mining during the present war
puts them in the best position to decide whether the proposed scheme is practicable
in construction and maintenance and whether in the opinion of the Admiralty it is
the best scheme in sight for limiting the operations of enemy submarines, provided
that the Straits of Dover can be efficiently closed to the passage of submarines, which,
if possible, in the opinion of the department, should be done at the earliest possible
date.
The following reply in substance was received on October 23 from
the Admiralty:
The mine barrier has been approved by Admiralty and the Admiralty now con-
firms approval. The preparations are rapidly proceeding.
Admiralty's cable of 17th indicates the assistance desired from the United States of
America. This scheme is considered by the Admiralty best to be carried out at
a distance from the bases of the enemy. The Admiralty are working on a supple-
mental scheme for operation close inshore, but any such inshore operation has the
defect that a passage through for submarines can eventually be cleared by the enemy.
No scheme yet tried has been effective in closing the Dover Straits to submarines,
but measures are being constantly improved and they are at the least always a con-
siderable deterrent. Mining operations on an extensive scale against submarines in
the Straits of Dover commence in November. Owing to the lack of effective anti-
submarine mine, this has hitherto been delayed.
The general board completed its consideration of the project and
submitted its report to the Secretary of the Navy on October 24,
1917. A complete copy of this report is appended, but a summary
of its " conclusions" is quoted here:
* * * The general board is decidedly of the opinion that of the measures
discussed * * * the scheme of closing the North Sea offers the best chances of
success — that is, to close the North Sea by the Aberdeen-Ekersund barrier approved
by the British Admiralty, and to similarly close the Dover Straits.
The general board does not underestimate the practical difficulties that must be
overcome in providing the necessary material and transporting, placing, and main-
taining it in the face of the determined efforts of the Germans to render the barrier
abortive. Further, the barrier even when placed can not be effective without an
adequate patrol. The general board is, however, encouraged to give its indorsement
to this plan because it has the approval of the British Admiralty; it is proposed by it
as the best practicable plan to meet present war conditions; the Chief of Bureau of
Ordnance stated the material, mines, anchors, moorings, etc., can. be surely sup-
plied; and the accompanying memorandum of Capt. R. R. Belknap, United States
THE NORTHERN BARRAGE. 37
Navy, who has been actively engaged in conducting mining operations, points the
way to handling the details of transporting and planting.
It is assumed that the British Admiralty in approving this plan recognizes the
vital importance of the necessary patrol — that it is clearly seen by it where the
required number of vessels is to be obtained, and that the extent of the cooperation
required of the United States in this regard will be communicated to the United
States Navy Department.
If it is decided to proceed with the construction of the Aberdeen-Ekersund barrier,
the* general board recommends that the preliminaries be arranged at once, and that
suitable officers of experience in mining operations be sent to England to arrange for
our participation in the work.
The report of the general board was approved by the Secretary of
the Navy October 29, 1917, and on the following day the northern
barrage project was favorably acted upon by the President at a
Cabinet meeting.
On November 1 the Chief of Naval Operations cabled the
Admiralty :
Department concurs in project for mine barrier Scotland to Norway and has already
taken steps to fit out eight such mine planters to sail February 1. * * * Expect
begin shipment of mines January 15. Will send officers to confer and arrange details
in a few davs.
CHAPTER IV.
STATUS OF BARRAGE PROJECT ON NOVEMBER 1, 1917.
The American and British authorities having formally adopted
the northern barrage project, it is desirable to sum up its major fea-
tures as understood by the Navy Department, and more particularly
by the mine section of the Bureau of Ordnance, whose function it
was to procure and provide the mines appropriate to the project.
Referring to the previously quoted Appendix I, which dealt with
the details of the proposed barrage, which presumably was the basis
of approval by the Admiralty as well as our Navy Department, and
which was generally in accordance with the original proposition of
the Bureau of Ordnance, the plan embraced the following features:
(a) The British Navy to be responsible for mining the Straits of Dover. * * *
(6) The American and British Navies to cooperate in mining the Aberdeen-Norway
route.
(c) On the initiative of the British Admiralty, the northern barrage was divided
into three parts:
Area A: The "Notified area." This area to be made dangerous from the surface
to 200 feet below it.
Area B; Area C: Deep mines with surface vessels and aircraft patrolling.
(d) Area A: Middle area about 160 miles long. To be mined by United States with
American mines (antenna type). Barrage to consist of three systems, each system to
have a line of mines at each of two depths — 100 and 200 feet. Total requirement
36,300 mines.
(e) Area B: Western area, about 60 miles long. To be mined by British with
British mines (horn type). Barrage to consist of three "systems," each system to
have a line of mines at each of 5 depths — 65, 95, 125, 155, and 185 feet. Total require-
ment 67,500 mines.
(/) Area C: Eastern area, about 60 miles long. The British plans paper, Appendix
I, stated: "It is desirable that American mines should be used for this area, as the
number of sinkers required is thereby reduced considerably. A decision on this
point can only be arrived at when it is known what type of sinker can be used with
the American mine." This, taken in connection with the British inquiry of October
17 as to whether the United States could supply sinkers for United States mines,
which was answered in the affirmative, left no doubt in the minds of department
and Bureau of Ordnance officers concerned that the United States would mine Area
C. Required, 18,000 American mines.
The following additional points set forth in the above-mentioned
British paper were taken at their face value by American officers,
especially since these points were in accordance with the original
American proposition:
(g) The mine field must be guarded.
THE NORTHERN BARRAGE. 39
(h) The mine field should be as far from the enemy ports as other considerations
will permit to enable our patrols to intercept any submarines damaged but not sunk
outright by our mines. This implies the maintenance of a patrol.
(i) The barrage must consist of both deep mines and mines near the surface; or, if
deep mines only are used, the barrage must be patrolled in order to force the sub-
marine to dive to the level of the deep mines.
(j) It is also an advantage if the barrage is in such a position that our main fleet
can be based on the enemy side of it, as this will not only give freedom of movement
to our own fleet, but in addition should enable us to intercept any enemy vessels
which endeavor to interfere with our barrage or the vessels patrolling it.
(ifc) The line from Aberdeen to Norway is preferred for the following reasons:
(a) Its great distance from the enemy ports.
(6) The line is shorter than any other, with the exception of the Orkney and
Shetland-Norway line, which is considered impracticable, owing to the depth
of water and the strong tides in the Fair Island Channel.
(c) The grand fleet, if based on Rosyth, is on the enemy side of the line.
(d) Any submarines damaged by mines will have a long way to get home
and should be accounted for by our patrols.
(e) Whether Norway eventually comes in on the side of the Allies or not, the
eastern end of the line will be far easier to guard than the northern end of the
Good win- Jutland line, which has been suggested.
(/) It would be easier to bring pressure to bear on Norway to induce them to
take steps to prevent submarines passing through their territorial waters than it
would in the case of Denmark with their ever-present fear of invasion.
(g) The line Aberdeen-Norway deals with submarines using the Baltic exits
as well as with those coming from North Sea ports.
The British version of the plan differed from the American propo-
sition in one most important particular, namely, that the eastern
part of the barrage, Area C, was to be deep mined only, leaving the
surface safe for traffic and depending upon patrols to prevent the
passage of enemy submarines. This part of the plan was fore-
doomed to failure, since it was obviously impossible for patrols to
effectively guard such a large area, as had been demonstrated by
British experience in the much smaller area of the Strait of Dover;
but for the time being the plan was accepted by American officials,
with the understanding that, in case this part of the plan should
prove ineffective, surface mining could be extended through Area
C later.
It was on the basis of the above understanding of the project that
the Bureau of Ordnance proceeded with the design and procurement
of the required mining material and that the Navy Department
undertook all other necessary preparations for the project. The
planting of the barrage was to begin as soon as possible in the fol-
lowing spring, 1918, to assure its completion during favorable weather
of the summer or early fall. Therefore, there was little time in
which to complete the details of design of the new mines, launch the
huge manufacturing project, and obtain production in adequate
quantities not later than February, which was necessary in order
that the mines could be shipped abroad, assembled, and made ready
for use by April, 1918.
CHAPTER V.
COORDINATION OF PREPARATIONS.
To insure a proper coordination of all necessary preparations for
the northern barrage project, Capt. R. R. Belknap of the Office of
Naval Operations was placed in immediate charge in that office of
the plans for the entire operation, which involved in greater or less
degree all bureaus of the Department. The Bureau of Ordnance
was to furnish the mines and mining material; the Bureau of Con-
struction and Repair was chiefly concerned in the structural con-
version of certain merchant ships into minelayers; the Bureau of
Navigation had to furnish the officers and men Jo man the new mine
squadron; the Naval Overseas Transport Service was to allocate
sufficient cargo tonnage to maintain adequate and regular ship-
ments of mining material; the Bureau of Supplies and Accounts was
to take measures to handle the shipments of mines and other mate-
rial; and so on.
All the above and other preparations constituted only one of the
major naval operations then in hand; and there was the possibility
that some essential part of the preparation might not be given its
due precedence, either within the department or at some navy
yard, unless the various activities were carefully watched and their
importance kept constantly to the fore. -This was all the more
necessary by reason of the fact that the new mine and its objective
use were shrouded in mystery, very few officers being let into the
secret, which it was hoped could be kept from the enemy until we
were ready to begin actual mining operations in the North Sea.
Throughout these preparations the project was mentioned in
writing as little as possible, information and instructions to those
concerned being communicated orally so that secrecy might be
assured.
It was principally by means of informal conference between
officers concerned that the many bureaus and offices quickly and
effectively solved the multitudinous problem incidental to such
a project. "Red tape" and formal routine methods were for the
time being abolished, and those officers immediately charged with
the work of preparation were practically accorded carte blanche.
40
• THE NORTHERN BARRAGE. 41
In this connection, it is pertinent to note that the Secretary of
the Navy, at the time of the project's adoption, stated that it had
the strong interest and approval of all in high authority; that he
himself desired every effort made to expedite it; that all who might
be called upon for assistance should be informed of his wishes hi this
regard so that they should cooperate to the fullest extent; and that
he should be immediately resorted to in any case where his action
or influence might be needed.
CHAPTER VI.
DESIGN OF THE MINE.
The possibility of the northern barrage depended upon the suc-
cessful design of the new mines to a far greater degree than is usual
in such matters. Had nothing better than the ordinary type of
mine, such as that used by the British, been available, the northern
barrage project would have been utterly impossible of execution
within the time allowed by reason of the enormous number of mines
required for a barrage 280 miles long. The combined resources of
the United States and the Allies, especially in the matter of high
explosives, could not have produced the required number of mines,
nor could the combined mining forces have planted them in a single
year. By the use of mines of the American (antenna) type, the
number required was reduced to approximately one- third; and the
project became possible, provided always that the design of the new
mine was right.
On November 1, 1917, after the barrage project had been finally
and definitely adopted, the only parts of the "Mark VI mine that
had been completely designed were the firing mechanism and the
mine case. However, the mine section of the Bureau of Ordnance,
under the immediate direction of Commander Fullinwider, felt no
doubt of its ability to complete a satisfactory development of the
new mine and to get it into production in due time, its optimistic
view of the situation being based on the facts that the only radically
new element of the mine was the firing mechanism, which had
been fairly well tested; that the war experience of the British had
evolved a satisfactory type of mine anchor which doubtless could
be adapted to the American mine; and that the remaining features
were matters of mechanical detail certainly susceptible of quick
solution. In the circumstances, it was absolutely necessary to
take chances, else the project would be delayed a full year and
therefore be too late. It was fortunate that Rear Admiral Earle,
the Chief of Bureau, was willing to accept the final responsibility in
this matter and that he had sufficient confidence in the mine sec-
tion to give it practically a free hand.
If the Bureau had been at all conservative in the matter of de-
veloping the design and placing contracts for the mines, the north-
ern barrage would never have been laid. It is a well known fact
42
THE NORTHERN BARRAGE. 43
that no mechanism as complicated as a mine, or even a much simpler
one, can be confidently expected to function as designed until com-
plete models have been tested under service conditions and the
usual minor defects have been discovered and remedied. Ordi-
narily, it requires at least a year to prove out such a design before
it is considered wise to put it hi to production. Judged by ordinary
standards, the action of the Bureau in bringing about the adoption
of this great project before there was any certainty of the efficiency
of the new mine, thereby committing two Governments to very
large expenditures, was, to say the least, hazardous. The Bureau
accepted the hazard advisedly, as the only thing to be done in the
circumstances, and well knowing the odium that would attach in
case of failure.
The problem confronting the Bureau was to build a mine around
an entirely new principle in minuig, and around a firing gear out-
lined but not perfected. This mine must be efficient and yet must
be capable of manufacture and assembly in great quantities, with as
little expense of money as practicable, and necessarily with as little
expenditure of time as absolutely possible. The bureau had departed
from the usual, or contact, mine with its new firing gear, and had
then proceeded to wipe the slate clean and make radical develop-
ments in the entire mine.
Practically all mines, except the later German types, had been
made up to that time with the explosive in separate charge cham-
bers, which were, after loading, placed within the mine case proper.
This presented the triple disadvantage of additional weight; cost of
time and money in manufacture, loading, and assembly; and, most
serious, the interposition of an air cushion surrounding the charge
chamber between the first explosive force and the water, thereby
greatly reducing the force of the water hammer blow caused by
the explosion, which blow was that relied upon to damage the
submarine touching the antenna. These difficulties were all obviated
by selecting an explosive, T. N. T., which could be readily cast and
cooled, and casting this direct into the completed mine case, using
no separate charge chamber.
In addition, similarly the practice of carrying the detonator
fixed in the explosive was a source of great danger in case of accident
or fire or in case the minelayers were engaged in action with the
mines on board. The safety chamber device of service fuses was
adopted, so that the detonator might not be in contact with the
main explosive until after the mine had been launched and sub-
merged.
The design of antenna gear presented a problem that had, as far
as was known, no precedent in the military or commercial arts, and
required considerable initial design ability and experimentation.
44 THE NORTHERN BARRAGE.
As a matter of fact, the officers responsible for the mine freely
admitted to themselves the certainty that the design would have
to be modified more or less after service tests, and therefore shaped
the design so that any one of its features could be modified during
production with little or no effect on the others. In other words,
every possible precaution was taken against possible loss of time
and money. The result was very satisfactory. Very few changes
were necessary after getting into production, and when the first
complete mines were assembled and tested under service conditions
in March, 1918, they functioned as designed, and only very minor
improvements, involving no delay in the project, were found to be
desirable or necessary.
During thex initial plans for the mine, the mine section of the
bureau consisted of Commander S. P. Fullinwider, Lieut, (subse-
quently Commander) J. A. Schofield, U. S. N. R. F., and, acting as
the experimental officer of that section by virtue of his experimental
duties in the bureau, Lieut. T. S. Wilkinson, jr. As the project
began to take shape and became approved, the bureau added to the
mine section certain line and reserve officers, who will be mentioned
hereafter as their duties appear.
In the initial stages of design, Commander Fullinwider assumed
cognizance of the mine case, anchor, and antenna gear, leaving
Lieut. Wilkinson the firing gear, the extender, and the mine loading;
that is, explosives and detonator. With the advent of other officers
these duties were further subdivided as follows: To Commander
Schofield, the mine case; to Lieut. O. W. Bagby, U. S. Navy, and
Lieut. S. W. Cook, U. S. N. R. F., the mine anchor, in conjunction
with Lieut. Commander H. Isherwood, R. N. V. R. (noted below);
to Lieut. Commander W. A. Corley, U. S. Navy, the antenna gear;
to Lieut. C. H. Wright, U. S. Navy, the firing gear and extender;
to Lieut. B. W. Grimes, U. S. N. R. F., the explosives. This division
of responsibilities held through the design stage and through the
production of the parts of the mine, as described in the succeeding
chapter of this history.
At various times during the period of design and experimentation,
the Bureau of Ordnance had the advantage of the advice and assist-
ance of three experienced mining officers of the British Navy. On
May 5, 1917, Lieut. Commander H. O. Mock, R. N. V. R., arrived
in the bureau, having been thus assigned by the British Admiralty,
to assist and advise in matters pertaining to mines. This was in
accordance with a plan adopted immediately upon the entrance of
the United States into the war, whereunder each of the two naval
departments undertook to furnish the other with information to
their mutual advantage. Lieut. Commander Mock brought to the
Bureau of Ordnance the latest information and experience regarding
THE NORTHERN BARRAGE. 45
the British mines and mining, more particularly information con-
cerning mine anchors.
During Lieut. Commander Mock's stay in the bureau, the Mark
VI mine-firing device (K-l device) was evolved; and he was present
during much of the experimental work in connection therewith,
although he did not assist in the evolution of the design. He was
an early convert to the value of the new device; and upon his return
to England in October, 1917, a model of the new device was trans-
mitted by him for the Admiralty's information, the question of
whether or not the British would join the Americans in the barrage
project being then under consideration. Lieut. Commander Mock
considered the K-l device of great promise, and looked upon the
new mine then in process of evolution as being superior for purposes
of anti-submarine warfare to any other then existing type.
Lieut. De Salis, R. N., arrived September 3, 1917, having been
sent to this country to examine the Mark VI mine and report to
the British Admiralty as to its probable value for the proposed
North Sea barrage. He was sent to this country on the initiative
of the British Admiralty and apparently with a view to satisfying
the Admiralty that our Navy Department really had what it had
previously stated it had — a mine superior to existing types and
peculiarly adapted to antisubmarine warfare. In short, the British
Admiralty took this means of confirming the Bureau of Ordnance
opinion and estimate of its own design and product before agreeing
to cooperate in the establishment of a barrage.
After Lieut. De Salis had reported to the Chief of Bureau on the
above-mentioned date, the chief of the mine section explained to
him the characteristics of the new mine firing device, and accom-
panied him that evening to the naval torpedo station, Newport,
R. L, to witness tests. These tests were carried out, with inade-
quate preparation and facilities, on the two following days, Septem-
ber 4 and 5. Lieut. De Salis was soon convinced that the new device
had merit. On September 7 he cabled the Admiralty in part as
follows:
The mechanism is safe and simple. Still in trial stage. It has worked perfectly
for safety and bumping. No vessel really suitable was present, so trials were rather
crude. Trial of countermining was not very satisfactory, but the faults revealed can
be remedied.
Mine designed is 33-inch diameter, and could be used with B. E. or Mark VI sinker.
A 38-inch diameter mine would be designed if desired. No sinker is yet designed
and it is intended to copy ours.
U. S. officials state that delivery of a thousand mines and mechanisms per diem is
anticipated to commence December 1.
Proposals are that combined operations should be worked out for use of these mines.
They would provide the mechanisms and mines, while the British provide mine-
layers and sinkers.
46 THE NORTHERN BARRAGE.
They offer a hundred thousand. Details of strategical proposals are known to
Admiral Mayo.
It is recommended that American offer should be accepted, our own output not being
decreased in consequence.
The questions to be settled subsequently are manufacture of sinker, size of mine,
and supply of explosive. They have sufficient crude T. N. T. and are willing to
supply it.
I still adhere to the opinions expressed September 3, but advantages to outweigh
them are: Simplicity, certainty of firing, large danger zone, and the element of sur-
prise if the secret is kept.
On September 10 the Admiralty cabled Lieut. De Salis:
Greatly appreciate offer of U. S. Fully recognize the value of the increased danger
zone near mines, but fear is expressed that if antenna only can fire mine, life in this
climate would be limited by durability of antenna, which is necessarily short.
Reply forthwith if antenna principle can be applied to horned mines, whose plans
are now in America; or, conversely, if American mines can be fitted with a firing
arrangement thoroughly reliable, or with horns so that effectiveness as complete mines
would remain after antenna has parted.
Lieut. De Salis, after consulting the Bureau of Ordnance, replied,
September 11:
Americans propose to fit fixed insulated projections of copper on mine case in
parallel to antenna, so that mine will remain effective on same principle if it is hit
whether the antenna is in place or not. Firing battery will then determine life of
mine. It is sealed up, and no current is taken from it until moment of firing.
On September 12 Lieut. De Salis again cabled the Admiralty, in
part as follows:
United States officers are extremely confident as to life of battery. In addition,
halfway down antenna a float will be fitted, in which case wave action should not
much affect lower half.
Acceptance of the offer as it stands is strongly recommended.
Design could subsequently be altered for fitting horns should endurance trials,
which are now in hand, prove unsatisfactory.
Admiral Benson wishes to be informed of the proposed strategical use which may be
decided on if offer is accepted, and of the numbers required.
The Bureau are requesting that a mine designer may be lent them to cooperate and
insure fitting of mine on sinker.
Lieut. De Salis, during his connection with the Bureau of Ordnance,
was an observer for the British Admiralty and probably had much to
do with the Admiralty's favorable consideration of the proposed
joint project. In addition, Lieut. De Salis furnished the bureau
information of a general nature regarding British mines, mining
equipment, and mining practice. He did not, however, have any
influence on the design of the Mark VI mine. Lieut. De Salis spent
much of his time at the naval torpedo station, Newport, where he
conducted some tests with floats and antennae. He returned to
England in December, 1917.
In the original proposition for a joint American and British bar-
rage operation, it was proposed by the Bureau of Ordnance that the
THE NORTHERN BARRAGE. 47
British should furnish the anchors and that the United States should
supply all the mines. This proposition was put forth for several
reasons: First, there was a shortage of tonnage available for the
shipment of the material abroad, and this shortage was growing more
and more serious from day to day as the result of the great activity
at that tune of the enemy submarines. The dead weight of the an-
chors alone required for the barrage was estimated at about 40,000
tons. Second, the British had a quite satisfactory type of anchor,
which had been proved out during the war, and which, with minor
modifications, could be adapted to fit the American mine. Third, it
was originally contemplated that British mine planters would assist
the United States mine force in the planting of mines, and therefore
the mine tracks and mining equipment in general should be stand-
ardized hi the two services. Fourth, it was considered only fair that,
if the barrage was to be a joint operation, the British should bear a
share of the cost and production of material.
After much delay in arriving at an understanding, it was finally
decided to produce all the anchors as well as the mines hi this country.
To facilitate the design of the anchor, and particularly with a view
to making it standard with British mine layers' equipment, the
British Admiralty was requested to send an officer to the Bureau of
Ordnance who was competent to modify the British design of anchor
to adapt it to the Mark VI mine. The admiralty properly acceded to
this request, and Lieut. Commander Isherwood, R. N. V. R., arrived
hi the Bureau early in October, 1917. He brought with him the de-
tailed design of the British Mark VIII sinker (mine anchor) , and this
was found upon examination to require very little modification to
suit the Mark VI mine. Lieut. Commander Isherwood, with the
assistance of Bureau of Ordnance draftsmen, completed the redesign
of the British sinker, referred to hereafter as the anchor, Mark VI;
and on November 10 the design was ready for submission to the pro-
spective bidders.
While the Mark VI anchor was very similar to the British Mark Vlll
sinker,, it differed in detail sufficiently to have warranted thorough
tests before its adoption, had the tune been available. However, as
not a day could be lost without correspondingly delaying the execu-
tion of the project, it was decided after very careful study of the de-
sign that it would be reasonably safe to proceed with production;
and contracts were placed immediately with three prominent auto-
mobile concerns in Detroit, Mich. Lieut. Commander Isherwood
remained in the United States until the anchors were well along in
production and until after practical tests with complete mines had
been carried out by vessels of the mine force just prior to their depar-
ture for the North Sea. The anchor proved most satisfactory hi every
respect, being, it is now believed, superior hi its functioning to the
British Mark VIII sinker from which it was adopted.
48 THE NORTHERN BARRAGE.
The mine case was entirely a Bureau of Ordnance design. It was
formed of two hemispheres of steel welded together at the equator.
It had an opening in the top 7 niches in diameter to receive the firing
gear, and a smaller opening in the bottom to take the booster cfharge
and the detonator extender mechanism. Built into the lower
hemisphere, in the axis of the case, was a steel tube which housed
the booster charge and extender mechanism. The charge of 300
pounds of grade B trinitrotoluol was cast directly into the lower
hemisphere of the case, it being found by experiment that the charge
was sufficiently anchored in place by the bond between it and the
surface of the case and central tube and by four stay braces which
supported the tube. This simple form of construction saved con-
siderable weight and permitted of the mine, case being kept within
comparatively small dimensions — 34 inches diameter. The British
mine had a diameter of 38 inches. The buoyancy of the Mark VI
mine was 285 pounds, which is ample for mines to be used where the
current is not greater than three knots. The mine case had welded
to it a lifting eye, also hooks for securing the antenna system and the
anchor. Four small holes in the case about 2 inches above the equator
were provided for attaching firing "horns" in parallel with the
antenna.
The extender mechanism, which carried the detonator in a retracted
or safe position, relative to the booster charge, and which, under a
hydrostatic pressure corresponding to a depth of 25 feet, extended the
detonator to its firing position hi the axis of the booster charge, was a
lazy-tongs device, which also was originated and designed in the
mine section. This mechanism provided an excellent safety device,
since a mine which floated or which was submerged to a depth less
than 25 feet would be safe.
A similar hydrostatic safety device was incorporated in the firing
mechanism; and both of these devices would have to fail to make
the mine dangerous on or near the surface.
The antenna floats, the fittings in connection therewith, and the
means of assembling the antenna system with the mine proved the
most troublesome parts to design though they appear very simple.
Experiments were first made with floats of water-proofed wood,
but without success, since it was found impracticable to guard against
their water-logging when subjected to deep submergence for consid-
erable periods. Ultimately, three different types of float were suc-
cessfully produced and used. For mines of the upper level a thin
walled spherical copper float was used; for mines submerged 150 to
300 feet a spherical-cylindrical steel float with a wall thickness of 0.1
inch was used. The third type, which finally replaced the copper
floats was made up of balsa and skiUfully waterproofed to withstand
hydrostatic pressure safely up to at least 100 feet submergence. For
mines of the upper level, two floats were fitted on each antenna, the
48-1
48-2
48-3
THE NORTHERN BARRAGE. 49
lower one being placed a little above the middle point of the antenna,
so that, hi the event of the upper float carrying away, no part of the
antenna could possibly come into contact with the mine case and
fire the mine.
The antennae of the lower level mines were provided with a single
steel float. These mines were at such depth as to be % entirely
unaffected by wave motion, and one float could be depended upon
for an indefinite life.
The mechanism by means of which the antenna and floats were
secured to the mine case until the mine reached a predetermined
depth and then permitted their release in such a way as to avoid
fouling, gave much difficulty, but the problem was very satisfac-
torily solved with the assistance of the Baltimore.
Discussion of many of the items of design, including that of the
K-l device, or firing mechanism, is omitted here as unnecessary
and because they are still regarded as confidential.
One of the most important and indispensable of the preparations
was the trying out of the new mine under service conditions. In the
earlier stages, complete mines were not available; and they did not
become available until March, 1918. In the meantime, however, the
Baltimore, which had been designated to carry out tests, performed
such experiments as could be had with improvised material, and
assisted in the design of some parts of the gear, notably the means of
assembling the antenna floats with the mine and their release gear.
This work continued until about December 20, 1917, when it became
necessary for the Baltimore to go to the yard for fitting out for service
abroad. It had been intended that this vessel should resume experi-
ments and practice with the completed mines in March, but before
that tune it became necessary to send her abroad to assist in a
British mining operation.
The mine trials were taken up by the San Francisco in March
when the first mines were ready. Trials were carried out in the lower
Chesapeake, later in Narragansett Bay, and finally off Cape Ann.
The results of these trials were all that could be expected. With
the exception of a very few minor mechanical faults which were
readily corrected, the mine and anchor functioned as designed;
and the action of the Bureau of Ordnance in having proceeded with
the manufacture of 100,000 mines in advance of such tests was thus
validated. A most important result of the trials was the confidence
engendered in the personnel of the mine force in' the value and
safety of the new mine.
It may be remarked in passing that the result of the trials lifted a
heavy load from the minds of those officers of the Bureau of Ordnance
who had staked all on a " paper design" and proceeded with an
enormous manufacturing program in advance of complete tests.
181063°— 2(
CHAPTER VII.
THE MANUFACTURING PROJECT.
The firing mechanism for the new mine was in quantity production
before any other part of the mine had been designed. The mine
section had made tentative sketches of the several principal fea-
tures of the mine, but none of the details had been decided upon.
One reason for this was the fact that until the firing mechanism had
been conclusively tested and adopted, late in July, there was insuf-
ficient information and data on which to proceed with the other points
of design. Another point was that until November, 1917, there was
insufficient personnel in the mine section to perform the duties of the
Bureau pertaining to mines and mining, depth charges, submarine
nets, etc.
The Bureau of Ordnance, having anticipated the favorable outcome
of the mine barrage proposition had placed a contract for 10,000 mine-
firing mechanisms (K-l devices) as early as August 9, 1917, and
another contract for 90,000 additional devices on October 3, 1917,
nearly a month before the barrage project was definitely adopted.
In view of the fact that there were so many uncertainties entering
into the design of the mine, it was decided that the only safe plan
was to follow the practice which is quite common in the automobile
industry — that is, to divide the mine into groups of parts, each group
being quite a separate design problem, all so standardized that the
several groups would assemble into a complete mine. Thus the mine
was separated into the following groups: Firing mechanism, extender
mechanism, mine case, anchor, antenna and floats, horn device, and
release gear.
Each group was designed and tested out quite independently of
the others, a very definite general plan for the mine, of course, being
kept in view. This method permitted of modifications of any one
group without detriment to the others.
Another reason for following this method of design was that it
would facilitate manufacture. There was no plant in the United
States that had had experience in the manufacture of mines except
the Norfolk Navy Yard, which yard was overwhelmed with other
work after the outbreak of the war and could not be depended upon
for any considerable manufacture of mine material. By designing
the mine as an assembly proposition, its many parts could be manu-
factured in commercial plants with great rapidity; and by carefully
50
THE NORTHERN BARRAGE. 51
standardizing all parts, they could finally be brought together and
satisfactorily assembled.
The general economic conditions of the country were such that at
the time when it became necessary to manufacture the Mark VI mine
the passenger automobile industry became available for war work
through a gradual decrease in output of automobiles. It is believed
that the Bureau of Ordnance was the first of the war agencies to take
advantage of the wonderful resources of the automobile factories;
and no difficulty whatever was found in obtaining keen competition
among these factories for the manufacture of parts. Generally
speaking, the automobile plant is ideal for the production of mine
material with the exception of the firing mechanism, because the
plant is organized for quantity production and the character of work
and workmanship is practically the same for automobiles and mines.
Still another reason for pursuing this method of manufacture was
that only by this means could secrecy regarding the characteristics
of the mine be preserved. It is obvious that if 100 different parts of a
mine are manufactured by as many different factories, most of which
are kept in ignorance of the fact that they are producing mine mate-
rial, no one would have sufficient information on which to visualize the
complete mine, and therefore no one could possibly betray the secret
to the enemy. This idea was carried still further. Even at the point
of assembly of the material for transshipment abroad, the parts were
not assembled into a mine, but were shipped in groups to the overseas
assembly bases. In short, no mines were completely assembled in
this country, with the exception of a few for test purposes on board
vessels of the mine force in March, 1918. It is therefore believed
that the enemy, notwithstanding his many sympathizers in the
United States, and his secret service, had no inkling of the character
of the mine until long after it was placed in use in the North Sea.
It was comparatively unimportant to maintain secrecy after the
mines were once in use, for it was probable that the enemy could not
devise any means of effectively counteracting or protecting himself
against the mine within, say, a year after he gained knowledge of it,
by which time it was expected that the war would be over. In this
connection, it may be stated that a number of American mines went
adrift in the North Sea, as is usual in such operations, and were cast
up on the coast of Norway, where they were recovered, disassembled,
and examined by Norwegian officials, but assurances were obtained
that information regarding these mines would be regarded as confi-
dential.
The firing mechanism has been referred to above as a unit of the
assembled mine; but, as a matter of fact, it was subdivided into its
component parts and manufactured by more than a score of different
52 THE NORTHERN BARRAGE.
factories, none of which was permitted to know that it was manu-
facturing mine material. Only certain officials of the private plant
that assembled the firing mechanism knew that it was intended for a
mine.
The Mark VI mine was designed to be very safe in handling; and
that this object was attained is well demonstrated by the fact that
85,000 of these mines were loaded and shipped abroad and that
about 57,000 of them were planted in the barrage without accident.
This result is the more extraordinary for the following reasons :
(a) The mines had to be manufactured by quantity production
methods, and rigid inspection was quite impossible under the then
existing conditions.
(b) The inspection force was inadequate in numbers, and it was
composed largely of inexperienced officers and men — inexperienced
not only in mine material but in inspection work in general.
(c) The manufacturers were inexperienced in munitions work, and
almost every one of the hundreds of plants engaged in the work was
an unknown quantity as to reliability, quality of product, possibility
of sabotage, etc. Due investigation and careful " sizing up" of the
managing personnel of each plant concerned reassured the Bureau in
almost every case.
(d) The mine had to be loaded, shipped, assembled, inspected, and
tested by personnel almost entirely without previous experience with
mines and explosives.
It was owing to these adverse conditions, together with the fact
that the mine was to be handled by the minelayers as ' ' fixed ammu-
nition," that it was designed to be as nearly foolproof as possible.
During the period of purchasing supplies, in the task of which
there was a multitude of details, Lieut, (j. g.) A. B. Peacock, Supply
Corps, IT. S. Naval Reserve Force, handled the purchasing matters
connected with this vast amount of divers materials, a duty that
required his working in close co-operation with the mine section of
the Bureau.
The design and manufacture of the various elements of the mine
was a work involving an immense amount of detail, which it is un-
necessary to dwell upon here ; but a few points are of special interest
in their bearing on the success of the project.
It has been mentioned above that the new mine was designed to
be issued to minelayers as " fixed ammunition." This was a radical
departure from conventional practice, and British mining officers
attached to the Bureau apparently never became reconciled to the
Bureau's view that practically all necessary tests and inspection could
and should be made prior to the receipt of mines on board. The
new idea was adopted primarily because of the obvious necessity for
rapid laying, the number of minelayers being limited. After having
THE NORTHERN BARRAGE. 53
become committed to this plan, it was fairly easy for the Bureau to
design, manufacture, and inspect accordingly. For example, the
mine case was designed to be as simple and foolproof as possible,
and it was given 100 per cent inspection at the factories for water-
tightness; so there was no good reason for subjecting the case to
another such test at the overseas bases or after its receipt on board
ship.
Another point to which the Bureau gave careful attention was to
insure that, in the event of a premature or accidental explosion of
a mine, it would necessarily occur only after a safe interval after
launching. As for taking mines aboard ship with the detonators in
place, the bureau adopted this plan only after conclusive tests had
shown that a detonator in the "safe" position could not explode the
charge.
The well-known fuel shortage in the winter of 1917-18, the almost
unprecedented severity of the weather, the freight embargoes on the
railroads and congestion of traffic generally, and labor troubles, all
operated to delay the production of mine material and other essen-
tial preparations for the project. The situation was very critical for
some weeks, largely because these conditions affected several hundred
plants engaged, and the failure of any one of them to produce its
share would have resulted in possibly disastrous delay to the whole
project. Some delay did, in fact, result, but as there was a nearly
corresponding delay in the completion of vessels of the mine force
and of. the overseas bases, the failure to meet the manufacturing
schedule proved of no particular consequence. It is estimated that
the above-mentioned adverse conditions resulted in delaying the
beginning of quantity production of complete mines about six weeks.
During the period of railroad freight congestion an immense
quantity of mine material was handled by express shipments, in
some cases whole trainloads being handled on passenger schedules
from Detroit to the seaboard. It is believed that every known
expedient was utilized to maintain production and expedite ship-
ment— armed guards and traffic agents accompanied shipments ; motor
trucks were used when other service was unavailable; freight em-
bargoes were lifted after great effort in special cases; tracing of missing
shipments was a constant work; and shortage of fuel was met and
overcome in many ways.
There was only one real failure of an important contractor to
deliver material on time, and this resulted in a slight delay in mining
operations. It was an almost invariable rule of the Bureau to divide
the order for any one part of mining material between at least two
contractors, in order to guard against a possible failure on the part
of a contractor and consequent shortage of essential material. In
54 THE NORTHERN BARRAGE.
the one case in which this rule was deviated from, the article being
a comparatively simple one and the contractor being apparently
more than able to meet his obligations, the contractor failed to
deliver the specified production, and it then became necessary to
tool up three other plants and cancel the original contract.
The Bureau planned for a production of 1,000 mines a day, and it
was found soon after getting into production that this rate could
easily be exceeded if desired. In fact, it became difficult to hold
the production of anchors and mine cases down to this figure. In
other words, the Bureau could have produced mines at any rate de-
sired, except possibly in the matter of mooring cable, the wire rope
manufacturers being heavily burdened with orders for wire for air-
craft, shipping, coal mines, etc.
CHAPTER VIII.
MINE-LOADING PLANT, ST. JULIENS CREEK, VA.
An important item of preparation for the barrage project was the
creation of a complete mine-loading plant capable of receiving, load-
ing, and shipping 1,000 mine cases a day, there being no plant in
the United States at that time capable of handling any considerable
number of mines.
The design of a plant that could handle the situation had to be made
by the Bureau of Ordnance and the Bureau of Yards and Docks in
consultation. Many proposals were sent out in order to obtain ideas
upon automatic machinery, and finally a plan, modified somewhat
after a scheme suggested by Boyle-Robertson Construction Co., was
accepted and completed. The plant was built by the Boyle-Robert-
son Construction Co., of Washington, D. C. Commander Kirby
Smith, Civil Engineer Corps, United States Navy, was responsible
for pushing to completion, in the midst of many difficulties, both in
design and construction, this mine loading plant.
It was decided to locate this plant near the navy yard, Norfolk,
Va., the point selected for the assembly and shipment overseas of
all barrage material: and the only immediately available site being
at the Naval Ammunition Depot, that point was chosen. Ground
for the plant was broken on October 25, 1917; but bad weather set
in early hi November and continued with unprecedented severity
until spring, so construction work was carried on under most adverse
conditions. Aggravating the situation, there was a labor shortage.
However, the plant was ready for work in March, 1918, or practically
as soon as needed, there having been delays in all parts of the project
due to extreme weather conditions, freight embargoes, fuel shortages,
labor troubles, changes of barrage plan, eto.
This plant, with its accompanying barracks for the housing of its
operatives, covers an area approximately 3,000 feet by 800 feet,
including the wharf, and consists of 22 buildings, including a mine
case storage building, 600 by 100 feet, capable of storing 5,000 empty
cases; a melting plant, capable of melting and pouring T. N. T. for
at least 1,000 mines a day; a cooling building, where the loaded mines
were permitted to cool preparatory to shipment; a T. N. T. ready-
storage building, capacity 4,000,000 pounds; a heating plant; and
a wharf.
55
56 THE NORTHERN BARRAGE.
The entire plant was excellently equipped with conveyors and
labor-saving facilities; and all parts were planned and constructed
to give the utmost efficiency consistent with safety. The rated daily
capacity of 1 ,000 was exceeded by about 50 per cent on one occasion;
and a total of more than 73,000 mines, involving the melting and
handling of over 22,000,000 pounds of T. N. T., were loaded here
without accident. In addition, 17,000 mines loaded by contract at
the du Pont Co.'s works at Barksdale, Wis., were received here and
shipped abroad.
The loading plant cost approximately $400,000, and its operating
,cost was at the rate of about $412,000 per annum. About 400 en-
listed men were required to man the plant; and, in addition, from
200 to 400 were employed in the shipment of mines, that is, in load-
them into mine-carrying vessels.
A loading plant of this type and scale had hitherto been unknown,
not only in this country, but abroad. Difficulties were encountered
in the construction thereof; and prophecies of accident, fortunately
unfulfilled, were made by visiting foreign experts skilled in amatol
plants. The Bureau of Ordnance, however, took every precaution
to insure that the operation of this plant should be attended with
the minimum amount of danger. The Chief of the Bureau took upon
himself the limiting of the steam pressure to a maximum which he
considered, from his experience with explosives, would result hi
satisfactory melting of T. N. T., and thus loading the mines, but
reduced the" danger of detonation in the process to the minimum pos-
sible. Exact knowledge upon this point is not .yet to be had, as
experience with this explosive has been too short to permit real con-
clusions. This decision was one that was very serious, as he had
before him the fact that, in the melting of high explosives abroad, a
detonation that destroyed an entire plant together with every person
in the same had occurred, and that the proposed automatic operation
of loading mines was in a nature exactly similar to the work under-
way in that plant.
Petty officers and enlisted men of the Naval Reserve Force were
secured for the operating personnel of this mine-loading plant. They
accepted the risk, which they knew was a great one, together with the
discomforts — such as working hi an atmosphere of T. N. T. dust,
working nights, and living in poor quarters in a very bad locality,
so far as health is concerned — cheerfully, and with most successful
results in the completion of the material for the northern barrage.
Commander W. L. Pryor, United States Navy, was in command of
this mine-loading plant in addition to his duties in charge of the ammu-
nition depot at St. Juliens Creek. Much work in connection with
loading of mines upon the mine carrier, after the T. N/"T. had been
cast into the mines, devolved upon Commander Pryor. The success
THE NORTHERN BARRAGE. 57
and general efficiency of the plant was brought about mainly through
the untiring efforts and care of Commander Pryor hi dealing
with the reserve personnel, making them acquainted with the neces-
sity for care and the reasons they were called upon to bear so many
discomforts and undergo the risks.
In order to prevent delay in delivery, which might have been caused
by delay in completion of this Navy plant, the Bureau arranged with
the du Pont Co. to load mines direct at its T. N. T. plant at Barks-
dale, Wis., and some 17,000 mines were loaded there during the
months of February and March, 1918.
The Army had plainly informed the Navy that it required all the
toluol hi the country for use hi the manufacture of its own explosives;
and, for this reason, it was imperative, if the mine barrage was to
be completed, to secure some other explosive for use in the mines.
The explosive effects of amatol, a substitute for T. N. T. hi general
use abroad, had been frequently criticised for lack of effectiveness.
Amatol also required more toluol than the Navy could obtain with-
out asking the Army to reduce its requirements., E. I. du Pont de
Nemours & Co. proposed to the Bureau the use of trinitroxylol, which
could be produced by the nitration of xylol, a by-product of coal tar
distillations, at that time not widely used. Further investigation by
Lieut. Commander T. S. Wilkinson, United States Navy, in collabora-
tion with chemists of E. I. du Pont de Nemours & Co., finally developed
the fact that trinitroxylol was an explosive substance which would
serve very acceptably as a diluent for T. N. T., and that the use of a
mixture of these two substances in mines would be practically as
satisfactory as the use of T. N. T. alone (the mixture adopted con-
sisted of 60 per cent trinitroxylol and 40 per cent of T. N. T.), although
the mixture was not quite as convenient to handle as T. N. T. Trini-
troxylol was subsequently known as T. N. X.; and the mixture of
T. N. T. with T. N. X. for mine charges was called toxyl.
CHAPTER IX.
ASSEMBLY AND SHIPMENT OF MINE MATERIAL.
Since the Mark VI mines were not to be assembled short of Bases
17 and 18 in Scotland, and since all component parts had to be at all
times available at those bases, it was essential that the flow of all
material from the many points of manufacture to the overseas ship-
ping point, Norfolk, and thence to the bases abroad should be main-
tained at the proper rate. Failure in this respect would result
either in a shortage of material and consequent delay of the planting
operations or in a congestion of an undue amount of material which
could not be stored and properly cared for.
At the inception of the movement it was decided between the
Bureaus of Ordnance and Supplies and Accounts that it would be
necessary to commandeer one of the large export terminal piers in
the vicinity of the navy yard> Norfolk, for the handling of mine ship-
ments; and after a survey of the situation Southern Railway Pier
No. 4 at Pinners Point, Va., was taken over by the Navy. This
pier, which is 875 by 270 feet and which can accommodate seven
cargo vessels of the "Lake" type at a time, was ideal for the purpose.
It, of course, is roofed over and has adequate rail facilities. The
rental of the pier was $81,000 a year, and the annual cost of operation
was about $350,000.
When the project was planned, it was contemplated shipping all
mine material, including the loaded mine cases, from this pier; but
the local authorities protested against the handling of explosives at
this point because of the danger to Norfolk and Portsmouth, and it
became necessary to load the explosive elements into the mine-
carrying vessels at the mine-loading plant at St. Juliens Creek, about
2 miles above the navy yard. To this end considerable dredging
had to be done at the mine plant; fixed moorings were put down;
and the dock facilities at the mine plant were enlarged and improved
to accommodate the carriers. Provision was made for working 24
hours a day at the mine plant and at the pier when necessary. Only
Navy personnel was employed. It would have been quite impossible
to operate satisfactorily at either the pier or the mine plant with
civilian labor, owing to the irregularity of working hours, the fre-
quent necessity of night work in order to get vessels loaded in time
to join the weekly convoys, and also the necessity of good discipline,
safety, and secrecy.
58
THE NORTHERN BARRAGE. 59
Pier 4 was used for storage as well as for shipments. It had a
capacity of about 40,000 mine anchors and other nonexplosive parts.
A naval force of about 400 men was continually employed at the
pier.
The receipt and shipment of mine material at the pier was under
the cognizance of a supply officer detailed by the Bureau of Supplies
and Accounts to that exclusive duty; but the Bureau of Ordnance
also had its representative there to act as liaison officer between the
Bureau and the supply officer. To this liaison officer were com-
municated by telephone complete detailed instructions daily as to
shipments, not only from the pier, but also the mine-loading plant,
such instructions being confirmed to the supply officer in writing.
There was never the slightest delay or confusion in the handling of
the business, this because of the excellent cooperative spirit and zeal
existing among all concerned in the project.
In the mine section of the Bureau of Ordnance, Lieut. Commander
H. E. Fischer had, as his principal duty, the maintenance of the flow
of material from its source to its final destination. By means of tele-
phone and telegraph he was in constant touch with the material situa-
tion from the hundreds of factories to the bases overseas, and his
records at all times showed the exact condition of affairs. In all
this he acted in close cooperation with the traffic and other offices of
the Bureau of Supplies and Accounts as well as with the officers of
the Mine Section. He also was in close cooperation with the Office
of Naval Operations regarding the loading and sailing of the mine
carriers.
Weekly inventory sheets and monthly reports showing receipts
and expenditures of mines and parts at Bases 17 and 18 were re-
ceived, but were not of much value, as they were about one month
old when received. Therefore, in order to anticipate shipments, it
was necessary to resort to speculation to a very considerable degree.
The results were, however, quite satisfactory.
In the inception of the project, the Navy Department secured the
allocation of a fleet of 24 cargo vessels of the "Lake" class for exclu-
sive use as mine carriers. These vessels, a list of which is appended,
were armed for defense against submarines, were given Naval Reserve
crews, and were handled by the Naval Overseas Transportation
Service (Operations). They were rather small, averaging about
3,000 tons dead-weight capacity, but by reason of their light draft
were well suited to the purpose, since larger and deeper vessels could
not have been so readily loaded or discharged at the terminals
selected; in fact, the harbor of one of the discharging points desig-
nated by the British authorities could not accommodate ships draw-
ing more than 20 feet. The carriers were selected also with a view
to carrying a comparatively small number of mines in each hull, so as
60 THE NORTHERN BARRAGE.
to minimize the effect on the whole project in the event of a vessel
being lost. Among other preparations requiring navy-yard work
was the fitting of these vessels with additional crew accommodations;
the provision for additional cargo coal for themselves, as they were
originally short-radius ships, and provision of facilities for carrying
300 to 500 tons of fuel oil cargo for naval vessels overseas.
In general, a cargo was made up of 2,000 mines with anchors and
fittings complete and of about 500 tons of such miscellaneous naval
supplies as were safe to handle in conjunction with high explosives,
the remaining 1,000 tons of cargo space being assigned to extra
bunker coal and fuel oil, the latter carried in the double bottoms.
The mines were shipped disassembled to economize space; but it
would have been undesirable in any event to ship them otherwise, in
view of the fact that the work of handling, testing, and inspection at
the overseas bases was facilitated by shipping them disassembled.
Sailings of the carriers averaged about two ships every seven or
eight days, half in Norfolk convoys and half in Halifax convoys. It
took a ship in a Norfolk convoy about 20 days to make the trip
across, and in a Halifax convoy 21 days. From 65 to 70 days were
required for a round trip or complete cycle.
Of the 24 carriers, only one, the Lake Moor, was lost, sunk by an
enemy submarine off the coast of Ireland on April 11, 1918, unfortu-
nately with the loss of most of her crew, and of about 1,500 tons of
mine material, mostly anchors.
CHAPTER X.
OVERSEAS MINE BASES 17 AND 18.
On account of the great demand for shipping, it was early realized
that in order to conserve cargo space, and for other reasons, it would
be necessary to ship the mines for the North Sea barrage disas-
sembled. In this manner it would be possible for a vessel to carry
approximately three times as many mines as she would have been
able to do had she been loaded with assembled units. On the other
hand, this procedure necessitated the erection of elaborate assembly
establishments in Great Britain; but this consideration was of sec-
ondary importance when compared with the great necessity for
economizing shipping. It may be mentioned in this connection that
there were no mine assembly facilities in the United States, since all
ammunition depots were congested with other work, and new assem-
bly plants would have had to be created in any event, either at home
or abroad.
It will be remembered that in the early stages of the consideration
of the barrage, one of the proposals made was that Great Britain
should furnish the men necessary to assemble the American mines.
Accordingly, a board was appointed by the Admiralty on October
6, 1917, which has generally been referred to as the Lockhart-Leith
Committee, to investigate and report on the various suitable locali-
ties for mine depots for this project. The report of the committee,
dated October 26, discussed in detail the possible locations for such
bases, reviewed the transportation facilities, and gave as then* decision
that the most suitable locations were the Dalmore Distillery, at
Dalmore, Alness, and the Glen Albyn Distillery, at Inverness. The
report went into considerable detail, ou timing exactly what buildings
would be required as well as the new construction and machinery,
and estimated the personnel requirements. This report and its
recommendations were approved by the Admiralty, and the distil-
leries at Dalmore and Glen Albyn were at once commandeered for
use as mine bases.
Under date of October 26, 1917, the Bureau of Ordnance cabled
Admiral Sims, informing him that the Bureau was preparing to manu-
facture mines in sufficient quantity for the operation contemplated,
and that it was expected that the shipment of these mines would
commence soon after the 1st of January, 1918. This cablegram
61
62 . THE NORTHERN BARRAGE.
further stated that the Bureau desired to send Commander O. G.
Murfin as its representative, under the Force Commander, to be placed
in command of the mine depots which were to be established at Cro-
marty, also that several officers from the Bureau were being trained
in the assembling and handling of mines and would be sent to assist
him. This cablegram was followed by a letter from the Bureau of
Ordnance, dated October 31, 1917, in which the subjects referred
to in the cablegram were commented on at length.
On November 1, 1917, the Chief of Naval Operations cabled
Admiral Sims to the effect that the Department concurred in the
project of the mine barrier from Scotland to Norway, and was taking
steps to outfit eight minelayers to sail about February 1, and that
they were also expediting the completion of 12 minesweepers.
This cablegram further stated that it was expected that the shipment
of mines would begin about January 15, and that officers would be
sent to confer and to arrange details within a few days.
The report of the Lockhart-Leith Committee was transmitted by
the Admiralty to Admiral Sims, in London, who, in order to give the
department early information relative to the selection and require-
ments of the two bases, sent the following cable on November 2:
Admiralty committee has investigated bases for northern mine barrage and Admi-
ralty 's full report on suggested organization of bases for assembling American mines.
is being forwarded. Plan calls for United States base at Invergordon handling 2,000
mines per week and at Inverness handling 1,500. Combined personnel required from
United States approximately 182 mechanics, 620 skilled laborers, 690 laborers, 40
clerks, and for dock working parties, 25 boatswains mates, 25 coxswains, 400 seamen
and ordinary seamen. Most important that all these be enlisted men to insure military
discipline and control and to avoid labor complications here. Commanding officers at
depots should be rank of commander and each should have five or six other officers as
assistants. Large distillery buildings will be taken over but there will be small amount
of new construction required. Shops must be fitted up. Scarcity machinery, cranes,
etc., in this country would make very welcome arrangement if United States could
furnish some of these. At least one of officers sent for conference mentioned Opnav 925
should have had experience in manufacture mines in United States naval yards as Naval
Constructor Knox has had. Some of depot staffs should come at same time as officers
who return after conference so they will be in touch with work from beginning.
Intended ship some mines by Lock Alsh and rail via Dingwall but ships for Kyle
must not exceed 280 feet length nor 20 feet draft. Other mines will come via Fort
William and by barge through Caledonian Canal. British Rear Admiral will be senior
officer in general charge joint operations these and British bases in Firth of Forth.
Admiralty desires verify immediately understanding that sinkers as well as mines will
be furnished from United States. Furnish information concerning general character
eight minelayers sailing February 1, and whether any other craft will be used for
minelaying. Would also like to learn approximate number and kind of mine carriers.
Will reply concerning Old Colony later". For localities mentioned see B. A. charts
115, 2182 B, 2167, 2635, 2676,
In reply to the questions contained in the above cablegram
relative to the United States supplying enlisted men for assembling
THE ^ORTHEKX BARRAGE. 63
the mines at the bases instead of employing British civilians, the
Chief of Naval Operations cabled on 8 November that drafts of
approximately 200 enlisted men per week would be sent over as
soon as the bases were ready to receive them. Upon receipt of this
information the Third Sea Lord wrote Admiral Sims as follows:
The Admiralty are most grateful and the decision of the Navy Department relieves
us of very great anxiety * * *.
In accordance with the requests of the Admiralty and the desires
of the Bureau of Ordnance that American officers who would be
associated with the establishment of the bases and then* operation
should be sent to Great Britain as soon as possible, Commander
O. G. Murfin, United States Navy, accompanied by Commander T.
L. Johnson, United States Navy, sailed from the United States on
13 November, 1917. The Chief of Naval Operations cabled Ad-
miral Sims on November 18:
Commander 0. G. Murfin, under orders to proceed to England. Is authorized to
speak for Bureau of Ordnance, discussing all details, depot arrangements, machine-
shop equipment, unloading and transportation arrangements, with British Admiralty
representatives, and make decisions in these matters. Commander Thomas Lee
Johnson accompanies to assist Commander Murfin in plans and returns here with
detailed information.
Commander Murfin and Commander Johnson arrived in London
on November 23, 1917, and reported to the Commander, United States
Naval Forces Operating in European Waters. The Force Commander
issued orders to Commander Murfin assigning him to duty in charge of
all matters relating to the establishment of United States naval mine
depots in Great Britain and to duty in charge of such depots upon
their establishment; he was further ordered to make his headquarters
in London during the preliminary negotiations in connection with
the bases.
On Novemoer 26, 1917, Commander Murfin and Commander
Johnson left London to inspect the sites selected for the United
States mine bases. They were accompanied by Capt. Lockhart-
Leith, R. N., Engineer Capt. Gaisf ord, R. N., Mr. Heap from the Admi-
ralty's controller's office, and Surg. Thompson, United States Navy,
from the United States naval headquarters. The party arrived in
Inverness on November 27, spent four days inspecting the base sites
at Invergordon and Inverness, and the two shipping points at Kyle
of Loch Alsh and Corpach, and then returned to London. Commander
Johnson left England on December 6, 1917, for the United States.
At the time of this inspection, whisky was being removed from
the distillery buildings preparatory to proceeding with the work of
establishing the bases. At Dalmore ground had been broken for
a branch railroad line to connect the distillery with the Highland
Railway. Other work was being held up pending decisions to be
made by Commander Murfin. These decisions having been given,
64 THE NORTHERN BARRAGE.
plans for expediting the work of establishing and outfitting the
bases were proceeded with.
The Navy Department designated the base at Inverness as Base
18, and the one at Invergordon as Base 17.
The work of preparing and outfitting the mine bases was done
by contract through the Admiralty. The construction work was
done under the immediate supervision of the superintending civil
engineer, Invergordon Dockyard; and the tools and equipment
were supplied through the controller's department of the Admi-
ralty. Rear Admiral Clinton-Baker, R. N., was the Admiralty's
representative in general charge of the work, and desired alterations
or additions to buildings or equipment were ordered on his approval.
The construction was somewhat delayed, due to inclement weather
conditions and to lack of suitable labor; but in spite of these handi-
caps good progress was made from the beginning. Commander
Murfin kept in direct touch with the work by correspondence, by
frequent visits to Eear Admiral Clinton-Baker's office at the
Admiralty, and by frequent visits to the bases themselves.
Much of the material for these bases could not be procured in
Great Britain because of the drain upon that country's supplies
made by the war. At the Bureau the mine section secured the
assistance of Capt. (then Commander) G. C. Schafer, Supply Corps,
United States Navy, in connection with providing cranes and equip-
ment of all kinds, assembly of material, and assuring delivery to the
mine bases abroad, remaining in Washington until deliveries being
assured, he proceeded overseas in March, 1918, and resumed this
work at the mine bases, as a member of the staff of Rear Admiral
Joseph Strauss, United States Navy, the commander of the operation
of laying the barrage.
The first draft of men arrived in Liverpool on the S. S. Philadel-
phia on November 27, 1917. Lieut. Commander Edwin A. Wolleson,
United States Navy, who arrived on the same vessel, was put in charge
of the 37 rated men in this draft and sent with them to the British
mine depot at Portsmouth for instruction at the mining school at
that place. The remainder of the men in the draft were sent to
Queenstown for distribution to the destroyer flotilla, owing to the
fact that the bases were not yet ready to receive them.
On December 3 the second draft arrived at Liverpool on the
S. S. New York. Twenty rated men from this draft were sent to
Portsmouth to join the detachment there, and the nonrated men
were sent to Queenstown to, be held until accommodations could
be provided at the mine bases. Lieut. Commander L. M. Stewart
arrived in London and reported at headquarters on December 4,
1917, and was sent to Portsmouth to assist with the instruction of
the men already there.
64-1
D w
o °°
5
LU O
z ">
. cc
3 LJ
64-2
EE
64-3
Ml NtE F^OOCr g j
PHOTOSTATIC CHART, SHOWING ORGANIZATION OF U. S. MINE FORCE.
64_4 (Page 8
THE NORTHERN BARRAGE. 65
Lieut. Thomas Newhall, U. S. N. B,. F., reported at headquarters,
in London, on December 10, and was assigned to duty as assistant to
Commander Murfin. On December 26, Lieut. Newhall was sent to
the bases as Commander Murfin's representative for keeping in touch
with the construction work.
On January 7, 1918, Lieut. Commander Stewart with 23 men was
sent to Base 18, and Lieut. Commander Wolleson with 22 men was
sent to Base 17. These parties arrived at their destination on Janu-
ary 8. These small forces were assigned to the bases to assist in the
arrangements for housing the personnel at the bases and to form the
nucleus upon which the organization could be started. As the men's
living quarters at the two bases were in an unfinished state, the men
at Base 18 were quartered in the old Muirtown Hotel, which was one
of the buildings taken over for base purposes and which was later
made into the sick quarters. The men at Base 17 were quartered in
the residence of the manager of the distillery, which was one of the
buildings taken over in the grounds and was subsequently converted
into the sick quarters at that place.
Commander Murfin left London January 25, 1918, and arrived at
Inverness on January 26, taking direct charge of the work at the
bases and establishing his headquarters at Base 18 and in the house
which had formerly been the home of the manager of the Glen Albyn
Distillery.
The United States national ensign was officially hoisted over the
office at Base 18 on February 9, 1918, and at Base 17 on February 12.
The raising of the flags at the two bases were made functions at which
British civil and military officials, as well as the officers and men
attached to the bases, were present and took part.
At the outset, the question of transportation appeared to be the
greatest problem that would be encountered. The estimated weekly
output of mines required for the minelayers was 3,500. The rail-
road from Kyle to Base 17 could only handle about 2,000 mines per
week, and the Caledonian Canal running from Corpach to Base 18
could transport approximately 1,500 mines per week. This made it
necessary to use two bases instead of one large base, for Inverness
Harbor could not accommodate the full minelaying force, nor could
the mines going through the Caledonian Canal readily be shipped to
Invergordon. Although the bases were separated by a distance of
33 miles by rail and 25 miles by water, no difficulty was encountered
hi unifying the efforts of the two establishments and coordinating
and directing the divided mine squadron anchored in the two harbors.
At Corpach mine carriers anchored hi the stream opposite the en-
trance to the Caledonian Canal. Their cargoes were discharged into
power lighters and dispatched to Base 18. The work of discharging
181063°— 20 5
66 THE NORTHERN BARRAGE.
the cargoes of the carriers into the lighters was done by a detachment
of 65 men from Base 18 permanently stationed at Corpach. The
lighters, owned by the British, were manned by British ratings and
their movements were directed by the British senior naval officer at
Inverness. After the lighters arrived at the canal quay at Base 18
they were discharged by the United States forces at that base.
Vessels arriving at Kyle were taken alongside a small pier and
their cargoes discharged directly into railroad cars, thence taken to
Base 17 via Dingwall. The work of discharging the cargo into the
railroad cars and shunting them across to the main line from the
pier was done entirely by the 65 men from Base 17, who formed the
detachment at Kyle. After being placed on the main line, the cars
were delivered on the siding at Base 17, from where they were again
handled by the United States personnel.
The first stores forwarded from the United States were sent via
Liverpool, and were received at the bases January 20, 1918. The
first mine carrier, U. S. S. Ozama, arrived at Kyle of Loch Alsh on
February 18, with stores and equipment but no mining material.
The second carrier arrived at Kyle on March 21, with general stores and
equipment; the third was also routed to Kyle, arriving there April 3,
with mine anchors and other mining material. The first mine car-
rier routed to Corpach arrived April 5, 1918, with mine anchors and
other mining material. The first carriers containing mine spheres
were the U. S. S. Ozama , which arrived at Corpach on May 21, and
the U. S. S. Lake Superior, which arrived at Kyle on the 29th.
Officers and men reported for duty at the two mine bases from time
to time until, on March 30, 1918, there were 18 officers and 414 en-
listed men on duty at Base 17, and 23 officers and 359 men on duty
at Base 18.
On March 1, 1918, both bases had reached such a state of comple-
tion that mines could have been received and assembly work could
have commenced, although operations at this time would have been
somewhat handicapped by the fact that a considerable part of the
work at the bases was still in an unfinished condition.
By April 1, 1918, the main construction work was practically com-
pleted and the bases ready in every respect for the purpose for which
they were established. Actual assembly work did not begin until
May 29, 1918, the date upon which the first mines were received.
In general, the following work was done at Dalmore in establishing
Base 17: The Dalmore Distillery was commandeered and taken over;
some of the existing distillery buildings were refitted and made into
barracks for the enlisted personnel, and others were refitted as store-
houses for general stores and mine equipment; buildings were erected
for workshops for mine assembly, for storage of mines and mine
material, both in assembled units and in component parts; railroad
THE NORTHERN BARRAGE. 67
tracks were laid in the base from the main line of the Highland Rail-
way and from the base to the pier at the dockyard, Invergordon;
wagon roads were built connecting various buildings within the base;
fire mains were laid, water systems provided; wash rooms, bath-
rooms, and other sanitary devices were installed; and commissary
and messing facilities provided. An electric light and power plant
was built, and other necessary equipment and adjuncts to a base of
this nature were provided.
At Base 18 the same provisions were made as at Base 17, with the
exception of the light and power plant — the lighting and power at
Base 18 being received from the city plant.
At Kyle four huts were erected as barracks, mess hall, galley, and
storage spaces for the men of the detachment at that place.
At Corpach a large private residence was taken over and converted
for use as barracks, mess hall, galley, and storehouse for that
detachment.
After unloading the mine parts from the railroad cars at Base 17 or
the lighters at Base 18, the various parts were sorted and placed in
bulk store. These stores were, in general, adjacent to the assembly
sheds, so that miscellaneous parts could be readily supplied as
required.
The work of assembling the mines was a highly organized process
developed in accordance with the present standards of manufacturing
efficiency, wherein each man performs one specific task over and over
again as the mines are moved along in front of him for the various
stages of assembly.
As soon as the commanding officer of the bases was informed of the
quantities and types of mines which would be required at each base
for the minelayers, the work of assembly began. The various com-
ponent parts for the mines began to pour into the assembly sheds
from the bulk storage rooms. The two principal parts constituting
the mine were the anchor and the mine sphere. As the anchors
arrived they were placed upon assembly tracks extending across
each bay. Along these tracks were stationed groups of men, each
group making some special adjustment, testing the brake tension,
release mechanism, etc., as the anchor was rolled along the track.
By the time the anchor reached the end of the track the mine case,
which had at the same time undergone preparation and testing while
moving along a traveling table, was completed and the two parts
were ready to be married to each other. This done, a few final
adjustments were made, and the mine was ready to be placed on
board a minelayer. From here the completed mines were either rolled
into ready-issue sheds directly opposite the assembly bays or else were
loaded directly into railroad cars to be sent to the ships.
68 THE NORTHERN BARRAGE.
From the railroad cars the assembled mines were carried back to
the canal siding at Base 18 or to the dockyard at Base 17 j where they
were loaded into barges. The barges carried from 50 to 60 assembled
mines, and were towed out to the ships and placed alongside while
the ship's crew whipped the mines aboard and stowed them on the
tracks ready for laying.
The original estimates prepared by the British as to the rate of
transportation from Kyle to Base 17 and from Corpach to Base 18
were far below that actually accomplished. The rate of assembly
and the possible rate of laying mines also much exceeded the orig-
inal expectations. Therefore, the rate originally fixed for shipping
3,500 mines per week from the United States was increased to 6,000
per week. In spite of the greatly increased amount of work in
assembly which developed on account of defects discovered in the
actual mining, the rate of assembly at the two bases was increased
from the original estimate of 500 mines per day to as high as 1,340
mines per day. Similarly, the time required for the minelayers to
refuel, take on water, embark mines and necessary supplies had been
so systematized that only two days in port were necessary before
they were ready for the next excursion. This made it possible to
carry out excursions every four or five days, depending upon the
distance it was necessary for the vessels to proceed in order to lay
their mines. As will be seen, delays almost heartbreaking occurred
which kept the squadron in port from two to three weeks between
excursions. While none of these delays could be foreseen, the mines
from the United States continued to arrive until the storage facilities
were most severely taxed. The original plan of the bases called for a
total storage of 12,000 mines at both places. At one time as many
as 20,500 had accumulated. Wise foresight, however, on the part
of the commanding officer of the bases had made it possible to stow
them all under cover, protected from the incessant rain of northern
Scotland.
The headquarters of Rear Admiral Joseph Strauss, Commander Mine
Force, and of Capt. Murfin were at Base 18. The two mine bases
were so organized that there were two executive officers, representa-
tives of the commanding officer, in complete charge of all administra-
tive and industrial activities at then: respective bases. Each base
was organized with military, industrial, supply, medical, and trans-
portation departments.
The industrial officer was responsible for the assembly of mines,
which work was organized along lines similar to those obtaining in
automobile plants in the United States. The various component
parts of the mines were received and stored and inspected prelimi-
nary to assembly separately. In the assembly process, the two major
THE NORTHERN BARRAGE. 69
parts, the mine case and the anchor, moved along on small trucks on
rails, the various minor parts being assembled progressively, to a
point where the mine and anchor were " married " together, and
thence placed in the " ready-f or-issue " sheds or loaded into cars for
delivery to the mine layers. This system, under which separate
groups of men, highly specialized, performed the same function for
each mine or mine anchor, proved most efficient, and produced
results never before attained in the rapid handling of mines.
Admiral Mayo, commander in chief, Atlantic Fleet, inspected the
bases September 25-27 and October 5-7, 1918, and reported most
favorably on their condition. Quoting from his report:
The personnel throughout, both commissioned and enlisted, appeared to be satis-
factory as to number and selection; their military appearance, bearing, and uniform
made a favorable impression. The men are granted liberty freely and their relations
with the natives of the towns and surrounding country appeared to be excellent.
Quoting further:
Owing to the relatively late start of the operations, it has been necessary for the
entire force, ashore and afloat, to work at high pressure in order to complete the
original and later plans before bad weather sets in. The response of the personnel
has been excellent and is considered indicative of a highly satisfactory state of
morale.
Admiral Mayo concluded his report with the remarks:
(a) The arrangements in force are remarkable for their conformity to the plans
prepared at home before the mine force crossed the Atlantic.
(6) The inspection of the mine force and bases and of the activities in connection
with the work incident to minelaying in the North Sea, revealed a highly satisfac-
tory condition and reflects great credit on the Commander Mine Force and on his
assistants.
CHAPTER XI.
ORGANIZATION OF MINE SQUADRON AND SELECTION
OF NEW MINELAYERS.
Prior to the decision to proceed with the northern barrage project,
the mine force of the United. States Navy included only two mine-
layers fit for the project, the San Francisco and Baltimore. This force
possessed very small minelaying capacity, and it became necessary,
as one of the first steps in preparation for the project, to greatly
enlarge the force by taking over a sufficient number of merchant
ships and converting them into minelayers, to obtain and train the
officers and crews for these vessels, and to secure the requisite mer-
chant tonnage for transporting the mines and other material to
Europe.
On the basis of an estimated output of 5,000 mines a week and of
one minelaying operation a week, the department concluded that
the mine force should have a capacity of at least 5,000 mines ready
to lay, which, if all went well, would insure the laying of the
northern barrage in three months.
The San Francisco and Baltimore had a combined capacity of only
350 mines. It was necessary, therefore, to create practically a com-
plete new mine squadron to secure the requisite capacity. Vessels
were desired of ample size, yet handy in tactical formation; service-
able condition as to engines, boilers, pumps, etc.; good cargo-
handling equipment adaptable for handling mines; internal arrange-
ment suitable for installation of mine tracks on two or three decks;
speed of 14 to 20 knots; and generally seaworthy. From data on
file in the Navy Department it was found that four vessels of the
Morgan Line, running between New York, New Orleans, and Gal-
veston, were generally satisfactory for the purpose. They had been
built by the Newport News Shipbuilding Co. to replace vessels of the
Prairie class, purchased by the United States Navy in the Spanish-
American War, and were in good condition. They were 391 feet
long, 48 feet beam, and 20 feet draft when loaded as minelayers.
They were capable of a sustained sea speed of 14.5 knots and had
ample bunker capacity. Their capacity was estimated at 800 to 850
mines each.
The Secretary of the Navy personally informed Mr. Hurley, pres-
ident of the Shipping Board, about the projected barrage operation;
70
THE NORTHERN BARRAGE. 71
and the department's request for the four Morgan liners was promptly
granted, notwithstanding the prevailing dearth of shipping and
despite the fast mounting demands for tonnage. The vessels were
delivered to the Navy as soon as they had discharged the cargoes then
on board or loading. The first taken over, the steamship El Did, re-
named RoanoTce, was delivered November 16, 1917, at Tietjan &
Lang's shipyard, Hoboken, N. J., where the work of conversion into
a mine planter was promptly undertaken. El Rio, renamed Housa-
tonic, followed at the same yard November 25; and El Siglo and
El Cid, becoming the Canandaigua and Cononicus, respectively,
arrived at the Morse shipyard, South Brooklyn, November 22 and 24.
Some high-speed vessels were desired for the mine force, but there
were few such vessels under the American flag. On the Atlantic
coast there were only three of suitable size and build, one of which,
the Old Colony , had been promised to the British Navy. The others
were the Massachusetts and Bunker Hill. These last two were taken
over by the Navy, were renamed the SJiawmut and Aroostook, and
were delivered at the navy yard, Boston, November 6 and 10, for con-
version. These vessels could each carry about 300 mines on one
deck. They had a speed of 20 knots, but a very short steaming
radius, about 2,300 miles at economical speed.
Two more vessels, the Jefferson and Hamilton, of the Old Dominion
Line, plying between New York and Norfolk, were requisitioned by
the Navy and taken over December 2 and 6, 1917. They were re-
named the Quinnebaug and Saranac, respectively, and the work of
conversion was undertaken at Robbins repair yard, Erie Basin, and
James Shewan & Sons' repair yard, both in South Brooklyn. Their
speed was about 16.5 to 17 knots and their capacity 600 mines each,
carried on two decks.
Thus a total of eight vessels was acquired for conversion into
minelayers, which, with the San Francisco and Baltimore, formed a
squadron of 10, with a total capacity of about 5,500 mines.
The conversion of the Morgan minelayers (Roanoke, Housaionic,
Canonicus, and Canandaigua} was an undertaking of extensive detail.
It involved enlarging the forward orlop deck; making a reserve
bunker in the hold forward of the boiler room, to replace the existing
upper bunkers which were cleared off the third deck; making a sep-
arate compartment in the hold for the elevator pumps, and rearrang-
ing smaller compartments for the dynamo room and machine shops;
closing the cargo ports and providing chutes for coaling over all with
mines on board ; cutting stern ports for launching the mines through,
and raising the rudder quadrant to give the needed clearance; repair-
ing (largely renewing) and resheathing the second and third decks;
enlarging the officers' quarters to accommodate the more numerous
naval complement; providing commissary, messing, and berthing
72 THE NORTHERN BARRAGE.
arrangements for a crew of about 400, including bakery, scullery,
and a naval galley — no easy matter with the large amount of interior
space to be reserved for the mines; building storerooms, magazines,
water tanks for storage and distribution, washrooms, and closets,
installing a fire system and magazine sprinklers ; replacing the anchor
engine and windlass with one of more power to handle larger chain
and heavier anchors, stowing on billboards; on deck, building gun
platforms forward and aft, lookout stations, and navigating and
signal bridges, together with speaking tubes and accessory apparatus
for fire control and other communications ; making and altering hatch-
ways for crews' use and for mine handling ; altering boat stowage and
davits for heavier boats; and installing davits and booms for em-
barking mines. Watertight subdivision far below the ordinary
naval standard had to be accepted, on account of the limited time
available; but some improvement was effected by making existing
bulkheads stronger and, with their openings, watertight where possi-
ble, and by building two new bulkheads, one forward and one aft, to
divide the largest compartments, so that the ships would have a
chance of keeping afloat, if only one compartment were flooded.
On the main machinery, the work to be done was chiefly overhaul
and repair; but to the auxiliary machinery much had to be added.
The electric plant was more than doubled. An evaporator and
distiller for fresh water, special hydraulic pump installation for the
mine elevators, refrigerating machinery, a larger radio telegraphy
plant, a considerable number of additional winches for embarking
and handling the mines, a steam heating system, and a machine
shop were all new.
The provision of adequate ventilation was a problem. In these
cargo ships it was entirely lacking where the crew were to be. In
the region where the ships were to operate, keeping the large hatches
constantly open for airing out below decks could not be counted
upon. In the crowded conditions that would obtain when the ships
were at sea with mines on board, considerable supply of fresh air
and exhaust for the foul was very important to ordinary comfort,
as well as for the prevention of possible spread of respiratory infec-
tion. The principal difficulty encountered was to obtain ventilating
blowers in number and capacity to meet the minimum requirements.
In this respect the conversion of these ships was least satisfactory.
The two Old Dominion liners (Saranac and Quinnebaug) required
somewhat different treatment in conversion. Their state of preserva-
tion was comparatively poor, and their original construction, in
general and in details, much inferior to that of the other ships taken,
A considerable part of the light upper passenger decks had to be
removed, the parts retained strengthened by extra side plating and
interior stiffening. Their general arrangement as minelayers, how-
THE NORTHERN BARRAGE. 73
ever, differed from that of the Morgan liners only in details and
in their carrying mines on two decks only, instead of three, with
correspondingly fewer elevators. The extra space above the main
deck made better provision possible for officers and chief petty offi-
cers, with consequently more room for the men below, and gave better
ventilation generally; but the additional height above water was
otherwise of no advantage. The single, low mast, which was all they
had at first, was afterwards lengthened by a topmast, to give the
necessary hoist for signals and radio.
In common with all other ship alterations in hand at the time, the
original plans had to be based on what could be done within a reasona-
ble time with material and labor scarce. There was no available
data for mining installations on the scale we had undertaken. Some
British mining memoranda were received, and later a few blue prints
from some of their plans. Also Lieut. De Salis,'R. N., placed all his
experience at our disposal. But as other nations had not made a
success of mine elevators or gone in for mine-carrying capacity to
the same extent we had, little of their data proved applicable. The
experience of the San Francisco and Baltimore during the past two
years, however, was invaluable, enabling the decision of many
questions of detail, both before and during the conversion, to be made
with confidence that subsequent results confirmed as well founded.
The plan finally arrived at for the mining installation of the new
ships consisted of two tracks for mines on each side of the second or
launching decks, extending about three-fourths the length of that
deck. On the deck below there were likewise four long tracks; and
inboard, aft, four or more short stowage tracks. In addition to
these, the four large minelayers — RoanoJce, Housatonic, Canonicus,
and Canandaigua — each had stowage tracks on the enlarged for-
ward orlop deck. Cross tracks and turntables connected all tracks
at points sufficiently distributed to insure against a breakdown at
any point cutting off the mines beyond. Mines were transferred from
the lower stowage decks to the launching deck by elevators. This
was a unique and typically American feature of these vessels. Ele-
vators had been abandoned by other nations as impracticable.
After considering various possible methods of transferring mines
from the lower decks to the upper decks so as to permit the whole
cargo of mines to be launched in one continuous string, the ele-
vators were chosen in preference to launching from two decks, or to
installing inclined planes, conveyor machinery, or ordinary whips
and trolleys. Rather than attempt to design a new elevator, the
representatives of the Otis Elevator Co. were called in at the out-
set and informed of the requirements. These representatives stated
that they would meet the necessary requirements, which was more
than borne out in the actual installation. The elevators were of
74 THE NORTHERN BARRAGE.
two types, electrical and hydraulic, with automatic stop and level-
ing devices, capable of carrying two mines and designed to make a
round trip in one minute, including the time of loading and unload-
ing the car. This rate was eventually doubled in use.
On the four large layers there was only room for one launching
port on each side of the deck. It was therefore necessary to install
a switch so that the mines on the two tracks on each side could be
planted from their respective ports without using a turntable. This
was also a novel feature which had been abandoned more or less as
impracticable by the British, but which gave most excellent service
as installed. On the other four new mine planters there was sufficient
room aft to cut four launching ports, one for each track, thus eliminat-
ing the necessity of switches. The San Francisco and Baltimore had
but one port each, and due to the limited space, it was impossible to
install another. All ports were closed by a substantial water-tight
door, the section of track in its wake being hinged back when the
door was closed.
In the process of planting, the mines on the lower decks were
brought forward to the elevators; hoisted to the launching deck;
then hauled aft to the launching trap after those originally stowed on
the launching deck had been planted. To haul the mines along the
tracks, they were made up in " fleets " of 30 to 40 mines, and moved
by means of a wire rope rove around a " bogie" attached to the end
of the last mine anchor and thence led to a winch. To keep the
mines moving at the necessary speed on all sections of the track
required an installation of as many as 13 winches on the largest
minelayers. As the mines arrived near the launching trap, the
" bogies" were disconnected and the mines were run aft into the trap
by hand. The trap consisted of a simple lever device, designed to
release one mine at a time, allowing it to roll overboard along the
slanting section of the track extending through the launching port.
The mines were embarked from the upper decks, using the regular
cargo booms or davits specially placed for the purpose. Small hatches
were cut for embarking the mines so they could be struck down
one, two, or three decks, and landed on tracks from which they could
be run to their stowage positions. By this method it was possible
to embark mines simultaneously at four points with such speed as
to load even the largest layers in less than five hours.
Shortly after the ships had been taken over and sent to the various
shipbuilding yards for conversion, the commanding officers and
executive officers were ordered to their ships to hasten the work by
keeping in constant touch with the various items on which least
progress was being made. About Christmas the San Francisco and
the Baltimore were sent to the navy yard at New York for their
final outfitting before sailing for Europe.
THE NORTHERN BARRAGE. 75
The SliawmMt and Aroostoolc having been constructed mainly for
navigation between Boston and New York by the inside route,
there was doubt of their structural strength for the open seas.
Thorough examination showed that then" steel hulls, though of
shallow depth, were well built, requiring no underwater strengthen-
ing, and that by doubling the main deck stringers and sheer strakes,
running a light plate deck and stiffening the structure above the
main deck, in order to secure longitudinal stiffness, they could be
made thoroughly seaworthy. These ships, of 4,500 tons displace-
ment, 375 feet long, 52 feet beam, 18 feet extreme draught, were
twin screw, oil-burning, of 20 knots speed with possibilities under
naval management and good fuel of making 21 or more. They
could readily be given a fuel capacity of 4,000 miles at lOlrnots and
1,000 miles at 20 knots. Through unremitting ^ efforts, in view of
the tactical value of these ships as a fast wing in general mining
operations or for "repairing fences" after such operations, they were
taken over November 6 and 10, purchased outright, and their altera-
tion begun. The objection to the inclusion of these ships hi the
force was directed against then" seagoing qualities and the extent
of the work required to convert them. This conversion meant
stripping them down to the main deck and rebuilding upward from
that point, for, as passenger ships, their entire upper structure was
of wood.
The Shawmut and Aroostook were placed in commission at Boston
Navy Yard, 7 December, 1917, and the assembling and organizing
of their crews proceeded concurrently with their conversion. Upon
removal of the superstructures, the crews were scattered to available
spaces in yard shops, and subsisted temporarily on various ships.
This continued during a most severe winter with the thermometer
many degrees below zero while the work was in progress. The men
were finally transferred to temporary quarters on a hospital barge
moored near by. The ships7 officers were established in a part of
the removed superstructure landed on the dock alongside. This
included the pilot houses, in which the officer of the deck was located.
The captains organized their crews in industrial gangs for structural
work, as well as for their duties in the ships. These gangs were
made up chiefly of members of the crews who had had previous
experience in the industrial trades of riveters, calkers, ship fitters,
carpenters, and were placed in charge of officers who had a knowledge
of structural steel working. They conformed strictly to yard hours,
including overtime — a normal condition — except that for their
overtime hours, the enlisted men received no additional pay.
Both ships were completed the same day, June 10, 1918, and in
all respects so thoroughly that only six days later they sailed for
Scotland.
CHAPTER XII.
TRAINING THE PERSONNEL AND COMMISSIONING THE
SHIPS OF MINE SQUADRON ONE.
The sudden expansion of the mine force from 2 mine layers to 10
entailed a proportionate expansion of mining personnel, which
offered considerable difficulty. In comparison with the projected
northern barrage operation, the United States Navy had had very
little experience in -mining, and this experience was confined to a
very few officers and men. It was partly for this reason that the
Bureau of Ordnance designed the Mark VI mine in such a manner
that it could be handled on board ship practically as " fixed ammu-
nition," so that a minimum of experience and training of the ships'
crews would be necessary to its successful use.
The officers and crews of the San Francisco and Baltimore, together
with selected officers and men who had had previous experience in
our small mine force, afforded a nucleus around which to build up
and with which to train the new force, and this last most important
work was promptly taken up.
In October, 1917, when the northern barrage plan assumed definite
form, the Dubuquc, which had belonged to the force but which was
too small to be of much use in extensive mining operations, was in
use as a training ship at Annapolis; and the tugs were temporarily
attached to the train, Atlantic Fleet, leaving only the San Francisco
and Baltimore for work in connection with preparations for the bar-
rage operation.
On the request of the Bureau of Ordnance, the Baltimore was
detailed to carry out certain practical experiments involved in the
evolution of design of the Mark VI mine. Thus the San Francisco
was the only vessel wholly available for the training of men for the
crews of the new mine planters.
One of the first measures taken to train the new personnel was the
establishment by the Bureau of Navigation of a mine force training
camp at Cloyne Field Barracks, Newport, K. I., a part of the canton-
ments provided for the second district Naval Reserves. Accommo-
dations were provided here for 1,050 men, who were subsisted and
carried for pay locally but were under the Commander Mine Force
in other respects. This camp was established on November 11.
The officers who were detailed to conduct the training at this camp
had had duty in mine ships. The men for each of the new ships were
76
THE NORTHERN BARRAGE. 77
grouped under officers of their respective ships. As the ships went
into com mission their crews were withdrawn from the training camp.
Capt. Belknap, in his History of Mine Squadron 1 , gives the following
account of the training of the crews and the commissioning of the
new ships :
The training was general, including seamanship, mines, gunnery, signals, infantry,
and boats. For five weeks the San Francisco and Baltimore were present, giving
practical instruction and experience in mine handling. A part of their regular crews
were transferred to the barracks and replaced by new men. These would be on board
for a week or 10 days, then another lot would come. There was not time to cover all
men in this fashion, but it was expected the information picked up would spread.
During the summer of 1917 a detail of 150 reserves, later increased to 400, had been
sent from Newport to New London, Conn., to work with the mine force on antisub-
marine net making and planting. The work being completed, a considerable number
of the first 150 were obtained for the new mine ships. Along with the net making,
they had been given a regular and systematic training by the Dubuque's officers, which
was now to prove of direct benefit in the mine force. During this training-camp
period at Newport, the weather was at times biting cold, but the results were well
worth while. The Sonoma and Ontario helped at this time in practical seamanship,
signals, and quartermaster training, until withdrawn to assist the Shipping Board to
get vessels out of the St. Lawrence River ice. The Patapsco and Patuxent carried on
the same work after completing repairs, about February 1 and March 1, 1918.
For radio instruction a class was established in mid November on board the San
Francisco, consisting of likely material from the training camp . When the -San Francisco
went to Shewan's yard, December 18, 1918, her radio force was largely augmented
by the best men from this class and instructions were continued during her overhaul.
This included visits to shops and to the radio laboratory at the navy yard, Brooklyn.
The remainder of the original class continued instruction under one of their own number
at the training barracks. When the San Francisco was about to leave Shewan's yard
early in March, her excess radio men were distributed among ships fitting out in New
York, to assist with the installation of their equipment and become familiar with it.
Later, when this squadron assembled, training in British procedure was taken up,
enabling the squadron radio force to adopt it within a day after arriving in Scotland.
For instruction in signals, especially British, flags and procedure, a class was formed
at Newport, January 29, to which signal quartermasters and signalmen from all ships
were sent for about a month's training. To these, 50 more were added from the signal
class at the Newport Training Station. All were divided into groups by ships and
given an intensive course in all kinds of signaling and quartermaster duty. Capt.
E. H. Campbell, commanding the Newport Training Station, placed all desired
facilities at the disposal of the force, and for practice afloat first the Patapsco and then
the Patuxent also were available. The value of this preliminary instruction was
later demonstrated by the excellence of the signaling during the mining operations.
Great credit is due to the leading chief quartermaster, William H. Kerens, of the
San Francisco, and the other chiefs, for the quick and accurate communication by
signals which they made possible.
The importance of a well organized and trained lookout service was early given
attention, resulting in an excellent arrangement of stations, communications, and
procedure.
For various reasons the full number of 1,050 for which training-camp accommodation
had been provided was at no one time complete, but the training was supplemented
elsewhere, so that few, if any, wholly untrained men were received by any ship. As
soon as she was ready for them three gun crews trained in the battleship force were
78 THE NORTHERN BARRAGE.
drafted to each ship. Similarly, the engineer department personnel were assembled
at Philadelphia and kept under training until wanted. The quotas of experienced
petty officers, artificers, and lower ratings began to be assembled on board the receiving
ship at New York in January, but the constant demands from other quarters inter-
fered much here. Permanent association of men with ships on a satisfactory basis
hardly began much before the ships went into commission.
For the officers, similar measures were taken to put them in touch with the methods
and the results of experience in the mine force. A conference of all new commanding
officers and executives with Capt. Belknap and Commander Butler was held on
board the San Francisco in Newport on December 3, at which the operation in hand
was described, along with the doctrine and other matters peculiar to the force and
to the particular service of the ships. The mine force training instructions were
reprinted and issued. Matters pertaining to training and organization were taken up
at the subsequent conferences held at New York and Boston through the winter,
and although the ships were as yet neither assigned to the mine force nor in commis-
sion, the acting Commander Mine Force, Capt. Butler, sent them for guidance copies
of all letters and instructions likely to be of useful information. In addition, the
mining officers were given practical instruction on board the San Francisco and
Baltimore in late November and during the mine experiments conducted by the San
Francisco in the spring in Chesapeake Bay, at Newport, and off Cape Ann.
The association of the new ships' officers at New York with one another and with
those of the San Francisco and Baltimore during January and February made for
good progress in working out the organization and future procedure on board the
new ships during minelaying. " Study of the blue-print plans made the officers
fairly familiar with the ships' installations, so that by the time they moved aboard
and began actual drills and tryouts much of the preliminary work had already been
done. To facilitate the early establishment of routine on a regular basis, so that time
might sooner become available for specialty training, the North Dakota1 s routine book
was revised so as to be suitable for the new minelayers, its adoption in whole or
part, however, being optional with each commanding officer.
The first ships to be commissioned were the Shawmut, Capt. W. T. Cluverius, and
AroostooJo, Commander J. H. Tomb, at Boston, December 7, 1917. Their crews had
been built up and organized comparatively early, their own labor considerably
hastening the completion of the ships, as told elsewhere. The popularity of their
prospective service was a great stimulus. Many applicants of all ratings from ships
visiting the Boston yard, keen to go across on the minelaying expedition, volun-
teered to the captains of these two ships.
Next to commission were Roanoke, Capt. C. D. Stearns, and Housatonic, Commander
J. W. Greenslade, on the 25th of January, 1918. Conditions in the neighborhood of
their shipyard and on board the ships made an earlier date impossible without retarding
their conversion. Living conditions were extremely rough amid the dirt and dis-
order, made worse by the slush and mud in the unpaved shipyards; but the presence
of officers and men on board exerted constant forward pressure on the work, while
they at the same time were becoming acquainted with the details of their ships. At
the Morse yard conditions were not favorable for commissioning until March 2. The
decision of the appropriate time for commissioning was left to the respective com-
manding officers, who, watching the work's progress from day to day, were in the best
position to choose. The Canandaigua, Commander W. H. Reynolds, and Canonicus,
Commander T. L. Johnson, commissioned March 2, the Quinnebaug, Commander D. P.
Mannix, not until March 23, but most of her crew had been assembled, organized,
and accustomed to the ship from a much earlier date. Last to commission was the
Saranac Commander Sinclair Gannon, April 9, 1918.
CHAPTER XIII.
COMPLETION AND SAILING OF MINE SQUADRON.
The date of departure of the mine squadron had been fixed ten-
tatively at February 1, 1918, partly because it was believed originally
that this program could be met if all went well and partly because it
was feared that other work no more important might be given pre-
cedence. It was soon found, however, that the date for completion
would have to be postponed because of unavoidable delays, and con-
sequently February 24, March 15, and March 21 were successively
worked for.
Throughout December to March, crowding in the shipyards,
scarcity of material, congested transportation, shortage of fuel, and
severe weather, made a combination of difficulties especially unfavor-
able for outside work on the minelayers, of which there was a good
deal to be done. By constant urging, anticipating probable causes
of delay, and persistently following up behindhand deliveries, the
work as a whole was kept always progressing, if at times slowly.
Work on the Morgan liners was undoubtedly helped by having them
in pairs at two ship yards, a good arrangement for mutual assistance
and emulation; and, as the time for completion drew near, some spirit
of competition was aroused between the managers of the two yards.
Of the other two ships at New York, which were placed singly, the
Saranac at Shewan's yard was greatly delayed, by some apparent
disaffection among the shipyard employees, and by partial strikes.
Special measures had at last to be taken in her case, finally getting
her to sea six weeks behind her sister, the Quinnebaug.
A great deal of the delay was undoubtedly due to lack of interest
on the part of workmen. The subsequently successful campaign of
addresses to the workmen by good speakers, explaining the need for
the ships and the men's own interest in doing their best, did not
begin until sometime in February and then only in a small way.
Another serious retarding cause, constantly present, was insufficient
supervision of the work. The contractors were new to Government
work, the vessels were of a type for which no model existed, and
plans were not forthcoming as fast as wanted, nor often in the logical
order. Several delays or losses of material in transportation held
up other work and one of the trades — shipfitter — in which labor was
shortest was the one on the completion of whose work much of the
other work was dependent. Finally, by the end of the first week in
79
80 THE NORTHERN BARRAGE.
April, five ships had been sufficiently completed to leave the ship-
yards and go to sea. Yet these ships, which with the San Francisco
and Baltimore represented three-fourths of the total mining capacity,
late as they were, were not behind the time the mines were ready,
the manufacture of these likewise having suffered from the prevailing
unfavorable industrial conditions.
First away from the shipyard, 4 April, 1918, was Roanoke. She
had been the first of the Morgan liners taken over, but to get her
away even then it was necessary to take her to the Brooklyn Navy
Yard for a few days, to concentrate on her electric wiring. Several
items were incomplete, but a break had to be made away from the
shipyards, and it did not become necessary to send her back. The
Housatonic followed close afterwards, 6 April, similarly incomplete;
then Canandaigua, 8 April. The latter had a long list of unfinished
or poorly finished items, including the ice machine and partial installa-
tion of the ventilation system. Quinnebaug and Canonicus, on 14
and 16 April, respectively, made a total of five ships ready about the
same time. Among these, the shortest time under alteration, was
4 months and 12 days; the longest, 4 months and 24 days.
A tentative schedule prepared by the British Admiralty in the
early part of December, 1917, named May 1 for the completion of
one system of the mine barrage, allowing one month to do the mine
laying. Subsequent events made that date impossible to meet, in
spite of all efforts; but the ships' officers were doing all they could
to advance their preparations for active service without retarding
the work of the shipyards, so that when the vessels did leave, they
should be coaled and stored as completely as the state of the supply
market permitted. A memorandum had been issued to them on
28 February, outlining the tentative employment of time prior to
going across, as follows:
(a) On leaving the yard, each ship was to drop down to Gravesend
Bay to receive 50 Mark IV mines to be used for training; these to be
turned in before departure for abroad.
(b) Each ship was to proceed to sea independently for one week,
for a shakedown, general clean-up, and preliminary ship drills,
finishing the cruise at Hampton Roads. At discretion, ships were
to go into Chesapeake Bay for part of the time, keeping clear of the
rest of the fleet.
(e) One week was to be devoted mainly to training in mining, first
taking half of the ship's capacity on board, for working out the
handling of winches, parbuckles, fleets, elevators, and crossovers.
During the following week, enough more mines w&re to be taken to
fill to capacity, less one track load on each side of the launching deck.
This was afterwards changed to leave one deck clear of mines, to
make room for extra men carried to fill the mine bases. At the end
NORTH SEA BftRRAGE
PHOTOSTATIC CHART, NORTH SEA BARRAGE.
Showing first proposed location after shifting barrage from Aberdeen-Ekersund line.
80-1
(Page 92.)
80-2
80-3
80-4
THE NORTHERN BARRAGE. 81
of two weeks, two to four days were to be spent in coaling, completing
with stores, and other final preparations.
(d) On the passage across there were to be tactical and gunnery
exercises and ample opportunity for moving mines about as desired
for training on board.
The final aim was to arrive at destination ready, after loading with
mines and coal, to begin planting. It was estimated that 45 days
after leaving the shipyard would suffice for the competion of this
whole program. The squadron was, therefore, working without a
definite date but within a definite lapse of time. Its arrival at the
mine bases in Scotland, during the night of 25-26 May, was on the
fortieth day from the time the last ship left the shipyard. On arrival
all were ready, requiring only coal and mines.
Having completed her final fitting out and conducted successful
experiments with the new mine in Chesapeake Bay, March 13-15, in
Narragansett Bay, March 20-21, and off Cape Ann, April 1-5, the
San Francisco returned to Hampton Roads; and there, on Wednesday,
April 10, 1918, Capt. R. R. Belknap, having been detached from the
Office of Naval Operations, assumed command of the Mine Squadron,
with additional duty as chief of staff to the Commander Mine Force,
Rear Admiral Joseph Strauss, who had already proceeded to the mine
force headquarters at Base 18, Inverness, Scotland.
On April 12, 1918, the first of the new minelayers, the Roanoke,
stood into the Roads, followed the same day by the Housatonic, and
the next day by the Canandaigua. Immediately upon arrival, these
vessels proceeded to take their complement of mines from the mine
carrier Lake Superior and from Southern Railroad Pier No. 4 at Pin-
ners Point.
So far all had gone smoothly; but early Monday morning, the
15th, the Housatonic, in getting underway from Pier 4, broke the side
of her hot well casing, completely disabling the main engine beyond
repair ip less than- 10 days. The work was taken in hand immediately
by a forcafrom the Norfolk Navy Yard, and at noon Tuesday she
was towed to the yard, where every effort was made toward early
completion. There was no choice but to wait and take advantage
of the time in completing and improving such work as had not been
done to satisfaction at the ship yards. In this respect, the enforced
delay was a benefit, as some navy yard help was given other ships,
too, which relieved the small repair gangs of the ships from a dis-
couraging amount of pressing work, hopeless of accomplishment
unaided.
It became evident by Thursday, the 18th, that the unfinished items
on board Canandaigua, which was the worst of any vessel in this
respect, could not be completed without navy yard help by the time
the Housatonic would be ready. The commandant at the Norfolk
181063°— 20 6
82 THE ITORTHEK1T BARRAGE.
yard was applied to that night by radio, and he and the officers of
the industrial department, appreciating the urgency for getting this
force off for the war zone, promptly took in hand every item of
unfinished work that could be completed simultaneously with the
work on the Housatonic.
On Wednesday afternoon the Quinnebaug stood in, and on
Saturday, April 20, the Canonicus, both reporting themselves ready,
making the squadron for the time complete. Except the Roanoke,
no ship had taken advantage of a full week for preliminary shake-
down. The last two ships took only three and four days. All of
them, however, experienced bad weather, which tested their sea-
worthiness rather severely for so early in their new career.
It had been planned to supplement the preliminary specialty
training of these new ships by giving them the assistance of experi-
enced petty officers and men from the San Francisco and Baltimore
during the two weeks period before sailing for abroad.
An urgent request had come from the British Admiralty about
March 1, however, for the services of one or two minelayers to
help out in laying a field in the North Channel to the Irish Sea,
using British mines. The Baltimore was sent in response to this,
sailing March 7 via Halifax. Consequently a double burden fell upon
San Francisco alone, of testing the completed mines and giving some
assistance to new ships in their training. Beginning at Hampton
Koads, two instruction parties, of experienced gunner's mates with
an officer, were transferred temporarily to the new ships in turn,
for practice instruction and supervision of all the operations of
testing, assembling, and preparing a mine for planting. This was
supplemented on deck by sending to some of the new ships one or
more experienced signalmen from San Francisco, in temporary
exchange for equal numbers.
A change in plan came about at this time in compliance with the
wishes of the Commander, Mine Force, for one or more planters to
be sent in advance of the others to assist the Baltimore, so that they
might together complete the mine field, on which Baltimore alone
was engaged, in time to join the squadron for the northern barrage
operations. For such an early departure, the Roanoke was the only
one that could be considered; Capt. Stearns declared his ship would
be ready to proceed as soon as some practice had been given in actu*al
minelaying. Inspection of the crew and ship by the Squadron
Commander confirmed this. Held only 16 days after leaving the
shipyard, the inspection showed that the time had been utilized to
the best advantage, the crew and the ship throughout being in a state
most creditable to Capt. Stearns, and his officers and crew.
The following Monday the Roanoke held some minelaying exercises
off Cherrystone, Va. Returning that night, she transferred to other
THE NORTHERN BARRAGE. 83
ships all but 160 mines, retaining these for drill, and at noon on
Wednesday she sailed, the first of the new minelayers to proceed
on active service. At Newport, R. L, she received a draft of 250
men for the mine bases in Scotland, proceeding thence via New
York for the Clyde. As it turned out, all this was fruitless except
for getting the men to the bases. The Roanoke was detained a few
days in New York, waiting to join a convoy, and after arrival in the
Clyde took no part in the Baltimore's mining operation, although
prepared to do so. She arrived at Base 17, Invergordon, Scotland, a
week before the rest of the squadron.
By Friday, April 26, as promised, Housatonw's repairs were com-
pleted and she went alongside the Lake Superior at the explosives
anchorage to obtain her loaded mine cases. Next day at noon the
Canandaigua did likewise, and by Housatonic's working all Saturday
night the squadron was at last ready for the first cruise in formation
at sea.
The four seagoing tugs, Sonoma :, Ontario, Paiapsco, and Patuxent,
which had for some years past been performing the duties of fleet
tenders, and for some months after the outbreak of war been engaged
with the mine force in submarine net planting and in mining experi-
ments, were fitted out to accompany the mine force abroad. The
Patuxent, Lieut. J. B. Hupp, commanding, and the Patapsco, Lieut.
W. E. Benson, were temporarily detached to escort a convoy of
submarine chasers abroad via Bermuda and the Azores to Brest, but
finally arrived at United States Naval Base 18, Inverness, Scotland,
June 24, 1918, where they were subsequently employed for inspection
and observation of mine fields and for communications between the
mine bases. The Sonoma and Ontario remained with the mine-
layers until their departure for Europe. The Sonoma, Lieut. J. S.
Trayer, accompanied the mine squadron on its trip across. The
Ontario, Lieut. Edmund Delavy, accompanied a group of submarine
chasers abroad and was then diverted to Queenstown for submarine
-patrol duty. Although it was originally intended to have 16
tugs, including the four above mentioned, attached to the mine
squadron as minesweepers, it developed that their services in this
capacity were not needed. Two tugs were able to handle the miscel-
laneous work at the bases; and, in view of the valuable wrecking
equipment on the Sonoma, she was released on July 11, 1918, and
ordered to Queenstown where she could be more profitably employed.
Sunday morning, April 28, Mine Squadron 1, consisting of
San Francisco, Quinnebaug, Housatonic, Canonicus, and Canandai-
gua, got underway for Provincetown, Mass., where standardization
trials ^and mine tests were carried out. On Monday, May 6, the
squadron proceeded to Boston, where Mark IV drill mines were
landed and the quota of Mark VI mines intended for the SJiawmut, ,
84 THE NORTHERN BARRAGE.
AroostooJc, and Housatonic were disembarked. That same night the
squadron got under way for Newport, R. L, the point of final depart-
ure, conducting subcaliber practice and tactical exercises en route.
The remainder of the week was spent in fueling and provisioning the
ships and making final preparations for departure. A draft of 500
men destined for the mine bases in Scotland was distributed among
the four large minelayers. The fuel ship Jason loaded with aviation
stores destined for Killingholme, England, was ordered to cross in
company with the mine squadron.
At midnight, May 11 and 12, the squadron, consisting of the
San Francisco, flagship, Housatonic, Canonicus, Canandaigua, Quinne-
laugj and Sonoma, got under way for Bases 17 and 18. During the
forenoon of May 12, the Jason joined the squadron. On the first
two days out heavy fog was encountered. The succeeding days were
used for gunnery exercises, training and tactical exercises. Wednes-
day morning, May 15, the Quinnebaug showed the breakdown flag.
She was taken in tow by the Sonoma, the squadron slowing to 7
knots. At the end of 24 hours repairs were completed and the
Quinnebaug stood on under her own power. May 16, gunnery practice
was held on a target towed by the San Francisco, in which all of the
new ships were enabled to exercise their guns. On Friday the wind
and sea increased until by 4 o'clock the Jason was unable to keep
in formation, having to head off the course in long zigzags. Fortu-
nately she had sufficient reserve speed to overtake the squadron when
the weather moderated, regaining her position at about 7 p. m. the
following day. She was again lost sight of on May 22 during another
spell of bad weather. The steering gear of the Housatonic broke
down on May 21, disabling her approximately for one hour, and again
the following day, necessitating reducing the speed of the squadron
while repairs were being made. In the meantime the Sonoma was
sent on independently. By the original plans she should not have
been in company with the squadron but should have turned off several
days before to the Azores; but on reaching the separating point;
she had proved so seaworthy and useful that it was decided to keep
her with the squadron in case of further emergency. In making this
decision, the chance had to be taken of bad weather separating her
from the other ships on account of her not being able to make the
necessary speed or hold the course. She was, therefore, sent on
ahead while the rest of the squadron remained with the Housatonic.
Up to this time the services of the Sonoma had been most useful.
In addition to towing the Quinnebaug while she was broken down,
she was of great use in carrying guard mail between the ships while
they were en route and in assisting in the gunnery exercises. On
Thursday morning, May 23, the Sonoma was overtaken and again
joined the squadron. On this day the weather was the worst of any
THE NORTHERN BARRAGE. 85
experienced. The wind and sea on the quarter caused such heavy
rolling that the San Francisco found it expedient to strike mines from
the main to the second deck and fill her boiler and engine room double
bottoms with salt water to improve her stability. There were no
accidents, however, all ships standing the test very well. During
the night and early morning the weather moderated, but fog had set
in which continued until noon May 24. At daylight Saturday
morning, the Jason, missing for four days, was sighted coming up
astern. Fifteen minutes before the squadron was due at the rendez-
vous she took her position in the formation, thus making the unit
again complete. At 4.52 a. m. four British destroyers appeared out
of the haze ahead, then two to the southward and a little later three
more to the northward, nine in all, with H. M. S. Anzac, hah* leader
of the fourteenth flotilla, the flagship. This flotilla escorted the
squadron past Cape Wrath, through Pentland Firth, and down
Moray Firth to Cromarty, where the squadron arrived at 12.40 a. m.,
Sunday, May 25. Pilots, charts, and mine force instructions were
placed aboard the ships at the whistle buoy. The San Francisco,
Canandaigua, Canonicus, and Sonoma then proceeded to Inverness
Firth and anchored off United States Naval Base 18. The Housatonic,
Quinnebaug, and Jason proceeded into Cromarty Firth, Base 1 7, where
the RoanoJce was already lying. That forenoon, in reporting to Com-
mander Mine Force, the squadron commander reported that all ships
were ready for their intended duty.
The remainder of the squadron, consisting of the Saranac, Shawmut,
and AroostooJc, cleared the yards where they had been converted on
May 23 and June 10, respectively. They were not delayed by uncom-
pleted work, as the others had been ; but the standardizing runs over
the Provincetown course proved that thsShawmut's and the Aroostook's
fuel consumption was much larger than had been reckoned, making
their fuel capacity insufficient for the passage across. This threat-
ened an indefinite delay, but the difficulty was solved by Capt.
Cluverius and Commander Buhner securing enough oil hose for the
Black Hawk to fuel the ships at sea. By expeditious management
the three mine planters, together with Black Hawk, were able to
sail in company on June 16. The only oil hose obtainable quickly
was of 4-inch diameter, nearly twice as heavy as that ordinarily
used for fueling at sea. The first fueling was done in a gale of wind,
and it was a novel undertaking for all concerned. Yet it was success-
fully accomplished. The second time fueling was done it was easier;
and without further noteworthy incident the detachment arrived at
Bases 17 and 18 in the evening of June 29. The Baltimore, having
finished her minelaying off the north of Ireland under the direction
of the British Admiralty, joined the others at Base 18 on June 2,
thus making the squadron of Minelayers complete.
CHAPTER XIV.
COMMANDER MINE FORCE— APPOINTMENT, ARRIVAL IN
EUROPE -PREPARATIONS FOR COMMENCEMENT
OF MINELAYING.
As preparations progressed it became apparent that our mining
operations were developing into one of the major war activities of
the United States Navy, and it was desirable that it should be com-
manded by an officer of appropriate flag rank. Accordingly, Kear
Admiral Joseph Strauss was appointed Commander Mine Force,
United States Atlantic Fleet, relieving Capt. R. R. Belknap the
middle of February, 1918.
This appointment was particularly suited to the capabilities of
Rear Admiral Strauss, who had spent a large part of his service in the
development and design of ordnance, and had preceded Rear Admiral
Ralph Earle as the chief of that bureau. The minelaying program
now in hand called for a vast expenditure of money for the production
of mines which, as a type, were unknown and untested. Minor tests
had, of course, been made of the constituent parts and were indi-
vidually gratifying, but in any complex mechanism such as a mine, a
torpedo, or a gun mount, an actual test of the completed unit under
service conditions is the only true proof of its efficiency. At the
outset it would seem that a mine should be extremely simple to design
and construct. Such is far from the case. Prior to the development
of this mine the United States Navy had never produced a really
satisfactory mine. The demand for immediate antisubmarine meas-
ures was so urgent in order to prevent the loss of merchant ships
from reducing the available tonnage below that required to success-
fully prosecute the war, that, tried or untried, it was necessary to
begin at once, on a large scale, the manufacture of this new American
mine.
After receiving his appointment as Commander Mine Force, Rear
Admiral Strauss spent several weeks in Washington on temporary
duty in the Office of Naval Operations, familiarizing himself with all
information bearing on the operation and with the preparations then
in hand, also reviewing the status of the work being done by the
Bureau of Ordnance in connection with the production of the mines.
Several days were spent in inspecting the new minelayers being fitted
out at New York and Boston; then arrangements were made to pro-
86
THE NORTHERN BARRAGE. 87
ceed to Great Britain to complete the preparations necessary to
enable minelaying to begin immediately upon the arrival of the
squadron.
After reviewing the correspondence in Washington relative to the
nature of the proposed mine barrage as then agreed upon, which, in
addition to leaving Pentland Firth open, left a clear passage nearly
10 miles wide between the Orkney Islands and the western end of
the barrage, besides some 110 miles which were deep mines only,
Admiral Strauss wrote to the Chief of Naval Operations on March 7 :
In considering the scheme to which the mine force's efforts are to be devoted, I
desire to invite attention to the following necessary conditions to insure success:
First, every outlet to the broad sea must be closed by mine barriers. This includes
the outlets to the Atlantic provided for in the proximate plans, as well as those to the
Mediterranean through the Dardanelles and the Adriatic. There must be no leaks
anywhere. While it would afford a serious check to submarine attack were our enemies'
submarine bases confined to the Mediterranean, nevertheless an enemy so enterprising
must not be given even so restricted an opportunity.
As to the means for accomplishing the end sought (the Mark VI mine), I think it
too soon to predict success for this factor of the problem. I believe that the Bureau
of Ordnance has done its work carefully and with the greatest intelligence, and we
can only hope for the best results. I am prevented from a feeling of assurance, how-
ever, by the fact that actual experience with the mine is very limited. Unfortunately
faults develop in every new mechanism, no matter how much skill and precision has
been employed to close every avenue of failure. It would be too much to hope for the
complete success of the new mine, and we must be prepared to make alterations in the
mines at the operating bases, where the first reports of extensive tests will be received.
At this date, as nearly as I can learn, no complete mines have yet been delivered for
shipment, but parts have been delivered, and complete mines are expected shortly.
On March 12, 1918, Rear Admiral Strauss, accompanied by Lieut.
Noel Davis, United States Navy, who had reported the previous day
for duty as aide, sailed from New York City on the S. S. New York.
Arriving in Liverpool, England, March 23, he proceeded at once to
London and reported that afternoon to Vice Admiral Wm. S. Sims,
Commander United States Naval forces, European Waters.
The following five days were spent at London headquarters going
over the recent developments in the status of the barrage, and in
calling on the various officials at the British Admiralty interested in
the enterprise.
On March 28 Admiral Strauss with Lieut. Davis left London, arriv-
ing at Grangemouth, Scotland, the same day, to call on Rear Admiral
Clinton-Baker, R. N., who commanded the British minelaying squad-
ron, which had been allotted to co-operate with us in the North Sea
barrage. Grangemouth, which is situated on the Firth of Forth,
about 18 miles west of Edinburgh, was the British mining depot from
which their first minelaying squadron operated. The afternoon was
spent discussing the plans for minelaying and in inspecting the
assembly plant.
88 THE NORTHERN BARRAGE.
The following morning, March 29, 1918, Admiral Strauss arrived
at Inverness, where he was met by Capt. O. G. Murfin, U. S. Navy,
commanding officer of United States Naval Bases 17 and 18. The
day was spent inspecting Base 18, and establishing the headquarters
of Commander Mine Force in the office building at that base.
The following week was occupied by inspection of the various sta-
tions under the jurisdiction of Commander Mine Force — Base 17,
Kyle of Lochalsh and Corpach. By this time the work of construc-
tion at the bases had progressed to such a point that it would have
been possible to begin the assembly of mines had the necessary mines
and minelayers been ready.
On April 10 Admiral Strauss visited the Grand Fleet at Scapa
Flow and called upon Admiral Beatty, Commander-in-Chief , to dis-
cuss the contemplated mine barrier. It was apparent that the Com-
mander-in-Chief was anything but enthusiastic about a mine barrier
across the North Sea. British minelaying had begun in area B, and
skimming sweeps had showed that some of the mines had not taken
the designed depth, and would have been dangerous to surface ves-
sels crossing the field. This undoubtedly alarmed the Commander-
in-Chief, and considering the restrictions on the freedom of move-
ment of the fleet imposed by such a barrage, it is only natural that
he was not enthusiastic. The main result of the visit, however, was
to make definite arrangements for the escort of our minelayers while
out at sea. No American destroyers were obtainable, and the mine
squadron was thus totally dependent on the Grand Fleet for escort
and could not leave the bases until such escort was provided. The
number and type of escorting vessels was to depend upon the dis-
position of the German Fleet at the time of the mining operations.
If the enemy fleet was at sea, it would necessitate sending out a
portion or possibly all of the Grand Fleet. The commander in chief
requested Admiral Strauss to telegraph him 48 hours before the
squadron was ready to go out and -escort would be arranged.
Capt. H. E. Mulleneux, K. N., was ordered to Inverness as liaison
officer between the two services and as the representative of Rear
Admiral Clinton-Baker at Grangemouth. Capt. R . E. Chilcott, R . N. ,
was ordered to Invergordon in a similar capacity. While the bases
were under construction (which was largely controlled by Admiral
Clinton-Baker), these officers were of much assistance. However, as
the construction drew to an end and the work of organization and
administration became the predominant factors, the usefulness of
liaison officers was very much lessened. One of the fundamental
stipulations in the agreements for the execution of the barrage was
that we should have entire freedom as to the manner in which our
mines were to be laid. In our operations we were associated princi-
pally with the following British officials: Commander-in-Chief, Grand
THE NORTHERN BARRAGE. 89
Fleet; Rear Admiral, Invergordon, and the Senior Naval Officer,
Inverness. As we were supplied with all the various British secret
and confidential publications, the question of communications, etc.,
became in a few weeks equally as simple as our own, and to transmit
all requests, communications, etc., via the liaison officer simply com-
plicated matters and added an additional link to the chain. The
result was, obviously, that there gradually became so little for them
to do that they were finally ordered to more important duty. Just
prior to the arrival of the minelayers the Admiralty, at the suggestion
of the Commander-in-Chief , Grand Fleet, kindly offered to send one
or two experienced officers to be attached to the staff of Admiral
Strauss to assist with the administrative and communication work.
Up to this time no' difficulties of any kind had been encountered
and their services were accordingly declined.
Much concern was caused when the U. S. S. Lake Moor, the fifth
mine carrier dispatched to the bases, was torpedoed and sunk in the
North Channel to the Irish Sea on April 11, 1918. The vessel was
attacked about 11 p. m. and sank very shortly after being struck.
The night was dark and rescue work was difficult. Fifteen survivors
were picked up. The cause of alarm, however, was from a totally
unexpected source. When the torpedo exploded it opened up the
hold in which the firing devices for the mines had been stowed. The
success of the North Sea barrage depended in a large measure in
maintaining the secrecy of this device, and the most stringent meas-
ures had been followed from the place of their manufacture until the
mines had actually been planted.
Each device was packed in a separate wooden box near the top of
which handholes had been provided to facilitate handling. The top
end of the firing device was heavier than the bottom, and as soon
as it fell into the water it toppled over with the heavy end down,
and the air trapped in the bottom of the case kept it afloat.
Four of these cases were picked up by a patrol vessel. As soon
as this information was received arrangements were made to have
the coasts in the vicinity searched and all cases found shipped to
Base 18. Besides the possibility of an enemy submarine picking up
some of these floating boxes, the accident occurred close to the Irish
coast and just at a time when the Irish situation was most critical.
Fortunately, however, it appears that none of these devices fell into
improper hands. The Germans, at any rate, did not learn the secret
of the American mines until possibly months later, when it might
have been obtained from mines washed ashore in Norway.
In response to a cabled request, Lieut. W. K. Harrill, United States
Navy, reported at Inverness on May 8 for duty on the staff of Admiral
Strauss as force radio officer. During the war the Grand Fleet had
greatly developed radio telegraphy and established special rules for
90 THE NORTHERN BARRAGE.
transmitting messages so as to prevent enemy stations from ascer-
taining by radio compasses the whereabouts of allied men-of-war.
Lieut. Harrill was immediately sent to the Grand Fleet to familiarize
himself with the current practice and the equipment which would
be required for our vessels in order that they might be brought up
to the necessary standards as soon as possible after their arrival.
As soon as possible after the ships arrived each radio force, including
the communication officer, was given one to two days thorough in-
struction by the force radio officer assisted by Lieut. Grant, United
States Navy, radio officer from the U. S. S. Delaware, with special
attention to the numerous confidential publications and also the salient
points in British radio procedure. This was supplemented by a
school established at Base 18 for ships in the "harbor. When the
squadron sailed on its first excursion June 7, all ships were equipped
with the special apparatus, and on the next excursion the mine
force conducted all radio communication in accordance with British
procedure.
The work of establishing a suitable organization to co-ordinate the
bases with the vessels, and the preparation of instructions for the
force was the most important task of Commander Mine Force
during the months of April and May. Mine parts were beginning
to arrive and it then appeared that sufficient would be on hand by
the time the squadron arrived to enable an excursion to go out
immediately. It was mandatory therefore that no administrative
oversight, such as insufficiency of provisions, supplies, current recog-
nition apparatus, etc., should cause a delay in the operations.
The mine force instructions were drawn up to include not only the
necessary instructions with regard to liberty, leave, patrols, repairs,
routine reports, etc., which commonly comprise such a publication,
but also specific instructions for passing the harbor defenses at
Inverness and Invergordon, obtaining water, coal and provisions,
the proper means of obtaining miscellaneous supplies from Admi-
ralty stores; special instructions for handling the various classes of
mails; censorship regulations; train schedules; arrangements for
handling liberty parties by British drifters allotted for this purpose;
the various recreation facilities on shore for officers and men — in fact,
effort was made to include in the one set of instructions all possible
information. These instructions were prepared in loose leaf form, so
that when it became necessary to make changes or additions it might
readily be accomplished to maintain in one volume practically every-
thing necessary for the operations of the force, and to eliminate the
necessity of hundreds of miscellaneous letters on equally, as many
subjects which are always most confusing because they are so diffi-
cult to keep in touch with.
THE NORTHERN BARRAGE. 91
Special contracts were arranged by the force supply officer with
local dealers for the supply of meats, vegetables, and other fresh
provisions at fixed prices. A channel was dredged in Inverness
Firth to permit minelayers to go further up the Firth to Beauly
Basin, which is adjacent to Base 18. The Firth, which is shallow,
was resurveyed and a new chart published. Moorings were laid to
accommodate the minelayers in the more restricted anchorages.
Taut wire measuring gear was obtained for each vessel and held
in readiness for installation on their arrival. This gear proved most
valuable for navigational purposes. It consists essentially of a drum
carrying 140 miles of fine piano wire. A suitable weight is secured
to the end of the wire and dropped overboard. The wire as it is
paid out is measured by a recorder which shows with remarkable
accuracy the actual distance traveled over the ground.
Arrangements were made for Commander Mine force to act as
the distributing authority for all United States and Allied secret
and confidential publications. British chart portfolios were ob-
tained for each ship. Special apparatus required for making recog-
nition signals were also procured and held ready for the ships.
By the time that the squadron was due to arrive all preliminary
work had been completed. The mine force instructions and necessary
harbor charts were taken on board by the pilots sent out to meet the
ships and bring them into Invergordon and Inverness upon their
arrival.
CHAPTER XV
CHANGES IN THE BARRAGE PLAN.
In view of the formal approval by the Navy Department and the
British Admiralty of the northern barrage plan as it existed on Novem-
ber 1, 1917, the Department, and more particularly the mine section
of the Bureau of Ordnance, naturally assumed that such changes as
might become necessary during the operation would be only of a
minor character and that the major features, notably the location
of the barrage on the Aberdeen-Ekersund line could be regarded as
definitely fixed, and on this assumption the manufacture of the
immense quantity of material required was taken in hand and pushed
to the utmost. This assumption soon proved, however, to be in-
correct, and from December until the cessation of hostilities there
were so many changes in plan and so much resultant confusion in the
manufacturing and shipping projects that the whole operation was
seriously delayed, its success gravely hazarded, and its effect undoubt-
edly much reduced below what was to have been expected from the
execution of the original proposition.
A communication of December 6 from the Admiralty to Admiral
Suns, written after the subject of the laying and patrol of the barrage
had been discussed in consultation with the Commander-in-Chief,
Grand Fleet, stated that :
It has become clear that there will be considerable difficulty in patrolling the eastern
portion of the barrage as at present proposed,' and in affording support by light cruisers,
etc., if no Norwegian port is available as a base * * *. An alternative position for
the barrage has accordingly been worked out on the line Orkney-Bergen in place of
Aberdeen-Ekersund.
The various advantages and disadvantages of this change were out-
lined and the suggested change submitted to the United States for
approval. The question was referred by Admiral Sims to the Navy
Department for decision as soon as the proposal of change was re-
ceived (December 7) which replied that:
Unless reasons for change are fundamental, advantage of new location would not
offset loss and delay by derangement of plan for mine material.
In this connection the British "History of Northern Barrage"
states that the Admiralty in its communications to the commander
hi chief, Grand Fleet and to Admiral Sims, made the -following points
among others relative to the proposed change:
The mine barrage is of no value unless the deep portions are patrolled, and the patrols
must be adequately supported to be effective * * *.
92
THE NORTHERN BARRAGE. 93
The provision of the 42 destroyers for the patrol of the eastern area would also prove
extremely difficult without assistance from the Grand Fleet.
The material will be equally suitable for the new line.
The proposed alteration should not delay completion.
The last two points quoted were entirely in error so far as American
mine material was concerned, since the proposed new location of the
barrage in deeper water would necessitate increased lengths of moor-
ing ropes and, as the manufacture of material was well along, delay
was inevitable.
The proposed change was based on broad strategical and tactical
grounds and the Navy Department was forced by circumstances to
agree to it, though most reluctantly.
In reply to the Admiralty communication of December 6, a memo-
randum was prepared by the planning section of Admiral Sims's staff
and issued January 1, 1918, which reviewed the entire situation and
set forth the views of the United States in part as follows :
The second position considered in this memorandum is the one now proposed by the
British Admiralty and accepted in principle by the Navy Department. There are
many factors pro and con that entered into a choice as between the two positions, but
of these a single factor controlled, viz: That the new position is deemed best by the
Grand Fleet, upon which will rest the responsibility for the support and patrol of the
barrage. The new position gives greater freedom of movement and greater ease of
support to surface vessels, while it imposes corresponding difficulties upon the opera-
tions of enemy surprise vessels. The change in position accepts the handicap of an
average increase in depth of water of about 15 fathoms. This handicap might be
considered serious were it not for the fact that the whole barrage is based on the assump-
tion that an effective mine field can be laid in 1,000 feet of water.* If this assump-
tion be true, then whether a portion of the mine field be laid in 40 or in 60 fathoms of
water is not material, except as the changes in plan introduces delay.
It will be noted that the original line extended from mainland to mainland, while
the new line extends from island to island and has in it passages completely navigable
to submarines. This condition is, in our opinion, undesirable.
The proposed character of the barrage does not provide for the full accomplishment
of the mission. The proposed barrage will not close the northern exit from the North
Sea because —
(a) The barrage is not complete in a vertical plane in ureas B and C.
(6) The barrage is not deep enough.
(c) The Pentland Firth is open.
(d) The waters east of the Orkney Islands, for a distance of ten miles, are open.
(e) Patrol vessels on the surface are not sufficiently effective in barring passages
to submarines, as witness the Straits of Dover.
The barrage is to be a great effort. It is our opinion that nothing short of a sound_
design will justify the effort.
The requirements of a sound design are, the extension of the barrage complete in
the vertical plane from coast to coast.
The necessity for an opening in the surface barrage is recognized, but it is held that
this opening should be in the surface barrage only, and that the deep barrage should
be widened so that the difficulties of navigating the opening submerged may be
practically prohibitive.
94 THE 'NORTHERN BARRAGE.
In conclusion it was tentatively decided (by U. S. planning sec-
tion) :
1. To accept the new position of the barrage aa outlined by the British Admiralty.
2. To urge that the barrage be completed in the vertical plane from coast to coast,
except an opening in the surface barrage at the western end and in Norwegian terri-
torial waters.
3. To carry the barrage to 295 feet (British plans 200 feet).
4. To have surface mines fitted with 70 foot and other mines with 100 foot antennae.
As then proposed, the barrage was divided into three areas desig-
nated and located as follows:
Area B . A 20 mile wide section extending 50 miles to the eastward of the Orkney
Islands.
Area A. A section 50 miles wide extending 134 miles to the E. N. E. from the eastern
end of the area "B ".
Area C. A 50 mile wide section extending from the east end of area "A" 60 miles
E. S. E. to Norwegian territorial waters.
The United States was to furnish the mines and material for and
lay both deep and surace fields in Area "A." Great Britain was
to provide and lay deep mine fields hi Areas "B" and UC", and
furnish trawlers and fast vessels to patrol these two areas.
The British Admiralty plans division answered the above memo-
randum with the opinion that —
The stopping power of the mine barrage should not be overrated. It is the patrol
craft armed with various antisubmarine devices on which we must rely to kill the
submarines. It is on the mine fields that we rely to give us intensity of patrol. Un-
til we have proved the efficiency of the American mine field, we must look on it as a
bluff. We must not attempt to put the bluff too high by notifying an area up to the
3-mile limit of Norway. The navigation of Pentland Firth by submerged submarines
is considered impracticable. As it is the patrol craft we rely on to destroy the sub-
marine, it is not considered that leaving the approach to Pentland Firth uncovered
is of vital importance.
It was further stated that it was not considered necessary to carry
the barrage to a vertical depth of 300 feet, that there was no reason
why the American portion should not be laid in accordance with the
United States views, but that the Admiralty would be prepared to
extend their barrage to a greater depth, if found necessary, and to
mine the surface if that should become desirable.
In view of these differences of opinion the U. S. planning section
prepared a memorandum of January 12, containing its understand-
ing of the status of the mine barrage and submitted it to the British
planning section for confirmation in order to reconcile the various
points and further unify the effort, by reducing to writing a concrete
plan which would be acceptable to both navies. Further than the
agreements regarding the supply of ah1 minelaying operations and
the assignments of provision and laying of mines in the areas as
previously noted, these efforts met with failure hi so far as formal
THE NORTHERN BARRAGE. 96
agreement on a written plan was concerned, the British apparently
desiring to reserve 'the privilege of altering the plans when expe-
diency so dictated while considerable scepticism existed as to the
ability of the Americans to execute satisfactorily their part of the
project. The above mentioned characterization of the American
mine field as a mere " bluff " was more or less indicative of the British
attitude.
The Admiralty did, however, accept the principle of surface
mining hi Areas "B" and "C" should experience indicate that the
surface barrage be more effective in preventing the passage of sub-
marine than the surface patrol.
After this discussion the planning section of the Admiralty not
being in a position to enter into any definite signed agreement, nor
to definitely recommend it to the Admiralty, Admiral Sims requested
the status of the plans in so far as the Admiralty's agreement with
them was concerned. This resulted hi a statement of January 18
which included :
United States to be responsible for provision of mines and minelayers for area A.
Great Britain for areas B and C. Area A to be mined from 10 feet below surface to
as near 300 feet as the American mines will permit.
Areas B and C to be mined from 65 feet below the surface to 200 feet.
When this belt is effectively mined, the question of extending the mine fields to
a greater depth will be considered.
The desirability of -extending the deep mine fields to the surface of areas B and C
will be considered when the situation has developed further * * *.
Thus early in January the character of* the proposed barrage
became so modified as to bear little resemblance to the original plan
and the original faith of its proponents in its effectiveness was no
longer felt to be justified. It was felt in America, in view of the
attitude of the Admiralty and the Commander in Chief of the Grand
Fleet, that the British had no real faith in the American mine and
were not whole-heartedly supporting the project. In particular, the
allocation of both ends of the barrage to the British to be mined with
an inferior mine hi an incomplete manner, and the further decision
that the American part of the barrage was not to be patrolled were
most discouraging.
Not the least discouraging feature of the situation to the Bureau
of Ordnance was the state of flux of the barrage plan and the obvious
reluctance of the Admiralty to commit itself to definite plans. The
British authorities had the appearance of not daring to give up the
whole operation for fear of possible later criticism and at the same
time of not being willing to cooperate to make it successful.
In Admiral Sims's review of the activities of his command it is
stated, in effect, that throughout the discussion of the barrage project
it became apparent that the Admiralty was influenced by two con-
siderations which may not clearly appear in the correspondence and
96 THE NORTHERN BARRAGE.
records, but which should not be underestimated in considering the
mine field historically:
First, the proposed effort on the part of the United States Navy Department was
such a handsome offer from an ally that, even if there were doubts of its success, it
would be poor policy to put only discouragement in the way of those who were willing
and anxious to go ahead with the project. The Admiralty naturally wanted to avoid
any possibility of not having tried the mine barrage, and subjecting themselves to
possible later criticism on the score that it was necessary and would have worked
had it been tried. In other words, the Admiralty at first was very dubious of the
success of the field, but considered the proposals for the above reasons more seriously
than they otherwise would have. As the details of the plans developed and the
reports of Mark VI mines were received, there was a very notable increase in the enthu-
siasm for the project. At the start there was no enthusiasm at all. Later there grew
to be considerable.
The second consideration which should be mentioned in explaining the Admiralty's
policy toward the project was its effect on possible fleet actions. The Navy Depart-
ment considered it almost entirely in the light of an anti-submarine measure. It was
apparent that although nominally under the Admiralty in London the planning for
the Admiralty in such matters as would in our organization be dealt with by the
Office of Naval Operations, rested almost exclusively with the officers of the Grand
Fleet in spite of the existence of a Plans Division in the Admiralty. Naturally they
considered it largely from their own viewpoint, and in studying possibilities of the
barrage they were influenced by the fact that even if it did not work it might be
something which would force a general fleet action. If there were a serious attempt
made by the Germans on the mine barrage itself, or raids on the vessels engaged in
working on it, cruiser actions at least would be probable and with the arrival of sup-
porting units it was quite possible that the two fleets might meet. They thought
that even if it did not work as a mine barrage it might be a bait for a fleet action.
It would make it harder for- raiders to get out. So long as the Grand Fleet did not
have its freedom of movement restricted (and the fleet was by no means so thoroughly,
convinced of the safety of the British mines in the deep mine fields as the Admiralty
was) they had no objection to it and were rather inclined to favor it for the reason
that it might help them meet the German High Seas Fleet. These reasons were at
times mentioned and were very apparent in discussions, but are hardly evident in
the records and were certainly not emphasized by the Admiralty in the correspond-
ence. It appears very essential, however, to a good historical understanding of the
northern barrage that they should not be overlooked, but should be most particularly
mentioned.
Another thing which might be mentioned in this connection is that later in the
discussion when the policy of the extension of surface mines into the end areas was
considered, this project was proposed and pushed by the United States planning
section and was always fairly well considered by the planning section in the Admiralty,
but an extremely large percentage of what opposition there was to it came from the
Grand Fleet, and it was only very grudgingly that the Admiralty, considering the
views not only of its own planning section, but also the recommendations from the
fleet, consented to the modification of the mine barrage, which later resulted in put-
ting surface mines in areas which were at first intended to have deep mines only,
although the United States had argued for surface mines in these areas as well.
The fundamental idea on which the mine section of the Bureau of
Ordnance designed the new mine and proposed the northern bar-
rage was that the barrage would be complete from coast to coast
and that it would be patrolled so that enemy submarines would be
96-1
96-2
96-3
9C-4
THE NORTHERN BARRAGE. 97
forced by the presence of patrols either to turn back or to risk
almost certain destruction by trying to pass the barrage submerged.
Any departure from this principle meant ineffectiveness.
The following remarks quoted from a memorandum prepared by
an officer of Admiral Sims' staff, at the time the change in plan
was under discussion, are interesting:
Position. — The more northern position accepts disadvantages as regards depth of
water in order to obtain certain strategical advantages. This statement, however,
is no more true now than it was when the southern line was previously decided upon
by all concerned. If we are disinclined to admit that a mistake was made in the
original instance by choosing the southern line, we must now show that the reasons
for the shift to the northern position are new reasons or things which did not hold
true at the time of the other conference. The only new conditions mentioned are
that whereas previously it had been hoped to obtain a Norwegian base one is now
no longer considered possible. The other reason is the increased activity of enemy
surface craft. Taking the first of these reasons, I am inclined to suspect that there
is not much to it. I think that a Norwegian base now is just as easily possible as one
previously was. I base this on a recent conversation with Col. Breckinridge who
is naval attache" in the Scandinavian countries and who had just been in Norway.
There is probably no useful point, however, to trying to get behino^this reason if the
Admiralty really sees fit to advance it. The second reason of the increased activity
of enemy surface craft looks like an excellent one after the losses of the two Norwegian
convoys recently. Steps have been taken to improve the Norwegian intelligence
service as to information about the enemy craft coming out of Skagerrak but this
will probably be offset by the increased incentive for the Germans to send out
raiders.
In looking over all the papers I can not help but believe that in the early con-
ferences the fleet was not so very thoroughly represented, and there were people from
the mining division who explained that sending the fleet over a deep British mine
field was nothing to hesitate about. The fleet was in Rosyth, south of the proposed
barrage, and was generally expected to stay there. Now with the fleet back in Scapa
I believe that they are beginning to assert their views to a greater extent and that
at least a large part of their insistence to move the southern end north to the Orkneys
arises from their disinclination to navigate over British deep mine fields. This is
not a reason which there is much point in emphasizing from the Admiralty's stand-
point, so it was really not presented but the argument was made along other lines.
Except as a matter of being perfectly frank with us I do not think that it matters so
very much whether the real reasons for the change in the position of the barrage are
those which they mention or others, equally good ones, which they hesitate to talk
about. For my part, I believe that the fact that Admiral Beatty, who is going to
support this mine field, says that it must go in the northern position finished the
whole discussion and is something that we need not go behind.
Character of barrage. — I believe that the width of the "C " area along the Norwegian
coast is much too great. Leaving it this wide seems to have been based upon the
idea:
(a) It is not good policy to unnecessarily crowd the Norwegian coast with the
notified area if it can be avoided.
(&) They have an idea of wanting to do the whole project on a 50-50 basis and
the deep mine fields of this width are symmetrically arranged. This is no reason
at all.
I can not help but doubt when I compare the width of this area with the Straits
of Dover and consider all conditions existing in that locality, that the deep mine
181063°— 20 7
98 THE NORTHERN BARRAGE.
field, particularly on the Norwegian coast, will not be efficient and it will have to
be later modified by strengthening with surface mines. I have met officers in the
Admiralty who privately expressed the same opinion and stated that in the end
they would be proved correct by the addition of surface mines in Area "C. "
Length of antenna. — Seventy feet for the top mines and 100 feet for the other rows.
This is based on the hope that at greater depths 100 feet may be effective and that
at any rate it will probably drive the boat to the surface, in which case the 70 foot
antenna of the top row of mines, which should be nearest to the edges of the field,
should get the boat and destroy it. Seventy feet all around would be better perhaps, but
submarines can now go so deep that it becomes a necessity to try to stretch out the
barrage vertically, even at the expense of some other small advantages.
Character of mine fields on the Norwegian coast. — The whole mine barrage scheme is
more or less of a tentative nature, because it is so big an undertaking that it can not
in all ways be perfectly designed to meet every conceivable counter measure. Also
it would be uneconomical and inefficient to try to plan it with any such final ideas
in mind. The final appearance of the barrage before the end of the war is something
which one would have to be extremely rash to care to prophesy. There are a few
things which our personal opinion leads us to believe will be the most urgent modi-
fications and the ones which we will see first. In my case I look to see the Norwegian
end of this field protected on the south by perhaps one system of antenna mines before
any great time has elapsed and the notified area appropriately extended. This will
relieve patrol craft in the "C " area of part of their difficulty.
The question of who takes the "C " area has not yet been decided. We have gone
ahead and made mines with long lengths of specially small diameter mooring line
which will do in this place. I foresee that we will eventually have to do something
with mines of this nature, and think it would be a very good thing to make a careful
analysis of conditions in Area "C," even although it is not our own area, with the idea
of seeing whether later on we may be able to use these mines additionally. Mines
intended for deep water like these can be laid in shallow water, but mines with short
lengths of wire (and the diameter of the wire is different) can not be used in deep
water. Can we not compromise in our present disagreement as to who takes the
Norwegian area by finding both kinds of mines are needed and helping to do that too?
In Area "B" the necessity is by no means so great. The Fleet does not want any
surface mines to obstruct its passage, but after finding patrolling rather difficult it may
look favorable upon a project of extending the surface mine area. The water is
not deep in this place. We will need no surface mines here until after Area "C" is
taken care of. It is not safe to look beyond that point * * *.
In order to focus attention upon the various points still unsettled
there was then prepared by Admiral Sims a paper dated February 19,
setting forth the different items in parallel columns and this was
submitted to the Admiralty. This was answered on February 26,
but as stated in a letter from Admiral Sims to the Office of Operations
on March 2, "It appears that although a number of the points have
been cleared up * * * there still remains a decided difference of
opinion in regard to certain important points."
It is believed that the Admiralty's disinclination to extend the Mark VI mines to
the end areas until their efficiency has been demonstrated in Area "A " is not based
on sound reasoning, for with the efficiency of the mine Area "A " or in any other area
the whole success of the barrage stands or falls * * *. If the more efficient min-
ing of these end areas is delayed, until the inefficiency of patrols in these areas is
demonstrated, it is believed that much valuable time will be lost in a case where time
is a most vital element.
THE NORTHERN BARRAGE. 99
Anticipating the necessity for this end area surface mining Admiral
Sims, on April 9, cabled to the Navy Department requesting prepa-
ration of mines for Area "C." Meanwhile deep mining had been
commenced by the British in Area "B" but, owing to unexpected
difficulties with the British mines themselves, the operations were
suspended before one complete line had been run.
The Commander in Chief of the Grand Fleet was much disturbed
by these unsatisfactory results and the Admiralty felt that they
could not continue laying the barrage in Area "B" until the faults
had been discovered and removed.
Shortly after this, in a letter of April 18, 1918, to the Officer of
Operations, Admiral Sims stated :
Owing to the apparent uncertainty in the Admiralty as to the further execution
for the plans of the Northern Barrage, I caused the matter to be brought up at the
staff meeting this morning at which I proposed the following: We lay two single lines
of surface mines over the southern portion of Area "C. " British to lay one "system "
of deep mines over the northern portion of Area "C. " Area "B " to be deep mined
as already planned, except that the mines are to be carried close up to the coast C Is-
lands) without leaving the 7 mile channel now shown on the chart.
The proposal in so far as it applied to Area "C" only was accepted
by the Admiralty formally on April 20.
Thus it will be seen that the original contention of the United
States authorities in regard to the need of a complete barrage, includ-
ing surface mining in the end areas} was not allowed to rest upon the
proof of ineffectiveness of surface patrols, for this particular barrage,
but the inefficiency of such patrols, as amply demonstrated hi pre-
vious mining efforts, was at last permitted by the Admiralty to
outweigh their desire for wide passages for the Grand Fleet.
But this was still only a partial conversion to the idea, for Area
"B" still remained in question. Here all niining was stopped. The
failure of the British deep mines was responsible for this, and although
the necessity was still acknowledged as noted in the Admiralty's
letter of May 10 to Admiral Sims it was said:
The deep minefield in area "B " can have no effect in restricting the areas through
which the submarines can pass and should not therefore be considered an essential
part of the scheme.
Although a verbal agreement was made that as soon as the defects
of the deep mines could be remedied the laying of Area "B" would
proceed, the safety of ships passing over the field could never be
guaranteed and in the memorandum of the deputy chief of naval
staff (Admiralty) received by Admiral Sims on July 25, the conclu-
sions were that either Area "B" was to be swept and left clear or
that it should be completed with deep and shallow mines. Also that
if the latter were done the channel between the western extremity
100 THE NOETHEEN BAEEAGE.
of Area " B " and the coast line would be so narrow that it would not be
available for general purposes.
The width of this channel, according to a report of the technical
committee (Admiralty), "will be eventually decided with the Com-
mander in Chief, Grand Fleet, but in view of experience at Dover and
difficulty of anti-submarine patrolling without mines it should not
be unduly wide."
To further the desire to actually complete the barrage the Bureau
of Ordnance was asked on July 31 to prepare American mines for Area
"B." Then as a result of a consultation between the Commander in
Chief, Grand Fleet, and Admiral Freeman tie about August 25 a note
was addressed to Admiral Sims including items to the effect that:
It will be seen^ that the Commander in Chief is very averse to proceeding at a
quicker rate than step by step, and that he considers that the next step should be
mining up to the 10-mile limit (10-mile channel east of Orkneys). There is a natural
reluctance to close the North Sea unless it can be actually guaranteed tight.
It is suggested therefore that we commence on the 2d of September to mine Area
"B" up to the 10-miles without declaring the area, and that when we eventually do
notify the area it shall include right up to the coast. Moreover, the fact that the
northern patrol force has failed as a killing force has altered the situation.
On September 9 surface and deep mines were actually laid in Area
"B" on a combined excursion of the British and American mine-
laying squadrons.
With the gradual closing of all areas, enemy submarines com-
menced to use Norwegian territorial waters to make the passage.
On discovery of this fact, the Norwegian Government, after much
negotiation and delay, announced September 29, its decision to
mine Norwegian territorial waters, which had the effect of closing
this gap.
Many minor changes in plan and material occurred from tune to
time as will be noted in other chapters of this narrative, but the
foregoing is sufficient to show the uncertainty and confusion
prevailing throughout the operation.
CHAPTER XVI.
MINING OPERATIONS.
Early in March, 1918, the British were ready to begin minelaying
in Area "B." Work started on March 2, and successive operations
took place on the llth, 19th, and 22d, laying a single row of mines
in the southern part of the area at depths of 65, 95, and 125 feet.
On March 22 H. M. S. Gailardia was sunk in the vicinity of this
field while engaged in the work of laying buoys to mark tha North
Sea barrage. Minelaying was stopped pending investigation. The
loss of this vessel caused considerable alarm in the Grand Fleet, and
on March 31 the Comm ander-in-Chief cabled to the Admiralty:
«* * * the chief point to settle is, are these mines safe if within
45 feet of the surface? Unless this can be guaranteed the policy
of laying mines in ricinity of principal fleet base is wrong."
As a result of this the Admiralty wrote the Commander-in-Chief
on April 24, 1918, that "It is not at present proposed to lay any
more mines in Area 'B.' '
From the United States point of view this was a most unsatisfac-
tory development, for it was our firm conviction that to make the
barrage a success it was absolutely necessary that the mines should
extend completely across the North Sea and that surface mines should
be laid in A^eas " B " and " C " as well as in Area "A." After repeated
representations a partial concession was reached on April 20, when it
was agreed that we should lay two rows of surface mines in Area " C " to
the southward of the contemplated lines of British deep mines. This
eliminated the necessity of patrols in Area "C" for the purpose of
forcing submarines down into the deep mines, although a smaller
patrol was still desirable hi order that submarines which were only
partially disabled by mines might be destroyed before they could
reach an enemy base. The announcement of the Admiralty that no
more mines were to be laid in Area " B " was most serious. Admiral
"Strauss recommended that unless the British Government definitely
agreed to carry out the plan of making the barrier at least as com-
plete as had previously been agreed to, that the United States should
withdraw from the operation entirely. Our views in regard to min-
ing Area " B " were presented to the Admiralty whenever occasion per-
mitted, witn the result that a verbal agreement was at last reached
that as soon as the defects of the mines could be remedied the mining
of this area would be resumed.
101
102 THE NORTHERN BARRAGE.
-On April 26 notification was issued in Notices to Mariners that
all shipping was to avoid the area bounded as follows:
(1) Lat. 59° 12.5' N., long. 4° 49' E.
(2) Lat. 59° 29' N., long. 3° 10' E.
(3) Lat. 58° 25' N., long. 0° 50' W.
(4) Lat. 59° 20' N., long. 0° 50' W.
(5) Lat. 60° 21' N., long. 3° 10' E.
(6) Lat. 60° 00' N., long. 4° 56'E.
and thence along the western limits of Norwegian territorial waters
to position (1). The area above outlined included Areas " A" and "C,"
but, as originally intended, Area "B" was not included.
Prior to the commencement of work on the North Sea barrage the
British had been carrying out minor minelaying operations in various
localities. In the early spring of 1918 the enemy's submarines were
very active in the Irish Channel, and it was decided by the Admiralty
to lay a deep mine field off the North Coast of Ireland in the North
Channel.
As all British minelayers were constantly employed elsewhere,
the Admiralty approached Vice Admiral Sims on the subject of
lending a United States minelayer for this purpose. The U. S. S.
Baltimore, Capt. A. W. Marshall, United States Navy, was promptly
detailed and arrived at the Clyde on March 8, 1918, being the first
American minelayer to arrive in British waters.
The Baltimore remained at the Clyde for about three weeks, during
which time she was fitted out with paravanes and taut wire meas-
uring gear, and opportunity was taken to send parties of officers and
men to Grangemouth for instruction at the mining depot, and on
board the British minelayer Princess Margaret in the British H-2
mine and Mark XII sinker.
During this period Capt. Marshall visited Grangemouth to discuss
matters with Rear Admiral L. Clinton-Baker, C. B., R. N., who had
been ordered by the British Admiralty to arrange all details in con-
nection with laying the above-mentioned mine field.
Capt. Marshall, United States Navy, and Capt. Lookhart Leith,
D. S. O., R. N., then visited Larne, Buncrana, Ardrossan, and
Lamlash, and discussed the procedure for carrying out the mining
operations with the senior naval officers at those ports.
Lamlash was selected as the base from which the Baltimore should
operate. Mines were supplied by train from the mine depot af
Immingham. These mines were the British H-2 star, with Mark
XII shakers (fixed moorings). They were fitted with deep switches
and calibrated so as to be inoperative when planted nearer the sur-
face than 50 feet. No sinking plugs were used.
The field was designed to consist of one line of mines at 65 feet
where the water was less than 20 fathoms: one line at 65 feet and
THE NORTHERN BARRAGE. 103
one line at 95 feet in water between 20 and 30 fathoms; one line at
65 feet, one line at 95 feet, and one at 125 feet in water of 30 fathoms
and above. The mines were to be laid in groups of four, spaced
100 feet between mines in each group, and groups to be 300 feet
apart.
All operations were carried out at night, the Baltimore being
screened by two destroyers. The operations consisted of the fol-
lowing:
13th-14th April, laid 179 mines 65 feet below L. W. O. S.
18th-19th April, laid 120 mines 95 feet below L. W. O. S; 60
mines 125 feet below L. W. O. S.
21st-22d April, laid 180 mines 65 feet below L. W. O. S.
27th-28th April, laid 180 mines 95 feet below L. W. O. S.
lst-2d May, laid 180 mines 125 feet below L. W. O. S.
The following extract from a report made by Hear Admiral Clinton-
Baker, R. N., who was in general command of the Baltimore's opera-
tions, is quoted:
It is considered that the Baltimore laid the lines of mines (as planned) with extreme
accuracy; this reflects the greatest credit on Capt. Marshall and his navigating officer,
Iming in view the strong cross tides (3 to 4 knots) that existed in that locality.
On the 6th May, minelaying operations were discontinued by
orders from the Admiralty on account of a skimming sweep of the
mine field having disclosed several shallow mines at the northern
end of the field, due in all probability to the very uneven nature of
the bottom. This skimming sweep was made at a depth of 30 feet,
giving from 30 to 33 feet at the cutters. Actean sweeps were used.
While the sweeping was in progress, one mine was swept up which
had 60 fathoms of mooring cable attached. As all mines planted
in this field were set for fixed moorings of approximately 45 fathoms,
tests were immediately carried out at Grangemouth to' ascertain
the reliability of the locking device in the Mark XII sinkers. The
results of this test showed the possibility of the locking nut stripping
the threads and allowing the full length of the cable on the reel to
run out. These sweeping operations began on May 1 and continued
until May 5, when a mine was exploded by the sweep in position
latitude 55° 33' 15" N., longitude 6° 42' 45" W. Extensive counter-
mining immediately took place in lines A, B, and C, lasting for a
period of between 15 and 30 seconds, and apparently detonating all
mines in these three rows. As described by the officer in command
of the sweepers :
There was a continuous series of explosions as rapid as the fire of a Maxim gun, with
occasional pauses, in which separate and distinct reports could be heard, followed
by a period of intensified sounds, in which separate explosions were indistinguishable.
Sweeping operations were resumed in the North Channel on the
20th of May, when the southwestern portion of D line was skim
104 THE NORTHERN BARRAGE.
swept at a depth of 36 feet — nothing found. The following day
sweeping continued, but again nothing was found. These sweeping
operations continued until the 29th May, when the entire North
Channel deep mine field had been swept at a depth of approximately
36 feet. A few shallow mines were found in lines D and E, but not
nearly so many as were found in the other lines. Soundings obtained
by the vessels engaged in making the skimming sweep showed con-
siderable irregularity in the bottom and much variation from the
survey soundings which were used for setting the fixed moorings.
This was particularly true of the northeastern part of the field.
Prior to the discontinuation of the laying operations by the Bal-
timore, it appeared as though it would be impossible for her to com-
plete this mine field in time to join the mine squadron for the first
operation in the North Sea barrage. Accordingly, the Navy Depart-
ment was requested to send either one or two of the new mine-
layers which were most nearly completed to assist her in order that
all vessels might be available as soon as operations could begin in the
North Sea.
In response to this request the Eoanoke sailed from the United
States on May 3. Before her arrival, however, the Baltimore's
operations in the North Channel had been discontinued. The
Roanolce remained several days at Lamlash, then sailed for Base 17,
where she arrived a week ahead of the other minelayers.
The Baltimore remained on the west coast for several weeks in
order to perform experiments for the British in connection with
minelaying and minesweeping, then proceeded to Base 18, where she
arrived on June 2, 1918.
In the meantime preparations for the commencement of mine
laying had been completed. Early Sunday morning, May 26, 1918,
the San Francisco, flagship of Mine Squadron One, accompanied
by the Canonicus, Canandaigua, Housatonic, and Quinnebaug,
arrived at Bases 17 and 18. The Squadron Commander reported
that all vessels would be ready to commence minelaying as soon as
as they had been watered and refueled. The delivery of mine parts,
however, had not come up to expectations and prevented the begin-
ning of operations at once. All of the necessary mine parts were on
hand except the antenna floats for mines planted at the lower levels,
and it was necessary to wait until a mine carrier had arrived before
sufficient of these floats were on hand to enable the necessary num-
bers of mines to be assembled for the first excursion.
The first excursion was to be a joint operation between the British
minelaying squadron, which had been designated by the Admiralty
as the first mine laying squadron, and our vessels which they had
named the second mine-laying squadron. We reported that our
squadron would be ready to go out on June 6, but it was necessary
THE NORTHEEN BARRAGE. 105
to wait one day while the British completed the assembly of their
mines. The United States squadron left the bases, rendezvoused
outside Cromarty Firth with the British destroyers sent to escort
them, then proceed via the swept channels and across the North Sea
until Udshire Light was sighted on the coast of Norway. This was
used as the point of departure, being the nearest point of land to the
position in which the mine laying was to commence.
No difficulties were encountered by any of the vessels with their
mining installations or the lack of experience of their crews. The
mines were laid with accuracy and precision and the ships, in spite
of the various types which constituted the squadron, maneuvered
well together.
When the mine field was first proposed it was intended to plant
the mines at intervals of 150 feet, but tests conducted by the San
Francisco while in the United States showed this distance to be im-
practical on account of the damage done to adjacent mines when one
mine exploded. As a result of these experiments it was finally
decided that 250 feet was the minimum distance at which mines
could safely be planted, and this spacing was used on the first
excursion.
Shortly after minelaymg had commenced mines began to explode
prematurely. This continued as long as the squadron was in touch
with the mine field, but the frequency of the explosions decreased
rapidly after the laying was completed. By counting the explosions
it was estimated that between 3 and 4 per cent of the 3,385 mines
laid had blown up. Some of these explosions took place almost
immediately after the mines went overboard, severely shaking the
vessels from which they were laid. Others did not explode until
days after they had been in the water. These explosions, which
occurred after each excursion, presented the most baffling problem
which the mine force was called upon to solve. Although a loss of
4 per cent of the mines did not seriously reduce the efficiency of the
barrage as a whole, such, a condition was, nevertheless, undesirable
and every effort was immediately applied to ascertain the cause.
There appeared to be some doubt as to whether the spherical-
cylindrical buoys, which were dropped upon completion of mine
laying to mark the end of the field so that the next excursion could
commence as close as possible without danger, would survive the
weather until the ships again went out. The Commander-in-Chief,
Grand Fleet, was therefore asked to send two sloops or trawlers to
stand by these buoys and assist the squadron in finding them when
taking their departure on the following operation. These vessels
while performing this duty were able to supply much valuable infor-
mation to the Commander Mine Force, as most of them were fitted
with listening devices which enabled them to hear and record the
106 THE NORTHERN BARRAGE.
explosions occurring between successive operations. From 1 to 11
explosions were noted daily for seven days. By that time prac-
tically all explosions had ceased. This seemed to indicate that slow
leakage was probably causing these later mines to fire.
Of the 12 marker buoys which were dropped at the end of the field
only three broke adrift during the following three weeks. Their
endurance was sufficient for the purpose intended and the Commander-
in-Chief was informed on July 27th that vessels would no longer be
required to keep watch on the buoys.
The British minelaying squadron proceeded separately to Area C
where then* mines were laid on the same date that ours were put
down.
As a result of the joint studies of the American and British plan-
ning sections, a somewhat radical but beneficial change in the nature
of the field in Area "A" was adopted shortly after the commencement
of active mine laying. As originally agreed upon the American mine
field in this area was to consist of three systems, each system com-
prising one line of mines at 80 feet, one at 160 feet, and one at 240
feet. This arrangement gave an equal density of mines from the
surface to the bottom of the barrage. Since, however, there was to
be no patrol in Area "A," submarines attempting to cross the field
would undoubtedly do so on the surface where the damage in case
of striking a mine would be the least. Also, submarines being pur-
sued by slow vessels would prefer to proceed on the surface where
their chances of escape were best.
Accordingly it was decided that the third system instead of con-
sisting of one row of mines at each of the three depths, should consist
of three rows of surface mines, i. e., 80 feet submergence.
Immediately following this alteration it was decided to double the
number of rows of mines in Area "A." The original plan had called for
mines to be laid 150 feet apart, but due to the damage caused by the
explosions of neighboring mines and the possibility of countermining,
this distance had been gradually increased until it had become 300
feet — just twice the original figure. It was therefore necessary to
double the number of systems to give the field the same approximate
effectiveness as originally planned.
After the above two changes the barrage in Area "A" was to
consist of:
10 rows of mines at 80 feet submergence.
4 rows of mines at 160 feet submergence.
4 rows of mines at 240 feet submergence.
As the mooring ropes for the mine anchors were cut in different
lengths to correspond with the three depths at which mines were laid,
the above change necessitated supplying a great many more anchors
for 80-foot mines and fewer for the deeper levels. Fortunately the
THE NORTHERN BARRAGE. 107
Bureau of Ordnance was able to meet the new demands without
causing delay in the operations.
Shortly after minelaying had begun in Area "C" the Norwegian
Government issued a decree to the effect that belligerent submarines
equipped for use in warfare must not traverse or stay in Norwegian
territorial waters except by reason of stress of weather or to save
life. Breach of this prohibition would expose them to armed attack
without warning. Norway also reduced the limits of her territorial
waters from four to three miles, since the former figure was not
recognized by the principal belligerent nations. This decree, rigidly
enforced, would have had the same result as if British and American
mines had been laid right up to the Norwegian coast instead of
stopping at their territorial waters, but there was good reason to
believe that the decree was not enforced against German submarines.
After the completion of the first excursion further minelaying by
the United States mine force was temporarily prevented by the non-
receipt of mining material. The first excursion had used up all but
three of the antennae floats for the lower level mines. Tests were
conducted in Loch Ness to ascertain whether the antennae floats
designed for the upper level mines would withstand the deeper
immersion.
There were plenty of these floats on hand and they could have been
used had they been suitable. They would not, however, hold up when
submerged to the necessary depth. The only other possible alter-
native for continuing mine laying was to lay the two lines of surface
mines in Area " C," which we had recently agreed to do, but here again
we were delayed. Although it was expected that the British would
agree to our laying surface mines in this area and the mines had
actually been ordered several weeks before the concession had been
obtained, there had not been sufficient time for these special anchors
to reach the mine bases.
In the meantime the British minelaying squadron had completed
its second and third operations on June 18 and June 30.
The necessary number of anchors for laying two rows of mines in
Area "C" finally arrived and four of the minelayers got underway
June 30, laying their cargoes of mines on the following day.
Again approximately 4 per cent of the mines exploded prematurely.
After the first excursion the probable causes which were thought
might be responsible for the premature explosions were gone into and
at the same time it was believed that they were largely caused by
inaccuracies in assembly and testing, due to the inexperience of the
personnel at the bases. The problem was not, however, allowed to
rest on this conclusion. Tests were undertaken in Loch Ness and
Loch Lochy to determine the accuracy of the depth taking mechan-
ism and the ability of the mine cases to withstand the pressure when
108 THE NORTHERN BARRAGE.
planted at the lower level (240 feet). The depth taking performance
was not particularly satisfactory, but the principal cause was dis-
covered and remedied before the second excursion. Out of the 22
mines submerged to a depth of 300 feet in fresh water, 6 of them were
crushed and leaks were discovered in 7 others. At 240 feet in fresh
water no mines out of 38 planted were crushed, and a leak was dis-
covered in only 1. It is probable, however, that the factor of safety
of the mine case was so small that leaks might be started in adjacent
mines by an explosion. This consideration made it desirable to in-
crease the distance between mines from 250 feet, which was used on"
the first excursion, to 300 feet, which was employed on all following
excursions.
The possible causes of premature explosions were many. Soluble
washers which were designed to dissolve about 20 minutes after the
mine had been planted were found to be very erratic, some of them
dissolving in less than a minute after the mine had been planted.
The antenna release mechanisms were not entirely satisfactory. Some-
times the shock of the mine striking the water was sufficient to release
the floats, allowing the antennae coils to foul the mine and fire it as
soon as the soluble washer had dissolved. Leaks in the mine case
could cause short circuits which would operate the firing mechanism.
In the original design of the mine it had included a circuit breaker
in the antenna circuit, which prevented the mine from firing in case
the antennas fouled the mine ease or the antennae floats carried away.
The production of the circuit breakers had, however, been delayed
and none had been on hand for the first and second excursions.
After carefully going over all the probable causes of premature ex-
plosions it was impossible to attribute them to any specific cause and
it was hoped that by using the utmost care in the assembly, adjust-
ment, and planting of the mines, the percentage of explosions would be
further reduced.
After the completion of the second operation it was again necessary
to await the receipt of mining material before the succeeding operation
could take place. The Bureau of Ordnance had been requested by
cable to ship antenna floats by a fast steamer as soon as a sufficient
number could be obtained from the manufacturers, in order to allow
the mining to continue with as little delay as possible. Thirty-five
hundred of these floats were shipped on the Justida, which arrived
on July 10.
On July 6 information was received that several groups of American
mines had been found on the Norwegian coast in the vicinity of Bergen.
As it was most important to learn the cause of their breaking adrift,
arrangements were made to send Lieut. O. W. Bagby, United States
Navy, to Norway to obtain all the particulars available. His efforts
were fruitless. The Norwegian Government would not permit
THE NORTHERN BARRAGE. 109
him to inspect the mines they had recovered and, after waiting several
days, he returned to Base 18. Later information received stated that
about 30 mines had been washed ashore and there were no signs of any
mooring arrangements. This indicated clearly enough that the moor-
ings had parted at the mine cases. The British had experienced simi-
lar difficulties and had found it necessary to use a spring buffer
between the mooring cable and the mine case to prolong the life of
their mines. Such a device would, at least, not be detrimental and
might materially reduce the percentage of mines which were breaking
away from their moorings so the Admiralty were asked to supply us
with the necessary buffers, which was promptly done.
Some of the mines recovered by the Norwegians were disassembled
and the principle of the firing mechanism obtained. The Germans
probably obtained the secret of our mine shortly afterwards, but as
far as can be learned, they took no defensive measures to protect
their submarines while passing over the barrage.
In order to ascertain if the explosions were still continuing and if
mines which had broken adrift were floating in the vicinity of the
mine field, the Patapsco and Patuxent were sent out on July 9. After
picking up the western end of the first excursion several additional
marker buoys were dropped and the tugs then steamed along the
southern side of the United States fields laid in Areas A and C. No
explosions were heard nor were any floating mines observed.
The fourth British operation was carried out on July 12, again hi
Area C.
Preparations were made for our third operation to commence on
July 14. On July 11 a cable was received from the Commander-in-
Chief, Grand Fleet, that no mining was to be done to the westward of
the Greenwich meridian. The excursion as originally planned was
to extend from the leaving off point to the first operation completely
across Area "A," thus finishing the first system of mines. This change
was not serious so long as it was only temporary, although it was, of
course, desirable to complete one fence of mines all the way across the
North Sea as soon as possible. The question was taken up with the
Admiralty by Admiral Sims and, in view of the fact that it was in-
tended only as a temporary measure, it was acceded to.
The assembly and loading arrangements were altered, and by
working night shifts it was possible for the squadron to adhere
to the original date of readiness, getting underway for the third
excursion on July 14. The following day 5,395 mines were laid
in 4 hours and 22 minutes, the largest number so far laid in a single
operation. By this time the mining installations had proved most
flexible and reliable. Each layer was able to lay its entire quota
of mines hi one continuous string at a speed of 12J to 13 knots.
110 THE NORTHERN BARRAGE.
Approximately 5 per cent of the mines exploded prematurely —
a slight increase over previous performances. This time it was
definitely determined that part of the explosions were caused by
countermining. On previous excursions groups had gone off almost
simultaneously but it was generally thought to be more or less a
freak occurrence of several mines individually exploding at practi-
cally the same time or due possibly to the reverberations of an
explosion which sounded like several mines individually exploding
at practically the same time when it really was but one. Now,
however, it was proved beyond a doubt that one mine frequently
was responsible for the detonation of several others. Curiously ?
mines sometimes as much as half a mile away were countermined,
while the adjacent mines laid only 300 feet away remained intact.
Upon completion of the operation, fog was encountered making it
impossible for the ships to check their position while proceeding
down the Scottish coast to Cromarty Firth. The swept channel
was narrow and close inshore, which added to the difficulty by
denying them the prerogative of keeping well clear of the coast.
Unfortunately Capt. Belknap, commanding the mine squadron, had
issued an order with respect to the danger of sounding, that caused
three of the commanding officers not to sound. At 4.20 a. m. July
16, while just north of Cromarty Firth, one of the escorting de-
stroyers sheered close in to the San Francisco and reported that
they were too close inshore. The squadron turned out, stopped
and backed but before headway had been checked the EoanoJce and
the Canonicus had grounded. The Canonicus was able to back
off but attempts to clear the Eoanoke were unsuccessful. She was
lightened as much as possible and came off easily on the following
high tide. No damage was sustained by either vessel. The Com-
mander Mine Force recommended no further proceedings and the
matter was disposed of by Admiral Sims in a letter, in part as
follows :
The Force Commander is of the opinion that a court of inquiry should have investi-
gated the causes for the grounding of the Roanoke, on July 16, 1918. It is, however,
and has been, impracticable, to order officers of sufficient rank, to compose such a
court; it is noted that damage to the Roanoke and other vessels concerned, was slight,
and that their availability for duty was not impaired.
In view of the foregoing, no further action will be taken by the Force Commander,
and the papers in the case will be forwarded to the Navy Department for such action
as may be deemed expedient.
About this time the question of the length of antennae again
arose. It will be remembered that the original design of the mine
called for antennae 100 feet long. Early in 1918, however, data
became available which showed that the mine charge was insuffi-
cient to do material damage to a submarine at this distance. The
THE NORTHERN BARRAGE. Ill
antennae was then shortened to 70 feet. Later on further experi-
ments showed even this distance to be too great to seriously cripple
a submarine on the surface. It was therefore decided to reduce
the length of the antennae on the upper mine to 55 feet. This
change had no sooner been decided on than actual experience
showed it was desirable to still further reduce this length. The
second week hi July, a German submarine while attempting to
cross the minefield on the surface struck a mine which exploded
but did not do sufficient damage to prevent her reaching port.
She reported her condition by radio, which was intercepted and
deciphered. The Grand Fleet immediately dispatched fast ves-
sels to attack her. She was able, however, to make sufficient
speed to reach her base before this could be accomplished. Upon
the representation of the Commander-in-Chief , Grand Fleet, and the
desires of some of our own representatives, it was decided to fur-
ther reduce the antennas for surface mines to 35 feet, planting the
mines 45 feet below the surface.
The fifth British operation was carried out on July 21 hi Area "C."
Several days delay was encountered before our fourth operation
on account of again " having to wait for mining material. The
squadron was reported ready to sail July 25 but it was necessary
to wait four days more for the escorting and supporting forces from
the Grand Fleet. The British and American operations had recently
been overlapping each other in such a manner that one squadron
was out at sea while the other was loading in port. As this necessi-
tated keeping a large part of the Grand Fleet at sea almost con-
stantly, the Commander-hi-Chief desired that we should wait until
the British squadron had again Ipaded, so that it would only be
necessary to send one force to support both squadrons.
The antennae for the surface mines were not shortened on this
excursion since the mines had already been assembled and loaded
on board the layers. The squadron sailed on July 29, laying 5,399
mines the following day. The premature explosions were much
more numerous than on any of the previous excursions, approxi-
mately 14 per cent of the mines going off. This was most discon-
certing. Instead of the explosions decreasing as experience was
gained in the assembly and laying of the mines, the percentage had
been gradually increasing and then had suddenly jumped to 14
per cent on this excursion. Losses of 3 to 4 per cent could possibly
be tolerated, but this latter figure was absolutely prohibitive, and
the causes of the explosions had to be definitely determined and
eliminated.
The same date the minelayers left their bases, Admiral Strauss,
accompanied by Lieut. Noel Davis, left Base 18 to represent the
112 THE NORTHERN BARRAGE.
United States at an allied naval conference to be held at Malta to
consider minelaying operations in the Mediterranean.
Due to the large number of premature explosions which occurred
in the fourth operation, the Force Commander ordered the suspension
of further minelaying operations until the cause of the explosions had
been ascertained and corrected. All conceivable reasons which might
be responsible were again gone over and further tests were conducted.
Of these, two seemed to offer the only possibilities of solution. Cir-
cuit breakers had been used in the antennae circuits for the first
time. This device consisted of a mercury cup which broke the cir-
cuit in case the antennae was not released from the mine, or if the
floats were carried away allowing the antennae to drop down upon
the case. In what adverse manner the circuit breaker might affect
the firing device could not be imagined, still there was a possibility
that it was at least partially to blame. The other cause was believed
to be due to difficulties in installing the horn bushings in the mine
case. .Unless this was most carefully done there was danger of ground-
ing the circuit of the firing device on the mine case which would
cause the mine to fire as soon as the soluble washer had dissolved.
Believing that the difficulties could be most quickly solved by
actual planting, arrangements were made for the next excursion to
begin on August 8. Mines were assembled with the electric circuits
to the horns disconnected, but in all other respects the same as before.
This was again a joint excursion by the British and American
squadrons, the British laying surface mines in Area " C " to the south-
ward of those laid by us on July 1 . This was a departure from the
original scheme by which the British were only to lay deep mines in
this area, but it was in line with the recent change in policy that the
surfaces should be more densely mined than the lower depths. Be-
sides this, all our mines which had been laid in Area "C" had 70-foot
antennae, which were unquestionably too long to insure the destruc-
tion of submarines on the surface.
The efforts to cure the premature explosions on this excursion were
found even less successful than before. After laying 1,596 mines the
operation was discontinued and the squadron returned to the bases.
Approximately 19 per cent of the mines had exploded.
Evidently the horn circuit could not be at fault and it must be
something else. Numerous experiments were again carried out in
hopes of discovering the secret of the explosions and another possible
cause was developed. Jt was found that the rubber insulation be-
tween the copper plates on the firing device caused sulphates and
sulphides to be formed with the copper which, when immersed in
salt water, set up a slight current in the firing circuit in the direction
necessary to operate it. Although the current was in most cases
112-1
112-2
112-3
PHOTOSTATIC CHART OF NORTH SEA BARRAGE.
1. Showing positions of lines and depths of all American and British mines.
2. Vertical projection showing relative density of mines.
(Page 122.)
VERTICAL PROJECTION SHOWING GROWTH OF
NORTH SEA
Uune 5, I9i« - Norfh 5eo Barrage offe
American O{>era f<oris.
Uuly 15. 1918 - ThrceAmerkJun a ndt four Br»f«5h EACursions Cttmj»J«fed. Min
to Westward of Greenwich Heridf'wn.
vear American and fcic|ht British Excursions Comptet'pd.
5eptem t>€r:
P»oci'c<il|y
-- Ffr»f M««es l.<i »dl "m Ar«a *B* thus
Nortlf d««L.
Ocfofeer *fe, I9>8 - Last |Vjifi«-& l.<iid *w Barr«^e b«for« ATm»5t«cc
Total American £»cursi«)vi* ; Thirteen . TotUl BriTis4i; Twetvr.
PHOTOSTATIC CHART, VERTICAL PROJECTION, SHOWING THE GROWTH OF
THE NORTH SEA BARRAGE. (Page 124.)
112-4
THE NORTHERN BARRAGE. 113
small, there was a possibility that if it were eliminated the mines
would then have sufficient stability so as not to explode after they
had been planted.
In order to carry out the practical part of the experiments after
the theoretical tests had been completed at the bases, the San Frarir
cisco proceeded to the mine field on August 12. The copper plates of
the K-l devices were carefully cleaned and circuit breakers were
fitted on half of the 166 mines which were to be planted. Seven of
this number exploded prematurely, four of which were due to the
antennae fouling the mine cases. In order to obtain definite data
in regard to countermining three mines were set to fire as soon as
the soluble washers dissolved. Each of these caused one additional
mine to explode. A depth charge was also dropped in the vicinity
of the field, which caused six mines to go off.
The improvement obtained in this test was sufficient to enable
minelaying to be resumed after cleaning the copper plates on all
mines. It was further decided to omit the circuit breakers, as they,
were additional complications of unknown value. The copper horns
of the mines were also shortened to. mere points to reduce the possi-
bility of the antennae becoming hooked around them.
The squadron sailed on the sixth excursion on August 18, and the
mmelaying was completed on the 19th. The British squadron pro-
ceeded at the same time to complete their lines of surface mines in
Area " C." Twelve per cent of our mines exploded prematurely. The
majority of these were due to countermining. The real cause of the
premature firing evidently had not yet been discovered, but the im-
provement obtained was sufficiently encouraging to permit another
attempt to be made.
On August 5 the Commander-in-Chief Grand Fleet lifted restric-
tions he had placed on mining to the westward of the Greenwich
meridian. The next excursion was correspondingly planned to com-
plete the first fence of mines across Area "A."
Admiral Strauss returned from the Malta conference on August
22. After the sixth excursion another probable cause of the pre-
mature firing was discovered, which proved to be the final solution of
the difficulties. The first lots of firing devices shipped to the bases
were adjusted to fire at a voltage between 25 and 40 millivolts. The
Bureau of Ordnance decided, from experiments conducted in the
United States, that this voltage was unnecessarily high and reduced
it so that the mines would fire between 10 and 25 millivolts. It was
not known when this later type of firing device first began to be in-
stalled. The original type was undoubtedly used on the first three
excursions, when a comparatively low percentage of the mines ex-
ploded. After that, it was probable that the majority of the mines
181063°— 20 8
114 THE NORTHERN BARRAGE.
were assembled with the firing devices which had been adjusted to
fire at the lower voltage.
It was therefore decided that on the seventh excursion the first
600 mines planted should be adjusted to fire between 20 and 35 milli-
volts ; then, if the observations on this part of the field indicated suf-
ficient improvement, this adjustment should be used on subsequent
excursions.
The squadron got under way August 26 and stood out toward
the mine field. The Saranac broke down shortly after leaving the
base and had to return to Inverness with her full cargo of mines.
The remaining nine ships, however, continued and carried out the
operation. Unfortunately dense fog was encountered practically
throughout the operation; so thick at times that it was impossible for
the vessels to see the next ship abeam, distant only 500 yards. These
conditions made observations extremely difficult for the Patapsco and
Patuxent, which were sent out with the squadron to follow astern while
^planting was in progress and count the explosions to determine the
percentage which occurred. From the data obtained from the mine-
layers and the tugs it appeared that only about 3 per cent of the first
mines exploded prematurely. In the remainder of the field, which
had the low-voltage regulation, approximately 12 per cent went off.
The adjustment of the firing device was undoubtedly the solution
we had sought for, but in order to test it further and to complete the
deficiency in this field caused by the breakdown of the Saranac, the
SJiawmutj and Aroostook were loaded with mines adjusted to fire
between 20 and 35 millivolts and sent out on August 30. Of the
600 mines they planted only 3 per cent exploded. This was the first
opportunity we had had to use these two vessels for their originally
intended purpose; that is, as a fast wing to the mining squadron.
Both ships proceeded to the field and planted their full quotas at a
speed of 17 knots with no difficulty. They could plant as easily at
their maximum speed as they could at 12 knots.
This final solution of the premature explosions was a great relief.
It explained, in addition, the probable reason for countermining.
The tests conducted to ascertain the effect of the copper sulphate
deposits on the plates of the firing device showed that as much as
10 millivolts could be generated. This was sufficient to rotate the
armature of the firing device through a considerable portion of its
arc so that a slight additional shock, which might readily be caused
by the explosion of a nearby mine, would be sufficient to shake the
firing ball from its cup and detonate the mine. By increasing the
tension of the hair spring on the armature, the voltage necessary to
fire a mine could be raised to the desired amount.
In the latter part of August information was received that another
enemy submarine was damaged while attempting to cross the barrage
THE NORTHERN BARRAGE. 115
and had been compelled to return to its base on the surface. These
repeated instances of submarines deprived of their principal means
of defense, pointed more strongly than ever to the necessity of having
patrol vessels stationed at intervals along the barrage to attack sub-
marines which had encountered mines but had not been completely
destroyed.
The question of mining Area " B " again came up, and a decision was
finally reached to mine it with both surface mines and deep mines.
The commander in chief, Grand Fleet, however, objected to mining
completely up to the Orkney Islands, and it was decided that a gate
10 miles in width would be left which should be closed later when
conditions indicated this step to be necessary.
The mines which had been laid in this area by the British in March,
1918, had hi the meantime been swept up. The British had also
placed a series of mine nets to the southward of Area "B," extending
part of the way between the western end of Area " A " and Duncansby
Head. These had not proved successful and were also removed before
the mining in Area "B" was resumed.
The eighth excursion was intended as a surprise excursion. Neu-
tral nations had not been notified that Area "B" was dangerous to
shipping, and with this knowledge, enemy submarines were constantly
passing through it on their way to the Atlantic. It was accordingly
decided not to notify the area but to secretly route all shipping so as
to avoid it, with the hope that submarines might still attempt to use
it after it had been mined. In order to prevent the enemy observing
the mining while it was hi progress, an elaborate patrol was arranged,
beginning the day before the operation and continuing until after its
completion.
British and American mining squadrons rendezvoused off the
Orkney Islands on September 7 and proceeded to carry out the
operation. We laid six lines of surface mines across Area "B " while
the British laid one line of surface mines parallel to ours. This was
really the first joint operation carried out by the British and American
squadrons. On several previous occasions both squadrons had been
at sea at the same time, but had not been working side by side, so
as to necessitate appointing one officer to command the expedition.
On this occasion Admiral "Strauss was designated to take general
charge of both squadrons while mining was in progress.
In spite of the high voltage adjustment of the firing devices, 13 per
cent of the mines exploded. About five-sixths of this number were
due to countermining, indicating that the mines were still too sensitive
and that the voltage must be still further increased. Tests that had
been made indicated that contact of the antennae with the hull of
the ship invariably gave voltages about 100 millivolts and it was
therefore considered entirely safe to further increase the adjustment
116 THE NORTHERN BARRAGE.
of the firing device to operate between 30 and 45 millivolts. This
was done for all subsequent excursions.
An interesting sidelight on the activities of the mine force were the
tests and experiments which were almost constantly in progress.
Besides the difficulties encountered in solving the problem of pre-
mature explosions, numerous other questions arose in connection with
the new American mine. The facilities at hand were ideal for mining
experiments. The chain of lakes forming the principal part of the
Caledonian Canal, which terminated at Base 18, offered smooth water
with depths varying up to 800 feet, which corresponded to the
maximum depth encountered in the North Sea barrage. The only
drawback was that the water was fresh instead of salt. During
July the British had conducted a series of experiments to ascertain
the accuracy with which their mines took their prescribed depth.
The results were not entirely satisfactory, and since our mine anchor
had been largely copied from the one they were using, it was also
probable that ours were not behaving as designed. Tests were carried
out in Loch Lochy during the first week in September when 50 mines
were planted with anchors adjusted to moor the mine 45 feet below
the surface. The average depth actually taken was 44.6 feet. The
shallowest mine was 39.2 feet, and the deepest one at 48.7 feet.
The results were entirely satisfactory and were all that could be
expected.
All the mines which had thus far been laid in Area " B " were surface
mines, and since this was still the weakest part of the barrage it was
decided that the following excursion should also be placed in this
area, laying two rows of mines at each of the three standard depths.
A delay of nine days was occasioned waiting on the British mining
squadron, since it was desired that both the British and American
squadrons should lay their mines on the same date in order to reduce
the possibility of the enemy observing mining operations in this area.
Delays of this nature were most serious. It was realized that mine-
laying operations would be interfered with if not altogether stopped
during the winter months on account of the severity and frequency
of the storms in the North Sea. It was also extremely desirable to
complete the barrage at the earliest possible date in order that oper-
ations in the Mediterranean might be undertaken.
The work of assembling mines at the bases, refueling the ships, and
embarking new loads of mines had reached such a stage of efficiency
that it was possible to reduce the length of time that it was necessary
for the ships to remain in port to two days. The vessels were ordi-
narily away from the bases two or three days, thus making it possible
to complete an operation every four or five days. At the same time
mines were being shipped at a faster rate from the United States
in anticipation of the speed with which they could be laid. Delays,
THE NORTHERN BARRAGE. 117
therefore, caused most serious complications at the bases on account
of the difficulty of stowing the material in the limited spaces provided.
Another phase which should not be overlooked was the effect on the
morale of the personnel aboard the minelayers. It was always neces-
sary to load the layers as soon as possible after their return to port since
delays could seldom be foreseen. This resulted in the vessels remain-
ing in harbor with cargoes of mines on board for a considerable period
of time. This caused serious inconvenience to the personnel since
practically all of the living space on board was occupied by mines,
making it necessary for the men to sleep on deck between the tracks
or wherever it was possible to find sufficient space to spread a ham-
mock. Messing arrangements, as well as nearly all of the other
accommodations existing on board ship, were badly interfered with.
These delays became more frequent and of longer duration as the
completion of the barrage drew near. Sometimes it was due to
having to wait while the British squadron was being loaded, but
more frequently was attributed to movements of the Grand Fleet,
making it impossible to supply the necessary destroyers to act as
our escort. Had it been possible to obtain sufficient of our own
destroyers for this purpose it would have enabled the barrage to have
been completed by approximately the 1st of October.
In the early morning of September 20, while the United States min-
ing squadron was on its way to the mine field to carry out the ninth
excursion a submarine was sighted off Stronsay Firth. She was
immediately attacked with depth charges by the escorting destroyers,
and at the same time a smoke screen was put out by both the escort
and the minelayers. Shortly afterwards she was again sighted just
ahead of the San Francisco and was again attacked. The behavior
of the submarine was most unusual. Although both times she was
sighted she was in good position and at a comparatively close range,
no attempt was made to fire a torpedo. It is highly probable that
she had been sent to this position to the southwestward of the lines
of mines which had shortly before been laid in Area B, in order that
she might make observations of the positions in which mines were
being laid in this area.
The squadron proceeded through Westray Firth and thence to
a position about 6 miles to the northward of the western end of the
field which was laid on the 7th of September, where the mining began.
In this excursion, 5,520 mines were laid in 3 hours and 50 minutes —
the record number that has ever been laid by a minelaying force in
a single operation. At the same time the British squadron laid
1,300 mines in a single line parallel and to the northward of those
laid by us. Rear Admiral Strauss, on board the San Francisco, was
in command of the American minelayers. Rear Admiral Clinton-
Baker, R. N., commanded the combined forces.
118 THE NORTHERN BARRAGE.
During the minelaying, when about midway between the ends of
the previous field which had been laid in Area "B," one of the escort-
ing destroyers sighted the body of a dead sailor floating in the water.
He was recognized to be a German by the type of the life preserver
he wore. Since no engagements with the enemy had occurred within
miles of this position, it is extremely probable that an enemy sub-
marine had been destroyed by one of the mines which had been laid
on September 7.
The reduction of premature explosions on this excursion was a
marked improvement, being between 5 and 6 per cent, as compared
with 13 per cent on the previous operation. The firing devices had
been adjusted to operate between 30 and 45 millivolts, and this
regulation could not readily be increased on account of the construc-
tion of the mechanism. It was perhaps as well that it should not be
further raised as the mine might be possibly made too insensitive to
operate when a poor contact was made by the antennae.
After completing the ninth excursion, work was resumed in Area "A."
On September 27, 5,450 mines were laid, slightly over 4 per cent of
which exploded prematurely. Only nine of the mine layers took part
in this operation.
On account of the great depths of water in which it would be neces-
sary to lay mines in the Mediterranean, it was necessary to develop
a special type pf mine. A satisfactory design had been evolved by
the Bureau of Ordnance, but it was essential to conduct a series of
practical tests before beginning the manufacture. No vessel was
available in the United States for this purpose, so the Baltimore was
ordered home to carry out the required experiments. She proceeded
as far as Pentland Firth in company with the squadron on their way
to the mine field for the tenth excursion, where she was detached to
Scapa Flow to obtain routing instructions across the Atlantic from the
Commander-in-Chief Grand Fleet.
The eleventh operation was carried out on October 4, again in
Area A, and approximately 6 per cent of the mines exploded pre-
maturely. Losses up to this amount had, however, come to be
accepted as normal for this type of mine. The Bureau of Ordnance
also considered this figure a reasonable loss on account of the various
defects which are invariably encountered in the production of material
in such vast quantities.
Since the operation in the Mediterranean would probably have
kept the mine force engaged until well into the summer of 1919, it was
considered advisable to have the minelayers docked prior to their
departure for those waters, where such facilities would be extremely
limited. After the completion of the eleventh excursion the Shaw-
mut and Arooslook were detached from the squadron and proceeded to
Newcastle-on-Tyne for this purpose. It was intended to send two
THE NORTHERN BARRAGE. 119
vessels there after each operation, having them return in tune to
take part in the second following excursion. Permission was ob-
tained for the ships' crews to do the work in connection with
scraping and painting the ships' bottoms — an arrangement which
had been found to very materially shorten the tune required for
docking.
With the mining of Area "B," the problem of enemy submarines
gaining access to the Atlantic became serious. Several submarines
had encountered mines in the barrage, but had managed to reach
their bases bearing material evidence of the existence of the barrier.
It was only natlural, therefore, that the enemy should look about
for whatever means remained of reaching the Atlantic without
risking passage across the mine fields. Small submarines occasionally
successfully ran the blockade at the Dover Channel, but this was
apparently not attempted by the larger boats. Pentland Firth and
the 1 0-mile gate to the eastward of the Orkneys were heavily patrolled.
Submarines evidently would not risk passage through Pentland Firth
while submerged on account of the dangerous currents. The only
remaining passage was through Norwegian territorial waters.
Although Norway had issued a proclamation that belligerent sub-
marines using her waters for this purpose would be fired upon, this
risk seemed less than any of the others and there was no apparent
hesitancy in using it. One enemy submarine, while passing through
these waters even went so far as to fire on a Norwegian vessel.
These repeated violations resulted in a statement on September 29
by the Norwegian Government that mines would be laid in the
vicinity of Udsire Island in order to prevent belligerent vessels using
her territorial waters for purposes contrary to the provisions of inter-
national law. This mining is understood to have been completed by
them about the 7th of October and had the effect of completing the
barrage from the end of Area "C" to the Norwegian coast.
On October 11 the British squadron laid two partial rows of surface
mines in the southwestern portion of Area " B." These proved to be
the last mines laid by them in the North Sea barrage prior to the
armistice a month later.
The U. S. mining squadron completed the twelfth excursion on
the 13th of October, losing 4 per cent by premature explosions.
The Roanoke and Canandaigua proceeded to Newcastle for docking
upon the completion of the operation.
Eight days' delay were encountered before the thirteenth and last
operation could begin. On account of the sequence of the British and
American operations in Areas " A" and "C," it had been impractical
to extend the mine fields so as to overlap each other. This left a
gap between the two areas approximately 6 miles wide. In order to
close this the next excursion was planned to consist of six rows of
120 THE (NORTHERN BARRAGE.
surface mines to the southward of the gap, continuing with two
rows into Area "C," so as to complete the four rows which the United
States had agreed to lay in this Area.
The first of the winter weather was encountered in this operation,
when it was necessary for the squadron to wait one day after having
reached the mine field before the sea moderated sufficiently to enable
the mines to be laid. Even then the ships were rolling as much as
20° to 30° on each side of the vertical. This provided an excellent
test of the mining installations with the result that no difficulties
were encountered by any of the ships, either in the stowing of their
mines or in the actual planting under such severe conditions. The
operation was completed October 26, having laid 3,760 mines, of
which slightly over 4 per cent were lost by premature explosions.
Although the U. S. mining squadron was again ready for the next
excursion by October 30, it was necessary to wait until the British
squadron had completed the operation which they had planned
before escort could be furnished us. Reliable information indicated
that enemy submarines were crossing the eastern portion of Area A,
and the British had decided to lay surface mines in this position to
the southward of those laid on our first excursion so as to strengthen
this part of the field which was the least effectively mined part of
the area. Weather conditions, however, prevented them from going
out for several days, and, in the meantime, the series of events
during the latter part of October and the 1st of November brought
the end of the war so plainly in view that further mining would have
been an unnecessary waste of time, effort, and material. The British
squadron did not carry out their contemplated operation, nor like-
wise did we. With the signing of the armistice on November 11
with Germany — the perpetrator of ruthless submarine warfare
against both allied and neutral commerce — came the end of building
the North Sea mine barrage.
CHAPTER XVII.
FINAL STATUS OF BARRAGE AND RESULTS OBTAINED.
On November 11, 1918, when hostilities ceased upon the signing
of the armistice, the status of the northern barrage, as set forth in an
allied naval council annual report, dated December 16, 1918, was as
follows:
1. The northern barrage extends from Norwegian territorial waters
to within 10 miles of the Orkney Islands, and lies in the area con-
tained by the following positions:
60° (X N., 4°54J'E.
60° 21' N., 3°1<X E.
59°2<X N., 005<X W.
W°2<y N., 2° S7 W.
5S°50' N., 2°27' W.
58°5<X N., 0°5<X W.
59°29/ N., 3°1(K E.
59° 12^ N., 4° 49/ E.
2. The barrage has been divided into three areas, "A," "B," and
"C." Area "C" extends from Norwegian territorial waters to the
meridian of 3° 10' E. Area "A" extends from this meridian to
0°-50' W. and Area "B" from the western extremity of Area "A"
to within 10 miles of the Orkneys.
3. Mine laying operations were commenced in March, 1918, by
Great Britain, and in June, 1918, by the United States of America,
British and American mines being used, and up to November 11 a
total of 56,760 United States and 16,300 British mines have been
laid.
4. The original intention was that the United States minelayers
should lay the mines in Area "A" and the British minelayers in
Areas "B" and "C," and this arrangement has in the main been
adhered to, but a certain number of United States mines have also
been laid in Areas "B" and "C." This was done in order the more
effectively to deal with the submarine situation at the moment, and
to make the best use of the greater minelaying capacity of the United
States minelayers.
5. The completion of the barrage within the Norwegian territorial
waters has been effected by Norway herself.
In July, 1918, conclusive evidence was obtained that German
submarines were habitually using Norwegian territorial waters.
121
122 THE NORTHERN BARRAGE.
Representations were made by the British Government to the Nor-
wegian Government that the only effectual way of securing the
observance by Germany of the Norwegian royal decree was for
Norway either to mine these waters herself or to allow the allied
and United States Governments. After protracted negotiations,
during which evidence as to the identity of submarines reported on
various dates to have been seen in Norwegian territorial waters was
furnished to the Norwegian Government, a note was received from
the Norwegian Government by the allied and associated Govern-
ments on the 28th September protesting against the violation of
Norwegian regulations by a British submarine (in a case which had
been previously admitted by Great Britain) and stating that hi view
of the numerous cases of infringement of her territorial waters by
submarines which had been established with certainty, it had been
decided to lay mines in certain localities.
6. On September 29, 1918, an official announcement appeared in
the leading Norwegian Government organ to the effect that mines
would be laid in Norwegian waters between latitudes 59° 8' N. and
59° 25' N., and to the westward of longitude 5° 10' E., and that
these waters would be closed for general traffic from October 7, 1918.
7. The depth of water in this area is from 50 to 80 fathoms. The
approved mine fields in this area will, when completed, consist gen-
erally of—
Nine lines of United States mines dangerous to surface craft and
to submarines at periscope depth.
Three lines of United States mines at a depth of 160 feet, the mines
having a dangerous area (above the mines) of 70 feet.
Three lines of United States mines, at a depth of 240 feet, with a
similar dangerous area.
Three more operations were required to complete the approved
minelaying in this area. Any reinforcement of the mine fields in
Area A would depend on the submarine situation at the time.
AREA "B."
8. The depth of water is from 40 to 75 fathoms. At the present
time the following lines of mines have been laid across the area:
One line of British mines dangerous to surface craft;
One line of British mines, at 95 feet deep;
Eight lines of United States mines, dangerous to surface craft and
to submarines at periscope depth.
Two lines of United States mines, at 160 feet deep, having a dan-
gerous area (above the mines) of 70 feet.
THE NORTHERN BARRAGE. 128
Two lines of United States mines, at a depth of 240 feet, with a
similar dangerous area.
Two further lines of British mines have been commenced across the
area. The submarine situation will determine any future action in
this area.
9. The depth of water is from 65 to 160 fathoms. At the present
time the following lines of mines have been laid across Area "C" :
Two lines of British mines, dangerous to surface craft.
Two lines of British mines, at 65 feet deep.
Two lines of British mines, at 95 feet deep.
Two lines of British mines, at 125 feet deep.
Four lines of United States mines, dangerous to surface craft and
to submarines at periscope depth.
Six lines of United States mines, dangerous to surface craft and to
submarines at periscope depth have been laid across the junction
line between Areas " A" and "C."
Any further mining in Area "C" will depend upon the submarine
situation at the time.
GATES.
10. There are no gates in the barrage, the only free passage through
being the 10-mile gap at its western extremity, which, however, is not
used more than is absolutely necessary.
PATROL.
11. The barrage is not patrolled.
Rear Admiral Strauss has summed up the final status of the oper-
ation and the results obtained from it is as follows :
Had it been possible to carry out minelaying operations as fast
as the necessary mining material was received and assembled, the
American portion of the North Sea barrage could have been com-
pleted by the latter part of September, 1918. The frequent delays,
especially during the latter part of the work, which were principally
due to the necessity of awaiting for escort to be supplied by the
Grand Fleet, or for the British mine squadron to complete its prepa-
rations so as to be able to go out at the same time, prevented the
barrage from being completed prior to the signing of the armistice
with Germany on November 11.
In all, 70,263 mines were laid, 56,611 being American mines, laid by
the United States Mining Squadron. Area " A," which was originally
allotted as the United States portion of the barrage, was completed
except for 6,400 mines more, which could have been laid in approxi-
mately 10 days. Besides mining Area "A" exclusively, the United
124 THE NORTHERN BARRAGE.
States mining squadron had laid 10,440 mines in Area "B," and 5,980
mines in Area "C." Thus it will be seen that in addition to mining
the part of the barrage originally assigned to the United States
Government, we had in addition laid more mines in the British Areas
"B" and "C" than they themselves had put down. One more small
excursion in Area "B" by the United States mine force would have
given it the same density of American mines as Area "A." Area " C "
was the weakest portion of the barrage. The British had originally
agreed to mine this area only to a depth of 200 feet, but were only
able to complete the work to a depth of 125 feet. This figure was
just one-half the effective depth of the remainder of the barrage.
Until the animosity incident to warfare has disappeared and the
freedom of dicussion of war-time secrets can be attained, it will be
impossible to accurately determine the actual results achieved by the
North Sea barrage. Such information as has been possible to collect
bears witness to its efficacy notwithstanding the short time the bar-
rage was in operation.
After the first two American excursions had been completed, two
enemy submarines were damaged in attempting to cross Area "C."
The first, the U-86, was damaged on July 9 while passing homeward,
reaching port successfully and bearing tangible proof that the North
Sea barrage was a reality and not a threat. The other, the UB-22, was
to have passed, but nothing has been heard from her since. The enemy
of course immediately routed his submarines through Area "B,"
which had not been proclaimed, or through Norwegian territorial
waters. On August 10, U-113 was damaged in the barrage on an out-
ward bound trip and was forced to turn back. The surprise mining in
Area "B" on September 7 obtained immediate results. It will be
remembered that when it was decided to place mines in this area no
notification was given to neutral nations that it would be dangerous
to navigation. Instead, a heavy patrol was placed around the area
to guard it and keep down enemy submarines while mines were being
laid. Just prior to the mining operations a large convoy was routed
across this area in order to deceive enemy submarines which might
possibly have seen the convoy, and thus lead the enemy to believe
that this area was to be maintained free of mines. On September 8,
the day following that on which the mines were laid, the TJ-92 was
sunk in this area, while another submarine was so severely damaged
that it was forced to return to its base immediately. This occurred
while the submarine was outward bound. Rather.than risk a passage
again through the same waters, she proceeded to Area "A," recross-
ing the barrage in that position without further damage.
After this it appeared that passages were attempted directly across
Area "A," which, due to the United States participating in the mining
of Areas " C " and " B," was comparatively poorly mined. The tenth,
THE NORTHERN BARRAGE. 125
eleventh, and twelfth excursions, however, during the latter part of
September and the first part of October added a great deal to the
effectiveness of Area "A," so that the loss of U-156 on September 25,
and TJ-123 on October 18 can most certainly be attributed to this
area.
With the information at present available, it appears that a total
of six submarines were destroyed in the barrage and possibly an
equal number were severely damaged. On account of the difficulty
of obtaining accurate information, such a short time after the armis-
tice was signed, it is highly probable that subsequent data will show
even greater damage to have been done.
It is well to remember that a mine barrage of this nature can never
be an absolute barrier possessing 100 per cent efficiency. On account
of the necessity of laying the mines at a distance of approximately
300 feet apart in order to reduce the possibility of countermining, it
would always be possible for a submarine with a beam of approxi-
mately 30 feet to successfully cross such a barrier no matter how many
parallel lines of mines may be laid. The danger in crossing, of course,
increases with the number of rows of mines but not in direct propor-
tion. The object, then, in constructing a barrage must be to make
the danger incurred by the passage of a vessel sufficiently great to
prevent submarines from taking the risk involved. The American
portion of the barrage was designed to offer the following resistances
to the passage of submarines:
A vessel passing on the surface or submerged above a depth of 50
feet stood one chance in three of making a successful passage; subma-
rines passing submerged between depths of 50 feet and 250 feet had
approximately two chances out of three of passing the barrage with-
out encountering a mine.
The object of making the passage across the surface barrage more
dangerous than at the lower levels was largely psychological, for,
even though a submarine which was forced to cross the barrage might
know that the danger on the surface was the greatest, the moral
factors involved were usually sufficient to induce them to accept the
greater hazard on the surface rather than face the- danger of striking
a mine while submerged.
In connection with the enemy's attitude toward anti-submarine
measures taken by the Allies, it is interesting to note the statement
of a captured German submarine commander who had had consid-
erable experience on that particular type of vessel. He expressed
the opinion that of all the anti-submarine measures which had been
taken, mines were by far the most dreaded by the German submarine
personnel, principally because there was nothing to indicate their
presence. Also, because the quality of allied mines had recently been
improved in a most unpleasant manner, the former practice of fish-
126 THE NORTHERN BARRAGE.
ing them up and taking them home for conversion into punch bowls
for submarine messes had now been entirely abandoned, he said.
One feature of the barrage which offered several possibilities but
was never more than partially put into operation was the question of
patrols to guard the mine field to force submarines into the deep
mines and destroy those which had not been completely disabled.
This measure had been argued for from the very beginning although
no definite agreements were ever reached. The first arrangement
was that Areas " B " and " C" should be deep mined only and that the
surface should be guarded with patrols. Area "B" was not mined,
however, until comparatively late in the work on the barrage and
during this time was only indifferently patrolled, thus affording a
comparatively safe passage for enemy submarines through this area.
The United States Government had been asked to lay two rows of sur-
face mines in Area "C" early in the history of active operations and this
had been done on July 1. Two lines of mines, however, form a very
ineffective barrier and patrols in this area would have been of the
greatest assistance, not only in driving submarines into the lower
level mines, which were more closely spaced, but also in preventing
submarines from using Norwegian territorial waters to get by the
barrage. This latter measure could have been effected by hydro-
phone vessels lying outside the Norwegian territorial waters where
enemy submarines could easily have been detected when attempting
such a passage. The question of patrols, especially for catching
crippled submarines after it became known that many of them were
not disabled when exploding a mine at a distance of 70 feet, arose
continuously but on account of the tremendous demands for such
vessels both for antisubmarine work in other waters and for escorting
coastwise convoys, it was impossible to obtain any vessels for this
purpose.
Although the enemy undoubtedly obtained the secret of the
American mine shortly afteY the first mines were washed ashore and
recovered in Norway in the early part of July, it is interesting to note
that apparently no attempt was made to fit their submarines with
protective devices which would have enabled them to pass safely
through the American mine fields. Such a device, although it was
unknown until after the armistice, was readily devised when the
necessity arose for protecting vessels which would be employed in
clearing the North Sea of mines after the end of the war.
Information had also been received indicating that the Germans
had built special vessels called mine barrier breakers of a practically
unsinkable character so that they could be used to clear passages
through mine fields. Evidently none of these vessels attempted
operations in the North Sea barrage.
THE NORTHERN BARRAGE. 127
The mine as a weapon of nautical warfare now presents greater
possibilities than ever before. The United States in less than one
year was able to construct a squadron of minelayers and produce
sufficient mines to keep them constantly employed, laying on each
excursion in less than four hours more mines than the United States
had ever possessed prior to her entry into this great war. Too much
credit can not be given to those who designed the mine. Clever,
simple, and effective, this mine proved, perhaps, the most efficient
single weapon against the enemy's submarines. Equally as remark-
able as the invention of the mine itself was the development and pro-
duction by the Bureau of Ordnance. Any complicated instrument
of this nature, ordinarily, requires years of experiments and modifi-
cations before it finally becomes sufficiently satisfactory and reliable
to allow it to be used. Tune, however, was the supreme factor.
Every minute counted in order to save the merchant shipping and
the wise forethought and judgment of those to whom the production
of the mine was entrusted should go down in history as one of the
most worthy achievements of the war. Minor defects and difficul-
ties, of course, were encountered in the actual operation and handling
of the mines, but these were also met and solved on the spot by the
United States mine force.
Minelaying, like the havoc wrought upon the battle fields by the
destruction of property, leaves its effects to be felt after peace is
obtained. Thousands upon thousands of mines have been laid in
European waters, a major portion of the work being concentrated in
the North Sea barrage. With the cessation of hostilities and the
resumption of free shipping these mines constitute an ever present
danger to the vessels on the seas. Many of them break adrift and,
carried by the wind and tide, often appear in waters which were
thought to be clear of mines. One of the first steps after the armis-
tice was to divide the work of clearing the seas among the various
nations involved. At an allied naval conference, the United States
volunteered to remove all mines which she had laid and arrange-
ments were immediately taken in hand to carry out this work. A
method of sweeping this peculiar mine, together with the develop-
ment and the organization of the force required, had been completed
and actual sweeping operations were commenced four months after
the armistice was signed.
CHAPTER XVIII.
CONTEMPLATED MINING OPERATIONS IN THE
MEDITERRANEAN.
The activities of enemy submarines in the Mediterranean had been
increasing at an alarming rate until in the early part of 1918 it was
realized that an energetic antisubmarine campaign must be made in
order to cut down the loss of tonnage in this area. The allied military
operations in Saloniki, Mesopotamia, and Egypt were supplied almost
entirely by vessels whose routes lay through the Mediterranean. In
addition to this, considerable shipping was carried on between Tunis,
Italy, and France. During the summer of 1918 there was an average
of 190 merchant vessels and transports, aggregating a total of 720,000
tons, at sea each day. Most of this shipping was forced at some
place or other in the Mediterranean to pass through comparatively
restricted channels, offering ideal conditions for submarine attacks.
Submarine operations were also greatly enhanced by the lack of
escort — approximately 22 per cent was inadequately escorted.
The enemy had gradually increased the number of submarines in
the Mediterranean by sending them from Germany around through
the Straits of Gibraltar to be based on Mediterranean ports, and also
by shipping the disassembled parts over land to be assembled there.
In June, 1918, there were approximately 68 Austrian and German
submarines based in the Adriatic, practically all of these operating
from Cattaro; and 21 submarines, including 14 ex-Russian boats
operating from the Dardanelles. Cattaro was an ideal base for sub-
marine operations, being strongly fortified and practically impreg-
nable in so far as attack by naval forces was concerned. Supplies to
this place were sent either over land on a narrow-gauge railroad from
Pola or else sent by water. The enemy surface craft were decidedly
in the minority and it would have been entirely feasible to prevent
supplies from reaching Cattaro by sea. To cut the rail communica-
tions would have required a military operation of considerable magni-
tude, in view of the strength of the enemy forces in this section. Even
then the result would have been doubtful, for assuming that we could
have forced the enemy to evacuate Cattaro by cutting off his supplies,
they had already prepared eight other bases in the Adriatic from
which their submarines could operate. The problem of destroying
the bases in the Dardanelles was also impracticable. The Gallipoli
128
128-1
128-2
128-3
128-4
THE NORTHERN BARRAGE. 129
campaign had been a failure. The British had laid mine fields about
the entrance of the Dardanelles, but sweeping operations could be
easily conducted by the enemy, whose shore batteries could keep off
the allied men-of-war while operations were in progress.
The Commander United States Naval Forces Operating in Euro-
pean Waters had been endeavoring for some months to induce the
other Allies to join with the United States in offensive operations
against enemy submarines in the Mediterranean. A plan was pro-
posed and partially developed by the Force Commander's planning
section in January, 1918, which was subsequently accepted by the
Allied Naval Council. This proposal was to lay a mine barrage in
the Adriatic from the Italian coast to one of the Dalmatian Islands.
After having been accepted by the allied council it was taken up for
consideration with the military representatives of the Supreme War
Council at Versailles, who finally concluded that the military situ-
ation on the western front was such that the necessary troops could
not be spared to be sent to the Adriatic for seizing such of the Dal-
matian Islands as would be necessary before the mining operations
could be undertaken. Any other location in the Adriatic for a mine
barrage involved depths of water of from 500 to 600 fathoms. The
possiblities of constructing a mine suitable to these greater depths
was, however, presented to the Bureau of Ordnance for solution.
On account of the North Sea barrage operations the United States
Mine Force would be engaged well up into the fall of 1918, using up
the mines practically as fast as they were manufactured, and none of
the Allies were in a position to undertake mining operations in the
Mediterranean on the scale required. The question of mining in
these waters was therefore allowed to rest until June, 1918, when the
Force Commander presented to the Allies an estimate of the general
situation in the Mediterranean, including a discussion on the various
locations in which mine barrages could be constructed.
In the meantime offensive operations had been undertaken in the
Adriatic against submarines operating from Cattaro and Darazzo.
A mobile barrage consisting of allied destroyers, submarines, trawlers,
sloops, and United States submarine chasers had been established in
the lower part of the Adriatic between latitude 39° 10' north and 41°
north. These vessels were equipped with hydrophones and depth
charges and as many vessels as could be procured were provided in
order to maintain a constant patrol over a considerable area. The
vessels were, however, small, and even during the summer months it
was frequently necessary for them to seek shelter during bad weather.
The mobile barrage was not an effective antisubmarine measure.
The Italians and French had also undertaken antisubmarine meas-
ures in the Adriatic in the form of a mine net between a point 10 miles
181063°— 20 9
130 THE NORTHERN BARRAGE.
offshore from Otranto across to Fano Island — a distance of about 35
miles. The 10-mile gap left at the Italian coast had been mined by
four rows of mines. This net extended from 33 feet below the surface
to 200 feet below. Experiments conducted during the previous win-
ter had shown that the type of net adopted possessed greater endur-
ance qualities than had even been hoped for. The two nations
engaged in the project, however, were badly handicapped by lack of
material for constructing the net and suitable vessels for placing it
in position. On July 15, 1918, only 10 miles of the 35 had been com-
pleted. The necessary material to finish it had been promised by
Great Britain and it was confidently expected that the net would be
in place before the end of the calendar year. Patrol vessels were
required to guard the surface above the net in order to force sub-
marines to dive to the necessary depth to encounter it. It was also
too shallow to be thoroughly effective. Recent information had shown
that submarines did not hesitate to dive 300 feet and frequently even
deeper if necessary. As soon as the enemy could discover the geo-
graphical position of this barrier it would be a simple matter for them
to submerge sufficiently to pass safely beneath it. On July 30 an
enemy submarine ran into the last section of the net which had been
completed and was sunk almost immediately. This event, occurring
just a few days prior to the date set for the Malta conference, aroused
the enthusiasm of the French and Italians tremendously and made
them decidedly partial to this form of antisubmarine measure in pref-
erence to a strict mine barrage.
Although the United States memorandum of the 17th of June
revived the interest of the Allies in the possibilities of minelaying in
the Mediterranean, it did not result in any active efforts on their part
to further the project, so a second memorandum was prepared by
the Force Commander on July 1 1 . This was essentially a resume of
the former one and was sufficient to start active discussion. Com-
ments were exchanged with the British Admiralty and a special emer-
gency meeting of the Allied Naval Council was called in London on
July 23 to discuss the possible projects. For this meeting there was
prepared by the United States planning section an informal memo-
randum laying down certain fundamental principles which should be
adhered to as far as practicable in the selection of locations and con-
struction of mine barrages. This memorandum was incorporated in
full in the report of the council. Although many of the points seemed
too obvious, they were subsequently found to be invaluable at the
allied conference held at Malta three weeks later, where many of the
various impracticable proposals for possible mining operations made
by different nations were easily disposed of by referring to the funda-
mental principles which had been adopted and approved by the allied
council. By this means it was possible to reach agreements for mine
THE NORTHERN BARRAGE. 131
laying which would otherwise have been practically impossible on
account of the controversies and arguments which would have been
presented by the various nations.
These principles were :
.(a) Both ends of a mine barrage should rest hi own territorial
waters to avoid the necessity for special military operations.
NOTE. — When military sources are available (a) may be modified
to read (both ends of a mine barrage should rest in waters under
military control from the shore).
(6) Both ends of a mine barrage should be secure against raiding
operations, so that any possible military advance of the enemy will
still leave the barrage effectively hit act. If the enemy holds shore
ends, he can sweep a channel safe for submarines under cover of
shore patrols.
(c) Barrages should exclude submarines from operating areas.
Barrages should be as short as possible on account of scarcity of
available mine material.
(d) No enemy submarines should be able to gain the sea, except
via the hazard of a mine barrage.
(e) A mine barrage extending to the surface is much more effec-
tive than any patrol can be, since it watches day and night, hi good
weather and bad, with equal efficiency.
(f) No deep barrage is effective unless it is thickly patrolled.
(g) Whenever a barrage to the surface is laid, the surface part of
the barrage should be densest, because submarines prefer to navi-
gate on th« surface, and will dive only when then* mission requires
them to do so.
(Ji) When a surface antisubmarine barrage is laid, it should in-
variably be superposed on a deep barrage, to prevent submarines
from diving under the surface barrage.
(i) There should be a secure harbor hi advance of a barrage, so
that any enemy naval raiding force reaching the barrage may be
cut off by the force based' on such harbor.
It was further recommended at this emergency meeting that the
first efforts in constructing mine barrages hi the Mediterranean
should be: First, across the Straits of Otranto, and second, in the
Aegean Sea. Both of these barrages, however, were dependent
upon the possibility of surmounting the physical difficulties of min-
ing in very deep water.
It was then arranged to hold an allied conference at Malta during
the first part of August in order to discuss and make definite recom-
mendations for mine-laying operations in the Mediterranean. Malta
was selected on account of the convenience to the various allied
commanders-in-chief in those waters, who were primarily concerned
with the policies which were to be adopted. Rear Admiral Joseph
132 THE NORTHERN BARRAGE.
Strauss, Capt. Charles R. Train, and Lieut. Noel Davis were sent as
representatives of the United States Government.
The conference met on the 6th of August, finishing its work on
the 9th. The main items which were brought up for consideration
and recommendation were:
(a) Dardanelles mine field — possibilities of extending and reen-
f orcing it.
(b) Adriatic barrage.
(c) Cape Bon, Sicily, barrage.
(d) Aegean barrage.
(e) Gibraltar barrage.
(A) DARDANELLES MINE FIELD.
Mining operations off the Dardanelles had been previously car-
ried out by the British. The field consisted of mines dangerous to
vessels on the surface and was designed to bottle up the enemy
men-of-war based at Constantinople and in the Black Sea. It was
not effective against submarines as they could quite readily pass below
the mines. Since the ends of the field rested on enemy shores, sweep-
ing operations could be carried out under the protection of the shore
batteries. On the other hand, the mines were laid mostly at night,
in small groups, variously placed, and served more as a trap than as a
barrage. The undertaking was of small magnitude and, since the
effects had already been rewarded with some success, and the mines
were available, it was recommended that the work should be re-
sumed. There was also the possibility that after the .collapse of
Russia their Black Sea Fleet had been put into commission by the
enemy. This would have given them a comparatively strong force
of surface vessels to engage the Allied Aegean Fleet or to be used as
raiders on the Mediterranean commerce. The Dardanelles mine
field might possibly be sufficient to prevent them from leaving their
bases. In view of the availability of material and the noninter-
ference with other operations, this work 'was given priority over
other minelaying projects in these waters.
(B) ADRIATIC BARRAGE.
The Adriatic mine barrage offered greater possibilities as an anti-
submarine offensive than any of the other projects proposed for the
Mediterranean. A successful mine barrage from coast to coast
across the Straits of Otranto would have bottled up practically all
of the submarines which were operating in the Mediterranean.
Unfortunately, the selections which were strategically the best
involved water of depths too great to be mined with any types of
mines which were then existent. The Bureau of Ordnance had been
investigating the possibility of producing such a mine, and on the
THE NORTHERN BARRAGE. 133
day the conference met a cable dispatch to Admiral Strauss an-
nounced that the bureau was prepared to construct mines for mining
in depths up to 500 fathoms. In discussing the various possible
locations for the Adriatic barrage, some trouble was encountered
with the French and Italian representatives, who were opposed to
the most desirable selection on the grounds that it might interfere
with their fleet movements. A barrage between Cape Otranto and
Cape Linguetta was preferred by the United States, British, and
Japanese representatives, .for, besides being shorter, there were no
depths exceeding 500 fathoms, for which the Bureau of Ordnance
had stated they could prepare the necessary material. The French
and It ah* an representatives, however, desired to place the barrage
farther to the southward, extending from Fano Island across to some
point on the Italian coast, between Cape Otranto and Cape Santa
Maria Di Leuca. This position, however, was beyond consideration
by us at that time, since it involved depths of water as great as 600
fathoms. In spite of the fact that the United States was offering
to provide all the material and do all the work in connection with the
construction of the barrage, it was impossible to reach an agreement
with the Italian representative which could be accepted by the United
States on account of the mechanical difficulties involved. In. the
final recommendations of the conference it was stated:
If, however, the objections presented by Italy could be overcome, the conference
was of the opinion that a complete mine barrier, with suitable gate, between Otranto
and Cape Linguetta should be laid in preference to the one proposed between Cape
Santa Maria Di Leuca and Fano Island. This would be done with the material
already designed, as the watfcr was shoaler and moreover the barrier would be less
exposed to the sea.
Admiral Salazar (Italian Navy) did not concur with the mine bar-
rier being placed in this latter position.
The details of the barrier were left almost entirely to the United
States representative, who proposed that the barrage should extend
from" 10 feet below the surface to 285 feet below the surface. This
represented an increased depth compared with the North Sea barrage,
which was desirable on account of the fact that submarines were
capable of diving to greater depths than had formerly been possible.
In order to care for the shipping to the ports in the Adriatic it was
necessary to leave a small gate at some point in the barrage. This
was decided to be left hi the western end and was not to exceed
5 miles in width, and should be narrowed in the future should experi-
ence warrant its reduction. This gate was to be free of all mines
down to a depth of 40 feet and was to be thoroughly patrolled by
craft capable of fighting submarines and in sufficient number to com-
pel submarines to dive into the minefield below the gate.
134 THE NORTHERN BARRAGE.
In order to avoid any mixed responsibilities for the execution of
the project, the United States accepted the task of providing and lay-
ing the mines, and insisted that the operation of laying, controlling,
and maintaining the barrage be entirely under the jurisdiction of
the^ United States. This was approved by the conference.
It appeared that Admiral Revel, the Italian chief of naval staff,
was supreme in deciding the policies and attitudes of naval operations
which involved the Italian Government. Intimation was given the
United States representative that by referring the question of the
location of the barrage to him it might be possible to obtain the Italian
Government's approval of the location desired by the United States.
This was immediately taken in hand, but his reply was not received
prior to the completion of the conference. One valid objection to
the barrage being placed on the line from Otranto to Cape Linguetta
lay in the fact that the military situation in Macedonia was at that
time somewhat critical. There was a possibility that the enemy
might concentrate his forces in an attempt to capture Valona Bay.
With this in enemy possession, the eastern end of the mine barrage
would have been extremely difficult to maintain.
(c) CAPE BON-SICILY BARRAGE.
N
A mine field extending from Cape Bon, Tunis, to the Island of
Sicily presented several features above those offered in the Adriatic
and ^Egean Seas. In the first place, the water was sufficiently
shallow to enable the present type of United States mines to be used,
of which there would be sufficient available by the time the work
could be undertaken by the mine force. A barrage in this position
would serve to restrict the operations of submarines which were
based at all of the enemy ports in the Mediterranean, to the eastern
part of the Mediterranean. Since approximately 70 per cent of the
Mediterranean shipping took place to the westward of the Cape Bon-
Sicily line, a barrage in this position would have been comparal^ively
effective from a protective point of view. For these reasons the
United States considered this should be the primary project in order
to relieve the losses of shipping at as early a date as possible. The
British, French, and Italian representatives did not approve of a
mine field in this position, unless very large gateways could be left
which would render the barrage practically useless, and further
wished a guarantee that vessels could safely pass over the deep mine
fields which were to be laid beneath the gates. In addition, sub-
marine operations would then be concentrated on the shipping in
the eastern Mediterranean, which was engaged principally in trans-
porting troops and carrying supplies to the allied forces in Saloniki,
Mesopotamia, and in Egypt. It was evident that it would be impos-
THE NORTHERN BARRAGE. 135
sible to obtain the assent and co-6peratipn of our allies to construct a
satisfactory barrage in this position, and the idea, therefore, had to
be abandoned.
(D) ^GEAN BARRAGE.
It was comparatively easy to obtain the approval of the various
allied representatives for the location of a barrage in the ^Egean
Sea in the position desired by the United States Government. These
waters, crowded with islands, presented many locations in which a
barrage might be constructed. In order to reduce the number of
mines required, it- was desirable to utilize the islands by blocking
the passes between them. One end of the barrage must necessarily
rest on enemy shores and the site which presented the greatest pos-
sibilities of maintaining a mine field was at Cape Kanapitza. The
project included a plan for establishing a garrison on the Island of
Samos for the purpose of guarding the narrow channel between that
island and the Turkish mainland. As this channel was narrow, it
could easily be guarded by artillery on shore, so as to prevent sweep-
ing operations by the enemy, once the mine field had been laid.
The location decided upon, and approved by the conference, began
at Euboea Island, and ran to Andros, Tinos, Mykoni, Nikaria,
Themina, Furni, and Samos Islands, and thence across to Cape
Kanapitza. This barrage was similarly to consist of mines from 10
feet to 285 feet below the surface, with a gate between 500 and 1,000
yards wide, free of surface mines, to be placed either in Doro Channel
or in Steno Pass. The recommendations of the conference also pro-
vided, as they had done for the Adriatic barrage, that the responsi-
bility for the provision, laying, and maintenance of the mine field
should be left entirely to the United States.
(E) GIBRALTAR BARRAGE.
Aside from the deep water and the very strong currents in the
Straits of Gibraltar, the advantages to be gained by a barrage in this
position were not of sufficient importance to demand the develop-
ment of the special mine which would have been required for this
purpose.
In addition to the mine barrages in the Adriatic and ^Egean, the
United States became involved in two minor projects which, while
considered of secondary importance by our representatives, were
agreed to on account of the great desire of the British and Italians
to have these measures carried out. The first was to supplement
the mine net which was being placed between Otranto and Fano
Island. This net extended only to a depth of 200 feet and in
order to make it more effective the United States agreed to place
four rows of mines below it and in the immediate vicinity so as to
136 THE NORTHERN BARRAGE.
complete the barrage to an approximate depth of 300 feet. The
second project was to assist the British in the Dardanelles mine
field by laying surface mines between Imbros Island and Cape
Gremea. This was acceded to by Rear Admiral Strauss, since it
would require comparatively few mines suitable for the deeper
water involved. Great Britain at that time had no such deep mine
in sight. The work was not to be undertaken until after all other
projects in the Mediterranean had been completed.
Further minor operations were discussed by the conference in
connection with the protection of the trade routes through the Gulf
of Patras and the Corinthian Canal around to Saloniki, and also the
protection of Eubosa Channel in order to form a safe drill ground
for the JEgean allied men-of-war. These were minor operations and
did not involve the United States.
Upon the completion of the conference, Admiral Strauss, accom-
panied by Commander Train and Lieut. Davis, left Malta to inspect
the various sites suitable for the construction of a mine base in
the Mediterranean. Argostoli, Corfu, and Taranto were inspected
prior to returning to Base 18. Corfu appeared to present the greatest
possibilities, although there were absolutely no facilities available
on shore which could be used in connection with mining, or in the
erection of an assembly plant. It also possessed the disadvantage
of being within bombing distance of the enemy.
While in Rome an unofficial report was received from the Italian
Chief of Naval Staff that the position preferred by the United States
and Great Britain for the location of the Adriatic barrage would be
acceptable to the Italian Government, except that they preferred the
western end of the mine field to terminate at Cape Cavallo instead
of Cape Otranto. This news was most welcome. The new position
and the alterations suggested by the Italians were equally accept-
able, since it involved slightly shallower water than the Otranto line,
but was somewhat longer. This unofficial report was later con-
firmed officially.
On September 13 and 14 the fifth meeting of the Allied Naval
Council was held in Paris to consider the recommendations of the
Malta conference and to decide upon the policies which should be
inaugurated. The recommendations were approved by the council
almost verbatim. The following priority for the establishment of
the barrages was laid down:
(1) Completion of Dardanelles mine fields, in accordance with ex-
isting plans.
(2) Adriatic.
(3) ^gean.
(4) Entrance to Euboea Channel.
THE NORTHERN BARRAGE. 137
(5) Entrance to Gulf of Patras after completion of the Aegean
barrages.
(6) Embros to Cape Gremea to be laid if and when material was
available.
In regard to reinforcing the Italian-French mine net barrage by
four lines of deep mines, it was decided that not only should mines
be laid below the net as previously agreed at Malta, but also above
the net so as to eliminate the necessity for a patrol, which there, as in
the North Sea, had been found to be almost entirely ineffective in
preventing the passage of submarines. Where the depth of the water
was too great to permit mines to be laid to reinforce the net, the net
should, if possible, be increased so as to reach to a distance of 285
feet below the surface of the sea. In order to establish a complete bar-
rage across the Adriatic at the earliest possible moment, it was later
decided by the United States Government that the work of supple-
menting this net should take priority over the main Adriatic barrage.
Several days before the meeting of the Allied Naval Council a reso-
lution had been conveyed to the Supreme War Council at Versailles
in regard to the necessity of taking all possible measures in Albania,
to prevent Valona from falling into enemy hands. This resulted in
Italy informing the Allied Naval Council that the measures for rein-
forcement which had already been taken were then proving effective.
It was decided that the selection of a base for mining in the Medi-
terranean should be left to the discretion of the United States who
was responsible for the provision and execution of the major mining
operations in the Mediterranean. They further requested that the
Government in whose territory the base was chosen should give all
possible support and assistance for the early construction of the
mining depot.
In the meantime detailed plans for the Adriatic and Aegean bar-
rages were developed by Commander Mine Force, and the neces-
sary mines were requested to be prepared by the Bureau of Ordnance.
Both barrages were to consist of mines at four depths so as to form
an effective field from the surface to a depth of approximately 300
feet. The surface mines were to be fitted with 30-foot antennae and
were to be laid in 10 rows, spaced 300 feet apart in each row. There
were to be four lines of mines at each of the three lower levels, the
mines also spaced 300 feet apart in each row, and these were to be
fitted with 70-foot antennae. This would have given the barrage a
theoretical destructive efficiency of 65.6 per cent for submarines pass-
ing through the barrage within 50 feet of the surface, and 34.4 per
cent against those passing between 50 and 300 feet below the surface.
(Assuming beams of submarines to average 30 feet.) This required
the use of 22;800 mines for the construction of the primary mine
barrage in the Adriatic with 8,000 additional mines for supplementing
138 THE NORTHERN BARRAGE.
the Franco-Italian mine net with four rows of mines above the net
and four below where the depth of water would permit. For the
Aegean barrage there would be required 26,800 mines. This made a
grand total for the Mediterranean of 57,600 mines or approximately
75 per cent of the number that it was intended to place in the North
Sea barrage.
The selection of a base for assembling mines in the Mediterranean
presented considerable difficulties. The few suitable harbors in Italy
were so overtaxed by their naval requirements as to render them
out of the question. Corfu, located within convenient distance of the
contemplated barrages in the Adriatic and Aegean, appeared to be the
most suitable position. Its greatest drawback was, however, the
possibility of enemy air raids, which, had they been successful, might,
have completely destroyed the base by blowing up1 the mines in
storage there. The most suitable location so far as natural facilities
were concerned was Bizerta, Tunis, and even here the facilities were
almost nothing. Its principal disadvantage was the great distances
from the contemplated barrages — 560 miles to the Adriatic and 775
miles to the Aegean — and through waters infested with enemy sub-
marines. These distances were a most serious handicap, even so
much so that it would have prevented two of the vessels of the mine
force from taking part in the construction of the Aegean barrage on
account of their limited steaming radius. In spite, however, of the
disadvantages entailed it appeared to be the most suitable location
that could be obtained and on September 28, Capt. O. G. Murfin,
United States Navy, who had established and commanded the mine
bases in Scotland, left London to establish a base at that place.
With practically unlimited resources to draw upon, it had re-
quired four months to construct the mining bases in Scotland. To
duplicate such an assembly plant in Bizerta would undoubtedly
have required at least the same length of time and possibly much
longer. It was, therefore, apparent that the first operations in the
Mediterranean must be carried out with mines assembled at Bases 17
and 18, and arrangements were made to have the necessary mining
material shipped to those bases for two operations. This would allow
approximately two months' additional time for the completion of
the base at Bizerta before they would be called upon to supply the
vessels with assembled mines.
Arrangements were made to obtain the necessary material for the
erection of assembly sheds, living quarters, storage plants, etc., from
the U. S. aviation forces in France with some additional mine-shop
equipment from Bases 17 and 18. It was necessary also to construct
a pier at Bizerta for unloading the mine carriers and for supplying
the minelayers with assembled mines. Capt. Murfin arranged con-
THE NORTHERN BARRAGE. 139
tracts through the local French naval authorities and the work of
construction on the pier was immediately undertaken.
The U. S. S. Lakeside, after discharging her cargo of mine parts
for Base 18, was loaded with such assembly material and other
equipment as could be spared from that base, and then was dispatched
to Pauillac, France, where the aviation material was to be taken on
board. The U. S. S. Lake Shore was similarly dispatched two days
later, proceeding to Bristol to be loaded with construction material.
The French did all in their power to advance the work of con-
struction, and after less than one month's hard work the ground work
of the base was well in hand.
The armistice with Turkey on October 31 and the occupation by
the Allies of the Dardanelles and the Bosphorus eliminated the neces-
sity of a mine barrage in the Aegean. Following close on top of that
came the armistice with Austria-Hungary on November 4. Although
many of the submarines based at Austrian ports were German and
might possibly escape and operate in the Mediterranean, these opera-
tions could only be of short duration and would undoubtedly cease
before our mining operations could be undertaken. On November 7
orders were, therefore, issued to discontinue work in connection with
the establishment of the mine base at Bizerta. At the same time
the Bureau of Ordnance was requested to suspend the production
of mines for the Mediterranean projects. The end of the war had
fortunately come before it had been possible for us to lay a single
mine in those waters.
The work of demobilization of the Bizerta base began almost imme-
diately. The Lake Shore and Lakeside, neither of which had reached
their destination, were returned to Inverness and unloaded. Most
satisfactory arrangements were concluded by Capt. Murfin for the
disposition of the material which had been supplied for the construc-
tion of the necessary buildings at the base. The French authorities
took over practically everything that could be used and much of the
remaining scrap material was disposed of to local merchants, leaving
the United States indebted only for the cost of actual labor which
had been expended and such construction and material as could not
be further utilized.
The Allied Naval Conference, in its session at Malta on August 6 to 9,
1918, touched on the question of the removal of the mines at the end
of the war. This subject was taken up more thoroughly at the meet-
ing of the Council held in Paris on September 13 and 14, and still
more thoroughly at the meeting of the Council held on October 31,
November 1, 4, and 5 in London.
As a result of conferences held in London by the Allied Naval
Council on October 31 and November 1, 4, and 5, 1918, concerning
clearing the seas of mines after the war, it was recommended that
140 THE NORTHERN BARRAGE.
Great Britain undertake to collate from the allied, associate, and
central powers and distribute to the maritime countries of the world,
intelligence regarding progress of mine clearance operations.
A committee of British naval officers with offices at the Admiralty
in London, known as the International Mine Clearance Committee,
has been convened to collate this information and in accordance with
a further recommendation of the Allied Naval Council mine clearance
intelligence officers were appointed by the allied and associated powers
to co-operate with this committee.
Mine warnings to mariners were issued from time to time by the
International Mine Clearance Committee and information received
from all reliable sources as to progress in minesweeping were com-
municated to the mine clearance intelligence officers for transmission
to their various governments.
In a memorandum from the British Admiralty to the Commander-
in-Chief dated December 7, 1918, it is stated as follows:
950. Arrangements are being made by which warnings of mine fields and indis-
pensable routes will be promulgated internationally from London:
2. This will be done by British authorities by issue of Admiralty mine warnings
to mariners — similar to Notices to Mariners, and printed green to distinguish, and
by telegrams to reporting officers prefixed "Route warnings."
3. This system will be introduced gradually and will replace existing system of
orders regarding routes which will be canceled as necessary.
* 4. Route warnings and mine warnings to mariners will be classified by areas as in
paragraph 8. Route warnings will be numbered serially in each class and will com-
mence with title of area, thus: Route warning North Atlantic 3 — Mine warnings to
mariners will be numbered consecutively irrespective of areas.
5. When orders for any area become sufficiently simple they will be communicated
to all reporting officers. Orders for other areas will at first be confined to route giving
officers to whom vessels concerned must then be ordered to apply.
6. Route warnings will give the most up-to-date information and should be used
to amend mine warnings to mariners when routing vessels.
• 7. Other governments will be given similar information through their representa-
tives in London.
8. Areas of classification of route warnings. Limits will be given in subsequent
route warnings. General, comprising notices affecting all areas.
1. Arctic. 6. East coast of France, Spain, and
2. North Atlantic and English Channel Portugal.
3. West coast of United Kingdom. 7. Mediterranean.
4. North Sea. 8. South Atlantic, Indian Ocean, Red
5. Baltic. Sea, and Pacific.
In accordance with the above-outlined policy, the International
Mine Clearance Committee has issued 245 mine warnings to mariners.
The first of these, No. 1 of the year 1918, was issued on the 10th of
December of that year. This was a general outline plan of the
operations of that office. Mine warning to mariners No. 2 issued on
the same date gives geographical areas to which all mine warnings,
subject to issue, are referred; in all, eight zones. Mine warnings to
THE NORTHERN BARRAGE. 141
mariners No. 3, 4, 5, 6, 7, 8, 9, 10, all issued also on the 10th of Decem-
her, describe the conditions of all the areas on that date and are
published herewith in explanation of the policy that was to be carried
out. In connection with these mine warnings to mariners, there
were published a series of charts showing the mine areas and safe
channels. These were republished by the United States Hydrographic
Office for the information of all mariners, in some cases being pub-
lished as a supplement to the United States Pilot Chart.
Nothing could more graphically show than these charts the extent
of surface that was dangerous to shipping by reason of mined areas.
The degree of danger is shown on the chart by the various forms of
shading. In the general chart British Islands, Dunbar to South
Forland, showing the east coast of England, it is made very clear what
a very restricted area was considered safe for navigation, even when
assisted by the exhaustive system of buoys as shown on that chart.
The removal of the mines began almost as soon as the armistice
was signed. From the professional point of view, this operation was
much more arduous and difficult than planting the mines. Mine
warnings to mariners and charts showing the areas cleared were
published from time to time in order that maritime commerce should
be kept apprised of the areas still remaining dangerous. The descrip--
tion of this enormous operation of mine clearing will form the matter
of a subsequent publication.
INDEX
A.
Page.
Aberdeen-Norway mine barrage,
details of 32
JEgean barrage 135, 136
Adriatic barrage 132, 136
Allied naval council. 29, 129, 130, 137, 139
American consideration and adop-
tion of project 35
Anzac, H.M.S 85
Appendix I. Mine barrage across
the North Sea 31, 38
Approval of the Secretary of the
Navy 41
Armistice with Austria-Hungary. . 139
Armistice with Turkey 139
Aroostook, TJ. S. S. , ex Bunker Hill,
s. s 71,75,78,84,114,118
Assembly and shipment of mine
material. 58
B.
Bagby, O. W., Lieut., U. S.
Navy 44,109
Baltimore, U. S. S., minelayer.. 49,70,
80, 102, 118
Beatty, Admiral, R. N 88
Belknap, R. R., Captain, U. S.
Navy 35,36,40,77,81,86,110
Benson, W. E., Lieutenant, U. S.
Navy, c. o. Patapsco 83
Benson, W. S., Admiral, U. S.
Navy, Chief Naval Operations. 35
Black Hawk, U. S. S 85
Boyle- Robertson Construction Co. 55
BrecHnridge, Colonel, naval at-
tach^ Scandinavian countries 97
Bridge, C. D. C., Commander, R.N. 16
British Admiralty 14, 140
British consideration of project. . . 29
Brown, S. J., Math., U. S. Navy. . 18
Browne, Ralph C., Mr., Salem,
Mass., inventor "Browne sub-
merged gun " 18
Browne submerged gun 18
Bureau of Ordnance 12, 107, 132
Bulmer, B. T., Commander, U. S.
Navy 85
Pige.
Butler, Commander, U. S. Navy. . . 78
Bunker Hill, American s. s.,
renamed U. S. S. Aroostook 71
C.
Campbell, E. H., Captain, U. S.
Navy 77
Canandaigua, U. S. S., ex El Siglo,
s.8 71,78,80,84,104,119
Canonicus, U. S. S., ex El Cid, s. s. 71, 78,
80, 84, 104, 110
Castle, Lieutenant Commander 17
Changes in barrage plan 92
Cape Bon-Sicily barrage 134
Character of barrage 97
Character of mine fields on Norwe-
gian coast 98
Chief of Naval Operations, letters
to 16, 19, 20, 62
Chilcott, R. E. , Captain, R. N . . . . 88
Clinton-Baker, Rear Admiral C. B.,
R. N 64, 87, 88, 102, 117
Cloyne, field barracks, Newport,
R. I., mine force mining camp. . 76
Cluverius, W. T., Captain, Shaw-
mut 78, 85
Commander, Grand Fleet 88, 92, 99,
105, 111
Commander, mine for£e, appoint-
ment; arrival in Europe; prep-
arations 86
Commissioning the ships of Mine
Squadron No. 1 76
Completion and sailing of mine
squadron 79
Conception and inception of the
northern barrage project 9
Consideration of the line to be
selected across North Sea 32
Contemplated mining operations
in the Mediterranean 128
Cook, S. W., Lieutenant, U. S. N.
R.F 44
Coordination of preparations 40
Corley, W. A. , Lieutenant, U. S. N . 44
143
144
INDEX.
D.
Dalmore Distillery 61, 66
Dardanelles mine field 132
Davis, Noel, Lieutenant, U. S.
Navy 87, 111, 132, 136
Delavy, Edmund, Lieutenant,
U. S. Navy, c. o. Ontario 83
Delaware, U. S. S 90
Department of Commerce inter-
ested in barrage 17
De Salis, Lieutenant, R. N 45, 73
Design of the mine 42
Dispatch of British chief of naval
staff 35
Dubuque, U. S. S 76
Du Pont Co., Barksdale, Wis.,
works 56
Du Pont, E. I., de Nemours Co 57
E.
Earle, Ralph, Rear Admiral, U. S.
Navy, Chief Bureau of Ordnance. 7,
12, 20, 35, 42, 86
El Cid, American s. s., renamed
U. S. S. Canonicus 71
El Dia, American s. s., renamed
U. S. S. Roanoke 71
El Rio, American s. s,, renamed
Housatonic 71
El Siglo, American s. s., renamed
U. S. S. Canandaigua 71, 78
F.
Final status of barrage and results
obtained 121
Fischer, H. E., Lieutenant Com-
mander U. S. Navy 59
Freemantle, Admiral 100
Fullinwider, S. P., Commander
U. S. Navy, chief of mines and
net section (ordnance) 7,
12, 16, 18, 35, 42, 44
G.
Gailardia, H. M. S 101
Gaisford, Engineer, Captain, R. N . 63
Gannon, Sinclair, Commander, U.
S. Navy, c. o. Saranac 78
Gates 123
Geddes, Sir Eric 30
General board, U. S. Navy 35, 36
General policy, Navy Department. 11
Gibraltar barrage 135
Glen Albyn Distillery 61, 65
Grant, Lieutenant, R. N 90
Page.
Greenslade, J. W., Captain, Housa-
tonic 78
Grimes, B. W., Lieutenant, IT. S.
N. R.F 44
H.
Hamilton, American s. s., renamed
U. S. S. Saranac 71
Harrill, W. K., Lieutenant, U. S.
Navy 89
Heap, Mr., Admiralty's control-
lers office 63
Housatonic, U. S. S. ex. S. S. El
Rio 71, 78, 80, 81, 84, 104
Hupp, J. B., Lieutenant,U.S.Navy,
c. o. Patuxent 83
Hurley, Edward N., U. S. S. B. . . 70
H-2, mine, British 102
I.
International Mine Clearance
Committee 140
Isherwood, H., Lieutenant, R. N.
V.R 44,47
Italian chief of naval staff 136
J.
Jason, U. S. S. fuel ship 84, 85
Jefferson, American s. s., renamed
U. S. S. Quinnebaug 71
Jellicoe, John, Admiral, R. N 29
Johnson, T. L., Commander, U. S.
Navy, Captain Canonicus 63, 78
K.
Kearney, T. A., Captain, U. S.
Navy, assistant chief, Bureau of
Ordnance 12, 23, 27
Kerens, Wm. H. (San Francisco).. 37
King, Commander, U. S. N 35
Knott, L. E., Apparatus Co., Cam-
bridge, Mass '. 18
K-l device 19,45,50
L.
"Lake" class vessels, used as mine
carriers 58, 59
Lake Moor, U. S. S., loss of 60, 89
Lake Shore, U. S. S 139
Lake Side, U. S. S 139
Lake Superior, U. S. S 66,83
Length of antenna 98
INDEX.
145
Page.
Lockhart-Leith, Captain, R. N. . . 63,
102, 103
Lockhart-Leith committee 61, 62
M.
Mannix, D. P., Commander, U. S.
Navy, Captain. Quinnebaug. . .
7S
Manufacturing project 50
Mark VI (type X) mine 16,
18, 19, 20, 24, 42, 52
Marsh, C. C., Captain, U. S. Navy
(ret.) 7
Marshall, A. W., Captain, LT. S.
Navy 102
Material for submarine mine bar-
riers 19
Mayo, Henry T., Admiral, U. S.
Navy, c. in. c. Atlantic Fleet. . . 23,
28, 29, 30, 31, 34, 35, 68
Massachusetts, American s. s.,
renamed U. S. S. Shawmut 71
Mine barrage across the North Sea,
Appendix 1 31, 35, 38
Mine -loading plant, St. Juliens
Creek, Va,
55
Mining operations ~ . . 101
Mining school, Portsmouth, Eng-
land 64
Mock, H. 0., Commander, R. N.
V.R 44
Mulleneux, H. E., Captain, R. N.. 88
Murfin, 0. G., Commander, U. S.
Navy 62,68,88,138
Morgan Line 70
Mediterranean, contemplated op-
erations in 128
N.
Naval Overseas Transportation
Service 40, 59
Newhall, Thomas, Lieutenant, U.
S. N. R. F 65
New York, American s. s 64, 87
North Sea barrage 9
Number of American mines re-
quired 33
0.
Old Colony, U. S. S.
Old Dominion Line.
71
71
Ontario, U. S. tug 77,83
Organization of mine squadron 70
181063°— 20 10
Page.
73
Overseas mine bases 17-18 61, 64
Otis Elevator Co.
Ozama, U. S. S.
66
P.
Patapsco, U. S. tug 77,83,109,114
Patrol 123
Patuxent, U. S. tug! 77, 83, 109, 114
Peacock, A. B., Lieutenant, junior
grade, U. S. N. R. F 52
Personnel and commissioning of
ships of mine squadron one 76
Philadelphia, American s. s ' 64
Planning section, British Admiralty 96
Planning section, United States. . . 35,
94,130
Position 97
Preparations for commencement of
minelaying 86
Princess Margaret, British mine-
layer 102
Proposed British-American joint
offensive operations, submarine
barriers; Mark VI mines
Proposed mining policy, North Sea
20
32
Pryor, W. L., Commander, U. S.
Navy 56
President of United States 16, 17, 37
Q.
Quinnebaug, U. S. S., ex Jefferson
s.s 71,78,79,84,104
R.
Results obtained 121
Revel, Admiral, Italian Chief of
Naval Staff 134
Reynolds, W. H., Commander U. S.
Navy, Captain, Canandaigua 78
Roanoke, U. S. S., ex El Dia . . 71, 78, 80,
104, 110, 119
Roosevelt, Franklin D., Assistant
Secretary of the Navy 17, 18
S.
San Francisco, U. S. S. mine
layer 49,70,80,104,110
Saranac, U. S. S., ex Hamilton s. s. 71, 78,
79, 114
Salazar, Admiral, Italian Navy — 133
Schafer, G. C., Commander, Supply
Corps
64
146
INDEX.
Page.
Schofield, F. H., Captain TJ. S.
Navy 35,44
Secretary of Commerce 17
Secretary of the Navy 35, 37, 41, 70
Selection of new minelayers 70
Shawmut, TJ. S. S., ex Massachu-
setts s. s 71, 75, 78, 83, 114, 118
She wan, James & Sons repair
yard 71
Sims, W. S., Admiral, TJ. S. Navy. 13, 14,
30, 61, 87, 92, 95, 98, 109
Smith, Kirby (C. E. C.), TJ. S.
Navy. 55
Sonoma, TJ. S. tug 77, 83
Status of barrage project on Novem-
ber 1, 1917 38
Stearns, C. D., Captain, c. o. Roan-
oke 78, 82
Stewart, L. M., Lieutenant Com-
mander, TJ. S. Navy 64
Study of types of barrage, nets,
mines, and bombs, Bureau of
Ordnance 14
Strauss, Joseph, Rear Admiral,
TJ. S. Navy. ... 7, 64, 68, 81, 86, 87, 111,
117,131, 136
Submarine chasers, United States. 83
Submarine sighted and attacked. . 117
Submarines, enemy, damaged or
destroyed 124
Suggested method of laying mines. 33
Supreme War Council at Ver-
sailles 137
Summary of cooperation to carry
out barrage plan:
Great Britain 22
United States . . 22
Page.
Strategical and tactical considera-
tion 27
T.
Thompson, Surgeon, U. S. Navy. . 63
Tomb, J. H., Commander, U. S.
Navy, Captain , Aroostook 78
Total mines laid 123
Toxyl 57
Train, Charles R., Captain, U. S.
Navy 132, 1 36
Training the personnel 76
Trayer, J. S., Lieutenant, U. S.
Navy, c. o. Sonoma 83
Trinitroxylol 57
U.
UB-22, German submarine 124
U 86, German submarine 124
U 92 , German submarine 124
U 113, German submarine 124
U 123, German submarine 125
U 156, German submarine 125
W.
Wilkinson, T. S., jr., Commander,
U. S. Navy, charge of experi-
mental section, ordnance. 12, 18, 44, 59
Wolleson, Edwin, Lieutenant-Com-
mander, U. S. Navy 64
Wright, C. H., Lieutenant, U. S.
Navy 44
Y.
Yates-Brown, Allan M., Comman-
der (acting captain), D. S. 0.,
R. N.. 29
O
DATE DUE
JUN. 7
K)tf9 t
N, ~r" *~*. r-» A f-\ [
»
•«0j <
JTORAGl
GAYLORD
PRINTED IN U.S.A.
S. Office of Naval D
Records and Library. 590
Northern barrage & TJ5^
other mining activities.
2 charts back pocket
"-f 5132 00252 4270
3 urllr^oime Pacific Library
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11