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DEPARTMENT OF THE ARMY
CORPS OF ENGINEERS

Marine Biologi:.zt i sbi-..
LIBR A RW

APR 18 iv4y

WOODS HOLE, M’=s.

THE

OF THE

BEACH EROSION BOARD

OFFICE, CHIEF OF ENGINEERS
WASHINGTON, D.C.

APRIL 1, 1949 NO, 2

DEPARTMENT OF THE ARMY

CORPS OF ENGINEERS

THE BULLETIN
OF THE

BEACH EROSION BOARD

TABLE OF CONTENTS

Page
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PUBLICATION OF
THE BEACH EROSION BOARD
CORPS OF ENGINEERS
WASHINGTON 16, D. C.
APRIL 1, 1949

VOL. 3 NO. 2

NAN

DEPARTMENT OF THE ARMY

\\RARITAN BAY

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LONG BRANCH #H

ASBURY PARK i

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INLET

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CORPS OF ENGINEERS

DUMP AREA

NEW JERSEY SAND MOVEMENT STUDY

LOCALITY MAP

10 20 MI.

BEACH EROSION BOARD, WASHINGTON,D.C., !7, DEC., 1948

SUBNITTED FOR APPROVAL: |

COMPILED BY: eo TO ACCOMPANY REPORT

CHECKED 8). DATED :
FILE NO:

PLATE |

SAND MOVEMENT STUDY AT LONG BRANCH, N.J.

For some time engineers doing beach erosion and shore protection
work have considered the practicability of nourishing eroded shorelines
with material dredged from nearby harbors.

A cooperative study between the New York District and the Beach
Erosion Board to test the feasibility of using the disposal of dredged
material to nourish eroded shores in the vicinity of coastal harbors
was authorized by the Chief of Engineers on 3 February 1948 to test the
method.

Division of Work

The New York District dredged, transported and dumped about
600,000 cubic yards of suitable material in an area off the coast of
Long Branch, New Jersey, and also provided for all navigation aids at
the dump area. The Beach Erosion Bodrd performed all surveys and other
work necessary to determine the movement of the dumped material, and
prepared reports on the experiment.

Location and Description of Project Area

The project area, comprising the city of Long Branch, New Jersey
and vicinity, is located on the North Atlantic Coast of the United States
about eleven miles south of Sandy Hook, the southern entrance point to
New York harbor. The city of Long Branch is highly developed as a
summer resort, and lies on a slight rise in the surrounding terrain at
about elevation 440 feet. The terrain slopes seaward to an elevation
of #20 feet and terminates at the crest of a timber bulkhead which retains
Ocean Avenue. Immediately below the bulkhead is a relatively steep,
narrow, yellow sand beach intersected by numerous heavy rubble mound
groins. Crossing the beach seaward from the center of the city is a
fishing and recreation pier 900 feet in length, which terminates in about
24 feet of water.

Northward from Long Branch the land lowers and extends to the north
as a barrier beach which is less than 300 feet wide at its narrowest
point. Along the greater part of this stretch of coast, the beach is
backed by a high rubble mound seawall, designed to prevent storm waves
from breaching the barrier.

The area covered by detailed studies in this investigation extends
from the Long Branch fishing and recreation pier northward to Shrewsbury
Rocks, which are seaward from the Monmouth Beach Coast Guard station.
The dump area, 3700 feet long and 750 feet wide, lies about 1/2 mile
from shore in 38 feet of water, with its southerly limit on an east-west
line about 1500 feet north of the Long Branch pier.

a

Procedure

The Beach Erosion Board's Field Research Group No. 2 moved
into the Long Branch area on 14 March 1948 and established their
field office on city-owned land adjacent to the project area.
The work of establishing control along four miles of beach, for
the seventy profiles to be duplicated at intervals in andes to-
trace sand movement, was started immediately. Sufficient hydrographic
work had been completed to permit delineation of the dump area by
mid-April .

Sand Dumping. The New York District hopper dredge "Goethals"
dumped the first load of material, dredged from the New York channel,
at the Long Branch site on 30 April 1948. Dumping at the site con-
tinued throughout the summer until 19 August 1948 when a grand total
of 601,991 cubic yards of sand had been dumped along the shoreward
side of the dump area.

Surveys. Prior to any dumping by the dredge a hydrographic survey
was made of the area to serve as the basic survey. Surveys were made
later of the dump area at about weekly intervals to determine the
movement of the sand dumped by the dredge, and also to insure the
safety of the dredge in operations over the dumping grounds. Compara=
tive hydrographic surveys of the entire area were made at three-month
interval] s.

Sampling. Sand samples of the offshore bottom material were
taken at selected locations, along with samples from the beach at mid-
tide level. A sample of each dredge load was taken before dumping at
the site.

Aerial Photographs. Aerial photographs of the shore line under
study were flown by the U. S. Naval Reserve of Willow Grove, Pa. on
7 September and 16 October 1948.

Oceanographic Conditions during Test

Weather. During the period of study, 15 March to 9 November 1948,
ocean’ and weather conditions were favorable to hydrographic operations
58% of the time. Adverse conditions, which included days of rain, fog,
haze and heavy seas, were encountered 42% of the time. During this
period storms of varied intensity visited the area. The first storm
of consequence struck the north Jersey coast on 15 May 1948. Winds
were from the northeast, 20 to 30 mph., with waves 6 to 8 feet in
height. The highest tide of the season was recorded at this time with
a maximum tide of 6.3 feet above mean low water. A second storm
starting on 4 October and lasting through 6 October 1948 was of greater
intensity. Winds were from the northeast with sustained velocities of
25 mph. and gusts up to 45 mph. Waves were from 10 to 15 feet in
height with 8 to 10 second periods.

2

A third storm started 23 October 1948 and lasted for four days.
Winds were again from the northeast with sustained velocities of
40 mph. and gusts up to 55 mph. Waves were 12 to 15 feet in height
with periods of 10 to 15 seconds. A hurricane of strong intensity
passed 300 miles to seaward of the area under study on 31 August 1948,
and waves 5 to 6 feet in height were experienced along the Jersey coast
as a result.

Waves and Swells. An examination of all wave data recorded by
the Beach Erosion Board's wave gauge during the period of study showed
average wave conditions to be as follows; severe storm wave — 12 foot
height and 10 second period, moderate storm wave —- 6 foot height and
8 second period, normal wave - 2 foot height and 6 second period.

Due to the configuration and bearing of the shore line and the
shelter afforded by Long Island, only those open sea swells approaching
from the northeast, east, southeast and south affect the area under
study. Information, taken from a swell diagram for the ten-year period
1932 to 1942, showed that swells approached the beach from these directions
40.6% of the time; viz. swell heights of 1 to 6 feet - 36.8%, 6 to 12
feet - 2.5%, and over 12 feet - 1.3%.

Winds. Using a wind diagram constructed from wind data obtained
by the United States Weather Bureau at Sandy Hook, New Jersey, it was
concluded that onshore winds prevail 59% of the time.

Characteristics of the Sand

Seven sets of sand samples, totalling 320 samples, were taken over
a five-month period. These were taken at 400 foot intervals, both
along the beach and the profiles, to determine the character of the
native materials. Mechanical analyses of these sand samples were made
at the Beach Erosion Board's laboratory. Four composite samples were
subjected to petrographic analysis to ascertain the existence of unique
minerals which could be used as tracers. Distinctive criteria were
lacking between the dredge, beach and bottom samples; neither geometric
mean diameter nor mineralogical composition was a satisfactory criterion
for determining sand movement in this case.

Comparative Dump Area Surveys

During the period 4 May to 27 October 1948, twenty-one surveys of
the dump area were made and quantities computed by the end-area method.
These computations showed that there had been 125,231 cubic yards or
about 21% loss of material from the dumped area during the course of
the study. The profiles as run over the dump area showed erosion over
nearly all their length with accretion in the lower pockets, probably
indicating a flattening of the dump pile. After all dumping had been
completed there were three peaks on the dump area. The major material
losses occurred on these peaks and on the steeper slopes; particularly
on the seaward side.

Comparative Seasonal Surveys

Seasonal surveys made in April, July and October 1948 were used
as a basis for determining changes in the position of the high-water
shore line and the 12, 24, 30, 36 and 42-foot depth contours. The
April survey was made prior to the first dump; the July survey near
the end of the dumping period and the October survey after all dumping
had been completed. The purpose of these surveys was to aid in
detection of any realignment of the depth curves and shore line
resulting from the movement of the dumped material.

An examination of the high-water shore line showed that in general
accretion had taken place on the beach during the periods April-—July
and July-October, except during the latter period in the area north
of the jettied section adjacent to the pier. Here there had been a
general shifting of the sands with a relative balance between accretion
and erosion. Seaward from the shore line, excluding the area where
the dredged material had been deposited, there had been a general
oscillatory shifting of the depth curves. The changes in shoreline
and depth curves, exclusive of the dump area, do not show a detectable
movement of the dumped material. Such changes as did occur are con-
sidered to be the result of natural Seasonal changes in oceanographic
conditions.

Discussion

An examination of all waves recorded during the course of the
study, including the three severe storms, showed average waves
available to move the sand to be 12-foot waves of 10-second period,
6=foot waves of 8 second period, and 2-foot waves of 6-second period.
The bottom orbital velocities for these waves were computed for two
depths; 40-feet at the seaward toe of the pile and 28-feet as the
minimum depth at the crest of the pile. These velocities, applied to
Filip Hjulstrom's curve “Lower Limit of Eroding Velocities" with a
graph of the sand particle size distribution of the dumped.material,
show that in all but one instance (velocity of the 2-foot wave with
6-second period over a 40-foot depth) wave velocities were sufficient
to erode material from the bottom. However these eroding forces on the
bottom are not unidirectional but oscillatory.

In view of the nature of these forces and the assumption that
other transporting forces are extremely weak or even non-existent, it
is believed that the sand will merely be shifted about, filling the
depressions and flattening the pile in general. That this action did
occur was confirmed by an examination of the comparative dump area .
profiles covering the period after all dumping had been completed to
the date of the final survey of the study.

During the period of study between April and October 1948,
125,231 cubic yards of material were eroded from the pile. This
amounts to only 21% of the material dumped. As an examination of
the comparative seasonal surveys did not show a mass movement of
the material, the reasonable assumption has been made that the
material eroded from the pile has been scattered in a thin layer
over a wide area.

Conclusion

As 476,760 cubic yards or 79% of the total dredge bin measure
dumped at the site was still in place at the conclusion of the study
and since no beneficial effect on the beach attributable to the
dumped material has been observed, there is presently no indication
that shoreward movement of the dumped material will proceed at a
sufficient rate to be of value in nourishing the eroded shore.

Future Work. and Study

The Beach Erosion Board proposes to continue its wave observa—
tions and periodic surveys in the Long Branch area until sufficient
data are available for a comprehensive report.

wu

Resume of a report prepared by J. V. Hall, Chief of Field
Research Group, Beach Erosion Board.

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CARGO DEGK OF "DUCK" SHOWING GENERATOR,

TRANSFORMER, AND LIGHT MOUNTING

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MERCURY VAPOR LAMP INSTALLED ON "DUCK"

FIG

SURVEYING IN HAZE AND FOG

The Field Research Group of the Beach Erosion Board has been
conducting littoral drift studies on the coast of California at
Anaheim and Santa Monica Bays. Throughout the conduct of these
investigations it was necessary to follow a strict schedule for
hydrographic survey operations in order to meet the work schedule.
Standard survey methods employed by this group had to be modified
in order to permit operations during periods of poor visibility
created by haze and fog. Several expedients which would increase
the range of visibility of the instrument-men were tried, but
only one method showed enough promise to warrant its continued use.
This entailed the installation on the sounding craft of a high
intensity mercury vapor lamp that would be visible from shore
during the frequent periods of haze and fog.

This equipment consisted of a 220 volt, 60 cycle, 1600 lumen
mercury vapor lamp with a 400 volt-ampere, 110-220 volt autotrans=
former. A 13 kilovolt-ampere generator, driven by a gasoline engine,
was provided as the source of power for the lamp. The Sounding
craft on which the installation was made was an Army 23-ton amphibian
truck (commonly known as a “Duck"). Accompanying siereenaplae show
the location of this equipment aboard the "Duck." Reasonable protection,
such as a canvas tarpaulin, had to be provided for the transformer
and generator to shield it from salt water spray. The lamp itself
required no additional protection as it is constructed of two concentric
pyrex tubes, the outer tube protecting the hot inner tube from breaking
due to contact with sea spray.

This equipment, exclusive of the generator unit, can be procured
and installed for a cost outlay of about $50.00. If a suitable power
source is not available on the sounding craft, a portable generator
unit similar to the one described in this article can be suet for
about $350.00.

When the apparatus was installed, a number of tests were made
which showed that the use of the lamp increased the range of working
visibility by fifty to seventy-five percent. The Field Research Group
of the Beach Erosion Board has used the equipment during hydrographic
survey operations extending over a period of several months, and
during this period it is estimated that time lost due to haze and fog
has been reduced by fifty percent.

BEACH EROSION STUDIES

The principal types of beach erosion reports of studies at SPPEEERE
localities are the following:

a. Cooperative studies (authorization by the Chief of
Engineers in accordance with Section 2, River and
Harbor Act approved on 3 July 1930).

b. Preliminary examinations and surveys (Congressional
authorization by reference to locality by name).

ec. Reports on shore line changes which may result from
improvements of the entrances at the mouths of rivers
and inlets (Section 5, Public Law No. 409, 74th Con~
gress).

d. Reports on shore protection of Federal property
(authorization by the Chief of Engineers).

Of these types of studies, cooperative beach erosion studies
are the type most frequently made when a community desires in-
vestigation of its particular problem. As these studies have, con—-
sequently, greater general interest, information concerning studies
of specific localities contained in these quarterly bulletins will be
confined to cooperative studies. Information about other types of
studies can be obtained upon inquiry to this office.

Cooperative studies of beach erosion are studies made by the
Corps of Engineers in cooperation with appropriate agencies of the
various States by authority of Section 2 of the River and Harbor Act
approved on 3 July 1930. By executive ruling the cost of these
studies is divided equally between the United States and the coopera-
ting agency. Information concerning the initiation of a cooperative
study may be obtained from any District Engineer of the Corps of
Engineers. After a report on a cooperative study has been transmitted
to Congress, a summary thereof is included in the next issue of this
bulletin. A list of cooperative studies now in progress follows.

COOPERATIVE BEACH EROSION STUDIES IN PROGRESS

NEW HAMPSHIRE

HAMPTON BEACH. Cooperating Agency: New Hampshire Shore and Beach
Preservation and Development Commission.

Problem: To determine the best method of preventing further
erosion and of stabilizing and restoring the beaches;
also to determine the extent of silting and erosion
in the harbor.

MASSACHUSETTS

METROPOLITAN DISTRICT BEACHES, BOSTON. Cooperating Agency; Metropoli-
tan ane Commission (for the Commonwealth of Massachus—
etts).

Problem: To determine the best methods of preventing further
erosion, of stabilizing and improving the beaches, and
of protecting the sea walls of Lynn Shore Reservation,
Nahant Beach Parkway, Revere Beach, Quincy Shore, Nan-
tasket Beach.

SALISBURY BEACH. Cooperating Agency: Department of Public Works (for
the Commonwealth of Massachusetts). 3

Problem: To determine the best methods of preventing further
beach erosion. This will be a final report to report
dated 26 August 1941.

CONNECTICUT

STATE OF CONNECTICUT. Cooperating Agency: State of Connecticut
(Acting through the Flood Control and Water Policy Com-
mission).

Problems To determine the most suitable methods of stabilizing
and improving the shore line. Sections of the coast
will be studied in order of priority as requested by
the cooperating agency until the entire coast is in-
cluded.

NEW JERSEY

ATLANTIC CITY. Cooperating Agency: City of Atlantic City.

Problems To determine the best methods of preventing further beach
erosion.

OCEAN CITY. Cooperating Agency: City of Ocean City.

Problen: To determine the causes of erosion or accretion and
the effect of previously constructed groins and
structures, and to recommend remedial measures to
prevent further erosion and to restore the beaches.

VIRGINIA
VIRGINIA BEACH. Cooperating Agency: Town of Virginia Beach.

Problem: To determine methods for the improvement and pro=
tection of the beach and existing concrete sea wall.

SOUTH CAROLINA

STATE OF SOUTH CAROLINA. Cooperating Agency: State Highway Depart-
ment »

Problem: To determine the best method of preventing erosion,
stabilizing and improving the beaches.

LOUISIANA

LAKE PONTCHARTRAIN. Cooperating Agencys Board of Levee Commission-
ers, Orleans Levee District.

Problem: To determine the best method of effecting necessary
repairs to the existing sea wall and the desirability
of building an artificial beach to provide protection
to the wall and also to provide additional recreation-
al beach area.

TEXAS

GALVESTON COUNTY. Cooperating Agency: County Commi ssioners Court
of Galveston County.

Problem: To determine the best method of providing a permanent
beach and the necessity for further protection or
extending the sea wall within the area bounded by
the Galveston South Jetty and Eight Mile Road.

CALIFORNIA

STATE OF CALIFORNIA. Cooperating Agencys Division of Beaches and
Parks, State of California.

Problem: To conduct a study of the problems of beach erosion
and shore protection along the entire coast of Calif-
ornia. The initial studies are to be made in the
Ventura-Port Hueneme area and the Santa Monica area.

10

ILLINOIS

STATE OF ILLINOIS. Cooperating Agency: Department of Public Works
and Buildings, Division of Waterways, State of Illinois.

Problems To determine the best method of preventing further
erosion and of protecting the Lake Michigan shore
line within the Illinois boundaries.

OHIO

STATE OF OHIO. Cooperating Agency: State of Ohio (Acting through
the Superintendent of Public Works).

Problem: To determine the best method of preventing further
erosion of and stabilizing existing beaches, of
restoring and creating new beaches, and appropriate
locations for the development of recreational
facilities by the State along the Lake Erie shore
line.

PENNSYLVANIA

PRESQUE ISLE. Cooperating Agency: State Parks and Harbor Commission
of Erie (for the Commonwealth of Pennsylvania).

Problem: To determine the best method of preventing further
erosion and stabilizing the beaches of Presque Isle
Peninsula at Erie, Pennsylvania. This will be a
supplemental report to the report dated 3 April 1942.

Cooperative study on Colonial Beach, Va., formerly reported,
has been completed but not yet submitted to Congress. The Hancock
County, MWiss., cooperative study has been cancelled at the request
of local authorities.

The following reports have been published as House Documents
and are available to interested parties.

Winthrop Beach, Mass., State of North Carolina, Palm Beach, Fla.,

Jupiter Island, Fla., Anna Maria and Longboat Keys, Fla., Harrison Co.,
Miss., and Punta Las Marias, San Juan, P. R.

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BEACH EROSION LITERATURE

There are listed below some recent acquisitions of the Board's
library which are considered to be of general interest. Copies of
these publications can be obtained on 30-day loan by interested
official agencies.

“An Investigation of the Energy Dissipated in a Surface Roller,"
G. A. Oosterholt, Appl. Sci. Res., Vol. Al, pp. 107-130.

This paper deals with the problem of the dissipation of

energy in hydraulic jumps. Description is given of experiments
and computations to determine the quantity of energy converted
into heat per cubic centimeter and per second in a surface
roller. The results probably can be made to apply to other
cases of similar flow, such as eddies and wakes.

“Diffraction of Water Waves by Breakwaters," J. A. Putman and R. 8S.
_ Arthur, Scripps Institution of Oceanography, Wave Report No. 67.

Application is made of a solution of the water-wave diffraction
problem of Penny and Price to diffraction by a semi-infinite
impermeable breakwater. Approximations are introduced to
simplify application of the theory. Comparison of complete and
simplified solutions is made with results obtained from a
laboratory investigation. Best agreement between theory and
experiment occurred in the lee of the breakwater. The simpli-
fied solution is shown to be adequate for.most practical
applications.

“Coastal Water Circulation off the East Coast of the United States
between Cape Hatteras and Florida," D. F. Bumpus and T. Jd. Wehe,
Technical Report No. 16 on the Hydrography of the Western Atlantic,
Woods Hole Oceanographic Institution, January 1949, 9 pp., diagrams.

This paper discusses water circulation in the area inshore of the
Gulf Stream, with information on surface temperature, salinity
and density. Within this area a theory is postulated of one
elongated cyclonic movement and possibly several smaller eddies
occupying the coastal shelf.

12

4

"The Equatorial Currents of the Eastern Pacific as Maintained by
the Stress of the Wind," Robert 0. Reid, Scripps Institution of
Oceanography, Oceanographic Report No. ll.

Ignoring lateral friction and thermodynamic processes, this
paper verifies that, in the eastern equatorial Pacific, the
predominant features of the distribution of mass and of mass
transport of water can be accounted for semi-quantitatively in
terms of the wind stress.alone. I1t is concluded that the
longitudinal mass transport increases nearly linearly with
distance from the continent, while the north-south transport
is practically independent of longitude and is a maximum

very near the boundaries of the countercurrent.

"Recent Shoreline Changes at Shirley Gut, Boston Harbor,"
Robert L. Nichols, The Journal of Geology, Vol. 57-No. 1,
Jan. 1949, pp. 85-89, 4 diagrams.

The history of Shirley Gut and analysis of the physiographic
processes causing its closing and joining of Deer Island
to the mainland are briefly presented.

“Annual Variations in Current Speeds in the Gulf Stream System,"
Frederick C. Fuglister, Technical Report No. 15 on the Hydrography
of the Western Atlantic, Woods Hole Oceanographic Institution,
November 1948, 10 pp., diagrams and Tables.

"The purpose of this paper is to show that the many hundreds of
surface current observations on file at the U. S. Navy
Hydrographic Office also give what appears to be a consistmt
picture of annual variations in the current speeds in various
segments of the Gulf Stream System. ---" The Gulf Stream
System is divided into ten segments, and annual current speed
variation from observed data and as calculated from harmonic
analysis with a combination of annual and semiannual periods
are compared. The comparison is carried further between
variation in current speed and compment of wind in the direction
of the current, and current speed variation and tide gauge
records.

13