TOM HIdTGRY AHJJ C0H3TRIWTI0M OF i'riB HAtfQVEK S2BBBS BRIDGE, IB l&LSIMOBB, MaRYLaUJ). TiiSSIS PRBPaRBJ) B2 JOxiJi P.HAZBAPJ) FOR IMISIASIOH luliu EEB MaK*LaIUj BB2A Ofl&PEBB OF XaU BBtA ?I FRAEBBIISX DBO. 2, 1934. The point in the right middle ground is "Ferry Bar. dulMARX 2xiox to 1856, communication from Ferry .oar, Baltimore City, Cj Anne Arundel County was "by ferries running to a number of points, in 18F6, Richard 0. Orisp and Hichard Gromwell wore given the right to build a toil bridge Iron Perry .Bar across to Brooklyn in Anne arundol County. This bridge was operated until 1880, when the oity of Baltimore and Anne Arundel County bought it. It was reconstructed of timber in 1891 and remained in use until 1J16, when the present bridge was constructed. The Hanover Street Bridge is a true cantilever bridge encased in reinforced cone rote to give the appearance of a true elliptical arch. The cantilever design was adopted on account of tno soft mud and troacherous bottom and economical construction, The piers are of concrete, with just enough reinforcing to bind and confine the mass. The supers true tore consists of a retaining wall resting on piles, a long arcade and twelve cantilever spans with a Hall type bascule bridge for the channel. The retaining wall extends for 250 ft. l J in. The aroucte is 4b0 ft, 10 in, long. The center to center distance between tno piers for the cantilevers is 103 ft. in., and the bascule is 286 ft, 4 in. long. The spans of the superstructure consist of ten arch ribs composed of structural steel. The total length of the bridge between abutments ia 8290 ft. Z in. There are 50 £oet of filaar roadway and two 8 ft. sidewalks. Included in the briage project was the cutting tnru the point of land -between the middle branch and the main branch of the ?atapsco River, and filling and building two bridges across the main branch, These bridges are of the reinforced concrete girder type 500 ft. and 100 ft. long. All condi- tions as to roadway, sidewalks, conduits, loading, etc. are the same as the main bridge across the middle branch. At the proseat time, the entire project while not unsafe for use, is in poor condition structurally. The arcade and the fill at tho nortu, or Baltimore end of the mam bridge, are settling. The concrete work is in poor shape on tne big bridge, having crumbled in numerous places. The fill at the main branch has settled and con- tinues to settle; and the north abutment of trie 500 ft. briage must be replaced. The entire job, in the opinion of various people, was poorly carriod thru, with the result that there has been a continual patching process required to keep the project in passable condition. BIBLIOGRAPHY Reports of the State Roads uonnission of iiaryland for 1914-16, S'ilea of tne Baltimore Sunday dun (B, Latrobe Weston). U on tract drawings in possession ot J. 2. (ireiner Co, " it ti it « harbor Engineer of B al t imo r e , 1 id . Partial Specifications in possession of tne State Roads Commission of Maryland. i'ho writer wishes to express his gratitude to the various engineers of the City of Baltimore ana tne state of Maryland who vsero very kind in placing at his disposal the various plans and specifications which were available. nowcver, due to the age of the structure and the little use of information on this bridge, the plana and specifications vii ere very incomplete. _1 _ HIS'fGHY 'She .?atap3Co Rivor, at Perry xiar, aep«rated the 8»u»k»ru part of Baltimore l're* we.** useu to be a peyuleua and. prosperous farming diatriot uround Broeklya in Anne Arundel County. True, tnere a&a a bridge across the iiver at Humphrey, Anne arundel County, but this route into Baltimore meant a detour o :' several miles. Eather tnan take this long trip, mo at of tne people of tne Brooklyn section resorted to ferries, of whiek there were several, running from *erry Bar to various points on the county ahoro. Possibly the most picturesque of the old ferryaen waa tiack ^lood known to the elder generation of Baltimore fox nis Beer Pardon on Ferry liar. Richard Oronwoll was a wealthy farmer , of the Brooklyn district, who owned a £00 acre fan*. 16 u.as the difficulty sn& expense of getting the products of his farm to aarkst that lod him with Eiohard 0. Grisp to petition the Maryland Legislature for tne right to build a toll bridge from ferry aar across to Brooklyn, jsy authority granted under Aots of 1056, Chapter 816, Laws of Maryj.anu, the two i'jen were grantee. the:r request, 'i'he briage which was constructed was the parent of the later Light Street Briage and the present Hanover Street span. The old bridge, _c ^ being one tail a loti^, »aa nicknamed "lone Bridge", and this nana stuck to the Light Street structure until its demolition in (1916). The bridge operated as a toll bridge on a well paying basis until 1880, when it was purchased by the Mayer and >Jity Council oi Baltimore and the county commissioners of Anno Arundel County at a cost of £.3600, ...f tor this time iho bridge was made free. in lbdl, the bridge naa rocons true ted of timber, with a turn draw over the channel at a cost of about $166,000* 'The reconstructed bridge was officially known as the Lignt Street jiriago because of tno fact that its Baltiaore end was at tne foot of Light street. This structure, with very* extensive repairs, remained in use until tne Hanover i treat .bridge was opened to traffic in ±1*16. The importance of the bridge as a link between Baltimore ana Annapolis and. Southeri Maryland increased aa time want on. The traffic ovor it, to these points, in- creased so greatly that a larger, more modern, and more permanent bridge became imperative. In 1913 the City of Baltimore voted on a bond issue of $2,000,000 to replace the bridge; but the loan was defeated by popular vote. In 1914 the Maryland Legislature appropriated yl.oOO.OOO from the .state road loan, under Chapter 367, to be used in Baltimore -5- Qity. ihe State Heads 'Jomnission was to orect a new "bridge along the liaos of the old Light 3 treat bridge or from the foot of uharles or hanover streets, to a point of land in Baltiraoro bounty, thence by a street across the joint of land in Baltimore bounty to the Patapaco P.iver, ana across the Patapseo River by a fill and bridge to .^irst Street, Brooklyn, inne Arundel Uounty. r i'hc point of land in Baltimore County, as well as Brooklyn, is now a part of Baltimore City, If there was any unexpended balance remaining, the ;3aae was to be spent on paving streets in Baltimore uity. m compliance with this Act she State Roads Commission made an investigation into the most logical location for the bridge, After exhaustive studies and a number of conferences with tohe unite a States Engineer's office, as well as wl tn those interested, it was deeiaea to construct, the bridge from the foot ox haaover street. This was done so as to interfere as little us possible with the commerce of the harbor and throw below the bridge a very much larger area which aould tie uaed for harbor purxjoses. At the same time, thia gave a great dual more pier frontage below the bridge so that vessels plyiag in this locality would not have to pass thru the draw. -4- GOJiSTRUOTIOa oj? v PRBSBNE BSIDSB i 1 he main bridge o*er tae Liiddle Branch la 2290 ft. 2 in. long, from its Baltimore, or northern extremity, to its southern abutment. Frem the northern end a reinforced concrete retaining wall resting on piles extends on a fill 2b0 it. 9 in. into the river. A rein- forced concrete arcade extends from the end of the retain- ing wall 450 ft. 10 in. to pier number 1. x'hero are twelve cantilever spans for which the piera are placed 1 'J5 ft. 3 in. center to center, and a Rail type bascule bridLge 2d6 ft. 4 in. in length over tho channel, 'ihe road- way is 50 ft. in the clear, and there are two sidewalks which are b ft. wide. The bridge is designed for a dead load of 1L50 pounds per square foot of surface, and two street car tracks weighing £50 pounds per lineal foot, The live load is for two b0 ten electric cars, one on each track with two four wheel trucks; on the roadway two 24 ton trucks; and on the sidewalks 103 pounds per square foot. xho live load stresses were increased by 16 per cent for iiapao t , a ver^ cloee investigation was made of the bottom for tho construction of tho substructure of the bridge. xhe depth of the water was from four to twenty- eight feet deep in the channel. Ihe sub soil consisted of 50 ft. of soft mud, then a strata of gravel and sand, then el ay, then a layer of gravel to solid oottom which was approximately 100 ft, below the surface of the water. The substructure for the retaining wall and arcade ooaaiats of Georgia long leaf pine piles driven firem 75 ft, to 100 it, below the surface of the water, and filled around with gravel and sand up to five feet above the water. The refusal of those piles was 1/8 in. movement per blow for five clows of a 3000 pound hammer, with a 15 ft. drop. The concrete in the wall was 1 - 2-1/2-5 mix below the coping; and 1 - 3-4 nix in the coping and above. The reinforcement consisted of 3/4 in, open hearth stool reinforcing rods placed 3 diameters apart. The arcade consists of 95 rein- forced concrete colunns resting on piles like the retaining wall. There are la transverse rows of these columns, b across. The piors are 15 in number. ?our of these are extra heavy because of tneir connection with the bascule. .mother, the first pier beyond the arcade is heavier than tne remaining piors. The piles, for the footings of all tno pi era, were driven any where from Vfc ft. to ±00 ft. below the surface of the water. Owing to the groat depth of soft mud, the foundations were difficult and extra- ordinary care had to be taken with the building and bracing -6- of the cofferdams. The «ud was pumped from tho cofferdams down to from 30 ft. to 40 ft. below the surface of the water. The pilea were then filled around with unwashed gravel to a depth of about b ft. The concrete was poured on the gravel ad a b^se. i'he ordinary piers, ef which there are ten, were aet on £L0 piles each. The footings at the base measure 26 ft. in. x 60 ft. t> in, and the total concrete in the ten piers id Z&bb ou. yds. of 1 - 2-4 nix and 6610 eu. yds. »f 1 - L-l/2-5 mix. The five larger piera are aet each on 319 piles. The footings at the base measure 30 ft. 4 in. x 80 ft. 6 In. The concrete in the i a Bear the bascule totals 17 52 eu. yds. of 1 - 2-4 mix ana 4624 ou. yds. of 1 - 2-1/2-5 mix, while pier do. 1 at the ond of the arcade contains 353 cu. yds. of 1 - 2-4 nix and 953 cu. yas. of 1 - 8-1/E-5 nix. Anchor bolts for the stool work of the super structure are set in each of the piers, .ill of the piers are reinforced horizon tally by a network of 3/4 in, reinforcing rods spaced 6 in. apart just above the bed of tho footing. The vertical reinforcing consists of ju3t sufficient reinforcement to bind and confine thu mass of the pier. The stability factor oi tho piers is 2. The south abutment of the bridge is built on a base of 130 reinforced concrete piles. The concrete used thruout the piers is granolithic. The working stresses -7- allowed in the concrete work are aa fellows: Compression stresses; coacreto under direct compression allowed 450 pounds per square foot; bending stress on concrete allowed on unoon fined surface of concrete is 6E0 pounds per square foot, There is no allowable tension stress in concrete. The tension stress for steel is 16,000 pounds per square foot. The shear stress for concrete is ISO pounds per square foot, while the shear stress for the reinforcing rods is 12,000 pounds per square foot, ihe spars ox the superstructure consist of 10 arched ribs composed of structural steel; i'he steel being made strong enuugh to carry the dead load of the concrete and the forms. The steel arch ribs were nude at Sparrows Point, fl oaten to tne siue of the bridge on lighters, and lifted into place by heavy derricks. Huts to tne anchor bolts were screwed down, trie ferns placed and the eoner«tiog begun. This nude the erection extremely simple and no undarbracing whatever was necessary. The spans are true cantilever and all stresses and strains wore computed for aueh.. The concrete covering gives the bridge the ap^je ara nee of a t ru« e 11 ip tic al arch , The sheet asphalt roadway of the bridge is carried on the reinforced concrete slab of the bridge. The side- walks are of reinforced slab concrete with a granolithic -8- finish. The guard rail of the bridge is of monolitnic re- inforced concrete about 10 in. thick. These raila are a con- tinuation of the sides of triage , being tied to the lower stricture "by the reinforcing rocis. The expansion joints, which were placed in the concrete work' of th» superstructure wnen tne bridge was built, proved inadequate and up until 1931, when extensile repairs wrre made, there was a continual patching going on at those joints. The draw span has a clearance of 38 ft. 6 in. above mean low water ana a width in the clear when open of 150 ft. i'he length between breaks in the roadway at each end is ^proximately 195 ft. 8 in. In eacn leaf there are two principal s4ruc+ural stael cantilevers one Hfc ft. on each side of the center line o^ che bridge. Their overall length is 110 ft. 8 in. The SI in. horizontal axles divide these into long and short arms of 80 ft. 8 in. and ^0 ft. The cantilevers are braced together with the flaor beams and top and bottom laterals, and carry the street car tracks and .roadway. The paving of the roadway on the draw consists of creosote! wooden blocks resting on the reinforced concrete slab of the bridge deck. The 8 ft. sidewalks are cantilevered outside the girders on structural steal brackets which are secured to the vertical members of the girders. The sidewalks on the draw consist of 1-1/2 in. planking placed transversely on the stringers and the railing on the draw is of steel. -9- Ihe trunnions are of hollow forced steel about 8 ft. long, SI in. in diameter at the bearing in the roller aad 12 in. in diamotcr on the innei end bearing. The short am on eaoh leaf contains a stool plate b©3c,h«ld«- ing the oo no rote and stone counterweight*. Ihen the Aruw is closed, thcro is a 4 in. clearunce between the ends of the loaves and the entire load is taken by the oaoi>a.iuvcr action of the short amis engaging the horizontal transverse anchorage reaction girder set in the heavy piers adjacent to tjiQ main bascule piors. There ia a «h«*ar look at the center o£ the spun consisting of two 5/4 in, steel plates b in. wide and having a loagltjudinal ««vaaent of lb in., which tends zo distribute the shearing force over both leaves. This lock ia louated in sno nor on leaf, vhe plai.es engaging sockets in the end of the south leaf. The locking device is controlled thru a system of gears and levers either by motor or by hand from the operating house at the aort.ieu.at corner of the draw. The operation of the draw is by tne Hall bascule method, the patent for which ia hold by the Strobel Steel Construction Go. of Chicago, 111. It consists of segmental racks bolted on to the short arm oi the cantilever girder* *nd travelling on a pivoted operating arm. at the same time, the trunnions which are mounted on rollers 80 in. in diameter and with 20 in, faces aevc taru a horizontal -10- distance of Iz it,, whul- She ends of tkm leaved rise. ihe racks on eacu Immt are driven by ewo General Electric 30 ii.P» .i.C motors which are i'uliy enclosed u.nd have waterproof insulation. ihe four 1x0 tors for fcha draw are all con trolled from the northeast operating house, the power for the motors on the south leaf being carried by a submarine cable across the channel, i'he motors and operat- ing machinery are set under the ends of the span, and they are controlled bj means 01" brake tan us, controllers, and resistances. The gears are all oust a to el, their teeth, rims, ore. running true. Their attachment to the shafts are a light drive fit Keyed. Mating spur gear wheels are placed so that the molding draft 01 their teeth is reversed. The teeth are all trimmed to template so chat the bearing marks extend over half their length. Eke gear teeth are of the involute curve typet having an ungle oi obliquity of 16°. ihe depth ox the teeth is 65 times their circular pitch. The journal blocks are of cast steel lined with babbit. Shafting over 4-1/2 in. diameter was forged ox rolled and turned while that of 4-1/2 in, diameter and under was cold rolled. All forging3 are annealed and carefully inspected, ihe trunnion bearings are provided with compression grease aupa, usin^' a £Ln« grade oj: graphite grease, i'he trunnion shafts are provided with 1/E in. slots to distribute the -11- grease, There are three grease eups to each bearing, ihere is also provided auxilliary hand gear operated "by a capstan for lifting the leaves of the bascule. These emergency devices are located one in the roadway at the bridge end of each leaf. The bascule piers are protected by buffers on each side of the channel. These buffers consist of rows of timber piles extending up and down the river for 100 ft. on either side of the bridge. These piles are placed 10 ft. from the piers. Three horizontal girts are bolted and spiked on the piles and vertical planking extending well below low water and about 15 ft. above mean low water was placed on the girts. At the ends of the buffers, clusters of piles, bound with wire cable, were placed. At this point, it will be interesting tc aote that it was necessary te dredge a now channel as one of the piers of the draw span stood directly in wic old channel. 175,000 cu. yds. of earth had to be removed at a cost of ££0,000 so as to arrange the now chancel to fit tfce draw opening. Ihere are four houses at the Axcw but enly one, that at the east end of the north pier, is used for an sperating house. The southeast and the northwest houses were, until a few years ago, used as comfort stations. How- ever, the failure of the construction engine ors to locate accurately the water mains on the bridge necessitated the -12- closing of these comfort stations due tc the impossibility of fi.aj.iig a burst wat«r *&iiu The sou un. west house is used merely as a storeroom and waiting station. The houses are of reinforced monolithic aoncice ^tending ciown to the draw piers and the heavy piers adjacent. (Hote - i'he contra k drawings called for these houses to be placed on a tooting of piles, iiowever, Mr. Kipp, the d&x'b»x Engineer of .Baltimore City, states that these houses ure merely spanner across adjacent piers, there being no footing below tnem) , The houses are about 29 ft. 6 in. long, IS ft. wide, and 54 ft. £ in. high. They are suraountea with ornamental copper lights, line re are two stories above the bridge and a companijnway leads to tne piers underneath. The operating house contains all the controls and automatic devices used in connection with the draw. Motor operated safety gates of the type used at railway grade crossings close the roadway on each side of the draw when tne draw is open. Those gat-es are controlled from the opciating hoiiso. The house contains, besides .he switch- board, brakes and oca trailers for various motors, many electrical devices which promote the safer operation of the draw. i'hero is a sy^em of lights showing tne position of each loaf or" the araw in various stages; open, nearly open, free, nearly closed, and closed. By means of this device, the operator may tell exactly where oaoh leaf is v^iuhoui; -13- leaving his post. There is a like system which indicates whether the shear lock at the centei of the span is locked or unlocked. There are navigation lights ahowlng up <*nd dew a the river which show rad while the dra?/ is closed but automatically turn to green when the draw reaches its full height. Included in the iianover Street, Brlape project was the cutting thru the point of land in Baltimore County and aaxrying the road acroj3 the j»ain branch of the Patupsco raver "by means of a fill, a 500 ft, bridge and a 100 ft. bridge to first Street, Brooklyn. The -entire length of this purv of the project is about 6800 ft. Approximately BOO, 000 QU. yds, of earth were removed from the cut and placed in the fill, iiue ouv at tne deepest point was 46 ft. The section of fill from the Baltimore county side of the 500 ft. bridge over the. channel of trie Patapaco River was placed over a veiy soft bottom and there is still trouble with Sale portion of the roadway settling. The two bridges are of the reinforcea concrete girder type. They ar* of the same width a3 uhe main bridge and are designed for the same loads. The design of the bridge wda vorked out under Che supervision of Ilr. J.JS. Greiner, Consulting Engineer, Baltimore, Md. The oeatruet for the eat and superstructure of the bridge across the Kiddle Branch was awarded to -14- H.T?. 0© averse and Oo. of £03 ton, iAeas. &e connect for the construe tien of the lift spans over the main channel was awarded to tha dtrobel Steel Construction Co. of 3ki©ag6, 111. The contract for the small bridges was awarded to the Ucican Contracting Co. of Baltimore, hd. The total cost 01 the main structure including paving, lighting, drawbridge, etc, *aa approximately $900,000. The cost of the cut and fill was approximately ^ 115, 000. The 00 st of the snaalj. bridges was approximately ^130,000. xhe total coat of %%m entire project was approximately $1,200,000, There have been extensive repairs made on the project sinae 1916, In 1917 and 1918 several of tne footings under the arcade of the main bridge had to be replaced* 'iiha nud had caused the old footings to shift and caused some dangerous conditions in the bridge. j?ro* 1925 on, each year there was werk dane on -no concrete ?<erK at „._e expansion joints uhieh were faulty. In 1031 the faulty expansion joints were replaced and since that time there has been very little trouble of this sort, at the fill in the main branch of the Patupsco River there has been much trouble with settlement due to the soft bottom. In 1932 the roaaway was torn up half at a time, so as not to interfere with traffic, and piles were driven to carry the roadway, however, the roadway continues to settle and there has been no satisfactory remedy worked out to date. -16- The north abutment of the 600 ft. bridge at the end of this fill is* at the present tine, in such a condition as to require replacement in the near future. G0HCXU3IQB The Hanover street Bridge is. in the opinion of the engineers in charge of its maintenance, an extremely poor pieoe of work. It was the first large bridge construction project that the State Beads uommission ever attempted, consequently, the inspectors on the job had little or no experience in the work they were expected to do. This fact is evidenced by trie absenae of the footings for the operating houses and the inadequate expansion joints, as well as the more serious impairment in the form of the shifting of the footings under the arcade, however, in the past few years, the repairs which have been made, and are being contemplated will keep the bridge in passable condition for several years. The draw is not very much used at present, Kost of the marine traffic under the bridge consists of tugs hauling barges and old schooners carrying lumber and bricks into the upper reaches of the niddle .Branch, The bridge, although itself none too good structurally, was a stepping atoae to better bridges for the -16- State Roads Commission. At the present time, it is carrying its volume of traffic to Annapolis, Southern Maryland, and the lately opened shore resorts along the uhesapeake and its rivers . It is performing the task for which it was built. —17— Map showing location of old and new bridges. View looking south across the Patapsco River from Terry Bar. Piles from the old bridge may be seen just offshore. —18- Yiew of Middle Branch bridge looking north from Broening Park. r sjjfc — ^I tt t: View of hridge looking west from Ferry Bar. -19- View under one of the arches showing the ten girders comprising each span. View of the west side of the south abutment. -20- View under the areade at the north end of the "bridge. View showing the under side of the south leaf of the Bascule, taken while the draw was open* -21- Two Tiews of the steel work of tha Bascule, -23- r One of the four nouses next to the Bascule. Plate on the Bascule.