The London County Council Holborn-To-Strand Improve- Ment, and Tramway-Subway.”

SOUT~ERNS,TATION IN KINQSWAY: SECTION ~t BB

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PLAN OF PORTION BETWEEN THE STRANO AND VICTORIA EMBANKMENT.

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8 November, 1910. ALEXANDERSIEMENS, President, in the Chair.

(Paper No. 3903.) (‘The London County Council Holborn-to-Strand Improve- ment, and Tramway-Subway.”

By GEORGEWILLIAM HUJIPHREYS, M. Inst. C.E. THE works forming the subject of this communication, which were commenced in 1899 and completed at the beginning of 1908, form the largest street-improvement that has been carried out in London since the making of Regent Street in 1820. They furnish the first example, in this country, of a shallowsubway for the use of the street-tramcar ; the, roadway provides a noteworthy north-to-south connectionbetween importanteast-to-west arteries ; andthe tramway-subwayaffords through communication in the centre of London between the tramway systems north and south of the River Thames.

HISTORICAL. The new thoroughfare, the main (north) part of which has been named Kingsway and the crescent (south) portion Aldwych, is near the site formerly occupied by a roadway between Holborn and the Strand that dated evidently from very early times ; it ran by way of Drury La,ne, which is probably on the site of the Via de Aldewyche, the ancientvillage of thatname giving to the authorities the inspiration for the present title. The need of communicationbetween Holborn ancl the Stra.nd more direct than that afforded by way of Little and Great Queen Streets and Drury Lane (Fig. 1, Plate l), or the tortuous streets to the east of thelatter, became more apparentas the population of London grew, and the cross traffic induced by the presence of the

large railway-termini in the north and south of London increased. In addition,the contraction of theStrand between St. Mary- le-Strandand St. Clement Danes churcheshad formed for some time a serious hindrance to the growing stream of traffic between east and west. Shortlystated, the scheme of improvement dealtwith in this Paper comprises the formation of a new street, Kingsway and Ald- wych, running north and south from Holborn to the Strand, the widening of Southampton Row, the widening of the Strand from Wellington Street to St. Clement Daneschurch, and incidentally the clearance of theinsanitary areas on or nearthe site of the improvement (Fig. 2, Plate 1). The network of mean and insignifi- cant streets covering the area through which the new thoroughfare was cut furnished a typical example of the evils brought about in thepast by the lack of a centralauthority having a controlling voice inthe formation of streets-a state of things which the Housing, Town Planning, etc. Act, 1909, if properly administered, should prevent in the future. Both the widening of the Strand between the two churches, and thestreet-communication between Holborn and the Strand, were included in a list of suggested improvementssubmitted to the House of Commons in 1836 by a SelectCommittee onMetro- politan improvements, but for financial reasons their consideration was postponed. In 1889 theLondon County Council promoted a Billfor the Strand widening, which was withdrawn, and the two questions of the Strand widening and the new street, with themeans of meeting the expenditure, occupied the Council’s attention at several times until, in July, 1896, it decided to apply for powers for widening the Strand only. The Bill embodying these proposals became law the following year in an amended form, under the title of the London County Council (Improvements) Act, 1897. A second part of the general improvement-scheme was initiated in thesame year, when a favourable opportunity presented itself for purchasing by agreementcertain buildings on theeast side of Southampton Row, between that street and Kingsgate Street ; and powers were obtained in the London CountyCouncil (Improvements) Act, 1899, toacquire certain other properties, contingent upon a scheme of widening Southampton Row. The area lying between Holborn and the Strand, on and adjacent tothe site of Kingsway, included some very insanitaryareas, covered withslum buildings of the poorest description,and a ProvisionalOrder for sanctioning a scheme promulgatedby the

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HOLBORN-TO-STRAND IMPROVEMENT. 23 Council for dealing with these insanitary areas was confirmed by Parliament in 1897. Authorityhaving been obtained tocarry into effect thethree schemes of the Strand widening, the Southampton Row widening, andthe demolition of buildings on the ClareMarket area, the financial and other considerations arising emphasized the necessity that, if a new street were constructedbetween Holborn and the Strand, all these schemes should be dealt with at one time. Accordingly, in 1898 the Council, after considering many designs, approved the scheme forthe formation of the new thoroughfare from Holborn to the Strand and the Strand widening in the form in which it was ultimately carried out, and in1899 a Bill embodying the proposals, which involved an estimated expenditure stated to be 25,134,500, wa3 introduced. This was probably the largest scheme of town-improvement ever before Parliament, and the principle of recoupment by sale of surplus lands was embraced to a larger extent than heretofore.The Bill metwith a greatdeal of opposition: severalimportant financial considerations were involved, andthc Council, in orderto avoidcompensating displaced owners on the basis of the Lands Clauses Acts, made agreements for reinstatement in many, and in the most important, cases. The Bill was ultimately passed, and received the Royal Assent under the title of the London County Council (Improvements) Act, 1899. " Betterment '' and " worsement " clauses were inserted, the provisions of the London County Council Subways Act, 1893, were incorporated,and, for rehousing persons who were dependenton fixed employment, the Council undertook to acquire, by agreement, land within a mile of the residences of persons displaced. The foregoing summarizes the procedure that was necessary to obtain the requisite powers for the street-works, as apart from the tramway-works. As regards the latter,in 1899 the Council ordered the preparation of a report on the practicabilityof constructing a shallow tramway- subway from Westminster, by way of the Strand, to the northern system of tramways ending in Moorgate Street (City). It decided, however, in 1901, to apply for powers to effect a junction with the northern system by way of a subway between Theobald's Road and theVictoria Embankment at WaterlooBridge, to be followed ultimately by a surfaceline along the Embankment east and west, and over WestminsterBridge, so as tolink up with the southernsystem. Powers for the Embankment extension were asked for in a Bill before Parliamentin 1902, but were refused,The Subway Bill,

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. 24 IIUYPHREYS ON THE LONDONCOUNTY COUNCIL [Minutes of however, was passed ; but, while it granted powers to make the subway through from Theobald’s Roadto the Embankment, it gave permission tolay the tramway only as fa,r as the Strancl. In 1906, however, permission to lay the missing length of subway-tramway was granted,and in the same year powers were obtained to lay the surfacetramways over Westminster Bridge and along the Embankment. It will thus be seen that the history of the obtaining of powers- parliamentary and otherwise-for the work about to be described extendedover a considerable period, andentailed the removal of a large amount of opposition ; it also involved the consideration of many and various points of principle, and the reconciliation of powerful and conflicting interests. The date fixed by Parliament before which the completion of the new street, the Strandwidening, and thesubway-construction should be accomplished was the 9th August,1906. This was extended in the case of the tramway-subway until the 8th August, 1909, as, owing to the restriction, imposed in 1902 and removed in 1906, of laying rails from Theobald’s Road as far only as the Strand, the subway atthis latter date had not been commenced asregards the portion between thenorth side of theStrand and the Embank- ment.Except in the special case justreferred to, only a formal extension of time had tobe applied for, as during theperiod between September, 1901, and the end of 1905 the whole of the improvement waspractically accomplished. The missing length of subway was completed inApril, 1908, or 16 months before the final lapse of powers.‘

MAIN FEATGRESOF THE SCHEME. Thenorth side of theStrand between WellingtonStreet and the Law Courts has been set back, and the churchyards of St. Mary- le-Strand and St. Clement Danes have been curtailed, the churches themselves being untouched. The least width between the buildings onthe two sides of theStrand will be about 100 feet,and the greatest about 120 feet. The corresponding widths of roadway are about60 feet and 80 feet. Where St. Mary-le-Strand Church forms an island, the minimum width of roadway for traffic in one direction is 33 feet. .- For further historical particulars reference should be made to the London County Council pamphlet,dated 14th October, 1905, “Opening of Kingsway and Aldwych ” and also to the various :Annual Reports of the London County Council.

The crescent-shaped street Aldwych, the twohorns of which rlebouch at the ends of the widened Strand, has a uniform width of 100 feet between buildings, and of 60 feet between curbs, each footwaybeing 20 feet wide.Two spur streets afford direct access from Aldwych to the Strand opposite Somerset House and Surrey Street respectively. Fromthe centre of the Aldwychcrescent the thoroughfare Kingsmay proceeds in a straight line so as to intersect Holborn at the mostfavourable angle to form a continuation of a widened Southampton Row. Thewidth of Kingswaybetween buildings is 100 feet,and twofootways of 20 feetwidth each leave a width of 60 feet between curbs. Thewidth of Southampton Row, wherewidened, ranges from 105 feet betweenbuildings and 73 feet betweencurbs to 80 feet and 48 feet respectively. In the widerportion is theentrance tothe tramway-subway, 27 feet B inchesover all, leaving clear roadways of 22 feet 9 inches for up and down traffic respectively. These features of the scheme are shown in Fig. 2, Plate 1. Thegradients of theStrand remainpractically unaltered. The gradient of Aldwych in the westernhorn is 1 in 56, and in the eastern 1 in 50. The steepest gradient of any communicating side street is 1 in 25 (Catherine Street). The gradient of Kingsway is 1 in 105 for the greater part of its length, and 1 in 75 just before it reaches Holborn. The two spur streets in the island site lying between theStrand and Aldwychpresented some difficulty as regardsgradient. The western one hastherefore been arranged to beon a level withthe Strand, terminating in stepsleading to Aldwych. TheRoyal Institute of BritishArchitects had beenconsulted withregard tothe generallocation of the scheme ; andas the LondonCounty Council has control of thearchitectural features connected with the improvement, the total length of the frontages of the newbuildings to be erectedbeing nearly l& mile, it procured designs from selected architects to guide it in theexercise of this power. Under the whole of Kingsway and the western horn of Aldwych a tramway-subway carrying two tracks has been built. Cars leave the surface in Southampton Row near the end of Theobald’s Road, descend by an open inclined approach of 1 in 10, 180 feet long, and runin tunnel under Holborn,Kingsway, and Aldwych, crossing under the Strand and Wellington Street to thelevel of the Victoria Embankment.The gradients of thetramway are shown inthe longitudinal section (Fig. 3, Plate 1).

SEQUENCEOF THE WORKS. The dates of commencement and the rate of progress of the work were decided primarily by the passing of the several Acts, and also by the progress of thenegotiations for the acquisition of the various properties. The work was undertakenin sections, as indicated inFig. 1, Plate 1, the following Table showing the date on which the Council

MAIK SE:CTIOKSOF THE SCHEME. I Ref. Acts of Parliament Section of Scheme. Dnte of Date of , ty; i Comnrence- Completion. obtained. i l Description. 1nent.

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L.C.C. (Improve- ~ 1 SewStreet (continuation of ments) Act, York Street) from Cathe-

pssed 6Bug. 1897 1 I rineStreet to Drury Lane Aug. 1S99 Feb. 1900 Temporary paving of Strand on site of Holywell Street block of buildings . . . Mar. 1900 July 1901 Ditto, Pavinground St. Clement passed 9 Aug. 1899 Danesand St. Mary-le- Strandchurches . . . Apr. l901 July 1901 kl'idening of Southampton Row between Eagle SL treet and Holborn . . . . June 1901 Nov. 1901 Widening of Strand between Catherine Street and Law Courts ...... Sept. 1901 June 1902 L.C.C. Subways 6 Eastern horn of dldwych . Dec. 1902 Sept. 1903 snd Tranlwny-s Western Apr. 1903 May 1904 Act, passed 7 ,, ,, ,, 8 Aug. 1902 8 Northernmostportions of Kingsway and Southamp- ton Row . . . . . Sept. 1903 Juue 1905 9 Central portion of Aldwych Jan. 1904 Mar. 1905 10 Westernjunction of Ald- wych andStraud . . . May 1904 Mar. 1905 11 Southernmostportion of Kingsway . . . . . Aug. l904 L4pr. 1906 l2 Central portion of Kingsway Apr. 1905 JL:Lr. 1906 13 Tramway trackwork in subway from Theobald's Road tothe Strand . . . . Sept. 1905 Jan. 1906 L.C.C. (Tramways 14 Subsidiary paving and other and Improve- works in side streets . . Nov. 1906 Jan. 1905 ments) Act,passed 15 Tramway-subwayaud track 4 Aug. 1906 fromStrand to Victoria Embankment . . . . Mur. 1907 Apr. 1905

passed theorder for the commencement of each section, and the approximate date of completion of each. It willbe seen thatthe first works authorizedand contem- plated before the passing of the 1899 Act were, withthe exception of a smallstreet between CatherineStreet and Drury Lane, works affectingthe Strand only. They included the curtailment of the enclosed areas around the two churches, to the benefit of the roadway, and a temporary widening of the Strand. The only matter of any moment in thisconnection was the exhuma- tion of some human remains at St. Clement Danes Church, which was carefullyand reverently carried out, the remains being re- interrecl in Brookwood cemetery. Theopportunity was takento construct the easternmost portionof the pipe-subway in the Strand, shown in Fig. 2, Plate 1. TheAct of 1897 only authorized the removal of ,the block of buildings to the southof what was HolywellStreet, and arrangements were at once put in hand to acquire the properties. The cellars and vaults belonging to them, many of which extended a good distance under tlle old Strand-insome cases up to within 15 feet of its southern curb-line-were filled in and consolidated, the whole area, being paved temporarily with 6-inchcreosoted soft- wood blockslaid on 9 inches of concrete. This work was entrusted to the Strand District Board of Works, now superseded by the Westminster City Council. Thelevels worked to were those which would allow, at the least expense, for a street tobe temporarily widened until thepowers then being sought, for setting back the northern curb-line and treating the Strand :LS :L whole, wereobtained. The Table on p. 26 shows that in September, 1901, it was possible to commence the widening proper of the Strand, and to construct the new pipe-subways and sewers, the outlineof which is shown in Fig. 2 ; by takingin hand one side of the thoroughfareat a time, a stoppage of traffic was obviated. In the early part of 1901the south end of Southampton Row was widened and the pipe-subways, etc., shown in Fig. 2, were constructed as far as the north side of Eagle Street. Theconstruction of otherportions of the improvement will be dealt with in n description of the tramway-subway, but there are certainfeatures common to all the road-work which can nowbe described. PIPE-SUBWAYSAND VAULTS. The London County Council Subways Act of 1893 empowers the Council to require that, where there are subways in a thoroughfare, gas-, water-, and other companies shall lay their pipes therein and

pya rent in respect of the user. A feature of the scheme is the provision ol a pipe-subway on the north side of the Strand, a,nd one :tt each side of both Kingswa.y ancl A41d~vych. Their shape is semi- circular, in places 10 fert but more generdly 12 feet across by 7 feet 6 inches high; they are formed of two rings of brickwork backed by concrete(Fig. 4: PltLte l). The floor i.; covered with 3 inches of gravel, and pipes or cables :%relaid by the various compxnies on this floor, or on suitnble iron brackets attached to the brickwork. Access to the subway is obtained by gratings flush with the p:\vement-level, the keys of which are kept by the London County Council or itre avd:Lble at :L fire-brignde station.Cast-iron ventilat,ing-covera 2 feet in diameter are fixed at intervals of about 75 feet. In Aldwych and Kingsway, five cross pipe-subways, 7 feet G inches wide by 7 feet 6 inches high, have been provided at suitable intervals, and where the level of the tramway-subwny has necessitated it, the cross subways have been carried undernea,th the tramway-subway, communication wit21 the longitudinal pipe-subwaybeing made by means of shafts at the side of the latter (Fig. 5, Plate 1). ,4t intervals of 10 feet glazed stoneware pipes, 12 inches in diameter, have been built intothe pipe-subways onthe side adjoining the building-sites, so asto permit of gas-pipes andother house- connectionsbeing put in and attended to wit’houtdisturbing the footpath ; G-inch connections with the sewers, about to be described, havebeen laid at 30-foot intervalsup to the outside line of the pipe-subways. Under the cent,re of t,he floor of the pipe-subway, and at a con- venientdistance below tosuit the existing drainage-gradients, sewershave been built.The prevailing section is an egg-shaped sewer, 2 feet 8 inches wide by 4 feet 6 inches high, built of two rings of brickwork on a concrete invert,and lined with blue bricksfor thenormal wetted perimeter. Access to the sewers is obtained by sideentrances and shafts outside the subways, but in some instances,where pipe-sewers have sufficed, access tothe variousinspection-chambers is given inthe floor of the snbways themselves. In order to prevent the pavements from being broken up for the purpose of constructingunder the footwaycellars or vaults for buildings to be erected to the new frontage-lines, it was decided to buildthese vaults at the sametime as the street. Accordingly, along the Strand andin the eastern and western horns of Aldwych, brickwork bays measuring 10 feet by 11 feet 3 inches by8 feet high were made. This style of construction was abandoned later in favour of :>continuous space I1 feet deep from the bnilrling-line ant1 8 feet

high, thepavement being supportedby a concrete wall forming the back of the space, and by rolled steel joists and steel stanchions spaced at 20-foot intervals. The vaults of both types of construction are quite independent of, and outside the building-line of, any structure that may be put up hereafter, and their cost is considered in negotiations for dealing with the building-sites.

STREETSURFACE WORKS, ETC. The powers andobligations of the London County Council applying to construction only, and the maintenanceof the thoroughfares resting with the metropolitan borough councils, the views of those authorities as to the material formiug the roadway-surface were ascertained;and ab theboundary-line between the City of Westminsterand the Borough of Holborn crosses Kingsway at about the centre of its length, the road-paving to the south of this is of soft-wood blocks, andto the north of compressed asphalt, these being the ma.terisls principallyused in the main thoroughfares of, and desired by, the respective road-authorities. Theasphalt waslaid by one of the firms holding contractsin London,and was specified to be a foreignnatural rock asphalt ground to powder; the thickness when rammed was 2 inches. The concrete foundation was in no case less than 9 inches in thickness, and in many cases, owing to the substructureof the tramway-subway, it was considerably more. The concreteconsisted of 1 part of Portland cement to 6 parts of Thames ballast, where it was 9 inches thick, l-to-8 concrete being used in greater thicknesses. The floating coat was mixed in the ratio of l to 3 and carefully laid to the necessary falls. An interval of at least 7 days is desirable between finishing the floating and laying the asphalt, but ina section of Kingsway this was reduced to 4 days withoutany unfavourable results. Where the found:ttionconcrete was laid on made ground the latter was toppedwith brick rubbishand rolled bysteam-roller. The wood- block paving was laid by one of the contracting wood-paving firms with creosoted soft-wood blocks 6 inches deep. They were laid with an open joint, having a maximunl width of a inch, as it was considered that this would give better foothold, having regard to the gradient in Aldwych. The cross fallson the roadways, both wood-block and asphalt, are generally 1 in 60 to 1 in 71 * 5, though in places 1 in 43. The curbs are of Aberdeen granite, and the footways are laid withYork paving 3 inches in thickness.This paving-stone was of a specially hard quality, riven at the quarry, difficult to tool, and rubbed down to a fair surface.

Treesare planted at 30-footintervals, the pavingimmediately wound them being replaced by a cast-iron grating 4 feet square, in two sections. Planesand acacias alternatethroughout the length of Aldwych ; planes and ailanthus in Kingsway ; elsewhere planes only.Many of the acacias havefailed and have been replaced with planes. The lighting is by means of high-pressure gas, each lamp being of 700 candle-power, andthe standards, 26 feethigh, are placed 80 to 100 feet apart.

TRAMWAY-SCBWAYAND ITS CONSTRUCTIOX. Except where the tramway crosses the Strand and runs underneath Wellington Street,it follows as stated the lineof the improvement ; and, with the exception of the small portion under Holborn and the widened south end of Southampton Row, the opportunity afforded by theconstruction of the roadway was utilizedsimul- taneously to form the tramway-subway. Except on Section 15 and forthe short lengths of tubetunnels the workwas all done by ‘‘ cut and cover.” It will be most convenient to describe the subway and its construction by following in the description those sections into which, for physical reasons created primarily by the order of acquisition of properties, it was necessary to divide the work, although for many items the description in one section will serve for others. The cross sections AA to DD, given in Plates 1 and 2, are illustrative both of the subways and of the street-works. Section No. 8.-Reference to the Table on p. 26 will show the order of constructing each of the sections. Sections Nos. 7 and 8 were first undertaken, and mere commenced within G months of each other, being underconstruction at the same time. Dealingfirst with Section No. 8, it will be seen from the plan and longitudinal section (Figs. 2 and 3, Plate l),that this included a tramway-station near Holborn, tunnelling under Holborn, and the formation of the open approach in Southampton Row. The question of the level of the rails under Holbornwas governed bythe existence of the Holborn branch of the Fleetsewer running along that thoroughfare, any diver- sion or interference with which would involve difficult and costly problems. The soffit of the tunnel only just clears the sewer; hence the necessity for the dip on leaving the station. The point of exit received special consideration, but, mainly on the score of expense, the Council decided on the arrangement carried out, which allowed single-deck cars runningup a gradient of 1 in l0 to reach the

surface atthe commencement of Theobald’sRoad. The landing- place is an awkwardone andnot free fromdanger, and a more satisfactory exit could havebeen obtained by continuing the line straightup Southampton Row towardsRussell Square, although further property would have hadto be acquired andthe main middle-level sewer which runs down Theobald‘s Road would have had to be avoided. A proposal for coming to the surfacefarther to the east in Theobald’s Road was examined but rejected, owing tothe cost of acquiring the necessaryproperties forstreet- widening. In connection with the question of the point of exit, the making of the subway large enough to take a double-decked car was also thoroughly examined and reported on. The practice in New York and elsewhere of running onlysingle-deck cars was cited, and afterfull consideration the Council decided upon theexisting arrangement, which allows single-deck cars alone to pass. In South London there are bridges over some of the routes which only admit of single-deckcars passing under them, andthe subwaycars are worked on these routes. It was decided to construct the subway under Holborn by means of cast-iron tube tunnels, driven with a shield, as being a method which would not involve anyinterference either with other structures or with the considerable traffic in this thoroughfare ; and the fact that the tunnelshad only to take single-deck cars facilitated the application of t.hismethod. The openapproach, which is 20 feet wide in the clear, is lined with white glazed brickwork and is guarded by a substantial railing and granite plinth with a safety footway 2 feet 9 incheswide. It communicates by abell-mouth with the cast-iron tube tunnels. These are lined with 4-to-1 ballast concrete in the invert, and 4-to-1 breeze concrete in the arch; and, although intended originally to be white-tiled throughout, they are, like the subway, whitewashed only, the stations having whiteglazed brickwork sides. A bell-mouth on the south side of Holborn leads to the station, which is roofedwith trough flooringmade of &-inchsteel plates stiffenedwith 4-inch covers. Theinside width of thestations is 30 feet; an island platform is provided, 100 feet long and 12 feet wide, standing 12 inches above rail-level ; and there is an entrance- stairway at oneend andexit-stairway atthe other.These lead straight up, by an average of thirty-three steps and an intermediate landing, to anisland refuge in the street. The stairway is6 feet wide between walls ; the stairs have G-inch risers and 12-inch non-slipping treads. A row of stanchions,made of 12-inch by 6-inchjoists

reinforcedwith $-inch plates, is constructeddown thecentre of the platform to carry a middle bearer for the troughing. South of the station tlle tram-lines converge to a distance apart of 9 feet between track-centres, and thence to Aldwych there is a uniform cover of 3 feet 2 inches, measured from the underside of the trough covering to the crown of the roadway. The walls of the subway are formed of G-to-l concrete 4 feet thick with a 2-inch skin of mastic asphalt, and are backed between the asphalt and the trench-side with 12-to-l concrete, 2 feet thick. The roof where the subway dips is of brick, arched and lined with glazed brickwork. Theasphalt skin was carried upas far as it was thought water could percolate, and there is a roofing of $-inch asphalt, in additionto a continuous asphalt damp-course of the samethickness over and embedded in theinvert concrete and joined upto the asphalt skin in the walls. Thestructure thus has an asphalt envelope embedded in the concrete. The dip under Holborn forms a natural sump for any small leakages or rain-water coming down the openapproach. A pit is provided hereand furnishedwith a small 3-inch-diameterelectrically-driven pump, which is automatically putin or out of motion by a float connected with a suitable switch. Work on this section (No. 8) wascommenced in September, 1903. Little Queen Street, which has been absorbed into Kingsway, formed, withGreat Queen Street,the principal north and south artery in the neighbourhood ; it carried a large number of pipes and cables forming important connections, aswell as sewers perform- ing similar functions. Little Queen Street having to be excavated forthe whole lengthand width to a depthvarying from 22 to 35 feet, it was felt that it would be inadvisable to attempt to keep the thoroughfare opened to wheeled traec, and arrangements were made to stop the roadway to all but pedestrians. Except for a very short period in the case of Southampton Row, this was the only case during the progress of improvement work where the passage of

vehicular traffic on the main roadways affected was not maintained ' throughout the work. Some intricatesewer-diversions at thejunction of Greatand Little Queen Streets were firstundertaken, and for the 7 weeks these were in handall through vehicular traffic in boththese thoroughfares was stopped. At theend of this time, about32 feet in length of the new roadway having been completed, it became possible to re-establish vehicular communication in Great Queen Street across the new thoroughfare (Kingsway), and, as fast as the roadway and substructure, working

towards Holborn, were completed, half its width on the west side was thrown into use. Through vehicular communication with Holborn was completely re-established in about 10 months, but only by making a temporary 16-footroadway on the westside of Kingswayfor about the last 200 feetbefore it reaches Holborn; there was a considerable amount of heavy underground work atthis point, which was completed at alater date. In carryingout the workgenerally between Holbornand Great Queen Street,although through vehicular traffic was stopped, access had to be maintained to several sitts and buildings in Little Queen Street. This, and the fact that building-operations were going on in the street,rendered it necessary to do the work in short lengths and in small pieces at different times-procedure not conducive to the most economical working. A large number of pipes and cables were met with at the junction of Greatand Little Queen Streets ; anduntil their permanent resting-places were provided in the new pipe-subways the timbering of the trenches had to be specially arranged to support them, the electriccables being carried on hoardings in specially-provided temporary cables. No accidentoccurred. Atthe southside of Great Queen Street the trench was carried up to within 10 feet of largeprinting-premises without interfering with their working, these premises being acquired and demolished later on for another Section (No. 12) of the improvement. The foundation of the tramway-subway in this Section (No. 8), and generally throughout its length, is everywhere in the London clay. When the made ground had been passed through, the layer of gravel usually found on the topof this clay was encountered, together with the inconvenience resultingfrom the water that it carries. It was decided to drivethe tube tunnels from theHolborn end,having regard to the drainage of the gravel-waterand the gradient of the tubes, and this was effected without the use of compressed air. The south face of the tunnels was designed to coincide with what is nearly the south building-line frontageof Holborn, and as the depthto the invert of the tubes at this point was about 34 feet, a face of over this depth, parallel and close to Holborn, had to be supported so as not to interfere with that thoroughfare. The construction of a shield-chamber was accordingly commenced by sinking a trench 5 feet in width parallelto Holborn having aretulm side 13 feet 6 inches long next to the Holborn Restaurant. In this trench a concrete wall of the same width was deposited, which waq afterwardsincorporated inthe walls of the subway. Two eyes 16 feet 4 inches in diameter were left in the wall, the face of $he [THE INST. C,E, VOL. CLXXXIII.] D Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. 34 HUMPHREYS ON THE LONDONCOUNTY COUNCIL [Minutes of excavation in the eyes was timbered, and when the concrete had set, a shield-chamber, 39 feet by 15 feet, was got out under the protection of the wall. The wallwas carried up only to the level of the top of thepermanent structure, the remaining 16 feetbeing heavily timbered.These arrangements proved quite satisfactory. No settlements or interference with the Bolbornroadway took place, and it waspossible to arrange hoardings in Holborn strong enough to minimize the possibility of anydanger to crowds,engendered by the presence of a deep cavity just behind the hoardings on the edge of the footway. The shield used was 16 feet 2 inches in diameter over the skin, 16 feet inside, and 8 feet 9 inches long; it was fitted with sixteen differentialrams 8 inches in diameterand a hydraulicsegment- erector, and was made entirely of mild-steel plates on the intercostal system, the outer skin being 1 inch thick. The outside diameter of the cast-iron tube-lining was 15 feet 10 inches. The design of the shield was chosen on account of its general strength, having regard to the fact that the shield would have to be taken to pieces and erected four times in order to carry out thecomplete scheme. Owing to the presence of the water-bearing gravel in the top of the face, which during driving varied between 1 foot and 12 feet in depth, progress was tedious. The east tunnel was started on the 6th June, 1904, andthe shieldemerged in one of thetunnel-eyes already constructed in Southampton Row, 253 feetdistant, on the 6th August. It was taken topieces and re-erected in theshield-chamber, anddriving re-commenced, butin the westtunnel, on the 22nd August, finishing on the 18th October, 1904. This gives for the first tube an average of 2 92 rings per 24 hours, exclusive of Sundays and holidays, the best day’s work (night and day) being 5rings, and for the west tube an average of 3 -04 rings per 24 hours, the best day’s work being 6 rings. The rings were l foot 8 inches long. Difficulty was experienced,owing tothe varyingcircumferential resistance of the clay and ballast face, in keeping the desired levels, especially whendriving up the I-in-l0 incline, and some slight damage was done to the pipe-subways in Southampton Rowwhen the shield passed underneath within 2 feet of their footings. All the joints in the cast-iron tunnel-lining were machined; no packings were used, but the joints contained a cavity on the inner edge 1 inch deep and 6 inch wide, which was afterwards caulked with cast-iron borings and sal ammoniac. The bolts, 14 inch in diameter, were screwed up on lead grummets designed to fill up a bevel left at the top of the bolt-holes. Considerable trouble was experienced in making the tunnel watertight. The rings were grouted immedi-

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HOLBOBN-TO-STRAND IMPROVEMENT. 35 ately after fixing, about 4 ton of groundblue-lias lime per ring being used. Some of the gravel passed through contained so much water that it forced channels through the grouting before it could set,and percolated into the tunnel. As theseleaks were stopped and a head of water put on the tunnel, the jointing and washering hadto be done againstthis head. Nearlyevery bolt had to be takenout, and a tarredyarn grummet inserted to aid the lead washer. The reason forthis trouble, in the Author’s opinion, is that the concentricity of the bolt-holes, and consequently the even flow of the lead washer around the shank of the bolts, cannot be assured.The lead washers werethus put to a moresevere test than has been the case when they have been used in a tunnel made under compressed air. A good deal of trouble was also experienced in making a tight joint between the end of the tubes and the concrete walls of the other part of the tunnel ; but when the work was completed the leakages were reduced to a minimum. The space available for the erection of the necessary machinery fordriving the shield, which was of an ordinarycharacter, was limited, but the plant was all accommodated on a piece of ground about 45 feet by 22 feet, close to the shield-chamber. The face of the excavation alongside the finebuildings of the Holborn Restaurant and those adjoiningwas heavily timbered with 4-inch runners, and strutted right across to the opposite side of the trench, no rakers being used where any pressure was expected. In February, 1906, however, it was noticed that some apparently old cracks in Holy Trinity Church, adjoining the Holborn Restaurant, and in this building itself, showed signs of movement ; and this, with a tilting of the curb alongside these buildings, pointed to a movement below and a leaning of the buildings towards the street. This movement coincided in date, within a couple of months, with thedriving of two of thestation-tubes of theGreat Northern, Piccadilly and Brompton tube railway under Kingsway, which at thispoint has three 22-foot station-tunnelsparallel with one another,the rail-level being120 feet below the surface(Fig. 3, Plate 1); and the bottom of the cracks lay at approximately the intersection with the ground surface of a plane, commencing at the station-tunnelsand inclined at anangle of 45 degrees withthe horizontal. It appeared, however, to be an open question to which works thedamage done was directlytraceable, and the cost of repairs was borne, by arrangement, equallyby the Railway Company and the London County Council. D2

Holy TrinityChurch was not repaired but has been recentlypulled down (1909) preparatory to rebuilding. The pipe-subways were carriedacross Holborn by blockingone side of the road at atime, and during the excavations the old disused Post-Office tunnel, lined with flatcast-iron plates and extending down Holborn and Oxford Street, was cut through. d section of the ground at Holborn is interesting, as there now exist in the samevertical plane, and one above the other in the followingorder :-the L.C.C.pipe-subways, the Post-O6ce cable- conduits, the Fleet sewer (Holborn branch), the tramway-subway, theCentral London Railway(two tubes), and finally theGreat Northern, Piccadilly and Brompton Railway (three tubes). Thework inSouthampton Row presentedno special features, and all was completed on this section (No. S) by June, 1905. Section No. 7.-Workwas commenced on the westernhorn of Aldwych in April, 1903.The tramway-subway in this sectionhas a curve of 563 feet radius and dips on a l-in-20 gradient so as to pass under the Strand. The top of the soffit of its arch descellds from 5 feet to 17 feet below the road-level. The subway is 20 feet wide between side walls, has a concrete invert 4 feet 3 inches thick, (being 9 inches thick below the asphalt envelope and 3 feet 6 inches above it, including the concrete of thetramway-track), and side walls 6 feet thick ; it is roofed with a four- and five-ring brick arch of 20 feet span, the side walls being made up of 3 feet 9 inches of S-to-l concrete backed with the asphalt envelope and 2 feet 3 inches of 12-to-l concrete. The soffit of the arch is linedwith glazed bricks and is 14 feet high from rail-level in the centre; the arch is backed with concrete,over which the asphaltenvelope is carried. Above the arch consolidated dry filling has been filled into the space between it and the underside of the roadway concrete. The trench was takenout in one32-foot width, with whole-timber struts. The old Gaiety theatre was standing and in use during the work, andthe trench at its deepest part (about 40 feet) was carried to within 15 feet of the building-line of the theatre. This section progressed rapidly,asthere wereno tratiicconsiderations to be respected, the site having been occupied previously by houses or abandoned side streets; it was necessary, too, to push forward the construction of thesouthern pipe-subway andto continue it nearly down to the Strand, so as to provide means of access to the new Gaiety theatre by the date of its opening in September, 1903. A slight settlement of the subway-arch took place where, owing to the rising gradient of the subway, the line of thrust of the arch passed throughthe sidesewers, and some reinforcement sf the

sewer-backing became necessary. The works onthis section were completed in May, 1904. Section No. 10.-A commencement was made with the construction of this, a continuation of the previous section as far as the Strand, in May, 1904. The necessity for not disturbing the old Gaiety theatre until thenew onewas completed, and forpreserving the old " Morning Post " offices in a partial state of efficiency, had made it necessary to defer the work here until this date. The length of tramway-subway included was only about 125 feet, but, as previously mentioned, the southern pipe-subway in Aldwych hadalready been constructed. This latter hadconsequently to be underpinned, and the side walls of the tramway-subway to be constructedin shortlengths ; consequently progress .was slow, and a great deal of care was necessary in jointing up and ensuring the tightness of the asphalt envelope. The subway in this section bifurcates into a loftybrick-arched bell-mouth 23 feet high, from which two tunnels commence, ending in eyes, into which the two cast-iron tunnels under the Strand were to be driven when powers were obtained for laying the tramway. These eyes were placed as near to theold " Morning Post " buildings as was consistent with leaving the building standing (a minimum distance of 7 feet). The faces of the eyeswere leftstanding on timber, and work was completed on this section in March, 1905. Section No. 9.-The central portion of Aldwych and the root of Kingsway were commenced in January, 1904. Near the beginning of this section the rail-level for the tramway was sufficiently near to the street-level to allow of the brick-arched roof being changed intosteel troughing, giving the minimum cover below the road- surface.The troughing is generallysimilar to thaton Section No. 8. The rail-gradient changes from 1 in 20 to 1 in 110, and the tramway runs round, each track in a separate tunnel, by curves of about 75 feetradius, from Aldwych into Kingsway. A station is provided inthis section (Fig. 5, Plate l), its constructionbeing practically similar to that of the one at the north end of Kingsway. Sections Nos. 11 and 12.-The southernmost portion of Kingsway, (Section II), was commenced in August, 1904, and as was the case with the section last described, it extended through the siteof small buildings and narrow streets. Rapid progress was therefore possible. The tramway-subway here is of the minimum section, being made close to the street-level. The clear width is 20 feet. There is 13 feet 6 inches headway above rail-level, and the inverthas a curved section 2 feet 9 inches thick (Fig. 4, Plate 1). The tramway-track concrete being laid afterwards, the extreme thickness of the invert became 5 feet 6 inches. The roof was covered with the usual steel troughing

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. 38 IIUMPHREYS ON THE LONDON COUNTY COUXCIL [Minutes of of 2 feet 8 inches pitch, and 129 inches deep, made of &inch plates with double covers in each corrugation,and, as elsewhere, a continuous $-inch stringer-plate has been fastened to the tronghing by steel angle-gussets. While work was progressing on this section, the closing length (Section No. 12) was commenced in April, 1905. The acquisition of the site for this latter section involved a lengthy procedure. The generating-station (4,000 kilowatts) of the MetropolitnnElectric Supply Company stood right across the newthoroughfare, its chimney-shaftin the centre standing almost onthe axis of the new street,and it was only piecemeal thatthe ground became available ; in fact, in many cases the workmen on the improvement had excavated right up to, and in some cases it may be said under, premises which had eitl~er not quite been acquired, or were in the hands of housebreakers, to whom thestanding buildings above ground-levelhad been sold, Operations, however, were vigorously pressed on both sides of the generating-station, until possession of this was obtained, shortly after which the building was handed over to the housebreakers. It was anticipated that His late Majesty King EdwardVI1 would consent to open the thoroughfare,and the signification of his intention to do so earlier than was expected rendered it necessary for exceptional efforts to be adopted in the last stages of the actual linking up. The dismantling of the electric generating-station was not commenced until July, 1905, and until the buildings were removed it was not possible to commence the demolition of the chimney-stack, which was standing untouched as late as the middle of August, so that it was the last week in August, 1905, before the removal of its foundationsand excavation forthe tramway-subway couldbe commenced. In 14 days all excavations had been removed, and the invertconcrete had been laid, so as to effect a junction between northand south. As thelength of subway dependent upon the demolition of the generating-station was upwards of 200 feet, and the invert only wascompleted on the 14th September, it will be seen from the cross section (Fig. 4, Plate 1) that a great deal of work hadto bedone between thisdate and the following 18th October, the date of the opening ceremony. By continuous night- and-day work, however, everything was so far accomplished as to permit of the ceremony taking place andthe thoroughfare being opened on the desired date. The track-work had been put in hand as soon as conditions per- mitted,and on the 24th February, 1906, a service of tramways

was inaugurated from the “ Angel,” Islington,to the station at the south end of Kingsway,the portion of subwaycompleted in Aldwych forming a depot, a site for inspection-pits, and shunting- space for the cars.

SUBWAYFROM ALDWYCHTO THE EMBANKMEKT. Section No. 15.-The finalsection of the tramway-schemecon- sisted in the extension of the subway from Aldwych (Strand end) to the Embankment, As previously stated, powers were granted to lay the tramway in August,1906, and it was then decided to commence the subway, whichhad been authorized previously. Theroute taken by the tramway is shown in Fig. 7, Plate 2. TheStrand is crossed in twocast-iron tube tunnels (Fig. 8, Plate 2), similar in allrespects as todetail to those under Holborn,and curving round at 168 feetradius so as toenter WellingtonStreet. They commence inthe twoeyes built in Aldwych atthe end of 1904, andterminate at about 250 feet from this point, in what is the abutmentof an approach-viaduct to WaterlooBridge. Wellington Street is, in fact, built, for about 300 feet of its length, on brickarches of 16 feet span, springing from brick piers generally 2 feet 3 inches thick and 90 feet wide, ancl the design of the subwaycontemplated the piercing of the northernabutment of thisviaduct to receive the tubes, andthe removal of such a length of the piers as would be sufficient to allow of laying a double line of tramway.The line, having to find an exit through the stairway part of the abutment of Waterloo Bridge, is not quite parallel to the centre-line of the viaduct, but cuts the piers at varying angles (Fig. 7, Plate 2). The tops of the soffits of the viaduct-arches were only about 5 feet 6 inches from the crown of WellingtonStreet, and any interference with the traffic over Waterloo Bridge was not to be thought of. It was decided, therefore, to carry the arches as they stood by cross-needling them at the springing-level, carrying these needles on two girders placed one on each side of the pier, each girder being supported at each end by steel stanchions placed outside of the width necessary for the double tram-line (Fig. 9, Plate 2). The substitution of steel supports for a continuous brick pier, concentrating the weight at four points only, made it essential to consider the design thoroughly from the point of view both of its durability and of the nature of the ground below the foundations of the supports. Thegirder- and stanchion-work was accordingly designed on liberal lines, and, having regard to the

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. 40 HUhlPHREPS ON THE LONDON COUNTY COUNCIL [Minutes of subsoil, the foundation was spread by making a raft structureof the invert of concrete, about 6 feet 6 inches thick and heavily reinforced with a grillage of steel beams. Referenceto the longitudinal section in Figs, 9, Plate 2, will show that the clay line, which had always been present at a favourable level in the subway to the north, rapidly drops away as the ground descends tothe RiverThames. It was found that each pier of the viaduct hadoriginally been founded on a timber platform, which was in a good state of preservation, and apparently had been laid on the old muddy foreshore, but without going down to the clay- level.Thc position of the rail-levelnecessitated the underpinning of some piers, andthis was done to each pier as necessary by takingout lengths of 6 feet at atime and pinning up in brick and cement. The tramway was designed to pass out through t,he western steps which were incorpolated in. the elongated abutment of the bridge, thesesteps emerging from a small archway flanked by aheavy masonrywing having oolumns and ornamental features. In order to preserve the architectural effect, the wing and extension of the abutment have been taken down and re-erected outside a widened archway which measures 22 feet 6 inches, as against 9 feet 9 inches formerly.These alterations involved the taking-downand re- erection of parts of the offioe of the Duchy of Lancaster, which is situated at the south end of LanttasterPlace, in buildings which stood in part immediately over the old wing of the abutment. Very little room was available in which to rmry out the work. A narrow passage extendedbetween the piers and the front of Lancaster Place, fromwhich an exit led into Savoy Street ; this gave valuable aid in obtaining access, but the spaces between the piers (sixteen in number) had been filled with made ground to heights ranging from 11 to 16 feet above assumed foundation-level. A start was madeby excavating and urting away the surplus earth between the piers, and at the same time by cutting into the stairway from the Embankment end and taking down the masonry wing. When the stairway had been pierced, the piers were carefully cut through: in some cases an existingopening needed widening only, and a passage-way of 8 feet clear width was obtained, through the piers, from the Embankment to the viaduct-abutment. The width of 8 feet, while permitting a one-horse cart to pass, was the least width that would allow of the main girders carrying the needles being brought in in one piece, thus avoiding the undesirable alterna- tive of erecting them in halves and riveting up in situ. Although the openings were somewhat large, no movement dueto cutting them

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HOLBORN-TO-STRAND IMPROVEMENT. 41 was detected, and all the girders were brought to the site, handled in one piece, and, by careful manceuvring, placed in their permanent positions. In thispassage-way a timber gantry was erected, carrying a tram-line for handling the girders and permitting of abottom roadway. When the northern abutment of the viaduct was reaohed a commencement was made with its underpinning, a depth of 10 feet being necessary, preparatory to cutting through it for the tube eyes. Themethod of puttingin theseeyes is shown in Figs. 10, the sections being numbered in the order in which they were put in. A hole 9 feet wide was first excavated on bhe site of the centre wall of the eyes ; this was concreted at once, and on the conorete a blue- brick pier carrying a double granite springer was bedded, and the abutment was cut through sufficiently to allow of the first 3 feet of the arch on each side of the springer being built. When this work

Figs. 10.

had been pinned up and had set, another hole, 7 feet 3 inches wide, on the extreme left hand looking north, was sunk, concreted, and pinned upto the springing-line. This was followed by the corresponding hole on the extreme right hand. The arches were turned by cuttingout lengths 4 bo 5 feetlong on each side of the centre, forming a centre on the brick dumpling, and building in a five-brick arch-ringbearing on thedumpling pinned up to the wall above. Afterthe arches were turned,the central portion forming the invert was excavated and put in, but this was done at a time to suitthe convenience of otherparts of the work. No movement or cracks were observed in the abutment. Vhile this work was going on, progress was being made with the underpinning of five piers of the viaduct, the foundation-levels of which called for such treatment, as also with concreting the areas

between other piers, and placing the steel grillage in position. In order to carry out this last operation,each pier had to be cut through for the two groups of 14-inch by 6-inch longitudinal joistsshown in Figs. 9, Plate 2, and pinned up on them. Pulling down theornamental wing andelevation tothe Em- bankment was also putin hand. as the space at disposal for working was verylimited, a Portlandquarry hand-crane capable of lifting 10 tons wasplaced inthe angle madeby thesteps and the bridge, and was secured by short stays to the parapet of the bridge.This crane took LIP a minimum of space, commanded the whole of the taking down and rebuilding, and, although slow in its motions, proved quite efficient for a task on which only a fewmen couldbe employed. All the stones were numbered, put aside, andre-erected, The ornamental columns onthe west side stood on what was apparently an old river-wall. To obtain a new good foundation at any reasonable depth by excavating was out of the question, so three screw-piles 12 inches in diameter with 3-foot blades were sunk to a depth of about 32 feetfrom ground-level. They were pitched in pits, and screwing-power was provided by a double-purchase steam-winch having an 8-inch cylinder andworking with 90 lbs. per square inch steam-pressure, acting on a capstan- head witharms 42 incheslong. Though theactual screwing was done through only 7 to 12 feet, and some pressure water was put on to ease the screwing, it was considered that any further power would have twist.ed the piles OR. Whenthe 14-inchby 6-inch foundation-grillage beams had been fixed, the stancllions were delivered and taken in along the uppertram-road on the gantry, the lower roadbeing fully occupied with the cartage of excavation, etc. The girders followed in a similar fashion, and were mostly jacked up on to the columns, there being little room for lifting-tackle. When R pair of girders embracing a pier was fixed, the needling wa.s commenced. The needles were composed of two8-inch by5-inch rolled steeljoists with top and bottom cover-plates 15 inches wide and 2 inch thick. Thegeneral length was 5 feet 10 inches, but a few were 6 feet 7 inches long; they were s.paced nominally at 2-foot 6-inch centres, but were varied slightly to suit joints in a stone springing-course a little above them. Breeze concrete was filled inside, between them, and over their ends. For fixing, a hole was cut above the girders large enough to take two needles, though this was afterwards, as a precautionary measure, reduced to a size sufficient to take one : the needles were then placed in position and pinned up in cement with bricks and slates. Enclosing the space above them with ten-

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. Proceec1i1lgs.] HOLBORN-TO-STRAND IMPROVEMENT. 43 porary casings and grouting under pressure instead of pinning by hand was tried, but the result was not satisfactory. After pinning upthe firstneedle a hole for another was cut ; this needle was placed in position and the pinning-up operationswere repeated. The shortest time taken to needle one pier, that is, to fix fourteen needles through a 2-f30t 3-inch wall-involving a total length of 32 feet- was 7 days,working nightand day.No undue pressure was put on,however, to hurry this part of the work, which required the greatest care, and it is satisfactory to note that only three or four hair-cracks appeared in the superstructure of the viaduct when all was completed. No other measures were taken for transferring the weight of the structure on to the stanchions : the girder-design was such that the deflection would be negligible ; and a factor in the successful carrying out of the operation-any failure in which would probablyhave endangered seriously thestability of theviaduct as a whole-was the excellentcharacter of the brickwork put in by thebuilders of the bridge. It was built in ahydraulic lime mortar, and left nothing tobe desired in the way of soundness and strength,the onlydanger being that its soundness might have tempted the taking of too great liberties with it. The needling, which commenced on the 6th November, 1907, was all completed by the 10th February, 1908. A ceiling of rolled steel joists in concrete, resting on the flanges of the girders supporting the needles, was provided ; these girders were cased in with breeze concrete, and the spacebetween the ceiling and the soffit of the arches was rendered available for use as permanent stores. Thetubes leading from Aldwych, to which theHolborn tubes aresimilar, are shown in cross section D D, Fig. 8, Plate 2. The west tube was started from theEmbankment endon the 30th September,1907, and reached the Aldwychsubway on the 13th November. The tube consists of two pieces of straight joined by a curve of 168 feet radius, and has a length of 255 feet. After driving the west tube, the shield-being the one used previously in Holborn-was taken to pieces and re-erected at theviaduct-abutment. It was re-started on the 3rd December, and reached Aldwych again on the22nd January, 1908. The clay-line was more favourable to progress than at Holborn, and these dates give an average rate of progress per 24 hours of 4 rings in the west tunnel and 3 74 rings in the east tunnel, the best day’s work being 6 rings in each tunnel. Difficulties withwater such asthose encountered at Holborn did notarise, and no damageresulted beyond asmall settlement in the roadway, and in the public convenience in Wellington Street, which the shield passed directly under, within about 6 feet

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. 44 HUMPHREYS ON THE LONDON COUNTY COUNCIL [Minutes of of the footings. Where the top was in ballast it wasclose-poled. Thelining and the track-work were putin hand continuously throughout the viaduct and tubes directly these were completed, as was also the removal of the temporary depot and sidings that had been put down in the subway under Aldwych to accommodate the tramway-service running from the north toAldwych station. Night- and-day work was resorted to, with the view of opening the through service as quickly as possible, and on the 10th April, 1908, that service was inaugurated, a car from Islington running right through and crossing the Thames by Westminster Bridge. At this date the workdescribed may be said to end, although some small items occupied attention for a few weeks later. At the date of writing (1910) the tramway-service can becon- ducted both to the east and to the west when leaving the subway, cars being able to cross the Thames by way of either Westminster or Blackfriarsbridge. The junctions necessary for these branches necessitated the removal of the covering to the District Railway, which runs alongunder theEmbankment, cast-iron girders with jack arcbes being replaced by steel troughing 15 inches deep with vertical sides, thedepth required for the tramway conductor-rail conduit rendering the changenecessary.

TRACK-WORK. The construction of the invert of the subway and the depth of theasphalt envelope would notpermit of the L.C.C. standard pattern of street track-work with yokes being used ; hence a special design was prepared. It is shown in Fig. 11, Plate 2, and provides for bedding the rails on longitudinal 12-inch by 6-inch half timbers, which are of pitch-pine.These timbers are bedded with grout in chases left in a concrete filling on the invert, and they are covered up and the rails parged with 8-to-1 concrete. Tie-bolts from the rail to the conduit are fixed in the tubes, with anchor-bolts on the curves. The conduit is formed in the concrete filling on the invert, 'and to facilitate inspection and removdof the conductor T-rail the slotis formed by two bulb-angles, in lengths of 7 feet 6 inches, resting on suitable supports fixed in the concrete. The bulb-angles can easily be removed with a lifting key, and have proved to be quitesuitable coverings. Thelast 4 inches of the formation have been filled in with ballast, and over the whole is run a 4-to-1 floating of sand and cement 1 inch thick, which is readily removable forrepairing purposes. Thisconstruction allows no inflammablematerial to be exposed, andhas proved satisfactory.

Downloaded by [ Syracuse University] on [12/09/16]. Copyright © ICE Publishing, all rights reserved. Proceedings.] HOLBORN-TO-STRANDIMPROVEMENT. 45 Special attention has been paid to the same point in the design of the cars ; there is hardly any woodwork in them, and what there is has been rendered non-inflammable.

PLANTUSED, ETC. The necessity for carrying out the work in disjointed pieces, and for attacking any spot directly the site became available, rendered the use of any extensive plant impossible. The excava.tions were all taken out by hand, and the concrete and other hard material was broken up with wedges and sledge-hammers, except when cutting through the foundations of the electric generating-station, where an explosive was usedfor a short time in a speed emergency.This, however, is a proceeding that cannotgenerally be advised in the middle of London, and would be impossible on any extensive scale. The excavatedmaterials were taken away by the one-horse cart generally used inLondon, which carries 14 to 14 cubicyard of loose material. No other system could be followed, as the only means of disposing of the excavated material was to tip it into a barge in the river, from which it was ultimately emptied on to the lowlands in the Thames estuary. This system, relatively to arrange- mentsthat can be made inother places morefavoured inthis respect, is a verycostly one, but it is common in otherwork in London. Travelling steam-cranes of 2 to 3 tons lifting-capacity, of which twelve to eighteen were used, and Scotch derricks at the north end of the Kingsway section,performed the whole of the lifting and concrete-depositing. No concrete-mixerswere used, partly on account of lack of space and partly because the ballast had to be broughtto the spot bestavailable for the week’s or evenday’s operations, which varied every few days. Beyond the special plant used fordriving the shields,cranes, portable railways, and a plentifulsupply of timber, of which avery large quantity was required, constituted the whole of the plant necessary. The work was carried through generally withoutany accident or mishapto the appliances. Three lives,however, were lost by accident, two workmen falling and sustaining injuries which proved fatal, and a lad similarly losing his life by falling down one of the deep-level cross pipe-subways while playing during the dinner-hour.

GENERAL. A summary of the actual cash expenditure on the improvement, and the netcost of it (partly estimated) up to the 31stMarch, 1910, is given in Table I of the Appendix. For the figures generally in this Table, which include other items than thecost of works, the Author is indebted to Mr. H. E. Haward, the Comptroller of the London County Council. The account may be now said to be practically complete, but there is a sum of a,pproximately .€54,000 included in current estimates as further expenditure, principally on account of acquisition of properties. No census has been taken by the London County Council of the traffic in Kingsway, but,as illustrative of the growth in the east-and- west thoroughfares, the following figures are noteworthy as repre- sentingthe numbers of allkinds of wheeledvehicles, including cycles and barrows, passing between 8 a.m. and 8 pm. on the days mentioned. 4 .July, 1ROd. 13 October, 1905. Strand, immediately east of Wellington Street . 10,750 14,826 Holhorn ,, ,, Southampton Row . 11,614 17,005 There is not much trafEc in the east horn of Aldwych, but if in future years the congestion on Waterloo Bridge should be relieved by the construction of another bridgebetween Waterloo and Blackfriars bridges this part of Aldwych will be the natural approach to it. The whole of the works referred to on p. 26, with the exception of Section No. 2 (the temporary paving in the Strand),were carried out by the London CountyCouncil without the interventionof a con- tractor, in pursuance of its policy (since abandoned) of direct employment of labourthrough its Works Department. The works of thisimprovement were notthe only ones thatthe Council’s Works Department carried out, as it was organized for and carried out a great deal of work of other kinds undertaken by the Council ; but this is an example of a large piece of work done by the method of administration. The figures in the Appendix, Tables I1 and 111, give the cost of each section involved. Before 1902, at which date the Strand widening only had been started, Sir Alexander Binnie, Past-President Inst. C.E., then Chief Engineer of the London CountyCouncil, was responsible for the works, the control of the Works Department and the construction being under the Manager of Works, who at that timewas Mr. W. Adams, M. Inst. C.E. In January, 1902, Mr. Maurice Fitzmaurioe, C.M.G., M. Inst. C.E., became Chief Engineer of the London CountyCouncil,

and as such has designed and been responsible for the whole of the tramway-subway and the street works of Kingsway and Aldwych. The Author was, from July, 1902, until its closing, in control of the Works Department of the London County Council, and therefore of the construction of practically all these works ; md he desires to express his indebtedness to the Chief Engineer, Mr. Fitzmaurice, to Memrs. C. Elwin and W. C. Copperthwnite, MM. Inst. C.E., of the ChiefEngineer’s Department, to Mr. Alex.Lade, of the Works Department, as also tothe resident and assistant engineers and others who have been engaged thereon,both for valuableadvice and for assistance during the execution of the works.

The Paper is accompanied by fifteen tracings and a print, from which Plates 1 and 2 have been prepared; there are also Tables of costs, some of which are given in the following Appendix.

[APPENDIX.

APPENDIX.

TABLEI.-HOLBORN-TO-STRAND IMPROVEMENT, AND WIDENINGS OF THE STRAND (HOLYWELLSTREET) AND SOUTHAMPTONRow ; AND TRAMWAY-SUBWAY FROM THEOBALD'SROAD TO VICTORIAEMBANKMENT.

COSTSTO 31s~MARCH, 1910.

Acquisition of Property, etc. to StrandHolborn to :- 2 S. d. Purchase moneys and compensations, professional charges andincidentals, also interest to dates of payment . .} 471087145 Hemoval of humanremains ...... 4,383 1 7 Deficiency of Poor Rate ...... 4,519 18 5 Reinstatement of premises ...... 180,602 7 1 Clare Market sites absorbed by the improvement ... 306,510 7 5 Strand (Holywell Street), and SouthamptonRow widening6 :- Purchasemoneys, etc...... 825,39419 3 Tramway-Subway :- Purchase moneys, etc...... 44,899 l l Proportion of cost of widening Southampton Row . . 28,105 7 5 --- 25,502,561 0 6

Sundry Cha'harges.

Holborn toStrand Architectural designs ...... 2,038 6 8 ,, ,, ,, Improvementcharge ...... 5,255 6 1 ,, ,, ,, Rehousing(excluding dwellings) ... 161,717 4 10 Strand (Holywell.- Street).. Improvement charge ..... 1,726 5 4 Southampton Row (VernonPlace to Hoiborn) Hehousing} 10,085 1o . (excludingdwellings) ......

2190,722 7 9

TABLEI-continzced. ll’orks (i,tcZttding ZncirlentuZs). 8 S. CL. Holborn to Strand ...... 150,388 13 11 Strand (Holywell Street) ...... 26,154 5 0 Kew Street, Catheline Street to Drury Lane (less contribu-\ tions) ...... ! 517 4 4 Southampton Row, Vernon Place to Hoborn ..... 16,72418 4 ,, Theobald’s Road to Fisher Street ... 350 0 0 Tramway-Subway, Theobald’sRoad to Victoria Embankment. 164,844 5 8 26,06114 9 1, ,, Track-work ...... --- --8355,0412 0 Surnrmry. Acquisition of property, etc...... 5,502,561 0 6 Sundry charges ...... 190,728 7 9 \Vorks (including incidentals) ...... 385,0412 0

-__I- 26,018,324-- 10 3 Tramway-Szcbzoay (included above). Land, etc. (proportion)...... 73,004 8 6 Worksand track ...... 190,906 0 5 $263,910 8 11 CKEDITS. Receiptsfrom sales (less expenses), Holborn toStrand. .. 261,846 14 11 ,, ,, ,, ,, ,, Strand (Holywell Street). 1,000 0 9 ,, ,, ,, ,, ,, Southampton Row . . 88,9644 11 Estimated value of surplus lands at 31st March, 1910 :- Holborn to Strand ...... 3,523,960 0 0 Southampton Row ...... 29,194 0 0 E3,904,965 0 7

NET COST OF IHPROVEYENT, INCLUDING TRAXNAP-SUBWAY,TO 31~~ MARCH, 1910. Expenditure...... 6,078,324 10 3 LessReceipts andestimated value of surpluslands. ...3,904,965 0 7 ---- ~€2,173,359 9 8

_I-- All the foregoing figures are independent of interest on capital outlay. In apportioningthe cost of worksbetween thestreet works andtramway- subway works the latter account has been debited only with the charges which remain after everything necessary to complete the street works has been charged to the account for street works. The cost of works is exclusive of engineering charges other than supervision on the site. [THE Ily8T. C.E. VOL. CLXXXIII.] E

TABLEII.-ACTUAL COST OF THE VARIOUS WORKS. - (Carried out by the Works Department.) 1 2 3 4 5 6 - - ! Nages for daterials, a-: abour, etc. Ldministration, gE Title of Work. 180 Super- Cartage including Use Total. .*-F and In- and Waste of a- ltendence on Site. zidentals. Plant. -m - -i Per .S B .S cent S 1 New Street,Catherine Street to Drury Lane . 1,419 2,314 298 7'4 4,031 3 Paving roundStrand l churches. . . . . l,785 2,912 376 7'4 5,073 4 Southampton Row widen- l ing, Eagle Streetto Holborn, and Eagle Street paving . . . 1,559 2,267 286 7.0 4,112 5 Strand widening, Cathe- rineStreet Law to Courts . . . . . 7,948 13,438 1,597 7.0 22,983 6 Eastern Horn, Aldwych 5,835 10,956 1,783 9.6 15!571 8 Northernmostportion of Kingswayand setting back frontages, South- ampton Row . . . 24,456 47,828 5,289 6'8 77,573 7 Western Horn, Aldwych . 9 Central portion, Aldwych 10 Westernjunction, Ald- wych andStrand . . 11 Southernmostportion of Kingsway . . . . 12 Central portion of ,Kings- way.. . *.. 55,675 116,633 12,861 7.0 185,169 13 Tramway-track in subway from Theobald's Road to Strand,to excluding rails, etc. . . . . 14 KeanStreet, Catherine Street and side streets. Also Exeter Street and pavingwork in small portion of Kingsway . .-! _- D8,677 196,348 22,490 l 7.1 317,515 15 Strand to Embankment portion of subwayand tramway track-workthere- in, excluding rails, etc. 14,080-~ 27,189 3,792 8.4 45,061 Total. . & 12,757 223,537' 26,283 362,576

1 Credit has been taken for &2,106 received as rent of advertisement-hoardinpa.

TABLEIII.-COST OF TRACK-WORK,ETC. Total cost of works in connection with the improvement Total Cost. andthe tramway-subway as Table I ...... ) f385,04l

Allocated aa follows :- 1: To the roadway, generally assuming that no tramwtq I 194, 135 had been necessary ...... i Tothe structure of the subway ...... 164,844 ,, ,, track-work in ,, ...... 26,062 Total ... %385,041

Totallengths of tramway-sub\r;ty :- Section X,), (p. ?t:). Lineal Yeet. S trand to EmbankmentStrand to ...... 1; 618 Vesternjunction of Aldwych wit11 Strand 10 125 Aldwych-Westerndection ..... 7 393 ,, Centralportion ..... 9 318 Iiingsway-southernportion .... 11 582 ,, Centralportion ..... 12 533 Sorthern portionand ,, 966 ampton Row ...... ___ YI5N

Or at a unit cost for :- Per Foot. of Length. Structure only ...... fi6.65 Includingtrwk-\vurlc ...... 254.02 Track-work only ...... $7.37 Structure and Track-work h subdivision of these w6ts isHppronimately as follows :- per Foot of Length. Ernbankmentto Strand, 618 feet ...... f77.80 Strand to GreatQueen Street, 1,951 feet. ....S46.30 Great Queeu Streetto uorthern end, 965 feet ...254.40 Cost of tube tunnel for one running-line and single-deck cars. External diameter 15 feet 10 inches, internaldiameter 14feet 5 inches with footway berm exclusive of track-work About 226 10s. per lineal foot, and itsfoundation, and incluciing all charges for plant credited at end of work at acrap- iron prices ...... Total amount paid in connection with altera-~ tions to pipesand cablesand incidentalworks f33g0009 Or per cent. Of the connected therewith, exclusive of any rein- ?xpellditure (pipe statements with Met. Electric Supply Co. . 'lons included) On works" Total approximate cost of the street-improvement for works only, per superficial yard of 12 10s. per superfid yard. surface affected or disturbed. .... Average cost of pipe-subways per lineal foot on all sections of the improvement, the cost ranging from about E4 53. to S6, according f5 4s' per linea' to foundationrequired ..... Average cost of vault-work on all sections per lineal foot of frontage, the costranging $4 10s. per lineal foot of frontage. fromabout 23 10s. to f5 .....t I About 22,150 should be added to this figure for liabilities incurred since Narcll, 1910. Ea