Proceedings.] 031LVIE OX L.S.W. AXD M.D. RAILWAYS’ WIDENING. 143 21 January, 1913. ROBERTELLIOTT-COOPER, President, in the Chair. (Paper No. 4045.) The London and South Western and Metropolitan District Railways’ Widening between Acton Lane and Galena Road.” By ERICALEXANDER OGILTIE. BEFORE1877 the Metropolitan District Railway Company’s western terminus was HammersmithStation, but in that year the line was extended to form a junctionwith the London andSouth Western Railway Company’s Kensington and Richmond line at Studland Street, and running-powers to Richmond were obtained from that company. Two years later a further extension, from Turnham Green Junction to Ealing, was opened for Metropolitan District Railway traffic. In 1905 the Metropolitan District system was electrified, which step, whilst it enabled the company to quicken its service to andfrom the western suburbs, had the effect of taxing to its utmost capacity the portion of line between Studland Street Junction and Turnham Green Junction; for, besides the London and South Western and Metropolitan District traffic, this section was also used by the Great Western Railway Company’s trainsand the Midland Railway Company’s coal-trains. It being found impossible to increase the train-service under the conditions then existing, a scheme, which forms the subject of this Paper, was prepared in 1909 for the widening and rearrangement of the lines between Acton Lane and Galena Road, and the assent of Parliament was obtained in 1910. Fig. 1, Plate 3, shows the position of the widening in relation to the railway systems of West London, and Figs. 2 the arrangement of the lines of the two companies before the works were undertaken. Downloaded by [ University College London] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 144 OGILVIE ON L. AND S.W. AND M.D. RAILWAYS’[Minutes of It willbe seen from Figs. 2 that, besides widening the lines between Studland Street and Turnham Green, it was necessary to provide for the crossing of the two companies’ lines at different levels-if complete separation of their traffics was to be attained and the signal-delays inseparable from a crossing on the level were to be avoided. It was found that the best point for a crossing was west of Turnham Green Junction, as the South Westernlines were there on a falling gradient, while those of the Metropolitan District were practically level ; and that, by slightly raising the latter lines, sufficient headway for a crossing would be obtained. Fig. 3, Plate 3, shows the scheme as prepared and carried out. Owing to the property on the north side of the line at Goldhawk Road being much more valuable than that on the south side, it was found that considerable saving would be effected by carrying outthe whole of the widening on the south side at this point, although it had the disadvantage of introducing reverse curvature. All curves of 30 chains or less radius are eased by means of transi- tion-curves, the method adopted being that described to The Institution in 1909 by Mr. W. H. Shortt,l Assoc.M. Inst. C.E. A minimum distance of 10 feet is provided between the tracks of the two companies where possible. It will be seen thatthe platforms at Turnham Green and Ravenscourt Park stations have been converted to the island type, and that a new station (Stamford Brook) is provided -at Goldhawk Road for the Metropolitan District Railway’s traftic ; also that all the tracks between Turnham Green Station and Acton Lane are altered in alignment,with the exception of the old South Western Railway down Richmond line between Fisher’s Lane Bridge and Acton Lane, which becomes the new Metropolitan District Railway down Richmond line. The Metropolitan District lines toand from Ealing cross the London and South Western lines at a point about 400 yards west of Turnham Green Station,and the MetropolitanDistrict down line to Richmond leaves the down Ealing line immediately west of Turnham Green Station, falling by gradients of 1 in 97 and 1 in 124 to Acton Lane, where a junction is made with the London and South Western down Richmond line.Provision is thus made for a standby forMetropolitan District Richmond trains, should a London and South Western trainfor Richmond be leaving Turnham Green Station about the same time.The Metropolitan District up Richmond line leaves the London and South Western up line * Yiuutes of Proceediugs Inst. C.E., vol. clxxvi, p. 97. Downloaded by [ University College London] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. ~roceedings.1 WIDENING FROM ACTON LANE TO GALENA ROAD. 145 at Acton Lane, and passes underthe Ealing lines by gradients rising 1 in 50 and 1 in 77, until it reaches the up Ealing track at Fisher’s Lane Bridge, where a trailing connection is made. In carrying out alterations to existing works and lines where there is a frequent train-service, one of the problems which requires careful consideration is that of maintaining the service without interruption ; and usually the quickest and safest method is tem- porary diversion of the tracks. In this case there was a daily service of more than 400 trains, and nineteen temporary diversions were necessary before the new lay-out could be brought into use. The time available for carrying out these diversions and for unload- ing the girders for the new bridges was very limited, as the period when trains were not running was only 55 hours (between 1.30 a.m. and 7 a.m.) on Sundays, and considerably less on week-days. The Author therefore proposes to describe some of the diversions. In order to construct the new bridge over the London and South Western tracks and form the new embanked approaches between Turnham Green Stationand Fisher’s Lane Bridge, the double junction and signal-cabin at Turnham Green were transferred temporarily to apoint adjoining Fisher’s Lane Bridge, andthe Metropolitan District tracks to and from Ealing were diverted up a temporaryincline of 1 in 45, to join the sued Ealingtracks. This also enabled the arch bridge over Fisher’s Lane to be raised, together with the regraded embankment adjoining. While these bridges, and theadjoining earthworkswhere possible, were in progress, the construction of the single-line viaduct on the south side of Turnham Green Station, together with retaining-walls Nos. 1 and 3 and the embankments retained by them, was pushed forward ; and the south platform was extended temporarily on to the new viaduct, to permit of the diversion of the whole of the up and down traffic to the south platform. By this means, possession was obtained of the old north platform, which wasof timber and had to be entirely reconstructed. Whilethis platform was under reconstruction, the widened embankment on the northside of the line between Turnham Green Terrace and the North and South Western Junction Railway was also being formed, and the building of the north span of the bridge over Turnham Green Terrace, together with retaining-wall No. 2, was pushed on with. This was necessary, as the next step was to divert the up trackfrom the north side of the south platform to the north side of thenorth platform, thus removing the remaining track on thecentre span, or old bridge, over Turnham Green Terrace. This bridge had to be reconstructed so as to give a span [THE INST. C.E. VOL. exc11.1 L Downloaded by [ University College London] on [21/09/16]. Copyright © ICE Publishing, all rights reserved. 146 OGILVIE ON L. AND S.W. AND M.D. RAILWAYS’ [Minutes of of 50 feet instead of 35 feet ; and, the whole of the widening being on the west side, the new abutment was built behind the old one before thetracks over the bridge were removed, so thatthere should be no delay in fixing the new girders when thetracks were removed. AS soon as the diversion already mentioned had been made, the superstructure of the old bridge, which consisted of three main girders, with cross girders andflat floor-plates, was removed by the following process :-The floor-plates, which were closely riveted to the cross girders, were cut through by means of the oxy-acetylene gas-jet, and the cross girders were cut through close to the main girders and lowered directly on to lorries in the roadway beneath. This method proved to beeconomical and expeditious. Themain girders were removed, and the new girders were placed in position, by a steam- crane standing on the diverted tracks. On the completion of this bridge the down track was diverted to thesouth side of thenorth platform, thusdiverting the whole of the traffic on tothis platform, and giving possession of the south platform, which had to be reconstructed. Simultaneously, the widening of the viaduct between the North andSouth Western Junction Railway and Galena Road was in progress ; here two diversions were necessary, owing to the recon- struction of existing bridges. The first was the diversion of the tracks on to the completed elliptic arch bridge over The Avenue, Ravenscourt Park,to allow of the old girder bridge over The Avenue being converted intoan elliptic arch-this being con- sidered a favourable opportunity for renewing the bridge. The secondwas the diversion of the up and down tracks on tothe widened portions of the viaduct at Ravenscourt Park Station, to alloy of new outsidegirders being fixed tothe old centrespan of the bridge over Studland Street; it was also necessary to alter the skew of the girders of this bridge to suit the new lay-out of the tracks. This diversion entailed the removal of the old double junction, and the laying of temporarypoints and crossings; also the moving of the old signal-cabin about 18 inches northward, to give the standard clearance from the new track.