Second Series Issue Number 201 the TIMETABLE for Period Beginning 4 October 1978
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Second series Issue number 201 THE TIMETABLE for period beginning 4 October 1978 Wednesday 4 October Library Evening, 1530. The Society's Library open for Inspection at 9A Dunrobin Court, 389 Finchley Road, London, NW5 6he. Saturday 7 October Morning visit to Lillie Bridge Permanent Way Depot. FULLY BOOKED Friday I3 October Talk by Mr.P.RoDavis, 'The Search for the Crystal Palace Pneumatic Railway'. I9OO for 1915 at Hammersmith Town Hall, Saturday 21 October The Society will be operating its Sales Stand at the L.O.T.S, Transport Spectacular at the Central Hall, V7estminster, SW 1., 1100 to 1530, Friday 3 November Afternoon visit to the Waterloo & City Railway. FULLY BOOKED. Tuesday 7 November Library Evening, I83O. Other details as for 4 October. Friday 10 November Talk on 'Railway Timetable Compilation' by Mr,D.Fox, London Transport, I9OO for 1915 at Hammersmith Town Hall. Saturday 25 November The Society vrill be operating its Sales Stand at the Transport Enthusiasts' Bazaar, Islington Town Hall, Upper Street, London, N 1. Monday k December Library Evening, I83O. Other details as for 4 October, Friday 8 December •The Underground Scene since 1975' -Film show and Commentry by Les Collings, 1900 for I9I5 at Hammersmith Town Hall. Published 12 times a year by the London Underground Railway Society Correspondence should be addressed to The Editor, Underground News Opinions expressed are thoseof contributors and notnecessarilyendorsedbytheSociety. @ The contents are copyright HAMMERSMITH MEETING AUGUST 1978. The subject of the meeting vms 'Train Performance and Testing on London Transport' and was given by Mr.F.G.Rutty, Traction Engineer, London Transport. MToRutty began by explaining that the Chief Mechanical Engineer's department was responsible for heavy overhauls and design, the latter being the responsibility of the Development Team. London Transport was unique amongst rapid-transit operators in largely designing its own cars and assuming detailed responsibility for their construction. When new rolling stock was to be designed, the length of a train was governed by platform lengths, whilst the length of the cars was determined by-the selected number of cars in a train, subject to restrictions imposed by line curvature. After the car had been designed, the weight could be estimated, and the Development Team could ask motor manufacturers to tender to supply motors suitable for the train weight and the speed—distance 'envelope' of the line, plus an allowance for potential higher performance. The guaranteed tractive effort of each motor enabled the numbers of motors per train to be calculated. After contracts had been placed, the first ten motors delivered were tested for performance, and subsequent deliveries were tested for conformity. l\'hen the first new trains were delivered, they were tested for compliance with specification. One of the most important tests was for braking performance, as the signal overlaps v;^ere based on braking performance figures supplied by the CME's department. The testing 'on the road' was probably the most interesting of the team's activities. The centre tracks between Acton Town and South Ealing were reserved for testing at certain periods, and there was a water-spray on the eastbound track. Brake tests were done by 'tripping' to simulate an emergency brake application. Higher speed tests were done between Amersham and Rickmansworth, but in this case an 'Engineer's Possession' could not be given, so that a brake application had to be made by dropping the deadman's handle at the correct predetermined place. This section of line also gave rise to problems with autiimn leaves on the running rails, and the most successful solution was to equip a rail-grinding car with some serrated collector shoes and to use water at high pressiare, MfcRutty then outlined some projects that his team had been engaged in or associated with, some regular, and others special:- (i) Tests at Upminster for ways of stopping a train from 20 m,p,h, by external mechanical means. Granite chippings about 3 to 4ft high with a 'dolly' at the buffer stops gave the desired result. The test train was unmanned, (ii) All new or redesigned bogies were strain-gauged for dynamic testing* 558 (ill) All new types of veli5.cle were breike-tested, including the Tunnel Cleaning Train (which had hydraulic motors for pi'opulsion at constant low speed irrespective of gradient), and Plasser Tamping Machines. London Transport had used non-metallic brake blocks since 1911, and was by far the largest user. (iv) Ultrasonic axle tests had eliminated axle failures. Tests were done yearly on older cars, and two-yearly or more on post-1967 cars, where a concentric groove in the axle helped to prevent faults. (v) Breakage of gear teeth was causing some concern at present; rheostatic braking may have contributed to the trouble. A solution was being urgently pursued. (vi) Diagrams were displayed, showing that A stock consumed 60% of the energy of T stock trains of similar length. (vii) Speed-distance curves were calculated for all lines, including proposed new lines, and existing lines with new stock. (viii) Gauging tests were done with cars fitted with a template and movable fingers. The cars were hauled at walking pace and men on the cars noted where the fingers touched the tunnel, etc. Tube tunnel sections were covered every 5 years, other sections every 3 years. (ix) Brake Block Tests. Sarah Siddons was used because her weight should prevent wheel locking and skidding. (x) Graphs showing the action of wheel-skid protection on the 1973 stock braking system were explained. (xi) A fram.eless air-metacone bogie for tube stock and the importance of wheel profiles were also discussed. Mr.Rutty concluded by answering questions from the audience, which included coasting to save power and articulated trains. The proceedings concluded with a hearty vote of thanks to Mr.Rutty for delivering a highly interesting paper. D.F.C. 13.8.78 LONDON TRANSPORT BRIDGES Further to the note in Underground News No,200, reviewing the talk given by Mr.Jobling on 'L.T. Bridges', Mr.Jobling has kindly given the Society the following notes for publication, Sjge of the Undertaking The Executive own 750 bridges, excluding footbridges, 500 of which are underbridges carrying the railway over highways, rivers etc., and 250 are overbridges carrying highways etc. over the railway. (Note: X7here two railvmys cross, one over the other, the bridge generally belongs to the company owning the railway which is being supported). Additionally, the Executive maintains a number of overbridges as agents for other authorities, such as the Department of Transport, G.L.C. etc. 559 or the 500 underbridges, I60 are brick arches, 80 are of wrought iron construction'(built before I903), 200 are of steel and 60 of concrete. In the interests of safety, but to the regret of the conservationists, the last of London Transijort' s cast iron arches, situated at Kilburn, has been removed and is being replaced by a bridge of modern design. The 250 overbridges consist of 70 brick arches, 60 wrought iron, 75 steel, 12 cast iron and 33 concrete. Of the underbridges, 23 are over rivers and 7 over canals. The longest bridge comprises two spans over the River Lea in East London, totalling 196' 3"o The longest single span of l60ft carries the Metropolitan Line at an acute angle over the Rickmansworth Road, Northwood, The oldest bridges still in use are on the Epping/Ongar section of the Central Line, having been built in I865. A number of the . -:i earliest reinforced concrete bridges were built to the designs of the famous French engineers Hennebique and Coignet, the earliest (I9I2) at Kings Cross being to the design of Coignet. Brick built viaducts, of which there are a considerable number, are not included in the count of bridges. The longest of these is from Shepherds Bush to Wood Lane and consists of 50 arches of 28ft each. Building or Rebuilding of Bridges Bridges are built or rebuilt when:- 1) A new bridge is required, for example, when a line is being extended. 2) It is required to widen the roadway. 3) The bridge is 'time expired', that is, it is an old bridge, which it can be forseen will require a lot of expensive maintenance in the future. It may be fortuitous that at times, 2) and 3) occur together, and the highway authority will then make a financial contribution to the cost of reconstruction. Replacing Old Bridges Bridges are at present being renewed at the rate of four per year. This figure is of course, variable within limits set by the availability of design staff, and the ever present financial stringency applicable at that time. The low rate of renewal is due, in part, to the high proportion of brick arches, \irhich seem to go on for ever. The reasons for the replacement of metal bridges are, in the main, corrosion and/or the fatigue of the metal, and subsidence or movement of the abutments, in the worst cases, all three occurring simultaneously. London Transport, in common with British Railways and other bridge owning authorities, are increasingly disturbed by the frequency with which their bridges are being struck by high vehicles. At best 560 this requirsa an emergency inspection to determine whether the bridge may still be used and carry its normal loading. At worst, the entire bridge may be displaced, causing a deformation of the railway tracks. In one recent case (not on London Transport), this was the cause of a derailment in which seven persons were injtired. Bridges must sometimes be replaced because, although still in good condition, their carrying capacity is insufficient to provide an adequate margin of safety when loaded by present day traffic.