The Branch Line Society


London Underground Signal Cabin Visits
Monday 2nd March 2015

Meeting at 09.45, ten members had a most interesting and enjoyable day visiting a wide variety of London Underground signal 'cabins'. Our very affable guide (chaperone?), Liz, was clearly well informed after 13 years in LU signalling. We started in the architecturally interesting Allsop Place offices behind Baker Street station, and were surprised to see a Westinghouse 1960s style green 'domino' tiled track layout on the wall, as found in many BR panel / power boxes of that era such as Swindon, Wolverhampton and Derby, although it dates from 1986.


This shows the trains (but has no control over) part of the Jubilee Line, the northern part of which from Baker Street to Stanmore used to be a branch of the Bakerloo. It interfaces with Harrow-on-the-Hill and goes to Tower Hill (exclusive) via Liverpool Street including the Aldgate triangle. Route setting is mainly automatic. Our guide showed how trains were cancelled or diverted in that day’s timetable and then the computer did as instructed. Afterwards we went to the separate 1986 line control office, where decisions are taken such as omitting intermediate calls between Baker Street and Harrow to get a late train back into its proper path. GSMR is installed because of the Chiltern line to Aylesbury. The new timetable is so intensive that if a train is more than a few minutes late, quick decisions have to be made about short workings, cancellations and ECS moves etc. before trains back up _ then the staff really earn their keep! It is hard to believe that at one time the 'King' lever would be thrown at Baker Street off peak and the Met. was then operated as a self contained branch to the north!

Edgware Road: (District / H&C) was like nothing the party had seen before. The oldest cabin on LU, it has a 1926 vintage miniature 38 lever frame. Every signal and each set of points is controlled by its own 6” lo􀅶g lever with indicators to confirm, just like on full size mechanical levers. There are four busy platforms and the notorious Praed Street Jct. to control. The lone signalman was on the go all the time and even recording all times in handwriting as the computer is too slow to cope with the intensive service! There is a 35 minute meal break in the eight hour shift but it was hard to see how he could otherwise make a drink or answer a call of nature. This was during 'normal' working; when something is amiss the phone/radio never stops! The trains are right in front of the box which even has its own whistle, now used to remind resting drivers of a green signal after changing ends. A complication is that there are many crew changes and terminating services at Edgware Road. The signal box diagram seemed to be more or less all permanently lit with very little unoccupied track and then only briefly. The general public on the latest modern trains passing by would be amazed, as indeed our members were.

Then it was off to Hammersmith H&C terminus, where the group were impressed with the way the three platforms had recently been extended at the buffer ends in keeping with the rest of this attractive GWR style station to accommodate the now longer new trains, although you can spot the joins. There they saw another (1951) Westinghouse miniature 35 lever frame with even dinkier levers, 4” high. Again the signalman was continually busy at this three platform terminus, also with plenty of movements in and out of the depot as well. The signaller has full control of the platforming and can override the train plan in this respect. He manually operates the 'next train' indicator (which may explain why some regular passengers look for the green signal!). Staff opinion was that the Circle now runs better operating out and back between Hammersmith and Edgware Road via the south side of the Circle. In the days when it just went round and round they regularly needed to 'step back' all the Circle Line trains if one was very late.

The party took the remarkably short walk to Hammersmith (Piccadilly and District Lines) then the Jubilee from Westminster to reach Waterloo for the last visit to the Waterloo and City control. This covers signalling with a 2007 VDU based system, line management and service control. There is a back up 1993 NX emergency control panel. The control room is hidden away off a secure car park to the high numbered side of Waterloo station and difficult to find, although this meant the party noticed the intact bridge over Waterloo Rd. that once carried the link line to Waterloo East (used from July 1865 to December 1867 and removed 26 March 1911) - if only…! The 1m 56ch (passenger run 1m 46ch) double track W&C is isolated by rail from the rest of the network so the carriages have to be craned in and out from above, although there is a lift for components such as bogies. In the peaks all five trains operate and one runs every 2¾ minutes from each end, carrying 800 passengers at a time (tidally to Bank in the morning and back to Waterloo in the evening). There is a well practised passenger queuing system and it is one of the few railways that requires 100% stock availability; when a unit is taken out for servicing every six months there are problems! Off peak, with three trains running, the signalling is automatic and ensures a uniform headway, but the party witnessed the controller having to change the normal off-peak platforming after the tripcock on one unit operated half way along the right hand platform (P7) approaching Bank. This is the preferred platform there for off peak operation as the train is slowing anyway on approach (and takes the crossover) with a faster departure on the straight. At Waterloo P26 is purely for arrivals, so unusually there are no advertisements on the trackside wall which looked very odd! The ECS then moves forward, reverses in depot Road 5 off peak and loads in P25. This ex-SR/BR line now operates all day SuX. Drivers either love or hate the W&C, but all W&C regular drivers (who volunteer for the job) refresh the Central Line by driving on it every six months and vice versa.

Thanks to our excellent LU guide and our member Rob Davidson for facilitating these superb visits. As one of the participants said, the group was treated 'like royalty'; Rob was the second very knowledgeable guide and also made sure no one got lost!