Clapham Junction 'A' signal box

Clapham Junction 'A' signal box was built in 1907 but it was did not became operational until 1912, the reason for the delay is not known, it is odd since tthe LSWR had pevious experience of these lever frames. When the signal box opened it was called Clapham Junction East. it was orignally fitted with an 84 lever British Pneumatic Railway signalling Company frame, this was the same frame type used in Grateley in 1901, two boxes at Salisbury in 1902, two boxes at Staines in 1903 and two boxes at Basingstoke in 1906. The British Pneumatic Railway signalling Company frame was replace in 1936 with the Westinghouse Brake & Signal Co. Ltd. Style 'L' Power Lever Frame.

At the same time in 1936
Clapham Junction South was re-named Clapham Junction "D",
Clapham Junction West was re-named Clapham Junction "E",
Clapham Junction East was re-named Clapham Junction "A"

The two boxes on the Central Section, Clapham Junction North and Clapham Junction South, were not re-named at that time. The renaming occurred during October 1924. Clapham Junction "D" closed on the day the L frame opened, so was never adjacent

The Westinghouse Style 'L' frames was commissioned on the 17th May 1936 and continued in use for 54 years until Stage 7b of the Waterloo area resignalling scheme. Clapham Junction 'A' finally closed on the 25th May 1990 when Wimbledon signalling centre took over its operation.

Clapham Junction station is a complicated affair with 12 parallel running roads, with 8 going to Waterloo, and 4 going to Victoria. Clapham Junction 'A' controlled the Waterloo lines with Clapham Junction 'B' controlling the Victoria lines. Going away from London the Waterloo tracks split with 4 continuing on the main line via Wimbledon, Surbiton, Woking and beyond, whilst the other 4 tracks became the local lines via Barnes and onwards Chiswick, Feltham and eventually Reading. There were also 52 sidings at the station and well as several connecting tracks to and from other Regions via Olympia.

Clapham Junction 'A' signal box exterior taken in 1981. Photograph 1

Over the years there have been several bridge cabins on the London south Western main line between Waterloo and Clapham Junction, but only West London Junction and Clapham junction 'A' survived into the late 1980's. Clapham Junction 'A' was originally built and opened in 1907, it defies architectural definition, consisting merely of a series interconnecting sheds on a bowstring girder bridge. During World War II a steel roof weighing around 40 tones was added as an air raid precaution. The framework for this can is clearly visible. The steel roof was removed in 1965, after the bridge subsided some 3½ feet at the London side, northern (left hand side) corner on Monday 10th May around 08:40. this collapse resulted in the complete closure of all Waterloo train services. The subsidence was caused by rust. The picture above shows the 16:38 London Waterloo to Salisbury Fridays excepted service approaching Clapham Junction station on the 27th August 1981.

Clapham Junction 'A' signal box exterior taken in 1988. Photograph 2

Picture above by kind permission of © David A Ingham. David can rightly say that he worked Clapham Junction "A" signal box, one of the busiest signal boxes in the world. The frame is a Westinghouse Style 'L' Power Frame which is all electrically locked. The frame was formed of 8 x 12 way and 1 x 8 way section which making a total of 103 levers, {8x12}+8}-1 = 103 levers, as the last “lever” space is unavailable.29 of these levers worked the points, 66 signal levers operated the coloured light signals, and 8 spare levers when the frame was supplied and installed. The working levers totalled 95.

Clapham Junction 'A' signal box exterior taken in 1988. Photograph 3

Here we have another clear picture of the signal box, this time taken from the main lines. This photograph was taken in 1988, reproduced by kind permission of © Jim Emmerson.

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This is the first in a sequence fo photographs of the interior of the signal box, which is earlier than the following photograph as the train describer on the left hand side are still the orignal wooden cased veriety, in the 2nd picture below they have been replaced by a VDU style train describer. This photograph was taken in 1988, reproduced by kind permission of © Jim Emmerson.

Clapham Junction 'A' signal box interior taken in 1988, with its Westinghouse Brake and Signal Co. Ltd miniature power lever frame showing diagram and train describers -1

The Westinghouse Brake & Signal Co. Ltd lever frame, with its indicators behind the levers, the 4 glass roundels showed the signal aspect, being Red, Yellow, Green & 2nd Yellow reading from bottom to top. The top indicator behind the signal lever is the "F" light and this became lit when the lever was normal, all points in the route correctly detected and all relevant track circuits clear. You could pull the lever at any time provided that the locking was correct but the signal would not clear unless the "F" light was lit before the lever was pulled. The train describers sending boxes are fitted on top of the frame box along with the receiving train describer units. This photograph was taken on 21st June 1988, reproduced by kind permission of © David A Ingham

Clapham Junction 'A' signal box interior taken in 1988, with its Westinghouse Brake and Signal Co. Ltd miniature power lever frame and train describers -2 with VDU.

Above and below are two good night-time photographs of the interior of the signal cabin. Reproduced by kind permission of © David A Ingham. The train describers are prominent on the top of the lever frame. This night shot was taken on 6th March 1989

Clapham Junction 'A'  signal box taken in 1988, with its Westinghouse Brake and Signal Co. Ltd miniature power lever frame night time photograph 2

A fire occurred on 15th June 1986, in which the frame and the wiring was damaged, as result all the points were clipped for straight running was instituted until the time the frame was rewired. This work involved the the transfer of all locking circuits away from the lever bands to relays. this night shot was taken on 6th March 1989

Clapham Junction 'A' signal box interior taken in 1988, with its Westinghouse Brake and Signal Co. Ltd miniature power lever frame and emergency block bells plungers.

Emergency bell plungers are provided next to adjacent signal boxes, mounted on the block shelf. Reproduced by kind permission of © David A Ingham. This day photograph was taken on the 21st June 1988.

Clapham Junction 'A'  signal box interior taken in 1988, with Westinghouse Brake & Signal Co. Ltd  track diagram.

The track diagram picture above the lever frame and train describers is seen here, it is reproduced by kind permission of © David A Ingham. To see a larger picture of the diagram double click the picture.

Clapham Junction 'A' signal box interior taken in 1988, with its Westinghouse Brake and Signal Co. Ltd miniature power lever frame nameplateCloseup shot of the lever frame nameplate, The serial number of this frame was L67 and was ordered in May 1935.

Clapham Junction 'A' The shunters train descrber instruments picture 1 worked between Clapham 'A'  Box and the Shunter's Cabin in the yard.

The shunters train descrber instruments pictured above and below worked between Clapham 'A' Box and the Shunter's Cabin in the yard. The bell codes were supposed to be sent on a separate single-stroke bell circuit, but in practice they would just put in a description and give one beat on the bell to draw attention to the fact that a description had been entered. To give an example, if the Signalman had an engine to go into the yard, he would press the appropriate button and give 'one' on the bell. In the yard were three groups of sidings known as 'Park,' 'Yard' and '49 Road.' The shunter's would send back to 'A' Box the description to show which road they wanted the engine on. Recollection are that there were moves in and out of the yard area every few minutes, so clearly these instruments facilitated faster working than using telephones. Reproduced by kind permission of © Mike Hodgson

Clapham Junction 'A' - The shunters train descrber instruments picture 2 worked between Clapham 'A' Box and the Shunter's Cabin in the yard.

Reproduced by kind permission of © Mike Hodgson

Top row: Middle row : Bottom Row
Indications from Pointsman's Cabin Indications from Pointsman's Cabin Indications from Pointsman's Cabin
Empties
U-W 1-2-2
U-M 2-2-1
Engine
W'loo 2-1-2
Loco 1-2-1
Engine or Vehicles
K'ton 1-3-1
D-M 3-2
D-W 2-3
Shunt to Sidings
1 5
Shunt neck 4-1
6 1-4
Replace 35 Shunt 3
FROM
Replace 34 Shunt 2-1
Park
Yard
49 Shunt
Last Description Cancel
Train or Engine
1 Siding 1-3
3 Siding 3-1
6 Siding 4
UM 3-5
On UW 2-2
On DW 4-4
UM Loop 5-3
Shunting Neck 2 2
Transfer sidings 5-2
Kensington 1-1-3
Ludgate 3-1-1
TO
DWL
Park
Yard
49 Shunt
Last Description Cancel
Train or Engine
1 Siding 1-3
3 Siding 3-1
6 Siding 4
UM 3-5
On UW 2-2
On DW 4-4
UM Loop 5-3
Shunting Neck 2 2
Transfer sidings 5-2
Kensington 1-1-3
Ludgate 3-1-1
TO
DWL
Park
Yard
49 Shunt
Last Description Cancel

Sidings 1,3 & 6 were the ones between the Main Lines and the Windsor Lines between “A” Box and West London Junction. 34 and 35 Shunts were out of the sidings in the V between the divergence of Main and Windsor Lines. 49 Shunt was a set-back from the Down Main Through platform

Diagrams

Attached is Southern Railway signal instruction 18 notice of 1936 and Signal instruction 18 track diagram of 1936 this can be downloaded in PDF format, this covers the opening of Clapham Junction 'A' and West London Junction signal boxes. These diagram(s) are taken from the website of the Signalling Record Society Research Note37. These images are copyright of the Signalling Record Society, and reproduced by permission.

Adjacent boxes

London Waterloo to Waterloo line (Main & Windsor Lines) - northbound

The only adjacent signal box was West London Junction signal box (1056yds away) and closed in the same stageworks as Clapham Jc A

London Waterloo to Reading South line (Windsor Lines)

Adjacent boxes (in 1934) were West London Junction signal box (1056yds away) and Clapham Junction "E" box (325yds away). Clapham Junction "E" box was re-named Clapham Junction "C" on 08/02/1959 and was closed on 02/11/1980 when Point Pleasant Junction box (1m 542yds away) became the adjacent box.

Clapham Junction "A" to Latchmere Junction line

Adjacent box was Latchmere Junction box (690yds away). Latchmere Junction box was closed on 24/04/1983 and Victoria Signalling Centre (located at Clapham Junction) became the adjacent box.

Clapham Junction "A" to Longhedge Junction line

Adjacent box (in 1934) was Longhedge Junction box (1718yds away). Longhedge Junction box was closed on 23/07/1978 and Stewarts Lane box (1m 620yds away) became the adjacent box. Stewarts Lane box was closed on 17/05/1980 and Victoria Signalling Centre (located at Clapham Junction) became the adjacent box.

London Waterloo (Main Lines) - southbound

Adjacent box was orignally Earlsfield box, when this was closed Wimbledon A box became the adjacent box and remained in service until Clapham Junction "a" closed

Signals in the vicinity of Clapham Junction A.

signal number WF76 which was Down Windsor Local Line Starter signal, the position 4 junction indicator was signal number 77, Down Windsor Local To Down Windsor Through signal.

This is signal number WF76 which was Down Windsor Local Line Starter signal, the position 4 junction indicator was signal number 77, Down Windsor Local To Down Windsor Through signal.
Photographed on 20th January 1989, reproduced by kind permission of © David A Ingham

Picture of Westinghouse shunt signal number WF.75 part of Clapham Junction 'A' signalling system, seen here with Clapham Junction 'A' in the background. This signal was the Down Windsor Local To Sidings Set Back signal.

This is signal number WF.75 which was the Down Windsor Local To Sidings Set Back signal. Photographed on 20th January 1989 with the box behind. Reproduced by kind permission of © David A Ingham

Clapham Junction A signal WF 101

This is signal number Westinghouse shunt signal number WF.101 part of Clapham Junction 'A' signalling system, which was the Platform 2 (Arrival Road) Starter. Photographed on 6th March 1989 with the box behind, reproduced by kind permission of © David A Ingham

Clapham Junction A signal WF 101

Closeup of Clapham Junction A signal WF 101. used to start the ‘Kenny Belle’ everyday as seen in the background This photograph was taken on the 25th November 1988, and is reproduced by kind permission of © Jim Emmerson.

Another view of Westinghouse shunt signal number WF.75 part of Clapham Junction 'A' signalling system, seen here with Clapham Junction 'B' in the background.

Another view of Westinghouse shunt signal number WF.75 part of Clapham Junction 'A' signalling system, seen here with Clapham Junction 'B' in the background which was decommissioned by this date. This signal was the Down Windsor Local To Sidings Set Back signal. Photographed on 20th January 1989 with the box behind. Reproduced by kind permission of © David A Ingham

Picture of Westinghouse shunt signal number WF.75 part of Clapham Junction 'A' signalling system, seen here with Clapham Junction 'A' in the background. This signal was the Down Windsor Local To Sidings Set Back signal.

3rd picture of Westinghouse shunt signal number WF.75 part of Clapham Junction 'A' signalling system, seen here with Clapham Junction 'A' in the background. This signal was the Down Windsor Local To Sidings Set Back signal.
Photographed on 20th January 1989 with the box behind. Reproduced by kind permission of © David A Ingham

Closeup of Clapham Junction A signal WF 75.

Closeup of Clapham Junction A signal WF 75. it is seen here with Clapham Junction 'B' in the background which was decommissioned by this date. This photograph was taken on the 6th September 1988, reproduced by kind permission of © Jim Emmerson.