London Transport Railways Inventory of Signal Cabins and Other Interlockings 1863 – 2020 Interlocking frames, signal boxes, control rooms and other signal controls on London Underground lines and their predecessors. Mike Horne © M.A.C. Horne Version 9.55 – 20 February 2020 Criteria for inclusion. 9. Where a change happens overnight the expression 'closed after [whatever date is]' is used. This means the change happened 1. A Signalbox or other interlocking (a) provided by LU, (b) taken over by immediately after the last train of the day (which chronologically can LU, or (c) in certain cases 'fringing' on locations that are (a) or (b). It mean early morning the following day). LT practice is used here such does not generally include boxes on main lines that came and went that (for example) the last Saturday night train is counted as running prior to LU takeover. on Saturday, even if it is actually early on Sunday morning. Note main 2. ‘Signalbox’ means any location at which control of signals or points line practice is different. (or both) are concentrated and includes ground frames and control 10. Colour - entries in GREEN are non LU installations, Entries in rooms. MAGENTA are training equipment and entries in BLUE are still extant. 3. Interlocking means any device or apparatus, whether electrical or Abbreviations used in Status column mechanical, whereby signals and points are interlocked to preserve safety and includes any other arrangements to prevent one or more C = Signalbox continuously open or opened regularly at published times signals giving a proceed indication if equipment intended to detect safe conditions is operated (or fails to operate) or where apparatus E = Signalbox broadly open as required (either for shunting or in intended for use by staff are operated. emergencies) 4. LU means London Underground Limited and all its predecessors in GF = Ground Frame (whether in open air or enclosed) title. IMR = Interlocking Machine Room (for the purposes of this listing it means a 5. The listing does not include signalboxes entirely controlled by any remotely controlled interlocking machine or signal frame available only for main line railways where LU trains merely pass through. It does use by signal department staff) include locations where there is train control, or surface stock gauge detectors, derailment detectors and point detection on handworked PBD = Push Button Desk or other type of control panel using push buttons to points, even if there is no signalbox. select a route 6. The list does not include the latest signalling arrangements where the RR = Relay Room within which signals and points are selected on instruction concept of a discrete interlocking has ceased to exist in its traditional from remote operator form. Westrace interlockings are included, but the case is marginal. Other observations Con = Control Room where operators have control or supervision of large areas (including whole lines) but which will normally not house interlocking 7. Where a date is given then this is intended to convey change equipment happened ON that date - small changes were often done during the day CBI = Computer-based interlocking. Any of the various proprietary interlocking computers used to control points and signals and based close to 8. Where a closure date is given then an attempt has been made to offer the sites they operate. the last day that the box or equipment was in service. There is more to do here as the position is chaotic with source material often quoting SER = Signalling Equipment Room - a modern name for a room tending to first date of no service, which can be the day following last day of house modern relay-based or computer based interlockings (CBIs) and which service but sometimes days or weeks afterwards (but never saying may contain local controls. SERs controlling purely 'plain line' track are not which convention is used). included here. PR = Proving (manually operated points or other equipment proved to be in correct position) Auto = A signalling layout designed only to operate automatically (on this list ordinarily arranged by relay-based equipment in a nearby Relay Room) Training = equipment used purely for training and not in control of live trains Exhibit = equipment used purely for display purposes (for example a museum or as a sales tool) and not in control of live trains (may or may not have operational capability) Depot (Tower or cabin) = Route setting apparatus provided in a depot, normally consisting of panel with selector switches to select route but can be other means (excludes GF described as such) Version 9.55 – 20 February 2020 — © M.A.C. Horne Page 3 Current Interlocking name Cabin Box Opened or Frame Sta- Frame Levers on Box or interlocking Closed Notes Source Queries Location when opened Code date of frame Type tus No. opening location Acton Town Mill Hill Park 1 July 1879 Shortly after Mech C 16 (4 spare) Replaced by ep box on new Need box location MT6/238/6 [MD-020-020] (originally Mill 24 April 1883 at opening site. It is assumed (likely at up end of SRS has 1903 Hill Park) mechanical box closed after stn). traffic previous day. Mill Hill Park 24 April 1883 10 June Mech C 41 (of which New signal box necessary to Box was located by MT6/368/7 (inspection 1905. 2 spare) cater for addition of Hounslow rear wall on up OS 1:1056-inch date, not extension. platform about half Map, (1894-6) actually way along. connected up) Mill Hill Park WL 11 June 1905 After traffic B C 29 47 Replaced Mechanical box at Located at east end T&RyWorld; [MD-020-020] 23 Jan 1932 (22p,19s,6c) Mill Hill Park. However, there of northern island. Westinghouse is some evidence it had been (Prior to island this List. equipped as early as was the northern February) platform at east end). Mill Hill Park Yard (In use 1901) Probably Mech GF 4 (1p) Mentioned in 1901 Appendix 1901 MDR [MD023-10] 1905 when as controlling shunting Appendix new box between down Acton Curve Exact date of opened and No 3 siding. Unlocked by opening still Annets key from main SB. needed Acton Town WL 24 January After traffic N C 171 119 New Box which has the Located on north side STC3/1932 1932 11 July 1965 (27p,67s,19l) honour of having the largest of line towards east (p42) frame ever installed on the end of platforms. Underground. Acton Town WL 12 July 1965 V IMR 36 (East Two new IMRs (East and One IMR on north STC26/1965 IMRs (2) IMR) and 36 West) controlled by local embankment just (West IMR) programme machines west of station, other supervised from the new on south side of line regulating room (Warwick by entrance to Acton Road) at Earls Court. Control Works. transferred from Earls Court to South Kensington (Picc) SCC from 24 February 2019. Acton Signal School - see under Signal School Aldgate Aldgate 18 November After traffic Mech C 55 (49 wkg & Signal box provided at Was situated on MT6/1609/1. OS LT1/01 1876 25 Sept 1909 3 spare and opening of line, apparently south side of line mapping 1894- [MT001-010] 3 spaces in with provision for expansion. opposite junction 1896. (see also 1907), all (adjacent to Minories box – at south end of wkg at headwall). closure. platforms) Aldgate H 26 September After traffic M1 C E2 30 New box for power frame. All Situated at east end Met Record of 1909 13 May 1927 (11p,15s,4c). Electric. of inner rail island Events and Initially may platform. Replaced by MT6/1881/5. OS have been Aldgate OB mapping 1915- 24 wkg 6 6. Photo of spare) inside of cabin. Version 9.55 – 20 February 2020 — © M.A.C. Horne Page 4 Current Interlocking name Cabin Box Opened or Frame Sta- Frame Levers on Box or interlocking Closed Notes Source Queries Location when opened Code date of frame Type tus No. opening location Aldgate H 14 May 1927 After traffic ?? C ?? 36 New box probably to allow New box on down TCs 1927. OS Need to confirm 18 May 1946 platform extension. No track side near tunnel mapping. frame type and and only minor signal mouth on site of old size. Harsig 1933 alterations. Possibly reused engine siding. diagram suggests frame. 36 levers 15 spare. Aldgate OB 19 May 1946 After traffic N C 183 59 Ordered 1937. Controls all New box over tracks STC 19/1946. 24 January (14p,39s,5c) three junctions and Aldgate at north end of UN 316 1988 East. The frame is reputed to station. have been borrowed by the Great Western Railway in 1938 as a temporary replacement for its own frame at Paddington which burnt out. Returned to LT in 1939 when GWR frame repaired (see Paddington). Frame bought by members of Quainton Railway Society. Aldgate IMR OB 25 January V IMR 48 New IMR controlled from new IMR located near STC 1/1988 1988 temporary PBD in Farringdon Minories junction in SB. Control of IMR angle between transferred from Farringdon District Line and to Baker Street control centre Outer Rail Circle Line. 26 July 1998. Aldgate East Aldgate East 1 October 1884 Frame OOU Mech C ?? Levers not established (c.12 Box on EB platform at MT6/1976/2 [MD002-030]. 15 July 1906 estimated) junction end. I have a date 26 Feb 1905 for something here but don't know what. Aldgate East EL 15 July 1906 After traffic 6 B C 61 15 (5p,9s,1c) New Frame Only. New frame [see above]. New MT6/1976/2 and October [all levers installed in old (original) box.