Signal box prefix codes

A (hopefully) comprehensive listing

'Boxes beginning T

Last update 16 June 2025

Additional information is always gratefully received, whether entirely new records (particularly historical records) or information to fill in gaps or correct errors, via the contact link under the Miscellaneous entry in the navigation bar above. Thank you.

Please select a starting letter from the links below:

Code Signal Box Note ELRMileage Opened Closed Control to
TW Taffs Well depot TWD 4 June 2023
TWO
TE Talacre CNH3201m 76ch 1903 late on 23 March 2018✖last train; official closure 26 March 2018 Wales Rail Operating Centre (FH)
T Tallington Downgraded to gate box 5 July 1975: line controlled by Helpston (H) ECM184m 64ch 13 April 1975 29 March 1998 Helpston (H)
TH Tamworth Formerly Tamworth Low Level LEC2110m 12ch 1910 23 August 2008 Rugby Signalling Control Centre (NL)
TH Tamworth High Level DBP123m 61ch August 1925 Saltley (SY)
TA Taplow Downgraded to ground frame 8 December 1963 MLN122m 30ch 30 June 1930 20 July 1974 Slough (S)
DM Down main line automatic signals
DR Down relief line automatic signals
TJ Tapton Junction SPC9≈146m 69ch 25 March 1972 Sheffield (S)
T
TC Tattenham Corner TAT23m 26ch 6 April 1925 25 September 1983 Purley (CU)
CA Automatic signals
DTC Distant signals
T Taunton East Junction Code from 12 May 1986 MLN1162m 63ch WTZ162m 63ch 13 December 1931 21 March 1987 Exeter (E)
TE Code to 12 May 1986
TS Tay Bridge South ECN256m 36ch 20 June 1887
TB Unclear whether code used
TY Tees Also known as Tees Yard DSN212m 70ch TSY12m 70ch 12 August 1962
T
D Down automatic signals
U Up automatic signals
NS Tees Signalling Control Centre Newcastle to Sunderland section DSN212m 70ch
Tees Yard See Tees
Teignmouth MLN1208m 78ch February 1896 14 November 1986 Exeter (E)
TE Templecombe BAE2112m 02ch 15 May 1938 27 February 2012 Basingstoke Signalling Control Centre (SE)
DM Down main line automatic signals
DUM Up main line down direction automatic signals
UM Up main line automatic signals
TE Temple Mills East SDC4m 54ch 29 June 1958 14 November 1987 Stratford (S)
TM Temple Mills Eurostar Depot TMD≈ 12.287km 2006
TW Temple Mills West SDC6m 08ch 29 June 1958 20 March 1988 Brimsdown (BD)
D Down line automatic signals
RTW Banner repeater signals
U Up line automatic signals
UM Up main line automatic signals
MY Temple Mills Yard Code shown on 2015 signalling plan SDC
U Tempsford Up direction automatic signals ECM147m 38ch 30 October 1893 23 July 1976 St Neots (SN)
TJ Terminus Junction CLY101m 44ch 7 October 1878 2 June 1974 Glasgow Central (G)
EX Teynham Crossing Downgraded to gate box 1967: line controlled by Sittingbourne (EV) VIR47m 78ch 8 March 1945 24 December 2011 East Kent Signalling Centre (EK)
TB Thames Board Mills Crossing Stop boards TLL16m 38ch 27 May 1996
T Thames Haven [also called Terminus ground frame?] THN≈30m 18ch Upminster IECC (UR)
TH Thames Haven Junction TLL26m 57ch 19 August 1973 Low Street (L)
TR Thames Valley Signalling Centre Original code DCL53m 38ch DWC0m 19ch 21 March 2010
BL Former Bristol signals (Filton-Westerleigh area)
DW Down Westbury line automatic signals. Code shown on signalling plan
FY Creep signals at Theale Foster Yeoman sidings
HY Hinksey Yard stop boards. Code shown on signalling plan
OD Oxford area signals. Code used from 16 July 2018
OOC Old Oak Common area signals. Code used on new station development plan
SB Former Swindon B IECC signals. Code used from 27 December 2012
SN Former Slough New IECC signals. Code used from 27 December 2011
SW Former Swindon signals
T Southern line signals. Code shown on signalling plan
T Oxford-Worcester line signals. Code shown on signalling plan but never used
T Reading area signals. Code used from 29 March 2013
TRK Kintbury crossing signals. Code shown on signalling plan
UW Up Westbury line automatic signals. Code shown on signalling plan
Z Draw forward signals near Stockley
TH Theale BHL41m 19ch 1920 17 September 1977 Reading (R)
TH The Hall NHL126m 39ch 5 April 1876 23 May 1965 Netherfield Junction (NJ)
D Theobalds Grove Ground Frames HDT Liverpool Street [new] (L)
U
T Thetford Code in use by 1980 ETN93m 44ch 1883 20 August 2012✖delayed from 25 June 2012 Cambridge (EN)
T Thingley Junction MLN196m 09ch January 1903 23 March 1968 Swindon (SN)
DM Down main line automatic signals
UM Up main line automatic signals
TK Thirsk Code used from 19 September 1965 ECM522m 34ch 5 November 1933 20 January 1990 York [IECC] (Y)
D Down line controlled and automatic signals. Code used from opening to 19 September 1965
DF Down fast line automatic signals. Code used from 19 September 1965
DS Down slow line automatic signals. Code used from 19 September 1965
U Up line controlled and automatic signals. Code used from opening to 19 September 1965. Slow lines have suffix S
UF Up fast line automatic signals. Code used from 19 September 1965
US Up slow line automatic signals. Code used from 19 September 1965
Thoresby Colliery Had draw-ahead signals lettered A to E, with no number TYC≈1m 05ch
T Thoresby Colliery Junction Also called Thoresby Junction. Out of use for some time before closure HIM17m 21ch TYC0m 00ch 1926 3 April 2022✖official date Clipstone Junction (CJ)
also had draw-ahead signals lettered A to E with no number
Thoresby Junction See Thoresby Colliery Junction
TH Thorington Downgraded to gate box 21 December 1958: line controlled by Thorpe-le-Soken (T) COC59m 43ch 1885 4 May 2009 Colchester [new] (CO)
TX Gate box code
TE Thornaby East DSN2≈11m 69ch Tees (TY)
TN Thorne Moor TJG2≈12m 32ch 2 December 1979 Goole (G)
TM Unclear if code carried
TH Thornhill Code used from 2002 GSW77m 58ch 10 October 1943
TL Thornhill L&NW Junction MVN239m 74ch Mirfield Junction No 3 (M3)
TMJ Thornhill Midland Junction MVN2? Healey Mills (HM)
U Up line automatic signals
T Thornton Abbey Formerly named Barton Road Level Crossing Gate box: line controlled by Ulceby (South) Junction (UJ) to 20 December 2015, then Goxhill (from 30 December 2015) BAR≈103m 11ch
BL Code when named Barton Road Level Crossing
CZ Thornton Heath VTB18m 50ch 21 June 1903 19 December 1976 Three Bridges (T)
CA Automatic signals
TC Thorpe Culvert GRS42m 20ch 1888 8 February 2003 Thorpe Culvert [temporary panel] (TC)
TC Thorpe Culvert [temporary panel] GRS42m 21ch 9 February 2003 18 May 2003 Thorpe Culvert [reopened] (TC)
TC Thorpe Culvert [reopened] Reopened original 'box following rebuilding GRS42m 20ch 18 May 2003
TG Thorpe Gates Downgraded to gate box 20 May 1973: line controlled by Selby West (S). Demolished 13/14 October 2013 HUL32m 27ch 1873 5 October 2013 Selby West (S)
T Thorpe-Le-Soken Code probably used from 23 July 1989 COC65m 07ch 1882 4 May 2009 Colchester [new] (CO)
D Down line automatic signals
RD Down line automatic repeater signals
RU Up line automatic repeater signals
U Up line automatic signals
CEGB Thorpe Marsh Power Station by 1980 after 1994 line closed
T
TM
A Unloading signals
B Unloading signals
T Thorpe On The Hill NOB127m 28ch 12 May 1907 19 March 1988 Swinderby (S)
TB Thorpes Bridge Junction MVN22m 24ch 26 September 1987 27 November 1982 Thorpes Bridge Junction [temporary] (TB)
TB Thorpes Bridge Junction [temporary] MVN22m 26ch 27 November 1982 6 December 1982 Thorpes Bridge Junction [reopened] (TB)
TB Thorpes Bridge Junction [reopened] MVN22m 24ch 6 December 1982 7 August 1998 Manchester North (MN)
CL Three Bridges VTB329m 34ch 27 April 1952 2 July 1983 Three Bridges [new] (T)
CA Automatic signals
T Three Bridges [new] VTB329m 28ch 25 June 1983
EB Eastbourne area signals
TD Three Bridges Depot Control Centre VTB3≈30m 00ch 13 July 2015
TL Three Bridges Rail Operating Centre London Bridge area signals VTB3 29 December 2014
TEB Eastbourne interlocking. Code used from 16 February 2015
TLW Lewes workstation. Code used from 2 December 2019
TVC Former Victoria Signalling Centre (Central) signals. Code used by June 2014
TVS Former Victoria Signalling Centre (South) signals. Code used from 15 March 2015
TWH Former West Hampstead signals. Code used from 15 March 2015
TC Three Counties ECM135m 51ch 1898 27 June 1976 Hitchin (HT)
C Code shown in October 1974 weekly notice
THS Three Horse Shoes EMP91m 05ch 1901
R Distant signals some signals had suffix R instead
TS Three Spires Junction Permanently switched out from September 1998 CNN3m 20ch 28 June 1914 23 February 2003 Three Spires Junction [new] (TS)
TS Three Spires Junction [new] CNN3m 19ch 23 February 2003 26 May 2009 West Midlands Signalling Centre (CN)
T Thrumpton Also known as Retford Thrumpton. Code used from 1965 MAC364m 46ch 15 March 1889✖inspection date
TN Code used from 23 September 2013
D Down line automatic signals. Code used from 1965
DB Down (Cottam) branch line automatic signals. Code used from 1968
U Up line automatic signals. Code used from 1965
UB Up (Cottam) branch line automatic signals. Code used from 1968
T Thurgoland Sidings MAC231m 55ch by 1880 ≈1959 Blackmoor Crossing (B)
T Thurlstone Crossing MAC127m 03ch 1899 18 July 1981 Line closed
T Thrybergh Junction WME7m 73ch 19 February 1909 2 August 1980 Sheffield (S)
TJ Tibshelf East Junction TCC137m 19ch 2 March 1969 11 October 1969 Trent (TT)
Ticehurst Road See Stonegate
T Tilbury Riverside TTE0m 15ch 1961 8 April 1996 Line closed
T Tilehurst MLN138m 44ch 1893 24 April 1965 Reading (R)
TS Tile Shed LEN393m 64ch 11 December 1988 East Boldon (EB)
TE Tinsley East Junction Taken out of use through fire damage ≈20 April 1985: reopened 21 June 1985 WME2m 68ch by 1926 6 December 1992 Woodburn Junction [new] (W)
MY Tinsley Main Yard Control Tower BTJ≈160m 10ch 27 October 1984 Tinsley Yard (TY)
TP Tinsley Park BTJ160m 65ch 29 November 1964 20 September 1992 Tinsley Yard (TY)
SY Tinsley Secondary Yard Control Tower BTJ≈160m 60ch 27 October 1984 Tinsley Yard (TY)
TW Tinsley West Junction SMC2m 54ch 1922 20 February 1998 Line closed
TY Tinsley Yard BTJ160m 02ch 11 April 1965 19 June 2010 Woodburn Junction [new] (W)
WDB Tisbury Code used from 1963 BAE296m 00ch 12 October 1958 5 February 1967 Gillingham [Dorset] (GM)
WDC Tisbury Gates Downgraded to gate box 1923. Code used from 1963 BAE297m 12ch 4 June 1892 28 July 1985 Gillingham [Dorset] (GM)
TJ Tiverton Junction This 'box may have opened in 1874, or that may have been a predecessor MLN1179m 11ch TIV179m 11ch 25 September 1932 3 March 1986 Exeter (E)
UM Up line automatic signals
T Tollerton Codes used from opening ECM59m 40ch 29 January 1961 10 December 1989 York [IECC] (Y)
D Down line automatic signals. Slow lines have suffix S
DF Down fast line automatic signals (until 28 July 1985)
DS Down slow line automatic signals (until 28 July 1985)
U Up line automatic and semi-automatic signals (until 28 July 1985). Slow lines have suffix S
PE Tonbridge XTD and RTT routes transferred to Ashford IECC (AD), control of TTH remains RTT41m 77ch XTD29m 24ch 18 March 1962 27 September 1993 in part Ashford IECC (AD) XTD and RTT routes only
A Automatic signals
TU Tondu Formerly named Tondu Middle BAL2m 70ch 1884
Tondu Middle See Tondu
Topsham EMT4m 23ch ≈1870 30 January 1988 Exmouth Junction [new] (EJ)
Torre TOR219m 09ch April 1921 13 November 1986 Exeter (E)
T Torside MAC115m 31ch 18 July 1981 Line closed
TE Totley Tunnel East MAS154m 62ch 1893 25 March 2024 York Rail Operating Centre (DE)
T Totnes Code in use by 1984 MLN1222m 63ch 7 January 1923 9 November 1987 Exeter (E)
TE Toton East THL 18 October 1969 Trent (TT)
WDU Totton BML282m 53ch ≈1875 28 February 1982 Eastleigh [new] (E)
Towneley Gate box: line controlled by Preston (PN) FHR622m 62ch 1878
TG Town Green SJO29m 79ch ≈1940 10 February 1994 Merseyrail (ML)
TP Trafford Park Junction MAJ≈31m 66ch 15 January 1904 inspection date Manchester Piccadilly (MP)
TI Tram Inn HNL15m 37ch 1894 Wales Rail Operating Centre (NS) (planned)
TJ Treeton Junction CHR 2 October 1982 Sheffield (S)
TS Treeton South CHR 2 October 1982 Sheffield (S)
TE Tremains East SWM2188m 70ch 19 April 1955 11 September 1965 Port Talbot (PT)
TT Trent Building also housed East Midlands Control Centre in 2007/2008 TSN1120m 01ch 27 September 1969 25 August 2012 in part; 19 July 2013 remainder East Midlands Control Centre (MS, NN, RT, TC, TD, TN, TT)
T Trent ECM1121m 50ch 6 March 1955 25 August 1969 Newark Crossing (NC)
T Trent Junction Also known as Frodingham Trent Junction DOW23m 60ch September 1914 31 March 1973 Scunthorpe (S)
T Trimley FEL82m 60ch 1891 17 April 1988 Trimley [panel] (T)
T Trimley [panel] FEL82m 60ch 17 April 1988 14 March 1999 Colchester [new] (CO)
TG Tring Shunt Frame LEC1≈31m 55ch Bletchley (BY)?
Tring Sidings LEC131m 37ch 1964
Trinity Lane Gate box: line controlled from Liverpool Street [new] (L) BGK13m 22ch
T Trowbridge Code in use by 6 November 1955 WEY105m 49ch 1896 8 September 1968 Westbury (W)
TL Trowell Junction TCC≈125m 09ch 18 October 1969 Trent (TT)
TL Trowse Lower Junction LTN1113m 67ch 1910 29 November 1986 Norwich Station (NO)
TSB Trowse Swing Bridge Earlier code for Norwich station area resignalling. Downgraded to bridge control cabin 29 November 1986 LTN2123m 46ch 1898 14 February 1986 Trowse Swing Bridge [new] (TSB)
TSB Trowse Swing Bridge [new] Earlier code LTN2123m 34ch 15 February 1986
TB Later code (post 2000) for Sheringham line resignalling
TU Trowse Upper Junction LTN1112m 79ch 1923? 21 September 1986 Trowse Lower Junction (TL)
TY Trowse Yard LTN2123m 24ch 1921 29 November 1986 Colchester [new] (CO)?
T Truro Named Truro East to 23 October 1971 MLN3300m 57ch 5 March 1899 11 March 2024 Exeter (CL)
Truro East See Truro
TJ Tuffley Junction BAG294m 72ch 7 December 1941 10 August 1968 Gloucester (G)
GC Tulse Hill BTH16m 15ch 1 July 1945 13 April 1969 Streatham Junction (BC)
EBN Tunbridge Wells Central Goods Code used from 25 March 1962 TTH33m 45ch ≈1879 15 May 1984 Tonbridge (PE)
A Automatic signals
TU Tunbridge Wells West B GJB249m 58ch 1876 12 August 1985 Line closed
U Turkey Street Ground Frame HDT Liverpool Street [new] (L)
T Turnhead HUL1 11 June 1967 Barlby North (BN)
T Tursdale ECM5≈59m 00ch 28 November 1971 Ferryhill (F)
TY Tutbury NSS24m 13ch 1872
T Tweedmouth Code to July 1990 ECM765m 78ch 10 December 1961
TW Code used from July 1990
D Down direction automatic signals (until 1981)
R Repeater signals
U Up direction automatic signals (until 1981)
TS Tweedmouth South Code presumed ECM7≈65m 42ch 10 December 1961 Tweedmouth (T)
D Down direction automatic signals
U Twenty Feet River Up direction automatic signals MSG226m 53ch 31 March 1974 27 November 1982 Line closed
T Twyford MLN131m 07ch 23 October 1961 11 March 1972 Reading (R)
DM Down main line automatic signals
DR Down relief line automatic signals
UM Up main line automatic signals
UR Up relief line automatic signals
TW Twyford West Possibly also code T MLN131m 08ch 1893 23 October 1961 Twyford (T)
TS Ty Croes Downgraded to gate box 2 April 1989: line controlled by Valley (VY) CNH3254m 32ch 1872
Tyne See Tyne Yard
T Tyne Coal Terminal Control Room Unclear if this is same as Tyne Dock had draw-ahead signals in sidings lettered A to D, with no number GLT≈1m 15ch
Tyne Dock Code unknown, but known to have existed by 1968 December 1967✖possibly 30 May 1981? Pelaw (P) Line later transferred to Metro
TS Tynemouth South TMB6m 31ch 10 August 1980? Line transferred to Metro
T Unclear if this is Tynemouth South or plain Tynemouth
D Down line automatic signals
T Tyneside IECC HLK0m 32ch 15 April 1991 25 December 2021 Tyneside Rail Operating Centre [temporary] (T)
T Tyneside Rail Operating Centre [temporary] HLK≈0m 33ch 27 December 2021 21 August 2022 Tyneside Rail Operating Centre (T)
T Tyneside Rail Operating Centre In same building as Tyneside IECC HLK0m 32ch 22 August 2022
BA Bebside, Bedlington and Green Lane interlocking areas. Code used from 5 August 2024
TY Tyne Yard Also known as Tyne. Demolished week ending 6 October 2014 ECM575m 62ch 21 April 1963 9 May 1991 Tyneside IECC (T)
D Down line automatic signals
R Banner repeater signals
RU Banner repeater for up line automatic signals
U Up line automatic signals
S Tyne Yard South Shunters GSP TEY≈76m 25ch
Tyseley Loco Yard See Tyseley No 1
TY1 Tyseley No 1 Formerly named Tyseley Loco Yard DCL126m 40ch 20 February 1949
TY2 Tyseley No 2 DCL Tyseley No 1 (TY1)?
TY3 Tyseley No 3 DCL Tyseley No 1 (TY1)?