Signal box prefix codes

A (hopefully) comprehensive listing

'Boxes beginning D

Last update 28 March 2024

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
DD Dagenham Dock TLL10m 49ch 1901 25 May 1996 Upminster IECC (UR)
DD Dagenham Dock Ground Switch Panel TLL11m 09ch 27 May 1996 18 May 2003 Upminster IECC (UR)
DH Dagenham Heathway/East FSS2≈11m 04ch ? Upminster (UM)?
DW Dairycoates West PHC1m 11ch 10 June 1984 Hessle Road Junction (HR)
DS Daisyfield At least three colour light signals DJH11m 25ch 1873
DJ Dalmeny Junction 1890 13 May 1979 Edinburgh (EY)
DP Dalmuir Park NEM510m 03ch 20 April 1897 2 July 1989 Yoker (YY)
DR Dalreoch NEM7 Yoker (YC)
D Dalry Junction Formerly named Dalry No 2 AYR422m 54ch 1906 6 April 1986 Paisley [new] (PG)
Dalry No 2 See Dalry Junction
D Dalston Junction Named Dalston Western Junction to 9 August 1987. Dismantled 29 March 2011 BOK12m 21ch 1891 4 January 2011 Upminster IECC (NL)
DW Code shown on signalling plan but unclear whether used
DWJR Banner repeater signals
Dalston Western Junction See Dalston Junction
DJ Dalton Junction Code used from 2008 CBC124m 37ch 16 April 1902
DE Dalwhinnie Code used from 1978 to 2002 HGL258m 53ch 17 May 1909
DW Code used from 2002
DM Darfield Main PED310m 54ch 17 November 1985 Line closed
DGS Darlaston Green Sidings PBJ10m 01ch Wolverhampton (WN)
D Darlington Named Darlington South to 13 May 1972. Code used from renaming ECM543m 70ch late on 6 May 1939 10 May 1991 Tyneside (T)
DS Code used to 13 May 1972 when named Darlington South
D Down line automatic signals. Code used to 13 May 1972
RU Up line banner repeater signals
U Some up line automatic signals. Code used to 13 May 1972
DN Darlington North ECM544m 27ch 13 May 1972 Darlington (D)
Darlington South See Darlington
DE Darnall East Junction MAC343m 44ch 30 November 1974 Darnall West Junction (DW)
DW Darnall West Junction MAC343m 11ch 16 September 1989full closure; ceased signalling up direction 10 September 1989 Woodburn Junction (WJ)
D Dartford HDR17m 23ch 1 November 1970 17 April? 2001 Ashford IECC (NK)
A Automatic signals
DC Semi-automatic signals controlled from Ground Frame C
DD Semi-automatic signals near Ground Frame N
DH Semi-automatic signals controlled from Ground Frame H
DJ Semi-automatic signals controlled from Ground Frame J
DK Semi-automatic signals controlled from Ground Frame K
DT Daventry International Rail Freight Terminal (DIRFT) control centre HNR80m 40ch 20 April 1997commissioning date
DN Dawdon Codes used from 2 August 1987. Demolished November 2010 LEN384m 22ch 1905 15 November 2010 Ryhope Grange (NS)
D Some up line signals and colliery branch
B Dawdon Colliery Bunker line signals 3 August 1986
also had draw-ahead signals lettered A to D (from new) and W to Z (later) with no number
D Dawley MLN1 Old Oak Common [new panel] (OO)
Dawlish MLN1206m 07ch 9 September 1920 14 November 1986 Exeter (E)
DM Daw Mill Colliery Draw ahead signals NWO2m 37ch 28 November 2011 West Midlands Signalling Centre (NW)
EBZ Deal BME290m 43ch 14 May 1939
DS Deal Street DSE31m 18ch MVE10m 32ch 10 March 1929 31 July 1998 Manchester North (MN)
DN Dean RTJ288m 14ch ≈1875 9 September 1980 Salisbury Tunnel Junction (SY)
DJ Deansgate Junction CDM17m 06ch 1957
D Dearne Junction SMJ1168m 52ch SMJ217m 27ch 3 May 1981 Sheffield (S)
DV Dearne Valley Colliery Sidings TJC3≈172m 05ch 6 March 1983 Sheffield (S)
DY Decoy No 1 ECM1154m 12ch 9 September 1979delayed from 7 July 1979 Doncaster (D)
D2 Decoy No 2 ECM1154m 22ch 20 May 1979 Decoy No 1 (DY)
DM Dee Marsh Junction WDB213m 78ch 1930
D Deepcar Downgraded to shunters' cabin 11 August 1985 (does not match closure date) MAC233m 40ch 1906 16 May 1983 Sheffield (S)
DC Code used in 1977 weekly notice
DJ Deepdale Junction PDB1m 31ch 25 September 1983 Preston (PN)
DW Deep Wharf Crossing Stop boards TLL16m 68ch 27 May 1996
DY Deganwy Named Deganwy No 2 to June 1967. Downgraded to gate box 19 February 1978, reopened as block post 19 March 1978 LLJ1m 22ch August 1915 Wales Rail Operating Centre (planned)
Deganwy No 2 See Deganwy
DX Denaby Crossing Downgraded to gate box 31 August 1980 PED517m 12ch ≈1885 15 February 1981 Sheffield (S)
D Denham Formerly named Denham Station. Code used by 15 February 1953 NAJ24m 47ch 1905 15 June 1975 Marylebone (ME)
Denham Station See Denham
DT Denton Crossing Downgraded to gate box 16 May 1971 HDR25m 10ch 16 December 1973 Dartford (D)
DJ Denton Junction DJO14m 13ch 1888
DJR Distant signals
DNJ Some signals on up main line
Denton Village Gate box: line controlled by Low Row NEC243m 65ch ? 6 April 2009 Low Row [new] (LR)
DY Derby SPC7128m 13ch 12 July 1969 late on 1 September 2018 East Midlands Control Centre (DY)
TP Temporary point ends, code not used on signals. Code used from 27 December 2017
F Derby Etches Park Depot Shunt signals
M Shunt signals, numbered in the form M1 B2. It is not known what the different letters mean
DR Derby Road FEL≈74m 67ch 1891 14 March 1999 Colchester [new] (CO)
D Derwenthaugh Code used from 12 August 1973 when temporary panel fitted NEC1≈3m 79ch Newcastle (N)
WBU Devonport Kings Road DAC239m 61ch 1890? 14 March 1965 Plymouth (P)
D Later code
D Dewsnap Sidings HAJ5m 61ch 21 May 1905 4 March 1984 Guide Bridge (GB)
D Didcot maintenance depot and fuelling point DCL 28 March 1993
D Didcot Power Station Code used in January 1970 weekly notice DPS January 1970? unknown line closed
DE Diggle Junction MVL314m 59ch 1885
D Unclear if code carried
D Dilston NEC2≈18m 20ch 31 January 1987 Hexham (H)
Dinnington Colliery Junction BKS3m 29ch 1907 29 November 1997 Worksop (WP)
DG Dinting Later code GDW0m 76ch HAJ11m 76ch 1905
D Code used when named Dinting Station
Dinting Station See Dinting
D Dinwoodie WCM131m 66ch ? 3 October 1972 Lockerbie (L)
Disley BEJ6m 03ch 1906 30 May 1999 Furness Vale (FV)
D Diss LTN1≈95m 04ch 5 October 1986 Colchester [new] (CO)
DN Ditton Formerly named Ditton Junction WJL2183m 00ch 18 December 2000 1 September 2020delayed from 14 April 2020 Manchester Rail Operating Centre (DN)
DJ Unclear whether code carried
Ditton Junction See Ditton
DN1 Ditton Junction No 1 WJL2182m 71ch ≈1 July 1956 11 December 2000 Ditton (DN)
DN2 Ditton Junction No 2 WJL2183m 12ch 7 November 1960 11 December 2000 Ditton (DN)
Ditton Shunters Control Unit WJL2≈183m 05ch 1 September 2020?
DS Ditton Sidings Ground Switch Panel WJL2183m 06ch 30 July 2017delayed from 18 June 2017 1 September 2020 Ditton Shunters Control Unit
D Dock Junction Down line automatic signals. Code used by 1978 SPC10m 76ch 15 July 1979 St Pancras (SP)
U Up line automatic signals. Code used by 1978
Dr Days Junction BSW0m 51ch 21 February 1932 7 March 1970 Bristol (B)
DO Dodworth PED23m 67ch 1959 10 April 1998 Barnsley (BY)
DJ Code uncertain
D Doncaster ECM1155m 65ch 8 July 1979
DS Skellow interlocking
DG Up Hull line automatic signal unclear whether this comes under Goole's interlocking
RD Repeater or distant signals
X Arksey and Bentley Crossing signals (may be separate gate boxes)
C Doncaster C ECM1156m 04ch 16 September 1979 Doncaster (D)
DC Doncaster Carr IEP Depot ECM1 20 November 2016
DN Doncaster North ECM1156m 07ch February 1949 7 July 1979 Doncaster (D)
N Doncaster North Ground Frame [Gate 5] ECM1≈156m 26ch
DS Doncaster South ECM1155m 68ch 9 January 1949 7 July 1979 Doncaster (D)
DS Donnington Telford International Rail Freight Park 2009
WFW Dorchester Junction BML2136m 11ch WEY162m 10ch ≈1896 9 June 1985 Dorchester South (DR)
D Distant signals
DWA Distants to automatic signals
WA Automatic signals
DR Dorchester South Downgraded to ground frame 28 June 1970, reinstated (9 June?) 1985 BML2135m 56ch 22 February 1959
MN Maiden Newton area points indicators
D Dore Formerly named Dore & Totley Station Junction DWS0m 36ch 25 March 1972 Sheffield (S)
Dore & Totley Station Junction See Dore
CBK Dorking Code used from new BTH322m 01ch 15 May 1938
CA Most automatic signals
DR Dorrington SHL6m 25ch 1872 Wales Rail Operating Centre (NS) (planned)
DN Unclear whether code used
DP Douglas Park WCM291m 51ch 12 July 1893 1 March 1970 Motherwell (M)
EDB Dover Marine Code used from 1961? FDM78m 17ch XTD76m 59ch 1914 5 July 1995
DP Dover Priory Code used from 27 April 1980 FDM77m 18ch 16 November 1930 12 April 1998 Folkestone East (YE)
EBW Code used to 1980
DJ Dovey Junction DJP79m 00ch SBA2≈79m 03ch 22 February 1959 21 October 1988 Machynlleth (DJ)
DM Downham Market BGK86m 04ch 1881
D Down Yard Ground Frame [Old Oak Common] OOC1 Old Oak Common [new panel] (OO)?
Drakelow Power Station had draw-ahead signals lettered SAA, SA to SK and NAA, NA to NK with no number ?? 1969
D Drax DRA2? 11 June 1972
RD Distant signals
DT Draycott SPC6122m 20ch 9 February 1891 29 September 1969 Trent (TT)
Drayton TBH226m 48ch 1876 1986 Chichester (CC)
D Driffield Code used from 12 April 1987 HBS19m 25ch 1875
DG Drigg CBC159m 78ch 1874
Dringhouses Hump Control Tower Unclear whether same as Dringhouses South Shunters Panel 3 March 1985 Yard closed
D Dringhouses South Shunters Panel ECM4≈187m 40ch 25 September 1983 11 May 1989 York [PSB] (Y)
DS Droitwich Spa OWW126m 26ch 7 April 1907
DJ Dryclough Junction MRB31m 37ch 26 July 1970 Halifax (H)
DR Duddeston Road DBP340m 41ch 1955 23 August 1969 Saltley (SY)
DH Dudding Hill Junction CAW6m 03ch 1902
DC Dudley Colliery Code used from June 1962 ECM77m 73ch 2 December 1979 Benton (B)
D Down line automatic signals
U Up line automatic signals
DP Dudley Port RBS2≈7m 33ch 8 January 1966 Birmingham New Street (NS)
Duke Street HXS317m 65ch 1921 11 March 1994 Merseyrail (ML)
DR Dullatur Code used from 1966 EGM1≈12m 70ch 6 June 1913 13 December 1971 Greenhill Junction (GJ)
D Code used to 1966
DM Dullingham CCH10m 55ch 1883
DH Code reported 1986
D Dumbarton Code used from 1960 NEM715m 75ch 28 October 1960 22 February 1992 Yoker (YD)
DS Dumfries South Code used from 1955 GSW92m 46ch 30 October 1955 17 March 1997 Dumfries Station (DS)
DS Dumfries Station Code used from 26 October 2002 GSW91m 59ch 5 May 1957
DE Eastriggs interlocking area. Code used from 4 August 2008
D Code used from 1957 to 2002 some signals remain with old code
ED Dunbar Temporary 'box and code until taken over by Edinburgh ECM8≈29m 05ch 1 February 1976 11 December 1977 Edinburgh (ED)
DB Dunblane Code used from 2002 SCM3123m 29ch 9 June 1902
DB Dunbridge RTJ284m 37ch 1875 14 November 1982 Salisbury (SY)
D Dundee Code used from 1985 ECN259m 17ch 17 March 1985
DR Banner repeater signals
Dunford Bridge No 1 See Dunford West
DE Dunford East Named Dunford No 5 to ≈June 1954 MAC124m 13ch 8 November 1900 18 July 1981 Line closed
D5 Code used when named Dunford No 5
D2 Dunford No 2 MAC123m 16ch Line closed
Dunford No 5 See Dunford East
DW Dunford West MAC122m 35ch by 14 June 1954 18 July 1981 Line closed
D1 Code used when named Dunford Bridge No 1
DK Dunkeld Code used from 2002 HGL215m 25ch 1919
DS Dunlop Sidings DBP3≈37m 50ch ? Saltley (SY)
Dunning SCM4141m 56ch 12 August 1951 1997 Hilton Junction (HJ)
DR Dunragit Code used from 2002 STR347m 72ch 19 June 1927
DB Dunston & Barlow North CHR≈147m 40ch 12 November 1981 Sheffield (S)
ME Dunton Green XTD20m 37ch c1905 2 August 1973 Ashford IECC (AD)
A Automatic signals
DN Durham North ECM5≈66m 23ch 23 November 1969 Tyne Yard (TY)
U Up line automatic signals
DS Durham South ECM5≈66m 08ch 23 November 1969 Tyne Yard (TY)
DJN Duston Junction North Unclear if code carried NMH≈0m 30ch Northampton No 1 (NH1)
DY Dyce Reopened Dyce Junction 'box ANI16m 11ch 26 November 2007 early on 10 August 2019 Inverness (HD)
D Dyce Junction Code used in 2002 ANI16m 11ch 1880 29 October 2007 Dyce [temporary] (DY)
DY Code used from 14 December 2002
DY Dyce [temporary] ANI1≈6m 11ch 29 October 2007 26 November 2007 Dyce (DY)
DJ Dynevor Junction RSB19m 22ch March 1915 25 February 1973 Port Talbot (PT)