Signal box prefix codes

A (hopefully) comprehensive listing

'Boxes beginning D

Last update 27 July 2021

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 ELR Mileage Opened Closed Control to
DD Dagenham Dock TLL 10m 49ch 1901 25 May 1996 Upminster IECC (UR)
DD Dagenham Dock Ground Switch Panel TLL 11m 9ch 27 May 1996 18 May 2003 Upminster IECC (UR)
DH Dagenham Heathway/ East FSS2 ≈11m 4ch ? Upminster (UM)?
DW Dairycoates West PHC 1m 11ch 10 June 1984 Hessle Road Junction (HR)
DS Daisyfield At least three colour light signals DJH 11m 25ch 1873
DJ Dalmeny Junction 1890 13 May 1979 Edinburgh (EY)
DP Dalmuir Park NEM5 10m 3ch 20 April 1897 2 July 1989 Yoker (YY)
DR Dalreoch NEM7 Yoker (YC)
D Dalry Junction Formerly named Dalry No 2 AYR4 22m 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 BOK1 2m 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 CBC1 24m 37ch 16 April 1902
DE Dalwhinnie Code used from 1978 to 2002 HGL2 58m 53ch 17 May 1909
DW Code used from 2002
DM Darfield Main PED3 10m 54ch 17 November 1985 Line closed
DGS Darlaston Green Sidings PBJ 10m 1ch Wolverhampton (WN)
D Darlington Named Darlington South to 13 May 1972. Code used from renaming ECM5 43m 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 ECM5 44m 27ch 13 May 1972 Darlington (D)
Darlington South See Darlington
DE Darnall East Junction MAC3 43m 44ch 30 November 1974 Darnall West Junction (DW)
DW Darnall West Junction MAC3 43m 11ch 10 September 1989 up direction only; 16 September 1989 fully Woodburn Junction (WJ)
D Dartford HDR 17m 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 HNR 80m 40ch 20 April 1997 commissioning date
DN Dawdon Codes used from 2 August 1987. Demolished November 2010 LEN3 84m 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 MLN1 206m 7ch 9 September 1920 14 November 1986 Exeter (E)
DM Daw Mill Colliery Draw ahead signals NWO 2m 37ch 28 November 2011 West Midlands Signalling Centre (NW)
EBZ Deal BME2 90m 43ch 14 May 1939
DS Deal Street DSE MVE1 31m 18ch 0m 32ch 10 March 1929 31 July 1998 Manchester North (MN)
DN Dean RTJ2 88m 14ch ≈1875 9 September 1980 Salisbury Tunnel Junction (SY)
DJ Deansgate Junction CDM1 7m 6ch 1957
D Dearne Junction SMJ1 SMJ2 168m 52ch 17m 27ch 3 May 1981 Sheffield (S)
DV Dearne Valley Colliery Sidings TJC3 ≈172m 5ch 6 March 1983 Sheffield (S)
DY Decoy No 1 ECM1 154m 12ch 9 September 1979 delayed from 7 July 1979 Doncaster (D)
D2 Decoy No 2 ECM1 154m 22ch 20 May 1979 Decoy No 1 (DY)
DM Dee Marsh Junction WDB2 13m 78ch 1930
D Deepcar Downgraded to shunters' cabin 11 August 1985 (does not match closure date) MAC2 33m 40ch 1906 16 May 1983 Sheffield (S)
DC Code used in 1977 weekly notice
DJ Deepdale Junction PDB 1m 31ch 25 September 1983 Preston (PN)
DW Deep Wharf Crossing Stop boards TLL 16m 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 LLJ 1m 22ch August 1915 Wales Rail Operating Centre (planned)
Deganwy No 2 See Deganwy
DX Denaby Crossing Downgraded to gate box 31 August 1980 PED5 17m 12ch ≈1885 15 February 1981 Sheffield (S)
D Denham Formerly named Denham Station. Code used by 15 February 1953 NAJ2 4m 47ch 1905 15 June 1975 Marylebone (ME)
Denham Station See Denham
DT Denton Crossing Downgraded to gate box 16 May 1971 HDR 25m 10ch 16 December 1973 Dartford (D)
DJ Denton Junction DJO1 4m 13ch 1888
DJR Distant signals
DNJ Some signals on up main line
Denton Village Gate box: line controlled by Low Row NEC2 43m 65ch ? 6 April 2009 Low Row [new] (LR)
DY Derby SPC7 128m 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 DAC 239m 61ch 1890? 14 March 1965 Plymouth (P)
D Later code
D Dewsnap Sidings HAJ 5m 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?
DE Diggle Junction MVL3 14m 59ch 1885
D Unclear if code carried
D Dilston NEC2 ≈18m 20ch 31 January 1987 Hexham (H)
Dinnington Colliery Junction BKS 3m 29ch 1907 29 November 1997 Worksop (WP)
DG Dinting Later code GDW HAJ 0m 76ch 11m 76ch 1905
D Code used when named Dinting Station
Dinting Station See Dinting
D Dinwoodie WCM1 31m 66ch ? 3 October 1972 Lockerbie (L)
Disley BEJ 6m 3ch 1906 30 May 1999 Furness Vale (FV)
D Diss LTN1 ≈95m 4ch 5 October 1986 Colchester [new] (CO)
DN Ditton Formerly named Ditton Junction WJL2 183m 0ch 18 December 2000 1 September 2020 delayed from 14 April 2020 Manchester Rail Operating Centre (DN)
DJ Unclear whether code carried
Ditton Junction See Ditton
DN1 Ditton Junction No 1 WJL2 182m 71ch ≈1 July 1956 11 December 2000 Ditton (DN)
DN2 Ditton Junction No 2 WJL2 183m 12ch 7 November 1960 11 December 2000 Ditton (DN)
Ditton Shunters Control Unit WJL2 ≈183m 5ch 1 September 2020?
DS Ditton Sidings Ground Switch Panel WJL2 183m 6ch 30 July 2017 delayed from 18 June 2017 1 September 2020 Ditton Shunters Control Unit
D Dock Junction Down line automatic signals. Code used by 1978 SPC1 15 July 1979 St Pancras (SP)
U Up line automatic signals. Code used by 1978
Dr Days Junction BSW 0m 51ch 21 February 1932 7 March 1970 Bristol (B)
DO Dodworth PED2 3m 67ch 1959 10 April 1998 Barnsley (BY)
DJ Code uncertain
D Doncaster ECM1 155m 65ch 8 July 1979
DS Skellow interlocking
DG Up Hull line automatic signal unclear if 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 ECM1 156m 4ch 16 September 1979 Doncaster (D)
DC Doncaster Carr IEP Depot ECM1 20 November 2016
DN Doncaster North ECM1 156m 7ch February 1949 7 July 1979 Doncaster (D)
N Doncaster North Ground Frame [Gate 5] ECM1 ≈156m 26ch
DS Doncaster South ECM1 155m 68ch 9 January 1949 7 July 1979 Doncaster (D)
DS Donnington Telford International Rail Freight Park 2009
WFW Dorchester Junction BML2 WEY 136m 11ch 162m 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 BML2 135m 56ch 22 February 1959
MN Maiden Newton area points indicators
D Dore Formerly named Dore & Totley Station Junction DWS 0m 36ch 25 March 1972 Sheffield (S)
Dore & Totley Station Junction See Dore
CBK Dorking Code used from new BTH3 22m 1ch 15 May 1938
CA Most automatic signals
DR Dorrington SHL 6m 25ch 1872 Wales Rail Operating Centre (NS) (planned)
DN Unclear whether code used
DP Douglas Park WCM2 91m 51ch 12 July 1893 1 March 1970 Motherwell (M)
EDB Dover Marine Code used from 1961? FDM XTD 78m 17ch 76m 59ch 1914 5 July 1995
DP Dover Priory Code used from 27 April 1980 FDM 77m 18ch 16 November 1930 12 April 1998 Folkestone East (YE)
EBW Code used to 1980
DJ Dovey Junction DJP SBA2 79m 0ch ≈79m 3ch 22 February 1959 21 October 1988 Machynlleth (DJ)
DM Downham Market BGK 86m 4ch 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 SPC6 122m 20ch 9 February 1891 29 September 1969 Trent (TT)
Drayton TBH2 26m 48ch 1876 1986 Chichester (CC)
D Driffield Code used from 12 April 1987 HBS 19m 25ch 1875
DG Drigg CBC1 59m 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 OWW 126m 26ch 7 April 1907
DJ Dryclough Junction MRB 31m 37ch 26 July 1970 Halifax (H)
DR Duddeston Road DBP3 40m 41ch 1955 23 August 1969 Saltley (SY)
DH Dudding Hill Junction CAW 6m 3ch 1902
DC Dudley Colliery Code used from June 1962 ECM7 7m 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 HXS3 17m 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 CCH 10m 55ch 1883
DH Code reported 1986
D Dumbarton Code used from 1960 NEM7 15m 75ch 28 October 1960 22 February 1992 Yoker (YD)
DS Dumfries South Code used from 1955 GSW 92m 46ch 30 October 1955 17 March 1997 Dumfries Station (DS)
DS Dumfries Station Code used from 26 October 2002 GSW 91m 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 5ch 1 February 1976 11 December 1977 Edinburgh (ED)
DB Dunblane Code used from 2002 SCM3 123m 29ch 9 June 1902
DB Dunbridge RTJ2 84m 37ch 1875 14 November 1982 Salisbury (SY)
D Dundee Code used from 1985 ECN2 59m 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 MAC1 24m 13ch 8 November 1900 18 July 1981 Line closed
D5 Code used when named Dunford No 5
D2 Dunford No 2 MAC1 23m 16ch Line closed
Dunford No 5 See Dunford East
DW Dunford West MAC1 22m 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 HGL2 15m 25ch 1919
DS Dunlop Sidings DBP3 ≈37m 50ch ? Saltley (SY)
Dunning SCM4 141m 56ch 12 August 1951 1997 Hilton Junction (HJ)
DR Dunragit Code used from 2002 STR3 47m 72ch 19 June 1927
DB Dunston & Barlow North CHR ≈147m 40ch 12 November 1981 Sheffield (S)
ME Dunton Green XTD 20m 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 8ch 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 ANI1 6m 11ch 26 November 2007 early on 10 August 2019 Inverness (HD)
D Dyce Junction Code used in 2002 ANI1 6m 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 RSB 19m 22ch March 1915 25 February 1973 Port Talbot (PT)