List of British Rail TOPS depot codes
Introduction From the introduction of TOPS in 1973, all British Rail diesel and electric locomotives and multiple units were allocated to a particular traction maintenance depot or TMD. Drawing from the terminology of steam traction, these depots were generally referred to as "sheds", and indeed most locations were those which had possessed depots for steam locos. Each TMD had a two-character code which was originally displayed underneath the number of each locomotive allocated there. Later this was extended to cover each carriage of diesel multiple units (DMUs), and even some coaching stock; at this time additional depot codes were added covering places with coaching stock allocations, and also works locations.
Allocations and TOPS depot codes Locations given a TOPS code included all TMDs, servicing depots (where minor work such as A exams could be undertaken), and some stabling points (SPs) where locomotives or multiple units would be parked when not required. The locations varied from comprehensively equipped depots, through covered accommodation with fuelling point, to a mere siding. The use of TOPS codes for SPs was somewhat haphazard, with Machynlleth (code MN) hosting one or two locomotives on some weekends while Wolverhampton station, which had no TOPS code, stabled more than a dozen locos.The application of a depot code was generally reliable as a guide to the base from which the locomotive or multiple unit operated but with some variations, mainly relating to shunters and departmental locomotives.EMU depots such as Birkenhead North (BD) often required a diesel shunter for moving stock when not powered. As there was no fuelling or maintenance capability at BD, a shunter allocated to nearby Birkenhead Mollington Street (BC) was used, returning to its home depot every four weeks. This arrangement also existed at other locations such as Ilford/Stratford.Departmental locomotives, by the nature of their use, were sometimes reported as allocated to a base location or even to a region in general rather than an official depot. The Western Region sometimes followed this practice, with number 20 (latterly 97020) reported as allocated to "Reading Signal Works" throughout the 1970s. Locomotives used for research purposes would be reported as allocated to the Derby Research Centre.
List of TMD, Servicing Depot, SP and other non-works codes +  TOPS code Shed name Origins CommentsAB  Aberdeen Ferryhill  AC  Aberdeen Clayhills  Carriage maintenance depotAF  Ashford Chart Leacon AK  Manchester ArdwickAL Aylesbury AN  Allerton  AY  Ayr  BA Basford Hall (Crewe) BB Beachbrook Farm EWS BC  Birkenhead Mollington Street  LNWR and GWR jointBC  Bicester BC Beachbrook Farm Freightliner BD  Birkenhead North  Wirral Railway EMU depot, from BN from 1976BE  Bedford Midland Station  No allocation - Fuelling Point only.BG  Botanic Gardens (Hull) BG Billingham BH  Barrow Hill (Staveley)  Midland RailwayBI  Brighton Lovers Walk  EMU depotBJ  Bristol Marsh Junction   DMU depotBK  Birkenhead Central  Mersey Railway EMU depotBK Bristol Barton Hill  from 1992BL  Blyth  BL Basford Hall Freightliner BM  Bournemouth  EMU depotBN Birkenhead North  to BD from 1976BN  Bounds Green   HST depot, from 1976BP Beattock  to 1976BP  Blackpool   Carriage maintenance depotBQ  Bury   EMU depot, from BV from 1975BR  Bristol Bath Road GWRBS  Bescot  BT Bo'ness BU  Burton  BV Bury  to BQ from 1975BW  Barrow BW Barry BX  Buxton   DMU depotBY  Bletchley  BZ  St. Blazey (Par)  Cornwall Minerals RailwayCA  Cambridge  DMU depotCB Crewe Basford Hall CC  Clacton  EMU depotCD  Crewe Diesel Depot CE  Crewe Electric Depot  CF  Cardiff Canton  CG  Croxley Green  EMU depot, to closure in 1985CG  Crewe Gresty Lane GWRCH  Chester  CJ  Clapham Junction  No allocation.CK  Corkerhill  DMU depotCL  Carlisle Upperby   Carriage maintenance depotCM  Camden Carriage maintenance depotCO Coquelles (France) CP  Crewe Carriage Shed  No allocation - Fuelling Point only.CQ  Crewe Heritage Centre  Crewe Heritage Centre Storage Facility & Heritage CentreCR  Colchester CS  Carnforth West Coast RailwaysCV  Coalville  CW  Cricklewood CZ Central Rivers DA  Darnall   DMU depotDE  Dewsbury DE  Dundee DF  Derby Fragonset DI  Didcot Railway Centre DL Dollands Moor   No allocation.DM Dagenham DM Dee Marsh DN  Darlington  DR  Doncaster DT  Dunfermline Townhill  DY  Derby Etches Park  DMU depotEC  Edinburgh Craigentinny   HST depot Carriage Maintenance DepotED  Eastfield  EG  Edge Hill EH  Eastleigh EJ  Ebbw Junction (Newport) EM  East Ham   EMU depotEN  Euston Downside   Carriage maintenance depotEU Euston Station EX  Exeter St Davids  FB Ferrybridge FF Brussels Forest (Belgium)  Eurostar depotFH  Frodingham (Scunthorpe) FP  Finsbury Park FR Fratton (Portsmouth)  EMU depotFW  Fort William FX Felixstowe GC  Cowlairs (Glasgow)  Carriage maintenance depotGD  Gateshead  GF  South Gosforth   DMU depotGI Gillingham  EMU depotGL  Gloucester GM  Grangemouth  GU  Guide Bridge GW  Glasgow Shields Road   Electric locomotive/EMU depotGY Garston Yard HA  Haymarket  HD  Holyhead  HE  Hornsey   EMU depotHF  Hereford HG  Hither Green  HI  Hitchin HM  Healey Mills (Wakefield)  HN  Hamilton   DMU depotHO  Holbeck (Leeds) HQ BRB Headquarters  Paper allocationHR  Hall Road (Liverpool)  EMU depotHS  Hammerton Street (Bradford) HT  Heaton   HST and DMU depotHY  Hyndland   EMU depotIL  Ilford  EMU depotIM  Immingham  IP  Ipswich Station No allocation - Fuelling Point only.IS  Inverness  KD  Carlisle Kingmoor KK Kirkdale (Liverpool)  EMU depotKM  Carlisle Yard  No allocation - Fuelling Point only.KN MoD Kineton KT MoD Kineton KX  Kings Cross   No allocation - Fuelling Point only.KY  Knottingley  LA  Laira (Plymouth)   Intercity HST, DMULC Longsight International  Eurostar depotLE  Landore (Swansea)  LG  Longsight Electric Depot (Manchester)   Electric locomotive and EMU depotLJ  Llandudno Junction  LL  Liverpool Edge Hill  Carriage maintenance depotLM Long Marston (MoD) LN  Lincoln   DMU depotLO  Longsight Diesel Depot (Manchester)  LP Le Landy (Paris)  Eurostar depot, to 1994LR  Leicester LV  Liverpool Street  No allocationLY Le Landy (Paris)  Eurostar depot, from 1994MA  Manchester Longsight Carriage Maintenance Depot MB Middlesbrough MD Merehead ME  Marylebone  DMU depotMG  Margam (Port Talbot)  MH  Millerhill (Edinburgh)  ML  Motherwell  MN  Machynlleth  MR  March  MV  Manchester Victoria (Red Bank)  Carriage maintenance depotNA Newton Abbot  South Devon RailwayNC Norwich Crown Point   Carriage maintenance depotNG  New Cross Gate   Carriage maintenance depotNH  Newton Heath (Manchester) Lancashire & Yorkshire Railway DMU depotNL  Neville Hill (Leeds)  HST and DMU depotNT  Nottingham Carriage Sidings NM Northam NN Northampton NP North Pole International NR  NorwichNW  Northwich  No allocation - Fuelling Point only.OC  Old Oak Common  OD Old Dalby OH  Old Oak Common (Heathrow Express) Heathrow Express EMU depotOM  Old Oak Common Carriage Maintenance Depot ON  Orpington  EMU depotOO  Old Oak Common (HST)   HST depotOX  Oxford OY  Oxley (Wolverhampton)  Carriage maintenance depotPA St Pancras  No allocation.PB  Peterborough PC  Polmadie Carriage Maintenance Depot (Glasgow)  PH  Perth Station PI North Pole International  1994-1995PM  Bristol St Phillips Marsh  HST depotPO  Polmadie (Glasgow) PQ Parkeston Quay PZ  Penzance RB  Ranelagh Bridge  No allocation - Fuelling Point only.RE  Ramsgate  EMU depot. Changed to RM.RG  Reading   DMU depotRL  Ripple Lane RM  Ramsgate EMU depot. Was RE.RR Radyr RS  Reddish RU Rugby RY  Ryde   EMU depotSA  Salisbury  SB  Shirebrook SD  Selafield Direct Rail ServicesSE  St Leonards  DEMU depotSF  Stratford  SG  Slade Green   EMU DepotSI  Soho (Birmingham)  SL  Stewarts Lane   Electric locomotive and EMU depotSN Stranraer SP  Wigan Springs Branch SQ Stockport SR  Stratford Repair Depot  ST  Severn Tunnel Junction SU  Selhurst  EMU depotSV Wembley Chiltern SW  Swindon SY  Saltley (Birmingham) SZ  Southall  DMU depotSZ  Southampton Maritime  FreightlinerTB  Three BridgesTD Temple Mills TE  Thornaby (Tees)  TF  Thornton Fields (Stratford)  Carriage maintenance depotTG Tonbridge TI  Tinsley (Sheffield)  TJ  Thornton Junction TL Tilbury TN Taunton TO  Toton  TP Trafford Park TS  Tyseley   DMU depotTW  Tunbridge Wells West Station  DEMU depotTY  Tyne Yard  VR  Vale of Rheidol Railway (Aberystwyth)   Steam locomotive depotWA  Warrington Arpley WB  Willesden Brent Sidings  Carriage maintenance depotWC Waterloo & City line  WD  Wimbledon  EMU depotWH  Wath WH Whatley  from 1994WJ  Watford Junction  No allocation - Fuelling Point only.WK  Workington WN  Willesden  WO  Wellingborough  No allocation - Fuelling Point only.WS  Worcester WT  Westhouses   No allocation - Fuelling Point only.WY  Westbury YC York Clifton YK  York
Works codes +  TOPS code Works name Origins CommentsZB  Doncaster Works Wabtec ZC  Crewe Works  ZD  Derby Litchurch Lane Works ZE  Derby Locomotive Works  ZF  Doncaster Works Bombardier transportation ZG  Eastleigh Works  ZH  Glasgow Springburn Works ZH  Glasgow St Rollox Works  ZI  Ilford works  Bombardier transportation.ZL  Swindon Works  ZN  Wolverton Works  ZP  Horbury (Wakefield)  Bombardier transportation.
References ===Sources===*