Last update 20 November 2020
Please select a starting letter from the links below:
| Code | Signal Box | Note | ELR | Mileage | Opened | Closed | Control to |
|---|
| OA&GB Junction | MVL1 | 6m 7ch | 1965 | 14 January 1996 | Ashton Moss North Junction (AMN) | ||
| O | Oakenshaw | Formerly named Oakenshaw North | TJC3 | 182m 35ch | 1928 | 23 December 2007 last train; 27 December 2007 official | Wakefield Kirkgate [new] (WK) |
| OK | Unclear if code carried | ||||||
| ON | Code used when named Oakenshaw North | ||||||
| R | Repeater signals | ||||||
| UM | Up line automatic signals | ||||||
| Oakenshaw North | See Oakenshaw | ||||||
| OA | Oakham | GSM2 | 93m 56ch | 8 October 1899 | |||
| OM | |||||||
| O | Unclear whether code used | ||||||
| OP | Oakleigh Park | ECM1 | ≈8m 25ch | 13 July 1924 | 30 May 1970 | New Barnet (NB) | |
| OT | Oak Tree | DSN1 | ≈4m 28ch | 7 October 1972 | Darlington (D) | ||
| WO | Oatlands | BML1 | 18m 13ch | 1894 | 22 March 1970 | Surbiton [new] (S) | |
| Oddingley | Gate box: line controlled by Gloucester (G) | BAG2 | 62m 61ch | 1908 | |||
| OF | Offord & Buckden | Downgraded to gate box 25 July 1976: line controlled by St Neots (SN) | ECM1 | 55m 76ch | 6 February 1899 | 17 May 1998 | Peterborough (P) |
| OY | Oldbury | Downgraded to shunt frame 8 January 1966: line controlled by Birmingham New Street (NS) | RBS2 | 5m 14ch | ≈28 October 1981 | Birmingham New Street (NS) | |
| Old Dalby NNR | GSM4 | 111m 22ch | ? | ||||
| OM | Oldham Mumps | MPR3 | 7m 21ch | 1967 | 3 October 2009 | Line transferred to Manchester Metrolink | |
| F | Old Kew Junction | HOU | 10m 4ch | 18 October 1942 | 8 September 1974 | Feltham (F) | |
| LG | Old Lea Station | Temporary box intended for occasional use to increase capacity during Nottingham resignalling. Opened and immediately switched out, never used to signal trains. Lincoln to Gainsborough line signals | SPD3 | 95m 68ch | 30 June 2013 | 4 January 2014 | Lincoln Control Centre (LG) |
| OO | Old Oak Common | MLN1 | 2m 64ch | 8 October 1962 | 4 September 1967 | Old Oak Common [new panel] (OO) | |
| EC | Engine and carriage line signals | ||||||
| OO | Old Oak Common [new panel] | MLN1 | 2m 64ch | 4 September 1967 | 30 May 1995 | Slough New IECC (SN) | |
| DG | Down goods and carriage line signals. Code used by 1974 | ||||||
| DM | Down main line automatic signals | ||||||
| DR | Down relief line automatic signals | ||||||
| EC | Engine and carriage line signals. Code used by 1971 | ||||||
| OOO | Code shown in 1984 notice in error | ||||||
| UC | Up carriage line automatic signals | ||||||
| UM | Up main line automatic signals | ||||||
| UR | Up relief line automatic signals | ||||||
| UW | Up Wycombe line automatic signals | ||||||
| Z | Draw ahead signals at Hayes. Code used from 10 August 1983 | ||||||
| C | Old Oak Common Carriage Line Ground Frame | Believed code not carried | MLN1 | ≈2m 0ch | |||
| CR | Old Oak Common Crossrail Depot | Codes shown on development plans | MLN1 | ||||
| DC | |||||||
| WL | Old Oak Common Depot | Wheel lathe line signals | OOC1 | 28 December 2017 | |||
| A | Road A signals | ||||||
| B | Road B signals | ||||||
| C | Road C signals | ||||||
| OT | Old Town | DSN2 | 26 November 1967 | Middlesbrough (M) | |||
| OM | Olive Mount Junction | DSE | 2m 50ch | 1883 | 18 May 1998 | Edge Hill (LE) | |
| OC | Ollerton Colliery | Burnt down April 2006 | HIM | 19m 33ch | 1893 | 23 March 2009 | Thoresby Colliery Junction (T) |
| OY | Onibury | SHL | 22m 68ch | 12 December 1977 | Wales Rail Operating Centre (NS) (planned) | ||
| OL | Ordsall Lane No 1 | Believed code not carried | COL | ≈190m 20ch | 18 October 1978 | Deal Street (DS) | |
| OC | Orgreaves Colliery | Ambiguous source data: colliery branch removed 8 February 1981 | MAC3 | 45m 10ch | 1901 | 8 September 1985 | Darnall West Junction (DW) |
| OW | Orient Way Sidings | Code used from opening | SDC | ≈5m 70ch | 2009 | ||
| JE | Orpington [panel] | Code used from opening | XTD | 13m 49ch | 4 March 1962 | 22 February 1993 | Ashford IECC (AD) |
| JE | Orpington A | Code used from 1959 | XTD | 13m 47ch | ≈1904 | 4 March 1962 | Orpington [panel] (JE) |
| EBV | Otford Junction | Code used from 11 March 1962 | SBJ | 24m 55ch | 1 January 1898 | 5 June 1983 | Victoria Signalling Centre (VS) |
| A | Automatic signals | ||||||
| OB | Oughty Bridge | MAC3 | 36m 23ch | 24 July 1905 | January 1984 | Wadsley Bridge (WB) | |
| OB | Oulton Broad North | NOL | 22m 1ch | 1901 | 24 February 2020 | Colchester [new] (YL) | |
| Oulton Broad Swing Bridge | ESK | 116m 2ch | 1907 | 20 March 2005 | Oulton Broad Swing Bridge [new] | ||
| Oulton Broad Swing Bridge [new] | Renamed Oulton Broad Swing Bridge Operations Cabin 24 February 2020 | ESK | 116m 0ch | 20 March 2005 | |||
| OJ | Over Junction | SWM2 | 115m 53ch | January 1953 | 2 June 1969 | Gloucester (G) | |
| OE1 | Oxenholme No 1 | Code used from 29 April 1973 | CGJ7 | ≈18m 45ch | 12 May 1973 | Carlisle (CE) | |
| OE2 | Oxenholme No 2 | Code used from 29 April 1973 | CGJ7 | ≈19m 5ch | 12 May 1973 | Carlisle (CE) | |
| OX | Oxford | DCL | 63m 46ch | 7 October 1973 | 7 July 2018 last train; 16 July 2018 official | Thames Valley Signalling Centre (OD) | |
| BT | Signals protecting Bicester London Road level crossing | ||||||
| DM | Down main line automatic signals | ||||||
| DX | Down Oxford line automatic signals | ||||||
| OD | Code shown on some plans, believed never carried | ||||||
| UM | Up main line automatic signals | ||||||
| UX | Up Oxford line automatic signals | ||||||
| OR | Oxford Road | COL | ≈189m 37ch | Manchester Piccadilly (MP) | |||
| OS | Oxheys | CGJ6 | ≈1m 30ch | 3 February 1973 | Preston (PN) | ||
| OY | Oxley | WSJ2 | 143m 14ch | 30 March 1969 | 29 November 2010 | West Midlands Signalling Centre (OS) | |
| CS | Oxley Carriage Shed | WSJ2 | ≈143m 17ch | ||||
| O | Oxmardyke | Gate box: line controlled by Gilberdyke Junction (G) | HUL1 | 16m 22ch | 1901 | 23 November 2018 last train; 26 November 2018 official delayed from 3 April 2018 | York Rail Operating Centre (GH) |
| OX | Oxmarsh Crossing | BAR | 106m 39ch | 1959 | |||
| OM | Code reported but not seen on site | ||||||
| O | Oxspring Junction | PED2 | 0m 20ch | 1933 | 20 May 1973 | Line closed | |
| CCM | Oxted | Original code phased out 1985-1987 | SCU1 | 20m 32ch? | 1896 | July 1987? | Oxted [new] (OD) |
| OD | New code phased in 1985-1987 | ||||||
| OD | Oxted [new] | SCU1 | 20m 32ch | 11 July 1987 | |||