Last update 1 December 2020
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 |
|---|
| U | Uddingston Junction | WCM2 | 93m 44ch | 27 June 1937 | 18 September 1973 | Motherwell (M) | |
| UN | Uffington | PMJ | 12m 74ch | 26 June 1909 | |||
| U | Uffington | MLN1 | 66m 42ch | 1897 | 3 March 1968 | Swindon (SN) | |
| UF | |||||||
| DM | Down main line automatic signals | ||||||
| UM | Up main line automatic signals | ||||||
| UC | Ufton Crossing | BHL | 43m 39ch | 14 February 1943 | 3 December 1977 | Reading (R) | |
| UJ | Ulceby Junction | Formerly named Ulceby South Junction | BRI1 | 100m 32ch | 1910 | 30 December 2015 | York Rail Operating Centre (CB/MB) |
| UY | Code used with semaphore signals | ||||||
| D | Down line automatic signals | ||||||
| U | Up line automatic signals | ||||||
| Ulceby South Junction | See Ulceby Junction | ||||||
| UN | Ulverston | Code used from 2008 | CBC1 | 19m 47ch | 16 December 1900 | ||
| UC | United Colliery | WSJ2 | 203m 56ch | 9 August 1970 | 1 October 1974 | ultimately Chester PSB (CR) | |
| UCR | Distant signals | ||||||
| UC | Unstone Colliery Sidings | TJC1 | 149m 68ch | 15 January 1972 | Dore (D) | ||
| Uphill Junction | MLN1 | 138m 6ch | 1884 | 29 January 1972 | Bristol (B) | ||
| UM | Upminster | FSS2 | 15m 38ch | 17 April 1995 | Upminster [new] (UR) | ||
| D | Down line automatic signals | ||||||
| U | Up line automatic signals | ||||||
| UR | Upminster [new] | FSS2 | 15m 38ch | 11 September 1994 | 6 December 2019 (planned) | Romford Rail Operating Centre (UR) (planned) | |
| NL | North London Line signals. Code used from 4 January 2011 | ||||||
| UGF | Ground frame controlled signals | ||||||
| UE | Upminster East | FSS2 UPG |
15m 44ch 0m 5ch |
? | ≈1995 | Upminster [new] (UR) | |
| UW | Upminster West | FSS2 | 15m 15ch | ? | 6 February 1961 | Upminster (UM) | |
| UY | Upney | FSS2 | 8m 9ch | 27 March 1961 | Barking (BK) | ||
| M | Upper Abbey Mills Junction | FSS1 | 3m 61ch | 1 May 1961 | Fenchurch Street (F) | ||
| UH | Upper Holloway | TAH1 | 2m 76ch | 10 November 1985 | |||
| CCH | Upper Warlingham | SCU1 | 15m 30ch | 10 March 1884 | 2 November 1985 | Three Bridges [new] (T) and Oxted (OD) | |
| U | Upton Park | FSS1 | 5m 37ch | 1 May 1961 | Barking (BK) | ||
| UN | Urlay Nook | Downgraded to gate box 25 November 2013: line controlled by Bowesfield (B) | DSN1 | 7m 38ch | 1896 | 11 March 2019 | York Rail Operating Centre (B) |
| R | Distant signals | ||||||
| US | Usan | Code used from 2002 | ECN4 | 28m 48ch | 6 May 1906 | 2 February 2010 delayed from 28 January 2008 |
Montrose North (MN) |
| UH | Usworth | Code used from 24 April 1982 | FEP | 17m 45ch | 1898 | 1991 | |
| U | Uttoxeter | Two signals only. Last all-new mechanical 'box | NSS | 16m 0ch | 28 January 1981 | ||
| UR | Code used from 2 January 2008 | ||||||