Last update 1 December 2020
Please select a starting letter from the links below:
| Code | Signal Box | Note | ELR | Mileage | Opened | Closed | Control to |
|---|
| I | Ibrox Junction | AYR1 | 2m 5ch | 1904 | 3 September 1967 | Glasgow Central (G) | |
| IG | Temporary code until control passed to Glasgow Central. Code possibly plain G | ||||||
| IC | Ilford Carriage Sheds | Also known as Ilford Car Sheds | LTN1 | 8m 14ch | 26 September 1949 | 29 March 1997 | Liverpool Street [new] (L) |
| ICS | |||||||
| RIC | Banner repeater signals | ||||||
| DE | Down electric line automatic signals | ||||||
| DM | Down main line automatic signals | ||||||
| UE | Up electric line automatic signals | ||||||
| Ilford Car Sheds | See Ilford Carriage Sheds | ||||||
| IS | Ilford Station | LTN1 | 7m 17ch | 26 September 1949 | 24 August 1996 | Liverpool Street [new] (L) | |
| IY | Ilkley Junction | ILK2 | 211m 7ch | 1913 | 11 July 1994 | Leeds (L) | |
| BC | Immingham BSC Terminal | 11 December 1988 | |||||
| Immingham East Junction | BRI2 | 106m 34ch | 12 October 1913 | 21 November 2012 last train; 2 December 2012 official | Immingham East Junction [new] (IE) | ||
| IE | Immingham East Junction [new] | Downgraded to Immingham East Token Exchange Point 30 December 2015 | PYE2 | 0m 8ch | 2 December 2012 | ||
| S | Immingham NCB Sidings | KIL1 | ≈104m 55ch | ||||
| IR | Immingham Reception Sidings | BRI2 | 104m 30ch | 6 October 1912 | |||
| D | Down line automatic signals | ||||||
| U | Up line automatic signals | ||||||
| Immingham Token Exchange Point | See Immingham East Junction [new] | ||||||
| IW | Immingham West Junction | KIL1 | 105m 5ch | 25 March 1912 | |||
| IM | Code reported officially, but probably not carried | ||||||
| I | Ingatestone | Downgraded to gate box 19 October 1996: line controlled by Liverpool Street [new] (L) | LTN1 | 23m 39ch | October 1904 | ||
| IG | Unclear if this code carried | ||||||
| D | Down line automatic signals | ||||||
| U | Up line automatic signals | ||||||
| IH | Insch | Code used from 2002 | ANI1 | 27m 47ch | 1886 | ||
| IK | Inverkeilor | Code used from 2002 | ECN4 | 23m 10ch | 1 March 1881 | ||
| V | Inverkeithing Central Junction | ECN2 | 13m 20ch | 8 November 1914 | 30 July 1979 | Edinburgh (EV) | |
| I | Inverness | Code used from 1987 | HGL2 WCK | 117m 77ch 0m 6ch | 8 March 1987 | ||
| HA | Aviemore interlocking. Code used from 26 March 2019 | ||||||
| HC | Carrbridge interlocking. Code used from 26 March 2019 | ||||||
| HD | Dyce interlocking. Code used from 17 August 2019 | ||||||
| HE | Elgin interlocking. Code used from 17 October 2017 | ||||||
| HF | Forres interlocking (planned but HE used instead) | ||||||
| HK | Kincraig interlocking. Code used from 26 March 2019 | ||||||
| HM | Moy interlocking. Code used from 26 March 2019 | ||||||
| HN | Nairn interlocking. Code used from 17 October 2017 | ||||||
| HS | Slochd interlocking. Code used from 26 March 2019 | ||||||
| HT | Tomatin interlocking. Code used from 26 March 2019 | ||||||
| MO | Muir of Ord points indicators | ||||||
| IE | Inverurie | Formerly named Inverurie New Station. Code used from 2002 | ANI1 | 16m 79ch | 10 February 1902 | 17 June 2019 | Inverness (HD) |
| Inverurie New Station | See Inverurie | ||||||
| IG | Ipswich Goods Junction | LTN1 | 69m 1ch | 1912 | 5 April 1984 | Colchester [new] (CO) | |
| IS | Ipswich Station | LTN1 | 68m 58ch | 1883 | 5 April 1984 | Colchester [new] (CO) | |
| D | Down line automatic signals | ||||||
| Y | Ipswich Upper Goods Yard | IUP | 18 August 1984 | Colchester [new] (CO) | |||
| IS | Irchester South | SPC2 | 62m 8ch | 27 June 1897 | 6 December 1987 | Leicester (LR) | |
| Ironbridge Power Station | See Buildwas Power Station Control Room | ||||||
| V | Ivybridge | MLN1 | 235m 27ch | ≈26 April 1895 | 8 December 1973 | Plymouth (P) | |