Last update 22 October 2022
Please select a starting letter from the links below:
| ELR | Line name | Mileages | Datum | Notes |
|---|---|---|---|---|
| IAO | Island Road Loop | 0.00 - 1.36 | Barrow Station | Barrow Station to Shipyard Junction |
| IBB | Inkerman Brickworks Branch | 0.00 - 0.35 | Inkerman Branch Junction | |
| ICI | Callerton ICI Branch (shared with Tyne and Wear Metro) | see separate portions | ||
| ICI1 | Benton South Junction to Benton Metro Boundary | 0.00 - 0.10 | Benton South Junction | |
| ICI2 | Benton Metro Boundary to Kenton Bank Foot Metro Boundary | 0.10 - 5.00 | Benton South Junction | |
| ICI3 | Kenton Bank Foot Metro Boundary to Callerton ICI | 5.00 - 7.71 | Benton South Junction | |
| ICI4 | Callerton ICI to Ponteland | 7.71 - 8.61 | Benton South Junction | |
| ICS | Ilford Carriage Sidings | 7.63 - 8.30 | Liverpool Street | |
| IDH | Ilford Hostel | n/a | n/a | Bridge and buildings only |
| IGD | Ince Moss to Red Rock Goods Branch | 12.19 - 17.59 | Huyton Junction | |
| IGE | Inverkeithing Curve | 0.00 - 0.33 | Inverkeithing East Junction | |
| IGL | Ingliston Branch | 0.00 - 1.47 | Ingliston Junction | |
| IGN | Invergordon Harbour Branch Junction to Invergordon Harbour | 0.00 - 0.57 | Invergordon Harbour Branch Junction | |
| IHB | Irvine Harbour Branch | 0.00 - 0.66 | Irvine | |
| IKT | Ilkeston Town Branch | 126.42 - 127.17 | St Pancras | |
| ILF | Ilfracombe Branch | 211.32 - 226.19 | Waterloo | |
| ILK | Ilkley Branch | see separate portions | ||
| ILK1 | Apperley Junction to Burley | 201.79 - 207.68 | St Pancras via Cudworth | |
| ILK2 | Burley to Ilkley | 207.68 - 211.20 | St Pancras via Cudworth | |
| IMB | Inverness to Muirtown Basin (Caledonian Canal) Branch | 0.00 - 0.57 | Canal Junction | |
| IMD | Inveramsay to Macduff Branch | 20.10 - 50.19 | Aberdeen | |
| IMG | Ince Moss Goods Lines | 0.00 - 0.79/ 0.00 - 0.61 | Bamfurlong Junction | |
| IMG1 | "Example for the manual" | n/a | n/a | |
| IMS | Immingham Storage Co Branch | 106.43 - 107.35 | Manchester London Road via Woodhead | |
| INC | Ilkeston North Curve | 0.00 - 0.60 | Ilkeston West Junction | |
| ING | Ingliston Branch | 0.00 - 0.76 | Ingliston Branch Junction | |
| INL | Ingleton Branch | 0.00 - 18.72 | Low Gill | |
| INM | Inglebys Mill Branch | 0.00 - 0.40 | Junction near Tadcaster | |
| INN | Ingleton Branch | 242.04 - 246.21 | St Pancras | |
| INS | Inverness Harbour Branch | 117.58 - 118.14 | Perth | |
| INW | Immingham Dock North West Entrance Branch | 104.74 - 105.74 | Manchester London Road via Woodhead | |
| IOW | Isle of Wight Line (Ryde Pier Head to Shanklin) | 0.00 - 8.31 | Ryde Pier Head | |
| IPD | Ipswich Docks Branch | 0.23 - 2.63 | East Suffolk Junction | |
| IRE | Irvine Freight Depot | 0.00 - 0.66 | Irvine Junction | Also listed as 5.20 - 5.51 from Kilmarnock via Dreghorn |
| IRM | Inverurie to Old Meldrum Branch | 16.11 - 22.21 | Aberdeen | |
| IRR | Ipswich Ranleigh Road Depot | 68.47 - 68.74 | Liverpool Street | |
| ISC | Isabella Colliery Branch | 0.00 - 2.30 | Newsham North Junction | |
| ISL | Certain lines near St Pancras | see separate portions | ||
| ISL1 | probably North London Line connection | 0.000km - 0.705km | York Way South Junction | |
| ISL2 | probably Silo Curve | 0.000km - 0.305km | 0.901km from St Pancras | |
| ITB | Imperial Tube Works Branch (Coatbridge/Sheepford) | 0.00 - 0.52 | Coatdyke Goods | |
| ITW | Rosehall Junction to BSC Imperial Works Branch | 6.59 - 8.52 | Rutherglen East Junction | |
| IUP | Ipswich Upper Yard | 68.72 - 69.50 | Liverpool Street | |
| IVB | Inchture Village Branch | 0.00 - 1.32 | Inchture main line | |
| IVW | See IWV; shown on St Lawrence Shute bridge in error see this image | |||
| IWB | Isle of Wight Brading to Bembridge Branch | 0.03 - 2.65 | Brading | |
| IWC | Isle of Wight Newport to Cowes Branch | 9.74 - 14.25 | Ryde Pier Head | |
| IWF | Isle of Wight Newport to Freshwater Branch | 0.00 - 11.70 | Newport Junction | |
| IWM | Isle of Wight Merstone to Sandown Branch | 0.00 - 5.28 | Sandown Junction | |
| IWR | Isle of Wight Newport to Ryde Smallbrook Junction Branch | 2.10 - 9.74 | Ryde Pier Head | |
| IWS | Isle of Wight Shanklin to Ventnor Branch | 8.31 - 12.44 | Ryde Pier Head | |
| IWV | Isle of Wight Newport to Ventnor West Branch | 0.00 - 10.54 | Newport Junction |