Last update 4 August 2024
Please select a starting letter from the links below:
| ELR | Line name | Mileages | Datum | Notes |
|---|---|---|---|---|
| OAG | Oldham Ashton and Guide Bridge Line | see separate portions | ||
| OAG1 | Guide Bridge Junction to Crowthorne Junction (OA&GB) Line | 0.11 - 0.53 | Guide Bridge | |
| OAG2 | Ashton East Junction to Oldham Clegg Street (OA&GB) Line | 1.54 - 5.51 | Guide Bridge | |
| OAJ | Oakenshaw Junction to Oakenshaw South Junction Curve | 48.76 - 49.41 | Manchester Victoria via Rochdale and Wakefield Kirkgate | |
| OAU | Audenshaw West Junction to Canal Junction (OA&GB) Line | 0.00 - 0.28 | Audenshaw West Junction | |
| OAW | Over and Wharton Branch | 0.00 - 1.06 | Winsford Junction | |
| OBA | Dunblane to Crianlarich Line (Oban Branch) | 0.00 - 10.29 | Dunblane | |
| OBN | Oban Line | see separate portions | ||
| OBN1 | Crianlarich Junction to Crianlarich Lower Junction | 0.00 - 0.44 | Crianlarich Junction | |
| OBN2 | Crianlarich Lower Junction to Oban | 30.23 - 71.45 | Callander | |
| OBS | Oakbank Siding | 0.00 - 0.39 | Oakbank Junction | Near Midcalder Junction |
| OCB | Ollerton Colliery Branch | 19.00 - 19.03 | Chesterfield Market Place | = OLC?? Route thought to be about 1.17 long |
| OCD | Ordsall Chord | 190.05 - 190.34 | Euston | |
| OCL | Orchardhall Branch (Grangemouth) | 1.44 - 2.76 | Swing Bridge Junction | |
| OCR | Oakley to Comrie Branch | 0.00 - 2.57 | Oakley Junction | |
| OCZ | Old Carway Branch | 0.00 - 1.25 | Old Carway Junction | |
| ODT | Middlesbrough Old Town Branch | 0.00 - 1.31 | Old Town Junction | |
| OFB | Orbliston to Fochabers Branch | 0.00 - 3.00 | Orbliston | |
| OFF | Off Track Assets | see separate portions | ||
| OFF1 | Manchester area | 0.00 - 0.16 |
n/a | |
| OFF2 | Preston area | 0.00 - 0.00 |
n/a | |
| OFF3 | Liverpool area | 0.00 - 0.00 |
n/a | |
| OGD | Ormiston to Gifford Line (Gifford and Garvald Light Railway) | 0.00 - 9.25 | Ormiston Junction | |
| OGI | Ogilvie Colliery Branch | 20.34 - 20.70 | Cardiff East Dock | |
| OGM | Ogmore Branch/Nantymoel Branch | 0.00 - 7.18 | Tondu Middle Junction | 0.00 - 2.56 formerly BMZ. Line re-miled: Datum = Copper Works Junction after 1950 |
| OJS | Otford Junction and Sevenoaks Line | 24.54 - 26.61 | Victoria via Herne Hill | |
| OJW | Oakmoor Junction to Oakmoor Wharf Line | ?? - ?? | ||
| OKY | CEN Temporary Training Route |
8.40 - 25.00 | n/a | |
| OLC | Ollerton Colliery Branch Mid Notts | 19.00 - 19.05 | Chesterfield Market Place | Remaining portion of the Mid Notts Line to colliery, remiled from the LDEC |
| OLD | Oldbury Branch | 134.42 - 135.63 | Paddington via Didcot and Handsworth | |
| OLL | Ordsall Lane to Liverpool Line | see separate portions | ||
| OLL1 | Ordsall Lane Junction to Liverpool Road Old Station | 0.00 - 0.25 | Ordsall Lane Junction | |
| OLL2 | Ordsall Lane Junction to Liverpool Road Bonding Warehouse | ?? - 0.20 | Ordsall Lane Junction | |
| OLM | Oldham Branch (Greenfield Junction to Oldham Clegg Street) | 0.00 - 4.02 | Greenfield Junction | |
| OLW | Ordsall Lane Junction and Windsor Bridge Junction Curve | 190.28 - 191.10 | Euston | |
| OME | Olive Mount to Edge Hill Line | see separate portions | ||
| OME1 | Olive Mount Junction to Edge Hill Junction (Wapping Branch) | 0.00 - 1.38 | Olive Mount Junction | Olive Mount Junction Box to Wapping Bank Head Box |
| OME2 | Wapping Branch Junction to Pighue Lane Junction (Waterloo Independent Line) | 0.00 - 0.10 | Wapping Branch Junction | |
| OME3 | Edge Lane Junction to Pighue Lane Junction | 0.00 - 0.21 | Edge Lane Junction | Original definition; rebuilt 2008/9 |
| OME3 | Olive Mount Junction to Edge Lane Junction | 0.10 - 0.52 | Bootle Branch Junction via Edge Lane Junction (reverse count) | Later definition from 2008/9 |
| OMI | Omoa Ironworks Branch | 0.00 - 0.19 | Omoa Junction | |
| OMO | Omoa Branch | ?? - ?? | Possibly same as CMI, or Omoa Junction to Silverburn Colliery | |
| ONJ | Oxford North Junction | see separate portions | ||
| ONJ1 | Oxford North Junction Islip end | 30.51 - 30.55 | Bletchley | |
| ONJ2 | Oxford North Junction Didcot end | 63.74 - 64.00 | Paddington via Didcot | |
| OOC | Old Oak Common Yards | see separate portions | ||
| OOC1 | Old Oak Common No 1 Yard | 2.63 - 3.18 | Paddington | |
| OOC2 | Old Oak Common No 2 Yard | 2.68 - 3.22 | Paddington | |
| OON | Old Oaks to Nostell Line | 8.04 - 17.15 | Penistone West Silkstone Junction via Barnsley | |
| OOS | Old Oak Sidings, Willesden | 6.32 - 6.50 | Clapham Junction | |
| OPM | Overtown Paper Mills Branch | 0.00 - 1.10 | Berryards Junction | Upper Greenock Station |
| ORD | Miles Platting Junction to Oldham Road High Level Goods Junction Line (High Level Goods Loop) | 0.00 - 0.42 | Miles Platting Junction | |
| ORG | Miles Platting Junction to Oldham Road Goods Line (Oldham Road Goods) | 0.00 - 1.03 | Miles Platting Junction | |
| ORI | Oldham Road St Georges Incline | 0.58 - 0.73 | Miles Platting Junction | |
| OSC | Oakenshaw to Crofton East Junction Branch | 181.71 - 183.04 | St Pancras via Leicester, Toton and Barrow Hill | |
| OSL | Oulton Broad South to Lowestoft South Line | 115.47 - 116.74 | Liverpool Street | |
| OSN | Oakwell Junction to Stairfoot North Line | 0.00 - 1.07 | Oakwell Junction | |
| OTB | Otley and Ilkley Joint Line | 0.00 - 2.62 | Otley | |
| OTL | Otley Branch | 0.00 - 3.33 | Arthington South Junction | |
| OVE | Ogmore Vale Extension Line | 0.00 - 7.40 and 0.00 - 2.44 | Copper Works Junction and Tondu Middle Junction | |
| OWW | Oxford Worcester and Wolverhampton Line | 66.32 - 152.43 | Paddington via Didcot | |
| OXC | Oxley Chord | 0.00 - 1.02 | Bushbury (Oxley) Junction | |
| OXD | Oxford Branch | 0.00 - 31.22 | Bletchley | |
| OXO | Oxcroft Branch | 0.00 - 1.05 | Oxcroft Junction | |
| OXW | Oxenholme and Windermere Branch | 0.00 - 10.19 | Oxenholme |