| Route | South Wales Main Line (SWML) |
| Section | Gloucester Yard Jn to Johnston |
| Maps | SWM2 • Google • Gloucester , ELR change SAW-SSS , Chepstow , Severn Tunnel , Newport , Newport (West) , Cardiff (East) , Heath , Cardiff , Pontyclun , Bridgend , ELR change OVE-POR , Margham , Port Talbot , Briton Ferry , Neath , Llansamlet , Swansea , Llanelli , Kidwelly , Carmarthen , Whitland , Clarbeston Road , Milford Haven |
| Details | Track Curvature • Elevation Profile • Geology |
| Extent | 113M 0078y to 280M 1549y • 167.836 miles • 270.106 km |
| Measured | 270.052 km (-54m, relative to reported extent) ℹ️ Variation between reported and measured extents |
| Grouping | SWM1 , SWM2 |
| Neighbours | BAG2 , BAL , BAN1 , BAN2 , BGL1 , BRY , BSW , BUT , CAM , CAN , CCC , CCD , CEJ , CHL , CLL , CNW , CRL , CWT , ELY , EUB , EUJ , GAE , GNY2 , HNL1 , KID1 , KID2 , LLA , LLY , MAI , MCS , MIL , MLS , MRJ , NAB , NLL , NLP , NWL , NWN , OVE , PEM , RAD , ROA , ROC , SAW , SBK1 , SBK2 , SDI1 , SDI2 , SWA , SWL , VOG , VON , WYE |
| TRACKmaps | 🟠 Western & Wales |
| NR Region | 🟧 Wales & Western |
| LOR | 🟠 St Erth to St Ives GW690 🟠 Gloucester Barnwood Jn to Severn Tunnel Jn GW700 🟠 Pilning to Fishguard Harbour GW900 🟠 Clarbeston Road to Milford Haven GW960 |
Administrative Area
| Mileage | Country | Administrative Area |
|---|---|---|
| 113M 0078y to 143M 0340y | England | Gloucestershire |
| 143M 0341y to 151M 1132y | Wales | Monmouthshire |
| 151M 1133y to 164M 0560y | Wales | Newport |
| 164M 0561y to 174M 1176y | Wales | Cardiff |
| 174M 1177y to 179M 0626y | Wales | Vale of Glamorgan |
| 179M 0627y to 185M 0362y | Wales | Rhondda, Cynon, Taff |
| 185M 0363y to 196M 1440y | Wales | Bridgend |
| 196M 1441y to 210M 1264y | Wales | Neath Port Talbot |
| 210M 1265y to 221M 1418y | Wales | Swansea |
| 221M 1419y to 264M 1132y | Wales | Carmarthenshire |
| 264M 1133y to 280M 1549y | Wales | Pembrokeshire |
Nearest Place and District
| Mileage | Nearest Place | District / County | Distance |
|---|---|---|---|
| 113M 0078y to 114M 0010y | Barton | Gloucestershire - Gloucester | 450m - 713m |
| 114M 0011y to 114M 0758y | Gloucester | Gloucestershire - Gloucester | 542m - 724m |
| 114M 0759y to 114M 0868y | Kingsholm | Gloucestershire - Gloucester | 557m - 566m |
| 114M 0869y to 114M 0956y | Gloucester | Gloucestershire - Gloucester | 570m - 581m |
| 114M 0957y to 114M 1418y | The Island | Gloucestershire - Gloucester | 466m - 575m |
| 114M 1419y to 115M 0626y | Pool Meadow | Gloucestershire - Gloucester | 241m - 482m |
| 115M 0627y to 116M 0978y | Over | Gloucestershire - Tewkesbury | 157m - 1537m |
| 116M 0979y to 117M 0868y | Highnam | Gloucestershire - Tewkesbury | 1499m - 1833m |
| 117M 0869y to 118M 1550y | Minsterworth | Gloucestershire - Tewkesbury | 751m - 1825m |
| 118M 1551y to 119M 1550y | Oakle Street | Gloucestershire - Forest of Dean | 481m - 938m |
| 119M 1551y to 120M 1308y | Lower Ley | Gloucestershire - Forest of Dean | 887m - 1355m |
| 120M 1309y to 121M 0142y | Upper Ley | Gloucestershire - Forest of Dean | 1245m - 1367m |
| 121M 0143y to 122M 0670y | Northwood Green | Gloucestershire - Forest of Dean | 360m - 1234m |
| 122M 0671y to 123M 0868y | Westbury-on-Severn | Gloucestershire - Forest of Dean | 472m - 1086m |
| 123M 0869y to 124M 1110y | Broadoak | Gloucestershire - Forest of Dean | 86m - 911m |
| 124M 1111y to 125M 1616y | Newnham | Gloucestershire - Forest of Dean | 418m - 949m |
| 125M 1617y to 127M 0362y | Bullo | Gloucestershire - Forest of Dean | 212m - 1209m |
| 127M 0363y to 128M 0736y | Awre | Gloucestershire - Forest of Dean | 952m - 1888m |
| 128M 0737y to 130M 0076y | Gatcombe | Gloucestershire - Forest of Dean | 95m - 1874m |
| 130M 0077y to 130M 0274y | Etloe | Gloucestershire - Forest of Dean | 498m - 598m |
| 130M 0275y to 131M 0978y | Purton | Gloucestershire - Forest of Dean | 48m - 1588m |
| 131M 0979y to 132M 1528y | Naas | Gloucestershire - Forest of Dean | 310m - 1606m |
| 132M 1529y to 133M 1242y | Tutnalls | Gloucestershire - Forest of Dean | 650m - 1383m |
| 133M 1243y to 134M 1704y | Aylburton | Gloucestershire - Forest of Dean | 1076m - 1500m |
| 134M 1705y to 135M 0824y | Alvington | Gloucestershire - Forest of Dean | 1377m - 1507m |
| 135M 0825y to 137M 0274y | Plusterrwine | Gloucestershire - Forest of Dean | 659m - 1628m |
| 137M 0275y to 137M 0362y | High Woolaston | Gloucestershire - Forest of Dean | 1643m - 1651m |
| 137M 0363y to 138M 0472y | Stroat | Gloucestershire - Forest of Dean | 706m - 1647m |
| 138M 0473y to 139M 0098y | Wibdon | Gloucestershire - Forest of Dean | 662m - 1129m |
| 139M 0099y to 139M 1440y | Tidenham | Gloucestershire - Forest of Dean | 918m - 1132m |
| 139M 1441y to 140M 1000y | Old Bishton | Gloucestershire - Forest of Dean | 711m - 1066m |
| 140M 1001y to 141M 0296y | Tutshill | Gloucestershire - Forest of Dean | 509m - 777m |
| 141M 0297y to 141M 0692y | Chepstow | Monmouthshire | 404m - 634m |
| 141M 0693y to 141M 1660y | Hardwick | Monmouthshire | 154m - 574m |
| 141M 1661y to 142M 1198y | Bulwark | Monmouthshire | 462m - 955m |
| 142M 1199y to 143M 0846y | Beachley | Gloucestershire - Forest of Dean | 837m - 1490m |
| 143M 0847y to 143M 1396y | Bulwark | Monmouthshire | 1505m - 1807m |
| 143M 1397y to 144M 1000y | Mathern | Monmouthshire | 1745m - 1984m |
| 144M 1001y to 146M 0164y | Black Rock | Monmouthshire | 99m - 1971m |
| 146M 0165y to 147M 0142y | Portskewett | Monmouthshire | 181m - 1121m |
| 147M 0143y to 148M 0296y | Caldicot | Monmouthshire | 788m - 1197m |
| 148M 0297y to 149M 0318y | Rogiet | Monmouthshire | 397m - 1190m |
| 149M 0319y to 149M 1682y | Llanfihangel near Rogiet | Monmouthshire | 440m - 981m |
| 149M 1683y to 150M 1550y | Undy | Monmouthshire | 90m - 971m |
| 150M 1551y to 150M 1572y | Whitewall Common | Monmouthshire | 488m - 488m |
| 150M 1573y to 151M 1044y | Magor | Monmouthshire | 192m - 682m |
| 151M 1045y to 152M 1176y | Llandevenny | Monmouthshire | 28m - 1044m |
| 152M 1177y to 154M 0098y | Bishton | Newport | 485m - 1381m |
| 154M 0099y to 155M 0912y | Llanwern | Newport | 753m - 1396m |
| 155M 0913y to 155M 1220y | Ringland | Newport | 1390m - 1398m |
| 155M 1221y to 155M 1440y | Lawrence Hill | Newport | 1277m - 1387m |
| 155M 1441y to 156M 0670y | Alway | Newport | 529m - 1260m |
| 156M 0671y to 156M 1110y | Liswerry | Newport | 364m - 517m |
| 156M 1111y to 157M 0252y | Somerton | Newport | 174m - 532m |
| 157M 0253y to 157M 1264y | Maindee | Newport | 195m - 549m |
| 157M 1265y to 158M 0120y | Barnardtown | Newport | 257m - 434m |
| 158M 0121y to 158M 0318y | East Usk | Newport | 366m - 426m |
| 158M 0319y to 158M 0802y | Marshes | Newport | 253m - 413m |
| 158M 0803y to 158M 1418y | Gold Tops | Newport | 54m - 291m |
| 158M 1419y to 159M 0186y | Clytha Park | Newport | 152m - 301m |
| 159M 0187y to 159M 0384y | St Woolos | Newport | 273m - 358m |
| 159M 0385y to 159M 0890y | Stow Park | Newport | 367m - 657m |
| 159M 0891y to 159M 1088y | Stelvio | Newport | 669m - 761m |
| 159M 1089y to 159M 1220y | Gaer | Newport | 763m - 779m |
| 159M 1221y to 160M 1154y | Level of Mendalgief | Newport | 535m - 1136m |
| 160M 1155y to 160M 1176y | Maes-glas | Newport | 1155m - 1155m |
| 160M 1177y to 161M 1044y | Duffryn | Newport | 1148m - 1391m |
| 161M 1045y to 162M 0846y | Celtic Lakes | Newport | 1080m - 1385m |
| 162M 0847y to 163M 0428y | Coedkernew | Newport | 1096m - 1297m |
| 163M 0429y to 164M 1242y | Marshfield | Newport | 606m - 1341m |
| 164M 1243y to 165M 0186y | Pengam | Newport | 1347m - 1524m |
| 165M 0187y to 165M 1022y | St Mellons | Cardiff | 1493m - 1557m |
| 165M 1023y to 166M 0054y | Trowbridge | Cardiff | 1265m - 1548m |
| 166M 0055y to 166M 0714y | Newton | Cardiff | 1128m - 1259m |
| 166M 0715y to 167M 1044y | Pwll-Mawr | Cardiff | 199m - 1117m |
| 167M 1045y to 168M 0648y | Pengam | Cardiff | 440m - 835m |
| 168M 0649y to 168M 1264y | Tremorfa | Cardiff | 525m - 601m |
| 168M 1265y to 169M 0692y | Splott | Cardiff | 40m - 593m |
| 169M 0693y to 169M 1660y | Adamsdown | Cardiff | 285m - 514m |
| 169M 1661y to 170M 0362y | Cardiff | Cardiff | 437m - 526m |
| 170M 0363y to 170M 1110y | Central | Cardiff | 386m - 524m |
| 170M 1111y to 171M 0582y | Riverside | Cardiff | 75m - 608m |
| 171M 0583y to 171M 1594y | Canton | Cardiff | 354m - 611m |
| 171M 1595y to 172M 1286y | Victoria Park | Cardiff | 364m - 971m |
| 172M 1287y to 172M 1550y | Llandaff | Cardiff | 955m - 985m |
| 172M 1551y to 173M 0362y | Fairwater | Cardiff | 730m - 947m |
| 173M 0363y to 173M 1418y | Ely | Cardiff | 649m - 970m |
| 173M 1419y to 174M 1396y | St Fagans | Cardiff | 454m - 972m |
| 174M 1397y to 175M 0450y | Drope | Vale of Glamorgan | 701m - 960m |
| 175M 0451y to 176M 0428y | St George’s | Vale of Glamorgan | 78m - 783m |
| 176M 0429y to 177M 1044y | Peterston-super-Ely | Vale of Glamorgan | 118m - 1232m |
| 177M 1045y to 178M 0318y | Pendoylan | Vale of Glamorgan | 1061m - 1237m |
| 178M 0319y to 179M 1000y | Clawdd-côch | Vale of Glamorgan | 1165m - 1831m |
| 179M 1001y to 181M 0098y | Miskin | Rhondda Cynon Taf | 231m - 1821m |
| 181M 0099y to 182M 1088y | Pontyclun | Rhondda Cynon Taf | 21m - 1892m |
| 182M 1089y to 184M 0054y | Llanharan | Rhondda Cynon Taf | 77m - 1891m |
| 184M 0055y to 184M 0450y | Dolau | Rhondda Cynon Taf | 361m - 449m |
| 184M 0451y to 184M 1132y | Bryncae | Rhondda Cynon Taf | 327m - 472m |
| 184M 1133y to 185M 0054y | Brynna | Rhondda Cynon Taf | 379m - 540m |
| 185M 0055y to 185M 1528y | Brynnau Gwynion | Rhondda Cynon Taf | 81m - 793m |
| 185M 1529y to 186M 0648y | Pen-prysg | Bridgend | 437m - 776m |
| 186M 0649y to 187M 1022y | Pencoed | Bridgend | 69m - 1439m |
| 187M 1023y to 188M 1462y | Coychurch | Bridgend | 185m - 1451m |
| 188M 1463y to 189M 0120y | Waterton | Bridgend | 598m - 731m |
| 189M 0121y to 189M 1440y | Brackla | Bridgend | 661m - 945m |
| 189M 1441y to 190M 1022y | Tremains | Bridgend | 67m - 944m |
| 190M 1023y to 191M 0010y | Bridgend | Bridgend | 152m - 559m |
| 191M 0011y to 191M 0230y | Newcastle | Bridgend | 577m - 669m |
| 191M 0231y to 191M 1440y | Wild Mill | Bridgend | 391m - 729m |
| 191M 1441y to 192M 0472y | Pen-y-fai | Bridgend | 546m - 728m |
| 192M 0473y to 193M 1264y | Court Colman | Bridgend | 306m - 1630m |
| 193M 1265y to 195M 0252y | Cefn Cribwr | Bridgend | 1033m - 1623m |
| 195M 0253y to 195M 1000y | Kenfig Hill | Bridgend | 1262m - 1436m |
| 195M 1001y to 196M 1088y | Pyle | Bridgend | 469m - 1248m |
| 196M 1089y to 197M 0582y | North Cornelly | Bridgend | 579m - 1130m |
| 197M 0583y to 198M 0362y | Mawdlam | Bridgend | 1020m - 1490m |
| 198M 0363y to 199M 0516y | Eglwys Nunydd | Neath Port Talbot | 1180m - 1489m |
| 199M 0517y to 200M 0186y | Cwrt-y-defaid | Neath Port Talbot | 1285m - 1642m |
| 200M 0187y to 201M 1044y | Margam | Neath Port Talbot | 394m - 1652m |
| 201M 1045y to 202M 0868y | Taibach | Neath Port Talbot | 361m - 892m |
| 202M 0869y to 203M 1044y | Port Talbot | Neath Port Talbot | 111m - 1024m |
| 203M 1045y to 203M 1264y | Aberavon | Neath Port Talbot | 1031m - 1111m |
| 203M 1265y to 204M 0736y | Sandfields | Neath Port Talbot | 874m - 1102m |
| 204M 0737y to 205M 0714y | Baglan | Neath Port Talbot | 419m - 970m |
| 205M 0715y to 206M 0208y | Briton Ferry | Neath Port Talbot | 169m - 826m |
| 206M 0209y to 206M 0692y | Shelone | Neath Port Talbot | 298m - 524m |
| 206M 0693y to 206M 1088y | Brynhyfryd | Neath Port Talbot | 368m - 528m |
| 206M 1089y to 206M 1704y | Cwrt Sart | Neath Port Talbot | 304m - 474m |
| 206M 1705y to 207M 0582y | Penrhiwtyn | Neath Port Talbot | 305m - 465m |
| 207M 0583y to 207M 1374y | Pencaerau | Neath Port Talbot | 283m - 709m |
| 207M 1375y to 208M 0010y | Mount Pleasant | Neath Port Talbot | 707m - 748m |
| 208M 0011y to 208M 1374y | Neath | Neath Port Talbot | 243m - 746m |
| 208M 1375y to 208M 1550y | Rhydding | Neath Port Talbot | 735m - 832m |
| 208M 1551y to 210M 0076y | Neath Abbey | Neath Port Talbot | 39m - 973m |
| 210M 0077y to 211M 0208y | Skewen | Neath Port Talbot | 282m - 974m |
| 211M 0209y to 211M 0714y | Lon-las | Swansea | 528m - 837m |
| 211M 0715y to 211M 1506y | Llwynbrwydrau | Swansea | 87m - 510m |
| 211M 1507y to 212M 0252y | Peniel Green | Swansea | 67m - 257m |
| 212M 0253y to 212M 0934y | Tai’r-ysgol | Swansea | 125m - 389m |
| 212M 0935y to 212M 1374y | Pwllygrafel | Swansea | 263m - 390m |
| 212M 1375y to 213M 0582y | Cae-maes-y-bar | Swansea | 145m - 664m |
| 213M 0583y to 213M 1462y | Cwm | Swansea | 470m - 674m |
| 213M 1463y to 214M 0076y | Pentre’r-Gaseg | Swansea | 632m - 740m |
| 214M 0077y to 214M 0978y | Plas-Marl | Swansea | 377m - 747m |
| 214M 0979y to 215M 0208y | Landore | Swansea | 140m - 457m |
| 215M 0209y to 215M 0582y | Hafod | Swansea | 451m - 530m |
| 215M 0583y to 215M 0956y | Cae-Bricks | Swansea | 263m - 538m |
| 215M 0957y to 215M 1748y | Cwmbwrla | Swansea | 85m - 459m |
| 215M 1749y to 216M 0120y | Mayhill | Swansea | 462m - 490m |
| 216M 0121y to 216M 0670y | Cwmdu | Swansea | 498m - 620m |
| 216M 0671y to 216M 1220y | Gendros | Swansea | 524m - 626m |
| 216M 1221y to 217M 0736y | Cockett | Swansea | 47m - 606m |
| 217M 0737y to 218M 0384y | Fforest-fach | Swansea | 554m - 1243m |
| 218M 0385y to 219M 0384y | Waunarlwydd | Swansea | 265m - 1254m |
| 219M 0385y to 220M 0736y | Gowerton | Swansea | 147m - 1400m |
| 220M 0737y to 221M 1506y | Loughor | Swansea | 532m - 1388m |
| 221M 1507y to 223M 0076y | Bynea | Carmarthenshire | 611m - 1207m |
| 223M 0077y to 223M 1418y | Llwynhendy | Carmarthenshire | 884m - 1135m |
| 223M 1419y to 224M 1044y | Morfa | Carmarthenshire | 418m - 1131m |
| 224M 1045y to 225M 0318y | Ty-isaf | Carmarthenshire | 55m - 466m |
| 225M 0319y to 225M 1396y | Seaside | Carmarthenshire | 209m - 629m |
| 225M 1397y to 226M 0802y | Sandy | Carmarthenshire | 482m - 829m |
| 226M 0803y to 227M 1506y | Pwll | Carmarthenshire | 390m - 1592m |
| 227M 1507y to 228M 1682y | Dyfatty | Carmarthenshire | 102m - 1573m |
| 228M 1683y to 229M 0802y | Burry Port | Carmarthenshire | 37m - 567m |
| 229M 0803y to 230M 0098y | Furnace | Carmarthenshire | 388m - 614m |
| 230M 0099y to 232M 0318y | Pembrey | Carmarthenshire | 214m - 2577m |
| 232M 0319y to 232M 1550y | Llandyry | Carmarthenshire | 2262m - 2587m |
| 232M 1551y to 234M 1638y | Kidwelly | Carmarthenshire | 584m - 2259m |
| 234M 1639y to 235M 1660y | Llansaint | Carmarthenshire | 1325m - 1565m |
| 235M 1661y to 237M 1044y | St Ishmael | Carmarthenshire | 110m - 1461m |
| 237M 1045y to 238M 0120y | Broadlay | Carmarthenshire | 789m - 1048m |
| 238M 0121y to 239M 1110y | Ferryside | Carmarthenshire | 63m - 1666m |
| 239M 1111y to 241M 0956y | Pant Yr Athro | Carmarthenshire | 1082m - 2563m |
| 241M 0957y to 242M 0032y | Llangain | Carmarthenshire | 2272m - 2563m |
| 242M 0033y to 244M 0032y | Croesyceiliog | Carmarthenshire | 521m - 2258m |
| 244M 0033y to 245M 0054y | Pibwrlŵyd | Carmarthenshire | 124m - 1026m |
| 245M 0055y to 245M 0472y | Pen-sarn | Carmarthenshire | 612m - 663m |
| 245M 0473y to 246M 0318y | Johnstown | Carmarthenshire | 286m - 781m |
| 246M 0319y to 248M 0208y | Llanllwch | Carmarthenshire | 200m - 2359m |
| 248M 0209y to 249M 0362y | Merthyr | Carmarthenshire | 2137m - 2362m |
| 249M 0363y to 252M 0142y | Bancyfelin | Carmarthenshire | 273m - 2335m |
| 252M 0143y to 253M 1154y | St Clears | Carmarthenshire | 878m - 2343m |
| 253M 1155y to 255M 0428y | Pwll-trap | Carmarthenshire | 845m - 1627m |
| 255M 0429y to 257M 1154y | Pont-y-Fenni | Carmarthenshire | 152m - 1927m |
| 257M 1155y to 260M 0164y | Whitland | Carmarthenshire | 173m - 1911m |
| 260M 0165y to 260M 1154y | Cwmfelin-boeth | Carmarthenshire | 1859m - 1996m |
| 260M 1155y to 261M 0912y | Rhydywrach | Carmarthenshire | 1450m - 1997m |
| 261M 0913y to 263M 0560y | Llanfallteg West | Carmarthenshire | 149m - 1484m |
| 263M 0561y to 265M 0802y | Clunderwen | Pembrokeshire | 54m - 1907m |
| 265M 0803y to 265M 0868y | Bethesda | Pembrokeshire | 1903m - 1924m |
| 265M 0869y to 267M 1132y | Gelli | Pembrokeshire | 234m - 1887m |
| 267M 1133y to 268M 0120y | Bletherston | Pembrokeshire | 1564m - 1881m |
| 268M 0121y to 269M 1462y | Clarbeston | Pembrokeshire | 1085m - 1880m |
| 269M 1463y to 271M 1484y | Clarbeston Road | Pembrokeshire | 42m - 1656m |
| 271M 1485y to 272M 0318y | Bethlehem | Pembrokeshire | 1070m - 1432m |
| 272M 0319y to 273M 1044y | New Bridge | Pembrokeshire | 35m - 1183m |
| 273M 1045y to 273M 1440y | Poyston Cross | Pembrokeshire | 1200m - 1376m |
| 273M 1441y to 275M 0252y | Crundale | Pembrokeshire | 815m - 1365m |
| 275M 0253y to 275M 1550y | Prendergast | Pembrokeshire | 698m - 1280m |
| 275M 1551y to 276M 1506y | The Marsh | Pembrokeshire | 135m - 939m |
| 276M 1507y to 278M 0274y | Merlin’s Bridge | Pembrokeshire | 215m - 1103m |
| 278M 0275y to 278M 1374y | Skerryford | Pembrokeshire | 1024m - 1098m |
| 278M 1375y to 279M 0472y | Dreenhill | Pembrokeshire | 1080m - 1444m |
| 279M 0473y to 280M 0472y | Pope Hill | Pembrokeshire | 1060m - 1458m |
| 280M 0473y to 280M 1549y | Johnston | Pembrokeshire | 143m - 1057m |
Positional Accuracy Statistics
| Property | Count | Min | Max | Mean | Median | Std Dev |
|---|---|---|---|---|---|---|
| Linear Accuracy | 672 | -46m | 71m | -0m | -0m | 7m |
| Normalised Quarter Miles | 672 | 390y | 518y | 440y | 440y | 7y |
| Calibration Segment Length | 672 | 229y | 440y | 440y | 440y | 9y |