Infrastructure of the East Coast Main Line

The infrastructure of the East Coast Main Line consists of the tunnels, viaducts and bridges on the East Coast Main Line as well as the lineside monitoring equipment. The line is mainly quadruple track from London to Stoke Tunnel, south of Grantham, with two double track sections: one between Digswell Jn & Woolmer Green Jn, where the line passes over the Digswell Viaduct, Welwyn North station and the two Welwyn tunnels; and one between Fletton Junction (south of Peterborough) and Holme Junction, south of Holme Fen. The route between Holme Junction and Huntingdon is mostly triple track, with the exception of a southbound loop between Conington and Woodwalton. North of Grantham the line is double track except for quadruple-track sections at Retford, around Doncaster, between Colton Junction (south of York), Thirsk and Northallerton, and Newcastle.^[1]

With most of the line rated for 125 mph (200 km/h) operation, the ECML was the fastest main line in the UK until the opening of High Speed 1. The high speeds are possible because much of the line is on fairly straight track on the flatter, eastern side of England, through Lincolnshire and Cambridgeshire, though there are significant speed restrictions because of the line's curvature particularly north of Darlington and between Doncaster and Leeds. By contrast, the West Coast Main Line crosses the Trent Valley and the mountains of Cumbria, with more curvature and a lower speed limit of 110 mph (180 km/h). Speeds on the West Coast Main Line (WCML) were increased with the introduction of tilting Pendolino trains and now match the 125 mph speeds on the ECML.

Tunnels, viaducts and bridges

Major civil engineering structures on the East Coast Main Line include^[2][3]

Tunnels, viaducts and major bridges on the East Coast Main Line

Railway structure	Length	Distance from Edinburgh Waverley	ELR	Location
Calton North Tunnel	490 yards (450 m)	0 miles 27 chains – 0 miles 50 chains	ECM8	East of Edinburgh Waverley station
Calton South Tunnel	400 yards (370 m)	0 miles 29 chains – 0 miles 47 chains
St. Margarets Tunnel	3 chains (60 m)	1 miles 32 chains – 1 mile 35 chains
Dunglass Viaduct	6 chains (120 m)	36 miles 02 chains – 36 miles 08 chains		Between Dunbar and Berwick-upon-Tweed stations
(Former Penmanshiel Tunnel)	12 chains (240 m)	39 miles 52 chains – 39 miles 64 chains
		Distance from Newcastle
Royal Border Bridge	33 chains	66 miles 74 chains – 66 miles 41 chains	ECM7	South of Berwick-upon-Tweed station
Viaduct	3 chains	66 miles 33 chains – 66 miles 30 chains
River Aln	10 chains	35 miles 50 chains – 35 miles 40 chains		North of Alnmouth station
River Coquet	9 chains	30 miles 01 chains – 29 miles 72 chains		North of Acklington station
Bothal (River Wansbeck)	9 chains	17 miles 57 chains –  17 mile 48 chains		Between Pegswood and Morpeth stations
Plessey (River Blyth)	6 chains	12 miles 23 chains – 12 miles 17 chains		Between Morpeth and Cramlington stations
Great Lime Road	3 chains	5 miles 53 chains – 5 miles 50 chains		Between Cramlington and Chathill stations
Ouseburn Viaduct	14 chains	1 miles 18 chains – 1 mile 04 chains		North of Manors station
Red Barns Tunnel	98 yards (90 metres)	0 miles 70 chains – 0 miles 65 chains
Viaduct	28 chains	0 miles 40 chains – 0 miles 11 chains		East of Newcastle station
		Distance from York
Viaduct	14 chains	80 miles 04 chains – 79 miles 70 chains	ECM5	West and South of Newcastle station
King Edward Bridge	13 chains	79 miles 66 chains – 79 miles 53 chains
Viaduct	4 chains	79 miles 53 chains – 79 miles  49 chains
Chester-le-Street Viaduct	12 chains	72 miles 20 chains – 72 miles 19 chains		North of Chester-le-Street station
Chester Moor or Dene Viaduct	10 chains	71 miles 07 chains – 70 miles 77 chains		South of Chester-le-Street station
Plawsworth Viaduct	6 chains	69 miles 60 chains – 69 miles 54 chains
Durham Viaduct	12 chains	66 miles 06 chains – 65 miles 74 chains		South of Durham station
Relly Mill Viaduct	6 chains	65 miles 23 chains – 65 miles 17 chains
Langley Moor Viaduct (River Dearness)	6 chains	64 miles 39 chains – 64 miles 33 chains
Croxdale Viaduct (River Wear)	9 chains	62 miles 18 chains – 62 miles 09 chains		Between Durham and Darlington stations
Aycliffe Viaduct (River Skerne)		49 miles 17 chains
River Skerne Viaduct	2 chains	47 miles 26 chains – 47 miles 24 chains
River Skerne Viaduct	3 chains	45 miles 33 chains – 45 miles 30 chains
Croft Viaduct (River Tees)	6 chains	41 miles 11 chains – 41 miles 05 chains		South of Darlington station
Skelton Bridge (River Ouse)	4 chains	3 miles 16 chains – 3 miles 12 chains		Between Thirsk and York stations
		Distance from King's Cross
Ryther Viaducts (River Wharfe)	25 chains	180 miles 28 chains – 180 miles 03 chains	ECM3	Between York and Doncaster stations
Selby Dam Viaduct	7 chains	175 miles 20 chains – 175 miles 13 chains
Selby Canal Viaduct	2 chains	172 miles 44 chains – 172 miles 42 chains
River Aire	4 chains	169 miles 44 chains – miles 40 chains
Aire & Calder Navigation		166 miles 66 chains	ECM2
Balby Bridge Tunnel	95 yards (87 metres)	155 miles 38 chains – 155 miles 34 chains	ECM1	Between Doncaster and Retford stations
Bawtry Viaduct	15 chains	147 miles 24 chains – 147 miles 09 chains
River Idle Viaduct	2 chains	138 miles 23 chains – 138 miles 21 chains		Between Retford and Newark North Gate stations
Askham Tunnel	57 yards (52 metres)	134 miles 40 chains – 134 miles 37 chains
Viaduct		121 miles 40 chains
Muskham Viaduct	15 chains	121 miles 31 chains – 121 miles 16 chains
Peascliffe Tunnel	968 yards (885 metres)	108 miles 29 chains – 107miles 65 chains		Between Newark North Gate and Grantham stations
West Gate Viaduct		105 miles 54 chains		North of Grantham station
Stoke Tunnel	880 yards (805 metres)	100 miles 79 chains – 100 miles 39 chains		Between Grantham and Peterborough stations
Bytham Viaduct	4 chains	92 miles 63 chains – 92 miles 59 chains
Nene Viaduct	3 chains	75 miles 68 chains – 75 miles 65 chains		South of Peterborough station
Great Ouse Viaduct	3 chains	58 miles 18 chains – 58 miles 15 chains		South of Huntingdon station
Robbery Lane Viaduct		23 miles 32 chains		Between Knebworth and Welwyn North stations
Welwyn North Tunnel	1049 yards (959 metres)	23 miles 12 chains – 22 miles 44 chains
Welwyn South Tunnel	446 yards (408 metres)	22 miles 31 chains – 22 miles 11 chains
Welwyn or Digswell Viaduct	513 yards (469 metres)	21 miles 60 chains – 21 miles 37 chains		Between Welwyn North and Welwyn Garden City stations
Potters Bar Tunnel[4]	1214 yards (1110 metres)	12 miles 00 chains – 11 miles 25 chains		Between Potters Bar and Hadley Wood stations
Hadley Wood North Tunnel[4]	232 yards (212 metres)	10 miles 70 chains – 10 miles 60 chains		North of Hadley Wood station
Hadley Wood South Tunnel[4]	384 yards (351 metres)	10 miles 39 chains – 10 miles 21 chains		South of Hadley Wood station
Viaduct		8 miles 64 chains		South of New Barnet station
Barnet Tunnel[4]	605 yards (553 metres)	7 miles 70 chains – 7 miles 42 chains		Between Oakleigh Park and New Southgate stations
Wood Green Tunnels	705 yards (644 metres)	5 miles 73 chains – 5 miles 41 chains		Between New Southgate and Alexandra Palace stations
Copenhagen Tunnel[4]	594 yards (543 metres)	1 mile 12 chains – 0 miles  65 chains		North of King's Cross station
Gasworks Tunnel[4]	528 yards (483 metres)	0 miles 46 chains – 0 miles 22 chains