North Kent Line

The North Kent Line is a railway line which runs from Lewisham Vale junction (at the country end of St Johns station) where it splits from the Southeastern Main Line to Rochester Bridge junction  (just south of Strood station), then links up with the Chatham Main Line

Construction
The North Kent Line was the means by which the South Eastern Railway (SER) was able to connect its system to London at London Bridge. In 1846 the SER purchased the Thames and Medway Canal tunnel near Higham and laid railway tracks through it; in 1847 trains were working through from the Strood terminus, on the River Medway to Gravesend. From 30 July 1849 the line was extended, via Blackheath, to a junction with the London and Greenwich Railway at North Kent East Junction, near Deptford, and through trains were now working.

Electrification
The line is electrified (750v DC third rail). Electrification was initially to Dartford (6 June 1926) and was extended to Gillingham by World War Two.

The Route and Services
The North Kent Line is regarded as a high-frequency line, with all stations in the London area being served by at least 4 trains per hour, with Lewisham being served by 14tph.

A major timetable change was introduced in December 2009 in connection with domestic high speed services on High Speed 1. This has led to additional services from St Pancras International operating along High Speed 1, then using the North Kent Line from Gravesend, continuing then along the Chatham Main Line to Faversham.

All passenger services are provided by Southeastern, and interchange with the Docklands Light Railway is available at Lewisham, Woolwich Arsenal & Greenwich. From January 2010, Oyster Pay-as-you-Go has been accepted on services within the London Travelcard Zones. The entire line is also within the Penalty fare scheme.

The line has a mixture of fast, semi fast and slow services, and from 2009 high speed services on the High Speed One route from Strood & Gravesend to St. Pancras International.

From 1999–2002 there were semi-fast trains starting from Plumstead to London Victoria briefly resuming a 1980s service pattern. This service was for the Millennium Dome, the service called at, Woolwich Arsenal, Charlton, Blackheath, Lewisham, Peckham Rye then non-stop to London Victoria

Future
Abbey Wood is to become the eastern terminal for Crossrail.

Stations
Train services working the Line today take the following route; the first ten miles (16 km) passes through many tunnels, included on the list:
 * Lewisham
 * Blackheath – here is the junction for the Bexleyheath Line
 * Blackheath Tunnel [1 mile (1.6 km) in length]
 * here is the freight branch to Angerstein Wharf
 * junction for the line from Greenwich and the eastern connection with the London and Greenwich Railway, opened in 1878
 * Charlton
 * Charlton Tunnel [154 yd (138 m)]
 * Mount Street Tunnel [121 yd (108 m)]
 * Dockyard Tunnel [121 yd (108 m)]
 * Woolwich Dockyard
 * Coleman Street Tunnel [89 yd(80 m)]
 * George IV Tunnel [238 yd (214 m]
 * Calderwood Street Tunnel [58 yd (52 m)]
 * Cross Street Tunnel [134 yd (120 m)]
 * Woolwich Arsenal
 * Plumstead – here the Royal Arsenal railway system connected with the main line
 * Church Manor Way Halt – closed
 * Abbey Wood
 * Belvedere
 * Erith
 * Slade Green -includes the large carriage-servicing depot
 * here is the triangular junction with the Bexleyheath Line
 * here is the triangular junction with the Dartford Loop Line
 * Dartford
 * Stone Crossing
 * Greenhithe – to which has been added "for Bluewater"
 * ''Greenhithe Tunnel [253 yd (228 m)]
 * Swanscombe
 * Northfleet – this station is only 305m or so from Ebbsfleet International as the crow flies, but it is at least a 1km walk between the two stations.
 * Gravesend: was originally named Gravesend Central to differentiate it from the ex-London, Chatham and Dover Railway station at Gravesend West which closed in 1968
 * Milton Road Halt-closed
 * Denton Halt- closed
 * Milton Range Halt-closed
 * Hoo Junction Staff Halt, where the line branches ("The Hundred of Hoo Railway") to Grain. Currently for freight services (not electrified)
 * Higham
 * Higham and Strood tunnel – actually two tunnels [total 3931 yd (3595 m)] with a gap of 100 yd between.
 * Strood – the junction for the Medway Valley Line.

The North Kent Line connects with the LCDR Chatham Main Line at Rochester Bridge Junction, about 200 m beyond Strood station. It totals some 30 miles (48 km) in length.

Service patterns
, the service pattern is:

Off-peak & Saturday:
 * 2tph between London Cannon Street & Dartford via Greenwich (stopping service)
 * 2tph between London Cannon Street & Slade Green via Greenwich (stopping service)
 * 2tph between London Cannon Street & Slade Green via Greenwich, continuing to London Cannon Street via Dartford Loop Line
 * 2tph between London Charing Cross & Gillingham (semi-fast)
 * 2tph between London Charing Cross & Gravesend via Dartford Loop Line
 * 2tph between St Pancras International & Faversham via High Speed One

Sunday:
 * 2tph between London Charing Cross & Dartford via Greenwich (stopping service)
 * 2tph between London Bridge & Plumstead via Greenwich (stopping service)
 * 2tph between London Charing Cross & Gillingham (semi-fast)

Peak hour frequencies vary, with services from the Bexleyheath and Dartford loop lines also running to and from stations to Gillingham.