Fen line

The Fen Line is a railway line in the east of England that links Cambridge in the south to King's Lynn in the north. The line runs through Cambridgeshire and Norfolk and the name of the line refers to the Fens which cover parts of Cambridgeshire, Norfolk and Lincolnshire. It is 41 mi in length and has eight stations.

The line is part of the Network Rail Strategic Route 5 and comprises SRS 05.06 and part of 05.05. It is classified as a secondary line except between Cambridge and Ely where it is classified as a London and South East commuter line.

History
The line was completed in sections in the 1840s, and previously extended north to the seaside town of Hunstanton.

Great Northern
Great Northern operate through services to London King's Cross (via the Cambridge line). These services operate non-stop between London and Cambridge for most of the day, as part of the half-hourly "Cambridge Express" service. One train an hour is extended beyond Cambridge to serve all stations to King's Lynn, whilst the alternative services run to Ely.

These services are mostly operated by Class 387 electric multiple units. Before May 2017, Class 365s were the principal units.

Three Class 365 EMUs received names associated with the line:
 * The Fenman (365518) – previously a "named train" that used to operate on this line, consisting of locomotive-hauled InterCity (British Rail) trains;
 * Robert Stripe Passengers' Champion (365527) was named on 10 March 2006, after the 21st Anniversary of the Fen Line Users Association;
 * Nelson's County (365531) had a special livery applied to the outside which shows various scenes of West Norfolk however this was removed when Great Northern took over First Capital Connect.

Greater Anglia
Greater Anglia regularly runs services between Stansted Airport and Norwich on an hourly basis via the Breckland line, running non-stop between Ely and Cambridge North. Class 755 units are used for this service.

Until the timetable change in May 2023, Greater Anglia ran a few direct services between London Liverpool Street and King's Lynn or Ely (via the West Anglia Main Line). These services operated only during the morning and evening peaks. After the alterations, these services only run to and from Ely, and King's Lynn no longer has any direct services to London Liverpool Street.

CrossCountry
The section between Cambridge and Ely is also used non-stop by CrossCountry services from Stansted Airport (and onward to Birmingham New Street via Peterborough and Leicester). Class 170 units are used for this service.

Signalling
The line is double tracked except between Littleport and Downham Market and between Watlington and King's Lynn where it is bi-directionally signalled single track. In the Down direction, the entrance to the single line sections is protected additionally by SPAD indicators.

Signal boxes controlling the line are;
 * Cambridge power box
 * Littleport
 * Downham Market
 * Magdalen Road (Watlington)
 * King's Lynn

The signalling system is Track circuit block with multiple aspect colour light signals- with the exception of: In 2020, the Department of Transport announced funding to renew the signalling on the Fen Line to ETCS cab signalling.
 * one semaphore signal at King's Lynn which controls entry to the One Train In Section freight-only line from King's Lynn to Middleton Towers
 * two semaphore shunt signals at Downham Market station

Infrastructure
Traction current for electric trains is provided by 25 kV AC OHLE controlled by Romford Electrical Control Room. There are Neutral Sections at Shepreth Branch junction, Milton Fen and just north of Littleport bypass. The line has a loading gauge of W8 except for the section connecting the Ipswich–Ely line to the Ely–Peterborough line, which is W10.

Passenger volume
These are the statistics of the numbers of passengers on the line from the year beginning April 2002 to the year beginning April 2017. Comparing each station between the first and last years (14 years total), King's Lynn has increased by 68%, Watlington by 133%, Downham Market by 111%, Littleport by 157%, Ely by 113%, Waterbeach by 149% and Cambridge by 109%. Cambridge North was not open at the time of the publication of these figures.