Gainsborough line

The Gainsborough line is the current marketing name of the Sudbury branch line, a railway branch line off the Great Eastern Main Line in the east of England, that links in Essex with in Suffolk. It is in length and single-track throughout. The line's Engineer's Line Reference is SUD.
Prior to the Beeching cuts initiated in the 1960s, the line, then known as the Stour Valley Railway, continued beyond Sudbury to in Cambridgeshire. Today the line is part of the Network Rail Strategic Route 7, SRS 07.10, and is classified as a rural line.
As of December 2016 the stations and all trains serving them are operated by Greater Anglia. The typical service frequency is one train per hour in each direction, with a timetabled journey time between one terminus and the other of 19 minutes.

History

The Stour Valley Railway opened on 9 August 1865, linking near Cambridge with in Essex, with 13 intermediate stations along the line.
The first section between and Marks Tey was opened as the Colchester, Stour Valley, Sudbury & Halstead Railway on 2 July 1849 and was taken over by the Eastern Counties Railway on 7 August 1862.
The section between Shelford and Sudbury was closed on 6 March 1967 following the Beeching cuts, leaving and as the only stops between the termini.
In 2005 the line received around £3 million of investment, which saw around of old jointed track replaced with new continuous welded rail. Further investment was made in 2006 to replace around of track, leaving just the Chappel viaduct and Lamarsh to Sudbury sections in need of modernisation. This work was completed in 2007.
In 2006 the line was designated as a community railway by the transport minister and is part of the Essex and South Suffolk Community Rail Partnership.
The current name of the line commemorates the painter Thomas Gainsborough, who was born in Sudbury; the previous name was the Lovejoy line, after the television series Lovejoy, which was filmed in the Sudbury area.
All passenger services on the line are currently operated by Greater Anglia, which runs an hourly service in each direction. The last departure from Sudbury at the end of each day is extended to.

Notable sight

The line runs across the Chappel viaduct, which has 30 arches each with a span, with a maximum height of, and was the longest viaduct on the Great Eastern Railway.
The East Anglian Railway Museum is located alongside the station at.

Infrastructure

The line is single track throughout, has a loading gauge of W6, and a maximum speed of.
Unlike other branches in the area, such as the Braintree branch line and Mayflower line to, the Gainsborough line is not electrified. New bi-mode trains started operating on the line in January 2020.

Stations

The following table summarises the line's four stations, their distance measured from, and estimated number of passenger entries/exits in 2018–19:

Station	Location	Local authority	Mileage	Patronage
	Marks Tey	City of Colchester		604,902
	Chappel, Wakes Colne	City of Colchester		39,360
	Bures	District of Braintree		60,432
	Sudbury	District of Babergh		334,274

Accidents and incidents

On 12 July 1887 one person was killed at when part of a runaway train collided with a crossing gate.
On 27 January 2006 at least four passengers were slightly injured when a train ran into the buffer stop at. The 6:05 pm service from was travelling at a speed at the time of the collision of approximately six miles per hour. An investigation determined that the driver failed to apply the brakes in a "timely and appropriate manner".
On 17 August 2010 the Little Cornard derailment occurred when the 5:31 pm service from Sudbury collided with a lorry that had entered a level crossing without permission. The train driver and four passengers were seriously injured in the accident.