The British Rail Class 311

alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...

(AC) electric multiple units (EMU) were built by

Cravens Cravens Railway Carriage and Wagon Company Limited was a railway rolling stock builder in the Darnall district of Sheffield, England. Founded by brothers named Craven and known as Craven Brothers, later Cravens Limited, it remained a family busi ...

Sheffield Sheffield is a city in South Yorkshire, England, whose name derives from the River Sheaf which runs through it. The city serves as the administrative centre of the City of Sheffield. It is historically part of the West Riding of Yorkshire a ...

in 1967. They were intended for use on the line from to and , which was electrified in 1967.

Appearance

Outwardly, the units were virtually identical to the earlier Class 303 units built in 1960. The interiors were also very similar, including the panoramic full forward passenger view through the glass-walled driving cabs, although the Class 311 had

fluorescent lighting A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet ligh ...

instead of the tungsten filament bulbs used on the Class 303. The Class 303 units had been built by Pressed Steel at their factory in Linwood, Paisley, but by the time the Class 311 was required, Pressed Steel no longer built railway carriages, so Cravens of Sheffield worked to the same original drawings, updated at a few points, to build the new trains. Along with the Class 303, the wrap-around driving cab windows were replaced with flat, toughened glass in the 1970s to give better protection to drivers in the event of attacks by stone-throwing vandals.

Construction

19 units were built, initially classified as AM11 units, and numbered 092-110. This was later changed to Class 311 under the

TOPS Total Operations Processing System (TOPS) is a computer system for managing railway locomotives and rolling stock, known for many years of use in the United Kingdom. TOPS was originally developed between the Southern Pacific Railroad (SP), S ...

system, and the units were renumbered 311092-110. Each unit was formed of three carriages; two outer driving trailers and an intermediate motor coach. The technical description of the formation was BDTSO+MBSO+DTSO. Individual carriages were numbered as follows: *76403-76421 - DTSO *62163-62181 - MBSO *76422-76440 - BDTSO

Operations

The units were built to operate services on the newly electrified routes from to and to ; now known as the

Inverclyde Line The Inverclyde Line is a railway line running from Glasgow Central station through Paisley (Gilmour Street) and a series of stations to the south of the River Clyde and the Firth of Clyde, terminating at Gourock and Wemyss Bay, where it connec ...

. In practice, the Class 311 operated almost interchangeably with the Class 303 and could be found in service across the Glasgow electrified suburban network. Consideration was given to upgrading 11 of the units for use on the newly electrified

Ayrshire Coast Line The Ayrshire Coast Line is one of the lines within the Strathclyde suburban rail network in Scotland. It has 26 stations and connects the Ayrshire coast to Glasgow. There are three branches, to , and , all running into the high level at . ...

, but it was found to be cheaper to buy new units in the form of the Class 318 and the plan was cancelled.

Withdrawal

Being a much smaller and unrefurbished fleet, the Class 311 was withdrawn much earlier than the Class 303, being replaced by the new Class 320 in 1990. After being withdrawn from normal traffic, two units, 311103/104 were transferred to departmental duties as Class 936 sandite units, numbered 936103/104. These lasted in service until 1999, when they were withdrawn. They were not immediately scrapped as

Railtrack Railtrack was a group of companies that owned the track, signalling, tunnels, bridges, level crossings and all but a handful of the stations of the British railway system from 1994 until 2002. It was created as part of the privatisation of ...

was anxious to ensure that one of the units was preserved. In 2002, Railtrack donated one of the units to the

Summerlee Heritage Park Summerlee Museum of Scottish Industrial Life is an industrial and social history museum in Coatbridge, North Lanarkshire, Scotland. It is situated on the site of the Victorian Summerlee Iron Works and the former Hydrocon Crane factory. The m ...

museum in

Coatbridge Coatbridge ( sco, Cotbrig or Coatbrig, gd, Drochaid a' Chòta) is a town in North Lanarkshire, Scotland, about east of Glasgow city centre, set in the central Lowlands. Along with neighbouring town Airdrie, North Lanarkshire, Airdrie, Coatbrid ...

, and the other was scrapped in 2003. One of the driving coaches on the unit donated to Summerlee was scrapped in 2006.

Preservation

*311103 - 76414+62174+76433 - Summerlee, Museum of Scottish Industrial Life,

(76414 since scrapped) This unit was the former Class 936 sandite unit 936103, formed of 977844+977845+977846. In February 2017, work finally started on restoring the unit to its original condition.

References

Sources

* *

External links

{{British Rail EMU

311 311 may refer to: * 311 (number), a natural number * AD 311, a year of the Julian calendar, in the fourth century AD * 311 BC, a year of the pre-Julian Roman calendar * 311 (band), an American band ** ''311'' (album), band 311's self-titled album ...

Train-related introductions in 1967