British Rail Class 311

The British Rail Class 311 alternating current (AC) electric multiple units (EMU) were built by Cravens at Sheffield from 1966 to 1967. They were intended for use on the line from Glasgow Central to Gourock and Wemyss Bay, which was electrified in 1967.

British Rail Class 311
311092 at Glasgow Central in 1984
In service1967–1990[1]
ManufacturerCravens[1]
Order no.
  • 30767 (DTSO)
  • 30768 (MBSO)
  • 30769 (BDTSO)[1]
Built atSheffield
Family nameBR First Generation (Mark 1)
Constructed1966–67[2]
Entered service1967
Number built19
Number preserved1
Number scrapped18
SuccessorClass 320
Formation
  • 3 cars per unit:
  • DTSO-MBSO-BDTSO[2]
Diagram
  • ED211 (MBS)
  • EE214 (DTS)
  • EF212 (BDTS)[3]
Design codeAM11
Fleet numbers
  • 311092–311110 (units)
  • 76403-76421 (DTSO)
  • 62163-62181 (MBSO)
  • 76422-76440 (BDTSO)[1]
Capacity
  • 236 seats (total)
  • 83 seats (DTSO)
  • 70 seats (MBSO)
  • 83 seats (BDTSO)[2][4]
OperatorsBritish Rail
DepotsGlasgow Shields Road[2]
Specifications
Car body constructionSteel[3]
Train length199 ft 6 in (60.81 m)[4]
Car length
  • 63 ft 6+18 in (19.358 m) (MBSO)
  • 64 ft 0 in (19.498 m) (BDTSO, DTSO)[3]
Width9 ft 3 in (2.819 m)[3]
Height12 ft 8 in (3.861 m)[3]
DoorsDouble sliding leaf, pneumatic
Wheelbase46 ft 6 in (14.173 m)[3]
Maximum speed75 mph (121 km/h)[3]
Weight
  • 129 tonnes (127 long tons; 142 short tons) (total)
  • 34.4 t (33.9 long tons; 37.9 short tons) (DTSO)
  • 56.4 t (55.5 long tons; 62.2 short tons) (MBSO)
  • 38.4 t (37.8 long tons; 42.3 short tons) (BDTSO)[2]
Traction motors4 × AEI 221 hp (165 kW)[2]
Power output890 hp (660 kW)
HVACElectric[3]
Electric system(s)25 kV 50 Hz AC OHLE
Current collector(s)Pantograph
UIC classification2′2′+Bo′Bo′+2′2′
Bogies
  • Gresley ED11 (MBSO)
  • Gresley ET11 (BDTSO, DTSO)[3]
Braking system(s)Air (Auto/EP)[4]
Safety system(s)AWS[3]
Coupling systemBuckeye[4]
Multiple workingWithin class, and Class 303[4]
Track gauge1,435 mm (4 ft 8+12 in) standard gauge

Appearance edit

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 instead of the tungsten filament bulbs used on the Class 303. The Class 303 units had been built by the Pressed Steel Company 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 from 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 edit

19 units were built, initially classified as AM11 units, and numbered 092-110, the numbers following on from the Class 303.[5] This was later changed to Class 311 under the TOPS 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:[6]

  • 76403-76421 - DTSO
  • 62163-62181 - MBSO
  • 76422-76440 - BDTSO

Operations edit

The units were built to operate services on the newly electrified routes from Glasgow Central to Gourock and to Wemyss Bay; now known as the Inverclyde Line.

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

Withdrawal edit

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.[citation needed]

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 was anxious to ensure that one of the units was preserved.[citation needed] In 2002, Railtrack donated one of the units to the Summerlee Heritage Park museum in Coatbridge, and the other was scrapped in 2003.

One of the driving coaches on the unit donated to Summerlee was scrapped in 2006.

Preservation edit

 
311103 sits at Summerlee Museum of Scottish Industrial Life

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.[citation needed]

References edit

  1. ^ a b c d Longworth 2015, pp. 73, 139, 191–192
  2. ^ a b c d e f Fox 1987, p. 56
  3. ^ a b c d e f g h i j "Vehicle Diagram Book No.210 for Electrical Multiple Units (including A.P.T.)" (PDF). Barrowmore MRG. BRB Residuary Ltd. ED211, EE214, EF212. Archived from the original (PDF) on 3 March 2016. Retrieved 22 February 2016.
  4. ^ a b c d e "Class 311". The Railway Centre. Archived from the original on 7 September 2008. Retrieved 22 February 2016.{{cite web}}: CS1 maint: unfit URL (link)
  5. ^ Wiliams, Alan; Percival, David (1974). British Railways Locomotives and other Motive Power. Shepperton: Ian Allan. p. 149. ISBN 0-7110-0534-6.
  6. ^ Fox, Peter (1989). Locomotives and coaching stock. Sheffield: Platform 5. p. 237. ISBN 0-906579-93-7.

Sources edit

  • Fox, Peter (1987). Multiple Unit Pocket Book. British Railways Pocket Book No.2 (Summer/Autumn 1987 ed.). Platform 5 Publishing Ltd. ISBN 0906579740. OCLC 613347580.
  • Longworth, Hugh (2015). British Railways Electric Multiple Units to 1975. Oxford Publishing Co. ISBN 9780860936688. OCLC 923205678.

Further reading edit

External links edit

  Media related to British Rail Class 311 at Wikimedia Commons