Description

The British Rail Class 311 electrical multiple unit was built by Cravens at Sheffield in 1967. Outwardly, the units were very similar to the earlier Class 303 units built in 1960. 19 units were built, initially classified as AM11 units, and numbered 092-110. This was later changed to Class 311, and units were renumbered 311092-110. Each unit was formed of three carriages; two outer driving trailers, an intermediate motor coach. The technical description of the formation was BDTCOL+MBSO+DTSO. Individual carriages were numbered as follows:

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

Units were built to operate services on the newly electrified route from Glasgow Central to Gourock.

After being withdrawn from normal traffic, two units, nos. 311103/104 were transferred to departmental duties as Class 936 sandite units, nos. 936103/104. These lasted in service until 1999, when they were withdrawn. They were not scrapped immediately as Railtrack was anxious to ensure that one of the units was preserved. In 2002, it donated one of the units to a museum in Coatbridge. The other unit was scrapped in 2003. Class 334 units typically service this route nowadays.

Preservation

One complete unit has been preserved.

• 311103 - 76414+62174+76433 - Summerlee Heritage Park , Coatbridge

This unit was the former Class 936 sandite unit, no. 936103, formed of 977844+977845+977846.