British Rail Class 936 — departmental electric multiple units

Characteristics and modifications

Class 936 units typically retained the basic car bodies and traction equipment of their passenger origins but were modified internally and externally to suit engineering tasks. Typical changes included:

• Removal of many passenger fittings to create space for equipment and stores.
• Installation of tanks, pumps or dispensers for sandite and de-icing fluids.
• Fitting of spraybars, booms, or manual application gear and ancillary power supplies.
• Simple instrumentation or communication gear for route monitoring and crew use.

History and development

The Class 936 label arose from British Rail's departmental classification system, which reassigned redundant passenger EMUs to engineering duties rather than scrapping all examples. Conversions were carried out as operational needs emerged — for example, seasonal de-icing or autumn rail adhesion treatment — and units were allocated to regions where their electrical and mechanical compatibility suited the local network.

Uses and operational examples

Common roles for Class 936 trains included:

• Applying sandite in autumn to improve wheel-rail adhesion where leaf fall caused contamination.
• De-icing third-rail conductor rails and related equipment in winter.
• Occasional use for route reconnaissance, engineering train towing, or as mobile stores units.

Crews operating these units required training in handling the specialist equipment and in safe working on electrified lines. Units often wore distinct departmental liveries and identifying markings to differentiate them from passenger stock.

Notable distinctions and legacy

Class 936 units should be understood as part of a broader practice of converting surplus EMUs for departmental roles rather than a single homogenous fleet type. Other departmental classes covered different regions or vehicle origins. Over time, as newer purpose-built engineering trains and road-based equipment became available, many converted units were withdrawn and scrapped, but their service illustrates a pragmatic reuse of existing rolling stock for essential maintenance tasks.