The British Rail Class 08 is a class of diesel-electric shunting locomotive built by British Railways (BR). As the standard BR general-purpose diesel shunter, the class became a familiar sight at major stations and freight yards. Since their introduction in 1952, however, the nature of rail traffic in Britain has changed considerably. Freight trains are now mostly fixed rakes of wagons, and passenger trains are mostly multiple units or have Driving Van Trailers, neither requiring the attention of a shunting locomotive. Consequently, a large proportion of the class has been withdrawn from mainline use and stored, scrapped, exported or sold to industrial or heritage railways.

As of 2020, around 100 locomotives remained working on industrial sidings and on the main British network. On heritage railways, they have become common, appearing on many of the preserved standard-gauge lines in Britain, with over 70 preserved, including the first one built.

The ‘08e’ remains a Class 08. However, it is heavily modified and is fitted with modern ‘plug-in’ traction batteries and control equipment. The former contains battery cells, a battery management system and a battery charger. Up to six Lithium-Ferro-Phosphate 88kWh battery pods can be fitted to the locomotive.

The design is fully scalable with a range of battery configurations that are designed to meet the most demanding duty-cycles and power requirements. The cab modifications deliver all-round visibility while retaining the familiar Class 08 control desk. This reduces the driver and depot staff training time.

There are cab enhancements including double-glazing, remote monitoring equipment and a roof-mounted heating, ventilation and air-conditioning unit.

In 2021 the SVR teamed up with the University of Birmingham's Vanguard Sustainable Transport Solutions to work on the Harrier HydroSHUNTER project in Kidderminster TMD. This has seen the UK’s first-ever conversion of a diesel locomotive to run with a replacement hydrogen-hybrid power pack, powered using a large traction battery, charged by a hydrogen fuel cell.

The original traction motors, and most of the auxiliary equipment, exhausters, compressors and the like have been retained. The kit is essentially designed to be plugged into the generator output, and through a series of controllers and voltage converters, replicate exactly what the generator would output with the given driver’s input. It uses electrolysis to react hydrogen with oxygen, which generates an electric current, producing H2O as the exhaust.