Diesels for ‘455s’
Porterbrook is considering fitting diesel engines to redundant South West Trains Class 455 electric multiple units.
PORTERBROOK is considering fitting diesel engines to Class 455 electric multiple units, to create a new design. The type would become a diesel unit with the possibility of bi-mode operation on third-rail networks.
The Derby rolling stock company faces the return of 91 four-car Class 455s from South West Trains when next SWT operator First/MTR replaces them with a fleet of new electric trains.
Porterbrook has recently put the ‘455’ fleet through an upgrade that replaced their original traction control with new equipment, and replaced their DC traction motors with AC types. Adding a diesel engine and an alternator would provide electricity to power this equipment, making the type a diesel electric multiple unit (DEMU). Vivarail is doing a similar thing with former London Underground D-Stock trains ( RAIL 817).
Adding the engine will result in the ‘455s’ consuming more Porterbrook investment, but at the same time opening a new market because there is perceived to be a shortage of diesel units in Britain and a looming glut of electric types.
Porterbrook Commercial Director Olivier Andre confirmed the company was considering the conversion, but added that there was unlikely to be room to fit a pantograph to make them bi-mode trains capable of running under overhead line equipment.
If the rolling stock owner decides to proceed, the ‘455’ project would be its second EMU conversion, following the addition of diesel engines to Class 319s displaced from Thameslink ( RAIL 819). Andre said that Northern had signed up to eight of the conversions (known as Class 319 Flex), and that he had interest twice over from operators for the rest of the fleet (which totals 86 four-car trains).
Class 319s and ‘455s’ date from the 1980s and are based on similar bodyshells, also used by the Class 317. Despite this advantage, Andre described the conversion as complicated.
Porterbrook also owns 24 two-car Class 456s that will also be displaced from South Western services by First’s new fleet. Andre said that while these were set for scrap, he is seeking new work for his fleet of 36 five-car Class 458s - the latter were the subject of an expensive conversion programme from four-car units specifically for South West Trains, to allow the operator to run trains of up to tencars on inner-suburban routes.
Porterbrook’s commercial chief said he would be offering them to bidders for Southeastern. This franchise ends in December 2018, with prospective operators set to file their plans with the Department for Transport around the end of this year.
In theory, these third-rail units could be converted to AC operation, although there are many other AC types also looking for new homes, including Class 321s that have been subject to a major overhaul and refurbishment programme by owner Eversholt.