Re-tractioned SWT '455' to be released in September

The prototype re-tractioned Class 455 unit in the South West Trains fleet is to be released in September, ahead of commissioning and formal testing later this year.

Pilot unit 455732 is currently being fitted with a new Vossloh Kiepe traction package at Wimbledon depot, to replace the original English Electric EE507 motors.The EMU, which was built in 1984-1985 at BREL York works, is having the new equipment fitted to potentially extend its working life.

The re-tractioning project, a collaboration of SWT, unit owner Porterbrook and Vossloh Kiepe, involves removal of the air-operated camshaft and electrical resistance grids. The new equipment consists of DC to AC inverters of the insulated gate bipolar transistor (IGBT) type, needed to work with the new AC traction motors (as opposed to the original DC motors). 

SWT spokesman Andrew Commons told RAIL that the reliability of the units is expected to improve, while operational and maintenance costs will also be reduced.

The new AC traction system offers many benefits, including regenerative braking that allows electricity to be put back into the traction power supply for use by other trains on the network. The new systems also use less energy and are lighter, reducing energy costs while also increasing maintenance intervals from 10,000 to 15,000 miles.

SWT is currently dealing with a number of refurbishment and rebuild projects among its fleet, including the £15 million refurbishment and repaint of ex-Southern Railway Class 456 units at Wolverton Works by Knorr Bremse Rail Services.

The first ‘456’ to emerge in the red-based SWT ‘metro’ livery was 456003 on June 30, featuring a refurbished interior akin to that of the SWT Class 455 fleet.

Unrefurbished ‘456s’ have already begun operating in Southern livery on the Ascot-Guildford route, with the first refurbished examples expected to come into use this month (September). 

Each unit, which will be fully compliant with current accessibility regulations, features wider doorways to speed up boarding, as well as improved 2+2 seating, full CCTV and energy-efficient LED lighting. A remote monitoring system is also being fitted to help improve reliability and ensure earlier identification and rectification of any faults. 

SWT is also continuing to introduce longer, rebuilt Class 458/5s from 30 existing four-car Class 458/0s and eight former Gatwick Express Class 460 trains, to create 36 ten-car Class 458/5 units, with 458531-5 in service so far, and 458502 and 458504 undergoing testing and commissioning.

The introduction of the ‘458/5s’ has been delayed, owing to issues such as corrosion and the complexity of the engineering work required to essentially combine two existing fleets into one new class of train (RAIL 744).

The introduction of the ‘458/5s’ amounts to 60 extra carriages that are being introduced on the Windsor, Hounslow and Weybridge lines, with the five-car units doubled up to form ten-car trains.

Refurbishment work has included new floors and changing the interior layout to provide maximum seating capacity. The trains have also been fitted with selective door opening (SDO) in order to deal with short platforms on the SWT network.