British Rail Class 458

The South West Trains Class 458 (or 4JOP) electrical multiple units were built by Alstom at Washwood Heath between 1998 and 2000. These units are part of Alstom's Juniper family of units, which also includes Classes 334 and 460.

Description
Thirty of these 4-car trains were ordered by South West Trains (SWT) in 1998, to create extra capacity and to replace some of the aging Class 411 (4CEP) units, which at the time were on short-term lease. Deliveries of these units commenced in 1998. Units were delivered in SWT's mainline livery of mainly white, with a blue band, and red/orange 'swish' at cab ends.

The class suffered from major technical problems, so none of the older Class 411 units were withdrawn from service. It was six more years, in 2004, before the full fleet was in service. In 2004, reliability was so poor that despite the units being only six years old, it was planned to return them to the leasing company and replace them with new Class 450 Desiro trains. At that time, the Class 458 Juniper trains only managed an average of 4300 mi between failures, compared with an average of 21000 mi for a Class 450 Desiro and 50000 mi for the previous slam-door trains.

Since then reliability has improved sufficiently to allow them to be retained. As of 11 December 2005, timetable change, the trains were significantly lowered in diagrams and were only found on three diagrams on weekdays out of London Waterloo. In September 2005, two units (458001 and 458002) were transferred to Gatwick Express. The units recommenced service in 2007 on outer suburban lines, complementing the Class 450 Desiro fleet. The two trains previously allocated to Gatwick Express have now been transferred back to South West Trains.

30 units were built, numbered 458001-030. Each unit was formed from two outer driving motors, an intermediate trailer, and an intermediate motor. The trailer has the capacity to be fitted with a pantograph, thus allowing the units to be rebuilt in the future for overhead power collection at 25 kV AC, should the need arise. The technical description of the formation is DMCO+PTSO+MSO+DMCO. Individual vehicles are numbered as follows:
 * 67601-67630 - DMCO
 * 74001-74030 - PTSO
 * 74101-74130 - MSO
 * 67701-67730 - DMCO



Operations
When first built, the units were used on the half-hourly London Waterloo to Alton trains. Occasionally, they were found operating the Basingstoke semi-fast service and other general outer-suburban duties. The units were then transferred to the half-hourly London Waterloo to Reading service, mainly so that they were confined to one area of the network. The trains now solely reside on this line, however, sometimes operate services between Ascot and Guildford (during peak hours).

Occasionally the units have been noted to operate the Weybridge to London Waterloo via Hounslow services along with the more prominent Class 450 Desiro trains on the line. This operation has been less frequent recently due to fewer available 'spare' class 458 units during daytime periods with the refreshment scheme and the (now finished) 'regen' brake testing programme.

Refresh and testing
Bournemouth Train Care Depot has recently 'refreshed' these EMUs. The 'refresh' includes adding CCTV, new seats and tables in first class, an internal repaint, and Rail Vehicle Accessibility Regulations (RVAR) compliant lavatory, information display panels and door lights.

All Class 458 trains have been refreshed. In 18 months time, a refresh of Standard Class accommodation will take place alongside an exterior relivery.

Unit 458027 has been modified for testing of the regenerative brake facility and this has been carried out in the Weymouth area overnight recently. At least one other 458 was present each night to act both, as a standby and as a load unit. The testing programme was due to be completed in the first week of December (08) after which it is anticipated that application will be made to make the regenerative brake functional on at least two units for a trial period.

Two of the Class 458 fleet are now starting to test the technology in passenger service on the London Waterloo-Guildford and London Waterloo-Reading routes. The whole fleet of 30 Class 458 trains is expected to be fitted with the new regenerative braking software by the end of May 2010.

Future lengthening
Under the government's Rolling Stock Plan, SWT are due to receive up to 140 additional vehicles. Porterbrook, the owner of the Class 458 fleet, has proposed that part of this could be met through lengthening the 4-car Junipers to 5-cars using the mechanically similar Class 460 units currently employed on the Gatwick Express. 24 Class 458s would be lengthened using vehicles from the Class 460s, while the remaining Class 460 vehicles would be reformed into six new 5-car sets, leaving an additional vehicles for use as spare parts.