British Rail Class 458

The South West Trains (SWT) Class 458 (or 4JOP) outer-suburban electric multiple units were built by Alstom at Washwood Heath between 1998 and 2002. The 30 four-car units are part of Alstom's Juniper family of trains, which also includes Classes 334 and 460.

These trains have been used by SWT since they were built. From 2013 they are to be merged with the mechanically similar Class 460 fleet and reconfigured into 36 five-cars units, which will be designated Class 458/5.

Description
Thirty of these 4-car trains were ordered by SWT in 1998, to create extra capacity and to replace some of the ageing Class 411 (4CEP) units. Deliveries of these units began in 1998. They were delivered in SWT's mainline livery of mainly white, with a blue band, and red/orange 'swish' at cab ends. They are the only Juniper EMUs to feature end gangways.

The units are numbered 458001-030. Each unit was formed from two outer driving motors, an intermediate trailer, and an intermediate motor. The maximum speed is 100 mph.

The class initially suffered from major technical problems, such as leaky roofs and failing electronics. In 2004, when the full fleet was in service, reliability was so poor that SWT planned to return them to the leasing company and replace them with new Class 450 Desiro trains. At that time, the 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. At the 11 December 2005 timetable change, use of the trains was significantly reduced and only three were required each day.

Subsequently, reliability improved sufficiently to allow the trains to be retained. By the end of 2012, the fleet had achieved a Miles per Technical Incident Number of 106,049, becoming the most reliable fleet in Britain and the first fleet to achieve a 6 figure rating. As a result, the fleet was awarded Modern Railways Golden Spanner award in the New Generation EMU category on 23 November 2012.

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 also operate services between Ascot and Guildford on weekdays, along with the Class 450 Desiro.

In September 2005, two units (458001 and 458002) were transferred to Gatwick Express, but returned later that year.

Refresh and testing
In 2008–2010 Bournemouth Train Care Depot 'refreshed' these EMUs. The 'refresh' included 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.

In May 2010 two trains were in service with regenerative braking, with the intent to have all 30 units with new regenerative braking software by summer 2011.

Future lengthening to form Class 458/5
The Class 458 trains are to be merged with the mechanically similar (former Gatwick Express) trains, largely unused since September 2012, and each will form a 5 coach train. Six of the eight Class 460 trains will each lose three carriages in the process, leaving them as 5-car trains that will also be reconfigured as class 458/5 trains. The other two trains will lose 6 carriages each, the remaining parts being decommissioned for spares. This £42m scheme was devised by Porterbrook, owner of both fleets. The "new" 5-car sets will be designated Class 458/5 and coupled together to form 10-car trains to provide extra peak-time capacity on suburban services into Waterloo from the Hounslow, Weybridge (via Staines) and Windsor lines, using one of the five disused Waterloo International platforms, starting in 2014. The project is part of SWT's aspiration to become a "10-car railway".

Porterbrook signed the deal with SWT in January 2012. The work will be carried out by Wabtec, Doncaster and Brush Traction, Loughborough (Drive vehicles) on behalf of original builder Alstom. The first trains are scheduled to arrive in May 2013. It will involve replacing the existing retractable gangways and couplers between coaches. The cab ends both on ex-458 and on ex-460 driving vehicles will be redesigned to be compatible with the Desiro fleet. New Train Management System software will be installed to improve reliability. Internal refurbishment will include reconfiguring the seating layout to provide more standing room for passengers. Traction units will be re-geared from 100 mph, not required on the services for which the trains will be used, to 75 mph maximum to avoid overheating. The sets are to be painted in the SWT blue livery as on the Class 450 units.

Automatic Selective Door Opening (ASDO) is to be installed for use at a few suburban stations where it is not practical to lengthen platforms.

The first two of the 5-car sets were delivered in October 2013, and are undergoing testing ahead of the introduction of the first 10-car train into service in December 2013. Squadron service is planned for February 2015.