The Class 458 was the Alstom built EMU for slam door stock replacement, introduced in 2000 to South West Trains Waterloo – Reading services. The trains suffered a range of problems which took some time to rectify and resulted in SWT purchasing the main order for slam-door stock replacement with another company. The problems were eventually solved and the trains now routinely achieve over 30,000 miles per casualty. Traction equipment is Alstom’s “Onix” drive package, similar to the Northern Line underground units, Voyager and Pendolino trains. The unit’s six 270kW motors powered by three traction converters give good acceleration and require very little maintenance. Conversion to 25kv ac overhead operation is catered for in the design, so this equipment can be fitted if required. Interiors are bright and modern with 3 + 2 seating and facilities for the disabled.