The Class 450 third-rail DC electric multiple unit is part of the Siemens Desiro family and were introduced in 2003 across the South West Trains network, replacing existing Mark I-derived EMUs.
Provision has been made for future conversion to 25 kV AC overhead supply or dual voltage although, at present, none of the Class 450 fleet have been fitted with a pantograph. These trains are used for outer suburban services, on feature the South West Trains blue livery to indicate this. South West Trains have three distinct liveries: Blue denoting outer suburban, White denoting long distance or InterCity, and Red indicating inner suburban.
|Destination Display||Destination Display|
|A||London Waterloo via Guildford||N||Alton|
|B||London Waterloo via Basingstoke||O||Basingstoke|
|C||London Waterloo via Surbiton||P||Bournmouth*|
|D||London Waterloo Fast Service||Q||Clapham Junction|
|E||London Waterloo Direct Service||R||Guildford|
|F||London Waterloo Stopping Service||S||Haslemere|
|G||Portsmouth Harbour via Guildford||T||Not in Use|
|H||Portsmouth Harbour via Basingstoke||U||Poole|
|I||Portsmouth Harbour via Surbiton||V||Reading|
|J||Portsmouth Harbour Fast Service||W||South West Trains|
|K||Portsmouth Harbour Direct Service||X||Special|
|L||Portsmouth Harbour Stopping Service||Y||Weymouth|
|M||Portsmouth & Southsea||Z||Woking|