The Great Western Railway 4575 Class was a class of 2-6-2T locomotives often referred to as Small Prairie Class tank locomotives.

They were designed as small mixed traffic branch locomotives, and mainly used on branch lines. A  development of Churchward's 4500 Class they were fitted with larger side tanks and increased water capacity. Some 100 were built numbered 4575–4599 and 5500–5574, and 15  were fitted with auto apparatus in 1953 to enable them to run push-pull trains on South Wales lines with auto trailers.

No less than 11 have survived into preservation.

This fine 5” gauge version was photographed at a London Model Engineering Exhibition.