The Great Western Railway (GWR) 4500 Class or Small Prairie is a class of 2-6-2T steam locomotives.
They were designed as small mixed traffic locomotives, mainly used on branch lines. The design was based on the earlier 4400 Class, but with larger driving wheels and altered wheel spacing. This gave them extra speed. A total of 75 were built; 55 were built in four batches between 1906 and 1915 and a fifth batch of 20 locos was built in 1924, during Collett's tenure at Swindon.
Three of the class still exist, two of them survivors from Woodham Brothers scrapyard in Barry, Vale of Glamorgan, South Wales. All of them have run in preservation.
