5972 Olton Hall, GWR 4900 Hall Class

A preserved GWR Hall Class 4-6-0, built at Swindon Works on 30 April 1937 to Charles Collett's design. Withdrawn from British Railways service in December 1963. Rescued from Woodham Brothers' scrapyard at Barry, South Wales in 1981 by David Smith and restored to working order at Carnforth by 1997–98.

5972 Olton Hall is the most famous locomotive in the preserved Hall class — and possibly the most recognisable preserved steam locomotive in the world — by virtue of its role as the Hogwarts Express in the Harry Potter film series. When Warner Bros approached West Coast Railways at Carnforth seeking a locomotive to star in the 2001 film Harry Potter and the Philosopher's Stone, 5972 was selected, painted in a fictional crimson red livery and renamed Hogwarts Castle — a name suggesting a larger Castle class, though the locomotive is actually a Hall. It subsequently appeared in all eight Harry Potter films shot between 2001 and 2010, with location filming on the West Highland Line between Fort William and Mallaig providing some of the most celebrated sequences. Its boiler certificate expired in 2014 and it is now on permanent static display at the Warner Bros. Studio Tour London at Leavesden, Hertfordshire, in its distinctive red Hogwarts Castle livery — the locomotive through which tens of millions of people worldwide first encountered a preserved British steam engine.

Location verified April 2026 — Warner Bros. Studio Tour London, Leavesden, Hertfordshire. Operating status: Static display. Current livery: 'Hogwarts Castle' red.

Location, livery and operating status last confirmed pre-2024 and subject to change. Check with the owning organisation or heritage railway for current information.