4073 Caerphilly Castle

4073 was completed at Swindon in August 1923 at a cost of £6,841 as the first member of the Castle class. After a brief running in period it went to the British Empire Exhibition at Wembley in 1924.

BR motive power depot allocations since 1948.

Date Arrived	Depot
January 1948	Old Oak Common
July 1950	Bristol Bath Road
October 1952	St Phillips Marsh
February 1953	Bristol Bath Road
February 1957	Cardiff Canton

4073 was scheduled for withdrawal from service in 1955 but was given another overhaul at Swindon instead between August 1956 and January 1957. Its last overhaul was at Caerphilly Works.

It was withdrawn in May 1960 have completed 1,910,730 miles and refurbished for display purposes at Swindon at a cost of £11,000 before being formally handed over to the Science Museum as part of the National Collection in 1961. 4073 was handed over By Dr Beeching at Paddington station after which it was taken to the Science Museum in Kensington in June 1961.

Four days after being handed over the locomotive was hauled by Pickfords to the Science Museum in London where it went on static display.

Whenthe Science Museum decided to refurbish its display it was decided to move 4073 to the new STEAM – Museum of the Great Western Railway at Swindon. As this museum had not been completed Caerphilly Castle was moved in September 1996 to the Great Western Society’s headquarters at Didcot – a move that took three days. It remained on static display there for three years before going to the Steam Museum at Swindon in December 1999.

Upon preservation the engine was reunited with its original small Churchward 3,500 gallon design of tender which it was coupled to in 1923. It is not the same tender as the one it is now attached to was built some ten years earlier than the locomotive. Most of its life it had run with a 4,000 gallon tender.

The locomotive has never steamed in preservation despite being withdrawn from service shortly after overhaul and there are no plans to do so. It thus remains in the pristine ex works condition it was in when handed over to form part of the National Collection.

As of February 2024 it was planned that the locomotive would be staying at Swindon.