The 0-6-2 wheel arrangement was common on the South Wales railways absorbed by the GWR in 1923. They were useful locomotives on these lines as their high adhesive weight, power and good braking ability, but relatively low speeds, and small tanks and bunker made them ideal for the movement of coal the short distances from pit to port.
The 56XX class was urgently introduced as a standard replacement for many of the absorbed engines, which their previous owners had allowed to become very run-down. Although a Swindon product they clearly owe their origins to the Rhymney Railway class R and M tanks.
The first batch of 100 was built at Swindon between 1924 and 1927, but the requirement for a further 100 of these engines was so urgent that, unusually for the GWR, 50 were built by private contractors Armstrong Whitworth of Newcastle, the other 50 being built at Swindon. All were completed by October 1928, when the last batch of twenty, which included 6697, were received.
Operating mainly on the South Wales railways for which they were designed the locomotives were withdrawn between 1962 and 1969. Nine of the class have been preserved, all apart from 6697 coming via Barry scrapyard.
6697 was built by Armstrong Whitworth (Works No 985) in October 1928 and withdrawn in May 1966.
Purchased by the by the Bristol Group of the Society from Croes Newydd (Wrexham) depot in 1966, where with No. 5605 it had become the last of the class in service, 6697 went to the Society's Ashchurch depot, being transferred to Didcot in 1970. The engine ran at Didcot until the late 70s when a flue tube collapsed when the loco was running on the main demonstration line. The locomotive it is now on static display.
She has recently been cosmetically restored in an unlined green livery with the GWR in unshaded lettering.