Heritage Shunters Trust is a trading name of The South Yorkshire Railway Co. Ltd. which was founded in 1989. HST is a railway preservation society and is the only preservation society that solely specialises in the preservation of diesel shunters in the UK. The initials HST can be seen as a pun on High Speed Train (shunters being very low-speed machines).
Most of the locomotives are kept at Rowsley, Derbyshire on the site of preserved railway Peak Rail but the company is certainly a separate outfit.