Thomas Hill (Rotherham) Limited was a company which repaired and sold steam road vehicles, diesel and electric road vehicles and railway locomotives. It later made its name building and rebuilding diesel locomotives.
The Company was founded by Mr. Thomas A. Hill in 1937 with small premises at Whiston, near Rotherham, and was principally concerned with repair and maintenance of steam road vehicles, and in particular Sentinel steam waggons which were popular in the area. The Company also became involved in battery electric vehicles built by Douglas (Kingswood) Limited, and was incorporated in 1942 as Thomas Hill (Steam and Electric Vehicles) Limited, TH(SEV).
Around this time the Sentinel company was developing a diesel-engined road vehicle fitted with a Sentinel horizontal diesel engine. This innovative vehicle attracted the attention of TH(SEV) and in 1946 an agency agreement were signed between the two companies.
In 1947 Sentinel Waggon Works Ltd offered TH(SEV) to extend the agreement for diesel vehicles to include their range of steam locomotives and an agency was accepted by TH(SEV) for sales and servicing.
TH (SEV) were now engaged in sales and servicing of Sentinel diesel road vehicles, Sentinel steam road vehicles and Sentinel steam rail locomotives. In consequence of the diesel vehicles now being included in the Company's portfolio it was decided to change the Company's name to Thomas Hill (Commercial Vehicles) Limited.
None of these vehicles where wholly conventional in their design and this presented a challenge to the salesman. Managers and engineer buying vehicles tended to be conservative and not only did they have to be convinced that this was the better way to do it but also that it was worth paying more money for the Sentinel products. It became clear that the best way to convince buyers was to demonstrate the appropriate vehicle in the buyer's own works carrying out the actual duties required. This became the general sales strategy for many years, and involved moving locomotives from site to site in the United Kingdom. The locomotives travelled on British Railways and under their own power where possible. The demonstrations created considerable interest, two locomotives, one 100 hp and one 200 hp were continuously employed moving from one site to another, particularly within the National Coal Board and Steel Works.