DHP1 was a prototype diesel locomotive. Its name means Diesel Hydraulic Prototype number 1. Clayton built the locomotive in 1965 to show to British Railways. DHP1 was designed for mixed traffic work.[3][4] It had a steam boiler to give heating to passenger carriages. The body was painted red, with the top half of the cab painted cream.[4]
The locomotive looks similar to the Class 17, also built by Clayton. DHP1 saw little use. It was tested locally in Derbyshire. The locomotive ended up achieving only 459 miles (739 km) in service. British Railways passed over diesel-hydraulic technology in favour of diesel-electric transmission. Because of this, Clayton did not recieve orders for its model. DHP1 was eventually scrapped in April 1967.[5]