Three Rolls-Royce-engined diesel-hydraulic locomotives were built in 1967–68, and were supplied to an open-cast iron ore mine at Corby. When the iron ore was worked out, the locomotives were surplus to requirements, and were acquired by London Transport in 1971. They were numbered in the range DL81-DL83. All three were standard 0-6-0DH Sentinel diesel shunters obtained from Thomas Hill (Rotherham) Ltd (the Rolls Royce/Sentinel dealer). They were painted dark green and operated at Neasden and Lillie Bridge depots where they replaced the last of the ex-GWR pannier tank steam locomotives.