The most successful Lister engine was the D-type engine, introduced from 1931, most versions of which were rated at 1.5 horsepower at 700 RPM. More than 250,000 'D' engines were built until 1964. They were used for a wide variety of light tasks such as pumping and small-scale electricity generation. The Lister 'D' is still one of the most widely seen vintage stationary engines in the UK. Hand-cranked Lister diesel engines were used in many early dumpers. Lister took over Blackstone & Co in 1937 to form Lister Blackstone.