The Class 110 diesel multiple units were built by the Birmingham Railway Carriage and Wagon Company in conjunction with the Drewry Car Co. to operate services on the former Lancashire and Yorkshire main line. They originally entered service uniquely in this region, which earned them the name of the 'Calder Valley' sets. They were an updated version of the Class 104, with more powerful engines, a revised cab design and raised bodyside window frames.

The fact that they were primarily intended for services on the arduous Calder Valley route meant that Class 110 needed more power than other first generation DMUs, so they were fitted with 180 hp (130 kW) Rolls-Royce C6NFLH engines, and when delivered they had the highest hp/ton of any of the first generation DMUs, including the lightweights. With a set weighing 87½ tons (tare), this gave a power-to-weight ratio of 8.3 hp / ton, which was appreciably higher than any other DMU in use at the time using normally aspirated engines.

Five vehicles have been preserved.