Diesel multiple unit
diesel-powered railcar designed
A diesel multiple unit (DMU) is a multiple unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. When additional carriages are coupled on, their controls are connected through and a single driver can control every engine in the train. This also allows the driver to drive from a cab at either end, simplifying reversing. Diesel-powered single-unit railcars are generally regarded as DMUs for most operations, at least with smaller trains.
Advantages
The first diesel railcars appeared in the 1930s and DMUs became popular immediately post-war. They offered several cost-saving advantages, at a time when railway operations were short of funds:
Greater convenience of operation. They could go from parked and stabled to running a train in little time, unlike a steam locomotive that needed to be prepared hours in advance, then disposed afterwards. They could also run trains intermittently through the working day without needing to tend their fire or boiler even when idle.
Reduced crew.
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