Overview
The Ulster Transport Authority Multi-Purpose Diesel (UTA MPD) was a diesel powered railcar, used in Northern Ireland. It was developed by the Ulster Transport Authority (UTA) as a progression of the earlier Multi-engined Diesel (MED). The MED concept, while suitable for short commuter links, was not considered so for the Northern Counties Committee section, with its main line from Belfast to Derry where speeds of up to 110 km/h (70 mph) were required. A new railcar development was needed, and the MED was superseded by the MPD.
History
The new railcars were to operate on the former ‘broad gauge’ lines of the NCC which not only covered suburban services in and around Belfast, but also the long main line from that city to Derry.
The "new" trains, just as with the earlier MEDs, were converted from existing locomotive-hauled stock. These became known as Multi-Purpose Diesel (MPD) railcars and were built between 1957 and 1962. The first ten power cars being intended for the Derry line trains, with the others being for the Belfast local services. The power cars were originally fitted with a 275 h.p. Leyland engine, mounted beneath the chassis and driving both axles on the rear bogie through a torque converter. However problems were encountered with these engines and, in the mid-1960s, it was decided to re-engine 12 cars with 260 hp AEC engines and a further 17 with 275 hp engines from Rolls-Royce.
The Belfast - Derry express services, for which the first ten MPDs were built, called for a high power/weight ratio and, on occasion, saw the five-coach train formation made up of four power cars with a restaurant car. On local services the power cars operated with trailers.
From Wikipedia (CC BY-SA 4.0).