Other odd work in the early years of the new company included in 1924 a 36-seat petrol-fuelled rail vehicle for the Derwent Valley Light Railway. It was based on two Ford Model T chassis fitted with flanged steel tyres and coupled back-to-back, this rail minibus or petrol multiple unit seated 18 in each carriage and was driven from one end only, the rearward-facing car running in neutral gear with the engine switched off. When worked coupled fuel consumption was stated to be 14.33 mpg and if one unit was run the even more efficient figure of 17.55 mpg was obtained. It wasn't enough to save passenger operations on the line from oblivion however and the units were exported in 1926 to the County Donegal Railways Joint Committee (CDR) in the north-west of Ireland who converted them from standard gauge to 3 ft gauge, lowering the bodies in the process. The CDR thus became the first railway in Ireland to use internal combustion engines and by the time of closure ran all passenger services and a number of freights using Gardner-powered diesel units.