Interior, second-class carriage in service on the Austrian Railways.

Efficient and economical passenger working over secondary routes often presents something of a problem. On the London, Midland & Scottish Railway, experiments are at present being undertaken, on the 77-mile stretch of track between Oxford and Cambridge, with a new streamlined three-car diesel-driven light passenger unit, which may revolutionise branch-line operation.

The new diesel train is painted outside in aluminium and red. It is about 185 feet long overall, and weighs in full working order 73 tons. Seating accommodation is provided, in three saloon-type vestibule cars, for 24 first-class and 138 third-class passengers. A conventional main-line unit affording similar accommodation would weigh (with locomotive) 173 tons, so that, in weight alone, the diesel unit offers a substantial margin of economy. Arranged on the articulated principle, the three cars of the unit are constructed of high tensile structural steel. Drive is by six Leyland diesel-hydraulic traction units, each six-cylinder oil engine developing 125 h.p. at 2,200 r.p.m., giving a train speed of 75 m.p.h. All six engines can be simultaneously controlled from either end of the train by electro-pneumatic equipment, there being a driver's cabin and luggage compartment at either end. Each of the three cars is of the centre-vestibule type, and Empire timbers have been used for interior decoration. Altogether, we have here a most interesting light unit, which would seem to hold out great possibilities.