Class 155 Super Sprinter (Leyland Provincial Sector 2-car)

The Class 155 was a development of the Class 150 Sprinter DMU with longer bodies (twenty three metres) for longer distance Provincial Sector routes [1]. The Class 155 had a low-density seating interior and used a riveted bus like construction style. The original batch of thirty five sets were originally allocated to Cardiff with a follow-on batch of seven ordered for the West Yorkshire PTE, these still remain in service with Northern.
155 341 at Harrogate

Information
Number built: 84 (42 2-car sets)
Built: 1987-88
Builder: British Leyland
Engine: Cummins NT855R5 diesel per car
Power: 570 hp (430 kW)
Formation: Driving Motor Standard Lavatory (DMSL)+Driving Motor Standard (DMS)

The original thirty five Class 155s are no more however, they were converted to create seventy Class 153 single-car DMUs [2] to replace the ageing fleet of first generation railcars. 

The Class 155s have not been without their problems, the length of the cars plus the production methods used means that some warping and sagging has occurred in some coaches (a problem some 153s also have have). The doors also caused some problems early on, the fleet having to be withdrawn from service at one stage until the problems were rectified.
Another view of 155 341

[1] Brian Haresnape, Diesel-Multiple Units (The Second Generation & DEMUs) (Ian Allan, 1986) p. 79
[2] Colin J Marsden, DMU and EMU Recognition Guide (Ian Allan, 2013) p. 137