Length over buffers: 42' 7"
Length over body: 42' 4"
Outside width over panels: 8' 10"
Inside width at waist rail: 8' 6 1/4"
Floor height from rail (laden): 3' 8"
Interior door height, floor to ceiling: 7' 8 3/4"
Wheelbase: 22' 0"
Wheel diameter: 2' 10 1/4"
Unladen weight: 13 1/2 tons
Seating capacity: 56
Maximum speed: 55mph
Suspension was by Metalastik rubber units in two stages. Each axle was attached to a sub-frame through two pairs of Chevron-type rubber sandwiches; the main structure was supported from the subframe by eight Metalastik rubber spring units, four at each subframe. In side elevation the axles of the spring units made an angle of 15 degrees with the horizontal and the load was taken by the rubber in compression and shear. Damping was by separate vertical and horizontal telescopic hydraulic units (supplied by Girling Ltd) and brake torque reaction links were fitted at both axles.
The wheels were a resilient type supplied by Svenska Atkibolaget Bromsregulator (Sweden), the rims flexibly mounted relative to the wheel centres by a system of rubber bushes, reducing wheel shock and noise when traversing rail joints. The wheels were detachable from the hubs.
The general construction was based on an integral design with an all-steel underframe: the body being constructed entirely of aluminium alloy extrusions and panelling and completely integrated with the underframe for maximum stiffness. Sound and thermal insulation was achieved by filling the space between the interior and exterior panels throughout with a lightweight plastic insulating material. Acoustic panels, two inch thick, were fitted below the floor, which was covered throughout with sound deadening material below the wearing surface. All the windows were safety glass (supplied by Pilkington Bros Ltd) secured by the Eastern Coach Works Fastflex system. Six hopper type ventilating windows were fitted to each side of the body. Droplight windows were supplied by Beckett, Laycock & Watkinson Ltd (later known as Beclawat).
No retractable steps were fitted.
BR standard headcode lamps were fitted, supplied by BMAC Ltd. No buffers were fitted, but two tubular units, at standard buffer height and width, directly connected with diagonal struts to the main longitudinal frame members, supported a bumper frame.
The cars were finished in BR standard green, with lighter green banding, and were fitted with a polished aluminium moulding below the windows.