The trains had a saloon seating layout, divided into smaller sections by full-height partitions. They were provided with either two or three sets of hand-operated dual sliding doors per carriage side. Later sets were fitted with power doors. Interiors were split into smoking and no-smoking compartments until late 1978, with the abolition of smoking on trains, and carriages were designated as First or Second class until 1958, when one class travel was introduced. Most of the carriages were delivered without end gangways between carriages, but safety concerns led to these being added in the final five sets as delivered from mid-1966. These sets were also fitted with only two doors per carriage side rather than three, permitting additional seating and reflecting the increasing average travel distance.