A total of 25 cars numbered 76 to 85, 100 to 102, 119 to 122, 133 to 136 and 139 to 142 built in three batches were similar in design. Each was 31 foot 6 inch long with its interior divided into 4 compartments. The first and second class compartments being 11 foot 4 inch long with longitudinal seats. In the centre of each car was two toilet compartments each 3 foot 9 inch long, the whole being symetrical about the central portion. No movement of passengers or train staff was possible from one compartment to the other. The bodies were 7 foot 6 inch wide and the passenger capacity as built was 12 in first class and 12 in second class. The cars all had a 270 gallon water tank on the roof and originally lighted by oil lamps. Electric light and Westinghouse brakes were fitted between 1908 and 1913.
Through communication between compartments was later provided by cutting a door in the central portion and reducing the width of the toilet compartments to 2 foot 6 inch. The seating capacity was altered to composite 14 in first class and 16 in second, first class cars was 28 and second class cars 32.