In 1943, the New South Wales Government Railways awarded a contract for twenty steel sitting carriages to Waddingtons.
[1][2] Construction of these cars was shelved while wartime restrictions were in place and when the project resumed in 1945, it was decided the carriages should be air-conditioned and the order increased to fifty.
[1] The initial fifty cars numbered 2240 to 2290 were eventually built by Commonwealth Engineering, Granville (the successors to Waddingtons) between 1949 and 1952.
[1][2] The completed cars were formed into eight sets numbered 140-147 of seven 21.05-metre (69 ft 1 in) carriages coupled to one 15.25-metre (50 ft 0 in) long power/brake van, the sets were given the code RUB, with two carriages and one power van built as spares.
[4] The first set operated a trial to Moss Vale on 10 August 1949 before being unveiled to the press on 13 September 1949.
As part of this conversion the toilets at the men's end were removed & replaced by four small cubicles, two for each sex.
The ladies toilet, staff & hostess compartments were removed to allow for the main saloon to be lengthened.
[16][17] In 1989, ODS 2263 was rebuilt with a buffet & serving counter and a capacity of 30 passengers, being recoded RDS.
[2] In 1956, SFS 2267 & 2268 had their eight-seat compartment stripped and rebuilt for beverage storage and were recoded SFR.
In 1985 Nos.2287 and 2289 were converted by fitting of an interior partition to provide separate smoking & non-smoking sections, these 2 cars were recoded SDZ.
[2] Eight buffet cars coded RS were originally constructed by Commonwealth Engineering and numbered 2299 to 2306.
Food preparation was mostly carried out behind the counter, along with a small kitchen at one end of the car.
These cars were fitted with fixed tables and loose 48 seats, the separate kitchen was also enlarged and rebuilt.
Due to objections by the Victorian Railways these rebuilt cars were not used on their intended service but on the Gold Coast Motorail instead.
[2] In June 1989, RS 2301 was rebuilt as an 80-seat interurban car with no toilet to operate on the South Coast Daylight Express in company with 1100/1200 class carriages and recoded BKS.
[2] During the 1960s, the GM diesels were replaced with higher powered Caterpillar D343 generator sets on cars 2293 to 2298.