As built the first 16 carriages (2240 - 2256) were given the code SBS and could seat 31 passengers in 2 and 1 rotating and inclining seats. A further 6 could be seated in a compartment next to the ladies toilet. During the 1960s ten cars were converted to 2 and 2 seats which increased the seating to 48. In 1979 to differentiate between the different seating capacities the remaining lower capacity SBS carriages were recoded TBS. During the mid-1980s these TBS carriages were converted to day-night seating which altered the seating capacity to 48, these cars were then recoded TDS.
Four SBS carriages were converted to day-night cars (2245, 2252, 2255 & 2256) and recoded SDS.
During the early 1980s 3 SBS cars (2241, 2248 & 2249) had their compartment section altered to a storeroom for the dining cars on the Gold Coast Motorail. This reduced the seating capacity to 42, with these cars recoded SBZ. These three cars were further rebuilt between 1987 and 1989 and had new toilets fitted at one end, with the other end being rebuilt into a large luggage area with a guard's compartment, these cars then had a seating capacity of 36 and were given the code SBH.
The train nameboard is scripted and can be change under the options settings.