all of the wca class vehicles were powered by man engines coupled to voith transmissions. in the early 1990s, these engines were replaced by cummins kta19r engines. at 27.43 metres and with a top speed of 150 km/h, the wcas were the longest and fastest diesel railcars in the world. the trains made up of the wca/wce class units were the first in australia to have at-seat catering and up until their withdrawal, operated the highest average speed train service in australia.