In 1932 a prototype steel open wagon numbered X7732 was built at Midland workshops. It was intended for bulk wheat traffic and was fitted with a tarpaulin rail. No more wagons like it were built. The classification is also an oddity as with this one exception all four wheeled wagons had class letters in the A-P range with the later letters reserved for bogie wagons. By 1932 the other steel open wagons were in classes K and KW and a class in this group would have been expected. It is just possible that the X classification was a result of mistaking a K for an X somewhere along the way. It was withdrawn in 1979 and sold to the Bellarine Peninsula Railway.