For short haul interurban services, surplus 'Harris' electric suburban carriages were drastically modified for diesel haulage.
Asbestos was removed, doors blanked, interurban seating provided and the cars fitted for head end power. The cars were also fitted with air-conditioning units as used on suburban Comeng trains and they were fitted with chemical retention toilets.
The carriages were classes BH, the 'H' an indication of 'Harris' train heritage. The car numbers were 141 to 153. The conversions were done between 1983 and 1985.
BH cars were converted from _T__ and _BT_ cars. Car 153 was a 75' power door Harris trailer.
The train sets were were marshalled into three car sets; usually BTH_-BH-BCH_.