For the makeup of interurban car sets, the BTH car was introduced. This was a standard trailer car but fitted with Head end end power connections for coupling to the locomotive.
The cars were placed into service 1983/1984 with some extra cars added in about 1989.
The car numbers were 161 to 175.
The cars were converted from: _BT_ and _T__ Harris electric trailer cars.
Cars 174 and 175 were converted from _BH_ 150, 151 respectively in about 1989.