Tr 22 is another small diesel shunter, built by the Drewry Car Co in 1939, being one of 17 of these small (9 ton) locomotives to operate on New Zealand Railways. Powered originally by a 70 hp Parsons petrol engine through a four speed gearbox, Tr 22 was like other members of its class re-engined in the 1950s with a Detroit Diesel 4-71 100 hp diesel engine driving the wheels through a torque converter.
Tr 22 was withdrawn from NZR service and sold incomplete and engineless to the Diesel Traction Group in 1985. It was transferred to Ferrymead by road and the following year it was fitted with another 4-71 engine and torque converter and became the Ferrymead Railway's light shunting locomotive under a lease agreement.
In 1996 the Diesel Traction Group sold the locomotive to the Ferrymead Railway where it continues in regular use.
