New Zealand TR class locomotive

Petone Workshop built TR1, about 1925. AP Godber collection, Alexander Turnbull Library.

The first TR shunting locomotive built was TR1, constructed at Petone Workshops, New Zealand in July 1924. It was built from a standard Fordson 22 hp tractor, which was attached to a patent underframe supplied by the Adamson Motor Company of Birmingham, Alabama. It was used until the 1940s for light shunting in various parts of the North Island.[3]

In 1928, NZR purchased two small TR locomotives from Muir-Hill Equipment Limited of Manchester.[7] The locomotives were similar to one supplied to the Department of External Affairs for use on the Telefunken Railroad in Samoa. This locomotive was eventually sent to New Zealand to the Department of Public Works, and then handed to NZR in 1940. All examples were written off by 1948.[7]

A further three locomotives were ordered by NZR from A & G Price of Thames in 1930.[8] A&G Price constructed the locomotives to the same design as the two Muir-Hill locomotives previously supplied to NZR. They entered service in 1931. The last one was written off and scrapped in 1950.[8]

The original batch of six 0-4-0 TRs, 13-18, supplied in 1936 by the Drewry Car Co., was supplemented by TR 20-22 and 30-36 in 1939-40. These were powered by Parsons petrol engines. In 1939-40 seven 0-6-0 TRs (the only ones of this type), 23-29, were supplied and were fitted with Leyland 10-litre (610 cu in) petrol engines Wairarapa railcars. Finally, in 1950 five 0-4-0 TRs, 60-64, with diesel engines were introduced. The locomotives were built at various United Kingdom works including Vulcan Foundry and Robert Stephenson and Hawthorns. Two Drewry TRs are still in service today. This locomotive, TR 56, was KiwiRail's oldest locomotive (being introduced in 1936) and was used at their Hutt Workshops for light shunting duties,[2] until replaced by a battery shunt and transferred to Silver Stream Railway in 2022.[9] TR23 was restored by the Gisborne City Vintage Railway in February 2013 and is still in use by them.[10] TR18 is restored and active at Pleasant Point Museum and Railway.

Rebuilds

• TR 23-29 were re-engined from 1954 with Gardner 8LW engines developing 78 kW (105 hp) at 1200 rpm, transmission being a Wilson 4-speed gearbox.
• TR 13-18, 20-22 and 30-36 were re-engined from 1958, and TR 81 in 1968, with the Detroit Diesel 4-71 series engine developing 78 kW (105 hp) at 2000 rpm, transmitting through an Allison torque converter.

Hudswell Clarke TR 54 at Ferrymead Railway in 2012.

Built by Hudswell Clarke originally for the Public Works Department as part of a batch of 12 built in 1936, three locomotives were transferred to NZR, one in 1942, another in 1950 and the final in 1954.[11]

Bagnall built TR156 at Ferrymead

W G Bagnall built seven TRs in 1956-57. The first five were supplied with McLaren M6 engines, the last two with Gardner 6L3 engines, all with a Self-Changing Gears 4-speed gearbox. The McLaren engines were unsuccessful, so from 1973 TR 150-154 were re-engined with the Gardner 6LX with Twin Disc torque converters. These TRs were the heaviest and one of the more powerful types.

A&G Price built TR 170 (TR 724 TMS)

The long-established New Zealand engineering firm A & G Price of Thames supplied a total of 39 TRs, making them the largest single builder. Four different models were supplied: the Model 3 (TR 100-109), with Gardner 6LW engine and self-changing gears, 4-speed gearbox; the Model 9 (TR 110-118), powered by a Gardner 6LW engine and Twin Disc torque converter; the Model 4 (TR 157-161), McLaren M6 engine and SCG 4-speed gearbox; and the Model 6 (TR 162-176), engine Gardner 6L3, also SCG 4-speed gearbox. The McLaren engined TRs were re-powered from 1975 with Gardner 6LX engines and the gearbox was replaced with a Twin Disc torque converter. Three of the A & G Price TRs remain in service.[12]

In the 1960s Hitachi received an order for six TRs, 177-182, at a time when NZR was turning away from traditional English suppliers and purchasing an increased number of vehicles from Asia.[4] The locomotives were equipped with a Cummins 6-cylinder engine developing 138 kW (185 hp) and Niigata torque converter, making them the most powerful TRs. Five of the Hitachi TRs remain in service.[5]

The last TRs were manufactured by NZR at its Hillside workshops. Up to two were completed each year between 1973 and 1978 (TR 183-191). The design is an unusual (for a TR) centre-cab style with a single Gardner 6LX engine and Rolls-Royce torque converter. Standard parts such as DSC class windows were utilised in these TRs. Seven of these TRs remain in service.[5]