The small locomotive engine used for hauling logs on tramways was known as a lokey (also spelt ‘loci’) or loco. Steam had been used on some bush tramways since 1871, but in the early 1900s there was a revolution: the advent of steel rails, and geared lokeys. These locomotives were designed for the extremely steep grades, sharp curves, and uneven tracks in the bush.
Local geared lokeys
The first geared lokeys were imported from the USA in 1903, but local engineering works from Whāngārei to Invercargill soon offered alternative designs that captured the New Zealand market.
Some were very innovative, and unique in the world. They cost half the US price. Among the most distinctive were the Johnston 16-wheelers, built in Invercargill. Their weight was generously spread over 16 wheels, so they could take over from horse teams without the costly work of strengthening the tramway. However, the transmission called for 38 gears.
Also full of character were the Davidson patent chain-and-sprocket geared lokeys from Hokitika. Their cheap but rugged chain drive eliminated the costly universal joint, shafts and gears, and could be repaired on a forge and anvil rather than a lathe.
A. & G. Price of Thames produced top-end machines. They got away with copying the best features of the proven US patented designs.
Bogies were small, low, four-wheeled trucks for carrying logs. A long log would be loaded onto two bogies, known to the bushmen as a set. The length of the log determined the distance between the bogies. Each end of the log rested on a swivelling bolster, with the log forming the chassis between. It was held on the bolster by pieces of wood on each side, and chains over the top prevented rolling.
Brakemen had a dangerous job. To prevent a long log being carried too fast downhill, a brakeman would ride on each bogie, winding cranks that pressed wooden brakes into each wheel. They relied on the rails being well laid, or a sudden lurch and a roll of the heavy log could crush both men.
On small tramways that could not afford to upgrade to steam, horse teams were used until the 1920s. Then from 1924 rail tractors appeared. Over the next four years around 100 were sold, replacing the last horses on bush tramways.
Local engineering factories shut out the overseas manufacturer. Each had their own distinctive design and patents, with designs adapted from farm tractors, bulldozers and trucks. Marketing was built around press publicity and practical demonstrations. The Nattrass rail tractor was also sold in Australia. At the same time, motorbikes and cars were being converted to jiggers (small hand-cars or trolleys) to run on bush tramways and carry workmen.
New Zealand’s geared lokeys and rail tractors were innovative because they suited existing tramways and were cost-effective for small sawmillers. There was nothing quite like them anywhere else in the world.
The last geared lokey was built in 1943, the last new bush tramway opened in 1948, the last rail tractor was built in 1956, and the last bush tramway stopped operating in 1974.