C—3a

One of the problems facing sawmillers in New Zealand, in the conversion of steam log-haulers to Diesel, or in the building of Diesel haulers, has been the procurement of suitable gear-boxes, the heavy-truck type generally not being strong enough and giving trouble with the clutch, due to the uneven and shock loading. In British Columbia I found three types of gear-boxes giving satisfaction :—- (1) The Wilson transmission, built by Self Change Gear Co., Ltd., Lythals' Lane, Coventry, England. Agents in New Zealand are Richardson and McCabe' Wellington. These transmissions are built to withstand loadings from 100 ft./lb. torque to 1,550 ft./lb. torque, according to model, and are available in eight sizes. The three smaller units, up to 400 ft./lb., are preselective, and the larger models are air operated. There is no clutch, and gears can be changed from high to low instantaneously, simply with a hand control. Gears can also be changed under load without stopping. (2) The Gearmatic air-actuated quick-change transmission, manufactured by Gearmatic Co., Ltd., 636w 6th Avenue, Vancouver. These are designed in various models, and model 16 and 20 are designed for engines from 135 to 400 h.p. (3) Hydraulic torque converters, manufactured by Twin Disc Clutch Co., Hydraulic Division, Rockford, Illinois. I did not see any of the torque converters in operation, but was assured by the logging superintendent of Canadian Forest Products that they had a number giving excellent service. They are normally fitted to the Diesel haulers built by Tyee Machinery Co., Ltd. Various operators argued that with the torque convertor there was a heavy loss in engine efficiency in the lower ratios and in increase in fuel consumption. I am indebted to W. A. Crouse, Westminster Iron Works, 1135 Queens Avenue, New Westminster, and to J. S. Wilson, Tyee Machinery Co., Ltd., Granville Island', Vancouver, 8.C., for their assistance in this matter. Both of these companies built yarders and haulers of various sizes, and should any operator be interested I will be pleased to forward pamphlets and quotations handed to me by these people. The Westminster Iron Works normally fit the Wilson or Gearmatic transmission, according to the customer's choice, and Tyee Machinery Co. normally fit the torque converter. On the heavier-type machines fitted with Wilson or Gearmatic transmissions it is usual to fit flexible couplings on either side of the transmission and a fluid coupling on the input shaft. At the operations of the Fleetwood Logging Co. I saw one of the Diesel haulers m operation. It was a high lead operation, downhill pulling 12 chains to 15 chains, and they claimed to be pulling 1,800,000 ft. log measure per month with twelve men! The crew comprised— One leading hand (hauler-driver). One engineer. One rigging slinger. Three choker men (hooking on). One whistle punk (whistle boy). One chaser (unhooking). Three loading lorries (loaders). One loading engineer (hauler-driver). All timber is felled ahead of the hauling operations. The lead tree had been erected and was 146 ft. long with a 24 in. top. Timber was taken away by lorry and was pre-loaded with a McKone pre-loader. This is simply a frame to carry the bolsters, the load then being loaded on to the bolsters on the pre-loader. Upon the arrival of the truck the bolsters are removed, truck and trailer backed underneath, bolsters connected, and moved off.

83