198 LOGGING 
A special type of 3-wheelcd wagon is sometimes employed for 
hauling logs and luml)er with this engine. The front wheel is 
3§ feet in diameter, has a 12-inch tire and supports about one- 
fourth of the load. The remainder of the weight is borne on 
two rear wheels each 4^ feet high and with 16-inch tires. The 
load is borne on a frame built to carry from 10 to 12 tons. 
The manufacturers claim that a 60-horse-power engine will 
haul a load of from 40 to 60 tons at a speed of from 2 to 3 miles 
per hour, ascending grades as high as 10 per cent. Thirty thou- 
sand board feet of green lumber loaded on three trucks have been 
hauled up a 10 per cent grade, and 15,000 feet of logs have been 
hauled on two four-wheeled wagons over a rough log road down 
a 17 per cent grade. An engine hauling empty wagons travels 
3 or 4 miles per hour. 
MOTOR TRUCKS 
The use of motor trucks for logging purposes has grown rap- 
idly during recent years, especially in the Central Hardwood 
Region and in the Pacific Northwest. Their chief use is for 
hauling logs from the forest to the sawmill but they also are used 
for hauling camp supplies, pulling sleds loaded with logs, dragging 
timber over roads with steep grades and, when equipped with 
flanged wheels, as motive power for pulling cars on wooden- or 
steel-rail logging roads. 
]\Iotor trucks have proved a satisfactory form of transportation 
for moving logs from scattered areas containing from 500,000 to 
40,000,000 feet log scale, when the maximum-sized logs do not 
exceed 5000 board feet, and the average logs are not more than 
1000 board feet each and not more than 40 feet in length. When 
the timber is of larger size and the area contains more stumpage 
than the above mentioned maximum, a logging railroad would be 
more economical. 
There is a recognized limit to the length of profitable motor 
truck haul for general logging purposes, although loggers are not 
agreed as to what is the maximum. Some state that it is about 
10 miles, while others claim that a 15-mile haul may be profitable 
under favorable circumstances. The character of roadbed, and 
value of the logs are important factors in determining this ques- 
tion because the roadbed governs the size of load which can be 
hauled and the tune required to make a round trip, and more 
