210 
LOGGING 
capacity is from 10 to 15 tons, and the weight from 2 to 3 tons. 
When timber is moved for comparatively long distances the 
logs usually are loaded on wagons of greater capacity and strength 
than those used for animal draft. Several wagons constitute a 
load or train for one tractor. 
Although cable skidding by tractors has not passed the experi- 
mental stage, some machines are provided with a winch attachment 
Photouraph by A. Koroleff. 
Fig. 61.* — Loaded 4-wlieeled Log Wagons pulled by a 10-Ton Holt Tractor 
(left), and a Tractor with Empty Wagons returning to the Skidway (right). 
Idaho. 
for bringing logs out of hollows and swamps, and for other condi- 
tions where better work can be done with a cable than with a 
direct draw-bar tractor pull. Some crawler tractors have a two- 
drum winch in order to make possible the mechanical out-haul 
of the skidding cable. The speed of the cable, when skidding, 
is from 100 to 200 feet per minute, the larger drums having a 
maximum capacity of 800 feet of f-inch cable. The winch 
on a tractor also may be used for loading timber, for clearing and 
scraping work in road construction and for stump-pulling. 
