176 
LOGGING 
tion by a log rolled against them, while those nearest the skid- 
way may be turned down until the sled is loaded, in order not 
to offer interference. 
It is not practicable to attempt to take animal-drawn sleds 
up even occasional grades of 5 per cent or more, unless some hoist- 
ing device is used to pull up the sleds. This may comprise a 
steam boiler and engine driving drums on which a cable is wound 
that is attached to the forward part of the sled. The team usually 
, >' 
Fig. 48. — A Snubbing Device for controlling the speed of Loaded Sleds 
on Steep Grades. The free end of the rope in the foreground is attached 
to the sled. 
is detached before the load starts. In some cases the sleds are 
returned to the foot of the incline by means of a re-haul. 
The problem of lowering sleds down steep inclines is solved 
by the use of some form of snubbing device. The most simple 
type has a 1-inch or larger manila rope one end of which is fastened 
to the rear of the sled. The rope is then passed three or four 
times around a stump at the top of the grade. As the sled de- 
scends its speed is controlled by means of the rope, which is allowed 
to run around the stump as fast as desired. The operator con- 
trols the rope speed by means of a lever as shown in' Fig. 48. 
