SLEDS AND SLED-HAULING 
177 
The rope usually is from 50 to 100 feet longer than the slope so 
that a descending sled pulls the free end of the rope up the grade, 
and causes it to change ends when a sled load descends. 
A patent snul^bing device is shown in Fig, 49. This system is 
adapted for any distance up to 2500 feet and, by the use of rol- 
lers, may be used on any degree of curvature under 90°. The 
brake, which is snubbed to a stump at the top of the grade, has 
a heavy timber frame, mounted on steel-shod runners, which is 
faced on top with a f-inch steel plate. Four or six friction 
Fig. 49. — The Barienger Snubbing Device used to control the Speed of 
Sleds on Descending Grades. 
bases with hard maple faces are fastened to the steel plate. A 
cast-iron grooved wheel with a smooth friction face on the under 
side is mounted on a vertical steel post above each hard maple 
face. A steel spring holds the wheels above the maple blocks 
when the cable is running free. A control lever is provided for 
each two wheels by means of which they can be forced against 
the maple friction face and the speed retarded or the load stopped. 
On low grades one set of friction wheels may be adequate, 
while on steep grades all may be required. The lowering cable 
is f-inch plow steel and should be 100 feet longer than the grade. 
It is fastened to a wire cable sling which passes around the load. 
On well-maintained roads having favorable descending grades, 
four horses can haul from 5000 to 8000 board feet per load, while 
