362 LOGGING 
wheel, attached to the truck frame, into which mesh two pinions 
which are driven by a double rotating engine. One form of 
this loader uses a chain control for the rotary movement. The 
weight of the loader is borne on five cone-shaped rollers attached 
to the truck frame. 
The loader moves under its own power from one car to another. 
A feature of this loader is a slack pulling device which has 
a pair of friction sheaves mounted on the boom and driven by 
a belt. The power is controlled by a hand lever. 
Two sizes of loaders are made, the smaller, No. 10, having 
chain control, an oak lioom 25 foot long, a doul^le 6|- by 8-inch 
Fig. 122. — The Model C American Log Loader. 
hoisting engine with governor control and a 36- by 96-inch verti- 
cal boiler. 
The No. 12 loader has a steel boom 23 feet 9 inches long, gear 
and pinion rotary control, double hoisting engines with 7^- by 
8-inch cylinders, controlled by a balanced throttle, and a 50- by 
82-inch vertical boiler. The pull at the tongs on this machine 
is from 9 to 10 tons. 
The Barnhart, though a fast machine, is more expensive to 
keep in repair than some of the other types of loaders, and re- 
quires skillful labor to secure the maximum output. It is rarely 
used on narrow-gauge roads. The maximum log that it can 
handle is one containing about 1500 board feet. 
