POWER SKIDDING 
247 
for longer distances than when the logs are dragged along the 
ground. The Lidgerwood, MacFarlane, North Bend and other 
overhead skidders are used in addition to other types which 
have been developed especially for this purpose. The use of a 
double-sky line system for swinging logs in the redwood region 
is shown in Fig. 78.^ The logging railroad is located in a gulch 
Adapted from The Timberman. 
Fig. 78. — A Duplex Aerial Cableway System used to swing Logs from Two 
Yarding Engines located on opposite Sides of a Canyon. 
and higher up on both sides of the slopes yarding donkeys are placed 
which bring the logs under the overhead cable. A log is picked 
up on one side of the gulch and dropped within reach of the load- 
ing rig along the railroad, and the trolley is then run to the op- 
posite side of the gulch and a log brought from there to the rail- 
road. The machine thus alternately serves two yarding engines. 
The installation of this machine obviated the necessity of building 
expensive railroad grades up the slopes to the yarding engines, 
and enabled the operator to get his logs to the railroad with a 
minimum of damage from breakage. Special equipment has 
been devised to handle logs on very steep grades or to lower timber 
from a higher to some lower level. Some types of such equipment 
are discussed under aerial trams.^ 
Reading was formerly used extensively in connection with the 
ground system of yarding to move the logs from the yarding 
engine to the railroad or to some stream or bodj^ of water on which 
1 See The Timberman, August, 1922, p. 144. 
2 See Chapter XV. 
