146 BULLETIN 711, U. S. DEPARTMENT OF AGRICULTURE. 
The loaders unhooked the loads at the landing. The chaser em- 
ployed in the yarding crew, besides unhooking the logs as they were 
delivered to the snubber, assisted the hooker on in making up the 
loads for the snubber. 
The operator was working in relatively small timber, and so was 
not in a position to say how large a log could be handled over the 
lf-inch standing line. The largest loads handled did not exceed 
2,000 feet. 
The snubber handled the output of one yarding engine, about 
60,000 feet per day, when working at seemingly no more than one- 
half capacity. TThen working intermittently it made 50 trips per 
day, and it could have made 75 trips per day easily. 
In transporting large timber across canyons on a standing line, 
where conditions are such that the logs must be entirely suspended, 
Fig. 52. — Double sky-line system 
some operators have found it necessary to use a double standing line. 
The rig used by one operator is shown in figure 52. The method of 
tightening the double standing line, which is made of 1^-inch wire 
rope, is indicated in the figure, the power being furnished by the 
gypsy head on a standard wide-drum logging engine. The carriage, 
which is 3 feet 6 inches by 4 feet 6 inches, has five 14-inch sheaves. 
The tree jacks, through which the standing line leads, have three 
16-inch sheaves. The main line lead block has a 24-inch sheave. A 
1-inch main line and a f-inch trip are used. 
The rig has worked successfully with a span of 2,200 feet, hauling 
logs scaling as high as 7,000 feet. 
ROADING. 
Under some conditions rather large bodies of timber are trans- 
ported for long distances with ground logging engines, necessitating 
and justifying the use of pole roads. This is known as reading. 
