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LOGGING 
the hook m to open. The main cable is supported on a segment o 
which is pivoted to the hanger so that it will rock slightly towards 
the load when it approaches. Supports for hangers are placed 
from 350 to 500 feet apart depending on topography. 
Another type, known as the endless cable tramway, has been 
used for the transportation of shingle bolts. A tram of this 
Fig. 83. — The General Form of the Trolley and Hanger used on Some 
Western Aerial Tramwavs. 
character built in California had a f-inch moving cable supported 
at frequent intervals on 16-inch sheave wheels attached to cross- 
arms fastened on heavy poles. 
The cable was driven by a donkey engine geared to a 6-foot 
vertical drum around which the cable was wound several times 
and then passed out over the sheave blocks. About halfway 
between the two extremities the tramway turned a right angle, 
the cable passing around two loose drums at this point. 
Shingle blocks were brought to temporary platforms by chutes 
and were attached by hand to grips which were fixed at intervals 
along the cable. The bolts were tripped automatically at the 
terminus. 
One hundred grips were operated on the line one-half of which 
