POWER SKIDDING 
217 
this cable and also with an additional guy rope. The other end 
of the main cable terminates in an eye near the head spar tree 
and is connected, by means of a clevis, to an extension cable 
which passes through a block attached to the head spar tree. 
\ The extension cable is fastened to a stump 
in the rear by a "block and fall" attach- 
ment, by which, with the aid of a drum on 
the engine, the main cable is tightened. 
The head spar tree is also braced by 
cables as shown in Fig. 64. 
The trolley which travels back and forth 
on the main cable is operated by an out- 
haul rope and a skidding line. The outhaul 
rope is f- or f-inch in diameter and passes 
from a drum on the engine, through a block 
on the head spar tree, through the trolley 
and also through a block on the tail tree, 
after which it is brought back and attached 
to the rear of the trolley. It serves to 
draw the trolley out along the main cable. 
The f- or |-inch skidding line passes from a 
drum on the engine, through a block on the 
head spar tree, then through a block on the trolley. It serves 
as a point of attachment for tongs or other log-holding devices. 
The logs are dragged up to the main cable by this line, which 
TAIL TREE 
Fig. 63. — A Tail Tree 
showing the Method of 
attaching the Blocks 
to the Tree; also the 
Arrangement of the 
Guv Lines. 
LoodiDg 
Loading Csfriage 
UalD Cable E 
BmI Blocks Si lioi>a 
By permission of the Lidgerwood Mfg. Co. 
Fig. 64. — A Cableway Skidder, showing the Arrangement of the Lines for 
Skidding and Loading. 
also suspends them and serves to return the trolley to the head 
spar tree. 
When the trolley is run out from the head spar tree, the skid- 
ding line sags between the two points of support and its weight 
