POWER SKIDDING 219 



The main cable is i inch or i| inches in diameter with a 

 f-inch messenger Hne. The cable is operated on the slack-rope 

 system with the road engine located at the landing and a heavy 

 tail-sheave at a point a short distance above the yarding engine. 

 The messenger line which is placed near the main road but 

 outside of it so that it will not interfere with the operation of 

 the main cable is hung in snatch blocks located at suitable points. 

 The main cable follows the road and is kept in place by blocks 

 or by rollers where turns are made. Several logs aggregating 

 from 6000 to 11,000 feet log scale are fastened one behind the 

 other by grabs, and form turns which are attached to the main 

 cable by a chain or short piece of cable which is coupled to the 

 grabs on the forward log. The turns are made up by a grab 

 setter. A chaser follows the logs to the landing, often riding in a 

 rigging sled hollowed out of a log, which is attached to the rear 

 log. The chaser can signal to the road engineer at any point 

 along the line by pulling on a wire stretched along the road which 

 is connected to a bell or to the whistle on the engine. On arrival 

 at the landing the chaser aids in placing the logs on the landing, 

 removes the grabs from the logs and returns with the grabs in 

 the rigging sled to the yarding engine. 



A road engine requires a good road, because the route is used 

 for some time, and when the haul is long it is desirable to handle 

 maximum loads. The roads are constructed in two different 

 ways, one of which is known as the skid road,^ and the other as 

 the fore-and-aft or pole road.^ Both forms may be used on 

 different stretches of the same road, because skids are preferable 

 for level or ascending grades, and pole roads for rapidly descend- 

 ing ones. The skid road requires a right-of-way from 12 to 

 14 feet wide, which is swamped out carefully and graded to avoid 

 abrupt changes. It is better to make cuts than fills, because a 

 more sohd foundation is secured. Skids from 10 to 14 feet long 

 and from 15 to 24 inches in diameter are cut, and skidded along 

 the right-of-way by a yarding engine assigned to road work. 

 The skids are laid in transverse trenches 8 or 9 feet apart and 



1 See page 149. 



2 See page 233. 



