234 LOGGING 



to a landing, when power for moving the logs is provided by a 

 road engine. 



A fore-and-aft road consists of a trough from two to five poles 

 wide, made from long straight timber with a minimum diameter of 

 lo inches. The ends of the poles are beveled, fitted together and 

 drift-bolted to skids placed transversely under them at inter- 

 vals of from lo to 15 feet, thus providing a stable foundation. 



Fig. 67. — a Fore-and-aft or Pole Road used with a Road Engine. 

 Pacific Coast. 



Side braces placed at intervals of 15 or 20 feet prevent the poles 

 from spreading. The slide follows the ground level except where 

 it crosses deep depressions or streams, when it is supported on 

 cribwork. The roads are built as straight as possible to decrease 

 the loss of engine power through friction. 



A fore-and-aft road requires from 90,000 to 120,000 feet of 

 timber per mile according to the amount of cribbing neces- 

 sary. 



