SLEDS AND SLED-HAULING 



163 



road over which all the traffic passes to the landing, and second- 

 ary roads which radiate from it to the skidways. The roads are 

 laid out by the camp foreman usually without the aid of survey- 

 ing instruments, although in recent years, progressive woodsmen 

 have adopted a hand level for the determination of grades. 



The main road location is the more important because it is the 

 route over which fully loaded sleds pass. These roads often 

 follow the valley of some stream from the woods operation to 

 the landing, crossing and recrossing the watercourse as often as 



Fig. 38. — A Yarding-sled Road built up on a Curve to prevent the 

 Sleds from leaving the Road. Maine. 



necessary to maintain the desired grade. A minimum number of 

 bridges is desirable because they are expensive to construct and 

 to maintain. In order that logs can be hauled on a down- 

 grade from the secondary roads to the main road, the latter 

 should be located on the lower levels of the tract. 



A main road of easy descending grades is preferred because 

 on grades in excess of 5 per cent, heavy loads gain too much 

 headway and it is necessary to place hay, straw, gravel, sand or 

 brush on the road to check the speed. It is more satisfactory 

 and often cheaper in the end to make cuts or to detour ascending 

 grades rather than to return by them. 



