324 



WOOD TRANSPORT BY LAND. 



(d) Gradient. The amount of gradient is a most important 

 consideration in constructing slides. Too small a gradient 

 renders a slide useless, with too great a gradient the wood 

 will leave the slide and great danger arises to any person 

 who may be near at hand. The permissible limits are 

 5 % and 35 to 40 %, but the way in which the slide is used, 



Inch Lo IFoot 



Fig. 202. Deota sleeper slide. 

 Drawn by T. Marten, Indian Forest Survey. 



and the size of pieces of wood to be brought down, affect the 

 question. 



Thus there are dry slides, ice-slides, and wet slides. 



In the case of dry slides, a steep gradient is necessary, 

 which may go up to 40 per cent, and more. 



[If, however, the gradient be very steep, the slide should 

 be fairly straight, as, otherwise, the shocks to which it is 

 subjected by wood coming down causes too much wear and 

 tear. There is also always a danger of fire from friction in 

 dry slides with excessive gradients. Tr.] 



