LOGGiisra iisr the douglas fib EEGioisr. 



151 



haul the load. Whenever the load starts to travel faster than the 

 line, the jaws are released, permitting the grip to slide along on the 

 hauling line. Because of this the lines are not snarled and blocks 

 are not torn down, neither is there the amount of line breakage that 

 would occur under other conditions, since when the load slows down 

 the grip takes hold gradual!}'', the result being that the load does not 

 stop. This continuous movement of the load could not be secured 

 if the load were fixed rigidly to the line or if the load were attached- 

 to the line with a sliding ring, which would be engaged by a " bull 

 ring " on the end of the line when the load was picked up. 



(h) Another device (fig. 58) is 

 used with an endless line to snub 

 logs down steep chutes. The end- 

 less line is wound around the two 

 42-inch drums — one grooved for 

 four turns, the other for five — 

 four times in the form of a figure 

 " 8." It is operated by means of 

 one lever, which keeps the line 

 from slipping and enables the two 

 brakes to hold the line in control 

 on any grade. Two rings are fas- 

 tened to the snubbing line, which 

 is strung along the road, one at 

 the machine, the other at the tail block at the bottom of the hill. One 

 company used this device to lower logs a drop of 500 feet in one-half 

 mile, some of the grades being nearly 40 per cent. The logs were 

 hauled over a pole road by a road engine for a distance of 1 mile, the 

 turns averaging six logs. At the head of the sharp incline the turn 

 was stopped opposite the snubbing machine and fastened to the snub- 

 bing line. A man took his place at the brake of the snubbing ma- 

 chine, the signal was given, and the road engine started the turn 

 down the chute, the man at the machine regulating its speed down 

 the hill and stopping it at the bottom. The machine costs about $600. 



Several other types of snubbing machine are used. Figure 59 

 shows the method of using a compressed-air snubbing machine. 



Fig. 58. — Snubbing device. 



IMPEO\^MENTS. 



The improvements in the main consist of pole roads or chutes, 

 which, in short, are troughs formed by laying two or more strings 

 of logs side by side on the ground or on sills. These require 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, since a more solid foundation is thus secured. 



