150 
BULLETIN Til, U. S. DEPARTMENT OF AGBICULTUEE. 
hook when the hook is in use, and automatically drops over the point 
of the hook when the hook is run back by the trip line, thereby 
protecting the point and preventing the hook from catching or 
hanging up when the line is run back. This hook costs from $13 
to $17, depending on the size. 
Miscellaneous equipment. — Practically all the differences in equip- 
ment between roading and ground yarding will be suggested by the 
peculiarities of the two methods, making it unnecessary to enter 
into a discussion of the miscellaneous equipment used in roading. 
Special equipment. — TVhen the road is- so steep that the turn of 
logs runs, special devices are sometimes used. 
(a) One of these, the cable grip, is shown in figure 60. At one 
camp where the grip is used the operator had to contend with the 
following conditions : 
The topography of the country was such that the logs had to be 
hauled from one-half to 2 miles over pole roads by road engines. 
The aim was to secure a 
favorable grade of about 5 
per cent. Too often the to- 
pography of the country 
was such that the grade in 
places was much steeper 
than this, amounting to 50 
per cent at times. At one 
time two roads, each of which was from three-fourths to 1 mile in 
length, were used. One of these had a rise of 150 feet in the first 
2,000 feet; from then on for a distance of 2,000 feet the rise was 550 
feet, giving an average grade of 27J per cent. A part of the road in 
the last stretch rose 350 feet in 1,000 feet, the grade for 300 amount- 
ing to 50 per cent. TVhile the aim was to make the roads as straight 
as possible, it was necessary to put in curves to cheapen the con- 
struction cost, 
About 100.000 feet of timber per day was hauled over this pole 
road. This output, however, only indicated the possibilities of the 
method under these conditions; considerably more, without doubt, 
could have been handled. On another road, which was about If 
miles in length and had grades equally bad. a little more than six 
trips per day were made, 15 logs, having an average volume of 1.200 
feet, being taken at a turn. 
The success of these long hauls was attributed to the cable grip 
(fig. 57), by means of which the turn of logs is attached to the haul- 
ing line. It consists of two jaws which have a gripping action when 
the strain of the load is brought to bear on it. This action auto- 
matically clamps the line between the jaws with sufficient force to 
Road cable grip. 
