248 LOGGING 
the logs could be floated. Some of the earlier road engines were 
capable of operating for distances of 1 mile, and sometimes the 
logs were relayed by two or more machines. One road engine 
now seldom hauls for more than 3000 feet and at this distance 
it will handle the output of two ground yarding engines. For 
long-distance hauling, skid roads or pole roads were installed. 
The system is less frequently used today than formerly because 
a skid road or a pole road often costs nearly as much as the grade 
of a spur logging railroad and the cost of moving logs by road 
engine is more costly than by railroad. Today many loggers 
have replaced the road engine, either with an overhead system 
of transportation or with a short-distance ground system which 
does not require a skid or pole road, or else the logging spur is 
built to the setting of the ground yarder. Roading is most ex- 
tensivety practiced in certain sections of the Northwest in which 
a large part of the log input is rafted to market and in which a 
pole-road haul of from 1 to 2 miles will reach a driveable stream. A 
road engine is similar to a simple-geared yarding engine, but the 
drum capacity is much greater. It is mounted on a sled in the 
same manner as a ground yarding machine and is moved about 
from one setting to another under its own power. 
The main cable is 1 or 1| inches in diameter with a |- 
or f-inch haul-back line. The cable is operated on the slack-rope 
system with the road engine located at the landing and a heavy 
tail-sheave at a point a short distance behind the yarding engine. 
The haul-back line which is placed near the main road, but 
outside of it so that it will not interfere with the operation of the 
main cable, is hung in snatch blocks located at suitable points. 
The main cable follows the road and is kept in place by blocks 
or by rollers where turns are made. Several logs aggregating 
from 6000 to 11,000 board feet are fastened one behind the other 
by grabs, and form turns which are attached to the main cable by 
a chain or short piece of cable which is coupled to the grabs on the 
forward log. The turns are made up by a grab setter. A 
chaser follows the logs to the landing, often riding in a rigging 
sled hollowed out of a log, which is attached to the rear log. The 
chaser can signal to the road engineer at any point along the line 
by pulling on a wire stretched along the road which is connected 
to the whistle on the engine. On arrival at the landing the chaser 
aids in placing the logs on the landing, removes the grabs 'from the 
