356 
LOGGING 
with a long sharp strip of steel which prevents the logs from 
slipping forward or backward. 
Trucks are equipped with hand or air brakes; pin or auto- 
matic couplers; patent stakes or "chock blocks" for holding 
the bunk load in place; and chains for binding the load. They 
are built in a high and a low type, the former carrying the heav- 
iest loads. They are in common use on roads operated by 
loggers but are not operated on trunk lines, which will not haul 
them. 
Logs of approximately equal lengths are selected for a given 
load, and a truck is required under each end of them. The 
Fig. 120. — A Log Truck, Western Type. 
weight of the logs may be sufficient to hold them firmly on the 
bunk without the use of chains, however, if the train is long 
and the strain is severe, chains are used. When the cars are 
equipped with air brakes, extension air-brake hose is adjusted 
under the log or logs between the two trucks, and is held in 
place by chain or rope attachments placed around one of the 
logs. 
Trucks weigh from 10,600 to 13,500 pounds each and have a 
rated carrying capacity of from 50,000 to 75,000 pounds. 
In practice low trucks seldom carry more than 5000 board feet 
and high trucks 7500 feet. 
ROLLING STOCK AND MOTIVE POWER EQUIPMENT 
The number of logging cars required on a given operation is 
dependent on 
(1) The amount of timber handled daily. 
(2) Capacity of the individual cars. 
