236 BULLETIN 711, IT. S. DEPAETMElsrT OF AGEICULTUKE. 
the attachment of a collar with ball bearings. The rest of the shaft, 
or the part which is 10 inches in diameter, is set in a concrete base, 
high enough to allow the arms to clear the bunks, and far enough 
from the track to permit either arm when at right angles with the 
track to reach 1 foot be- 
yond the outer rail. The 
concrete base is 9 feet 
square at the bottom and 
6 feet square at the top. 
The repelling ends of both 
Fig 
Ground plan of two-poke log unloader. 
arms are fitted with steel castings. 
These steel castings have sharp cut- 
ting edges, one of which engages a 
load of logs as the train moves to- 
ward the unloading device, penetrat- 
ing the nearest log, thereby doing 
away with the ne- 
cessity of attaching 
the arms to the car 
by a cable or some 
other method. 
In unloading the 
train moves toward 
the unloader slowly, 
seldom finding it 
necessary to stop. 
The average time 
consumed in un- 
loading 15 cars of 
logs, containing approximately 70,000 feet, is about 
8 minutes, which includes the coupling of cars, 
knocking out the blocks, etc. 
The cost of making and installing the machine 
described above amounted to $1,000; $900 for mak- 
ing and $100 for installing. At the end of three years of use nothing 
had been spent for repairs. The cost of operation, other than train 
crew labor, consists of about one gallon of lubricating oil per year. 
Fig. 79. 
-Cross section of two-poke 
log unloader. 
Fig. 80. — Counter 
weight pile, two 
poke log unloader 
