338 LOGGING 



engine through a block on the peak of the boom, down under 

 the logs and the grab hook is caught on the bunk of the car or 

 on the buffer log of the rollway. The winding up of the cable 

 crowds the logs off the car onto the rollway. Two other drums 

 and cables are used, one for raising and lowering the boom 

 and the other for moving the unloader back and forth on the 

 track. 



Another form designed to unload heavy logs from cars while 

 the train is in motion consists of two steel arms 17 feet long made 

 of channel and angle iron. The arms are 18 inches wide except 

 at the ends, where they are made 36 inches wide to give a broad 

 surface to repel the logs. A heavy casting carrying a sharp 

 edge is attached to the outer end of each arm. The two arms 

 are bolted opposite each other on a 24-inch journal, and are 

 braced with a turnbuckle. The arms and journal are set on a 

 shaft II feet long, and 10 inches in diameter, cut down to 8 

 inches where the journal is fastened to admit the attachment 

 of a collar with ball bearings. The shaft is set in a concrete 

 base, high enough to allow the arms to clear the car bunks, and 

 far enough distant so that when the arm extends across the 

 track at right angles, it reaches one foot beyond the outer rail. 

 To unload a train load of logs, the loaded cars are pushed up to 

 the rear of the unloader, a loader arm is swung up against the 

 log, and the train put in motion. The sharp edge of the arm 

 grips the log and as the train advances the arm is turned on its 

 axis and the log or logs are gradually shoved off the car. The 

 momentum acquired in performing the work causes the arms 

 to revolve rapidly on the axis as soon as the logs are dumped, 

 and the opposite arm comes in contact with the logs on the 

 succeeding car. It is seldom necessary to stop the train during 

 the unloading process. The average time consumed in unload- 

 ing 75,000 feet of logs from 15 cars is eight minutes. 



An unloader similar in type is called the Hercules Log Un- 

 loader. It differs mainly in having one arm only and requires 

 the services of a man to attach the arm by means of a chain 

 and grab hook to the bunk of the log car in order to swing the 

 arm across the track. On releasing the chain the arm auto- 



