336 LOGGING 



consists of four latch timbers {A), which are ii feet long and 

 a fifth timber (B), known as the trip timber, which is 36 feet 

 long and of larger size. The frame is hung on a roller timber 



(C) 18 by 18 inches square and 40 feet 2 inches long which rests 

 on heavy cast-iron sills. The roller timber is bound with an 

 iron cylinder to facilitate its rotation. This roller is placed 

 off-center, the distance between the rail on the land side and the 

 center of the roller timber being 25 inches. When the latches 



(D) holding the frame are released the weight of the load will 

 automatically tip the frame toward the brow skid (E) through 

 an arc of 15 degrees. In operation, the cars are run on the dump, 

 the chains holding the logs on the cars removed, and the latches 

 (D) opened. The dump then revolves until the car bunk rests 

 on the brow skid (E). The majority of the logs will roll off, 

 although some must occasionally be started by means of a cable 

 which passes through a block rigged on a gin-pole. The cable 

 is pulled by a locomotive. The dump will not tip when the load 

 is heaviest on the land side, in which case it is operated by prying 

 up on the end of the trip timber {B). After the logs are off the 

 car the dump is brought to a horizontal position by having men 

 walk out on the trip timber (B) . 



The double dump will handle two cars of 40-foot logs, or one 

 car of long logs by spotting one truck on each track. Three 

 men can unload a car in two and one-half minutes and can 

 unload 350,000 feet or more daily. 



The cost of the dump was $2000, exclusive of the value of 

 the timber used. Including the cost of rebuilding the dump, 

 the annual repairs during the last seven years have been $300. 



An efficient unloader consists of a hoisting engine and two 

 drums mounted on a car equipped with a rigid boom. The 

 railroad track is built parallel to the rollway and the unloader 

 runs on an additional track on the land side of the dump. The 

 boom is so placed that it projects at right angles over the far 

 edge of the railroad track. The unloader can travel back and 

 forth under its own power for a distance of from 500 to 600 feet, 

 thus permitting an entire train to be unloaded without moving 

 the cars. A f-inch cable passes from the drums on the hoisting 



