LOADING AND UNLOADING CARS 



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tion, character of booms, and other details to meet special 

 requirements. They are used for loading flat or skeleton cars. 



The main features of a power loader are a steam hoisting- 

 engine and drums and an upright boiler. These are mounted 

 on a truck provided with some appliance for transporting itself, 

 and also carrying a rigid or swinging loading boom. Gasoline 

 engines have recently been substituted for steam on some pat- 

 terns, but they are not in extensive use. 



Loaders are built with a short swinging-base control boom, a 

 long swinging end-control boom, or with a rigid boom. The 

 first two types are adapted for loading on poor track, because 

 the logs can be centered on the car and less manual labor is re- 

 quired to build the load securely. They also are desirable 

 where the logs are scattered. Short booms are not adapted for 

 handling long lengths. Rigid booms are used to advantage on 

 good track where the logs are abundant and fairly well decked. 



There are two types of loaders. 



(i) Loaders operating from log cars. The Barnhart, Model 

 C American and the Rapid loaders are the best illustrations of 

 this type. 



(2) Loaders operating from the main railroad track. The 

 Decker, McGiffert, Surry Parker, American Models D and E, 

 and the Browning are the more common machines of this type. 



An advantage of the Decker and McGiffert loaders is that 

 the loader may remain in one place until all logs are loaded, 

 while loaders of the first type must change their base for every 

 car unless a locomotive is in attendance to move the train as 

 desired. 



(a) Barnhart. — This style of loader requires either perma- 

 nent or temporary tracks on the log car over which the loader 

 passes. Where permanent track is used, the rails are laid only 

 the length of the car bed, because if they were sufficiently long 

 to permit the loader to span the gap between cars they would 

 interfere when the train rounded sharp curves. The space be- 

 tween the rails on each car is spanned with two fl -shaped irons 

 placed on the car rails which can be removed as soon as the 

 loader has passed over the gap. Temporary tracks are made in 



