3o6 LOGGING 



gears that bear a relation to each other of from 2 to i or from 2^ 

 to I ; and by the use of swivel trucks on which the drivers are 

 arranged in pairs and connected, one with another, by means of 

 an articulated driving rod. The weight is distributed over a 

 long wheel base which permits the use of a smaller rail, fewer 

 ties, lighter bridges and a poorer track than for a rod locomotive 

 of the same weight. 



On poor track where a speed of from 6 to 12 miles per hour, 

 only, is possible, geared locomotives are preferable to rod because 

 they have large fire boxes, short stroke engines, and a high piston 



Fig. 86. — A Climax Geared Locomotive. 



speed. The slow cylinder speed of rod engines causes defective 

 draft on grades. 



There are two t}pes of geared locomotives, namely, the center 

 shaft and the side shaft. 



(i) Center shaft. There are several patterns on the market, 

 the ones most commonly used being the Climax and the Heisler. 



The Climax is mounted either on two or three four-wheel 

 swivel trucks. When two trucks are used, one is placed under 

 the forward and one under the rear end of the locomotive. 

 When three trucks are used, two are placed under the engine 

 proper and one under the tender. The boiler is of the horizontal 

 locomotive type, mounted on a steel channel frame, reinforced 



