TRACTION ENGINES 455 



slowly, while if starting it quickly the grip of the wheels 

 gives away before momentum can be put into the engine. 

 If stuck in a mud hole always uncouple the separator or 

 whatever load the engine is hauling, move the engine 

 out, then by means of a rope or chain pull the separator 

 across. If the engine is stuck in a soft place like a plowed 

 field often the hitching of a team in front will take 

 it out. 



596. Bridges. Before crossing a bridge or culvert the 

 engineer should make inspection to see if it will carry the 

 weight of his engine and the separator. If there be any 

 doubt and it is impossible to move the engine around the 

 bridge heavy planks should be placed across it to dis- 

 tribute the load. Always move slowly while crossing a 

 bridge. If trie engine has once broken through it can 

 sometimes be removed by winding a rope around the 

 belt wheel several times, then setting the friction clutch 

 and hitching a team upon the rope. As the rope gradu- 

 ally unwinds, it will move the engine by means of the 

 transmission gearing. 



597- Gutters. In road work often one drive wheel of 

 an engine will strike a soft place in the gutter. Owing 

 to the principle of the compensating gear this wheel will 

 then slip in the mud and revolve while the other wheel 

 will remain stationary and the engine not move. In a 

 case like this the compensating gear should be locked and 

 both wheels be made to revolve together. The wheel 

 which is on the solid ground will move the engine out 

 of the hole. To lock the compensating gear there 

 is generally some scheme, as in Fig. 335, whereby a pin 

 can be inserted in the pinion A and lock the pinion D 

 by means of the projection H. 



598. Reversing the engine on the road. When it is de- 

 sired to reverse a traction engine moving on the road 



