SOME USEFUL TRACTION ENGINE TERMS:- 

Reversing Lever:- This controls which way the steam enters the cylinder so the engine can be driven forwards or in reverse. 

Injector System:- With the use of a Clack Valve steam form the boiler create a vacuum to raise water from onboard tanks to keep water top up in the boiler. 

Fusible plug:- This is a safety device that protect the boiler against over-heating should ever the water level fall below to a certain limit. A fusible plug is made up off a brass screw plug with a lead filled centre. So if the water falls below the limit of the plug it will melt the centre which will allow steam to rush into the fire box putting the fire out to stop over heating. 

Flywheel:- This is fitted to the end of the crankshaft which keeps the engine running smoothly due to it weight. Very often it would have a wide rim to take a driving belt to which then could power equipment like a Saw Benches or a Threshing Machine. 

Safety Valve:- This can usually be found on top of the cylinder block or direct from the boiler. It is pre set to a safe working pressure for that engine. If ever the Pressure from the boiler exceeded the working pressure it will lift the valve to let steam escape to bring it back to a safe working pressure.

Priming:- This is a term used to describe that is generally caused by the boiler is over filled. Allowing water emission from the chimney as well as the exhausted steam from the cylinder.  This can cause problems if the drain cocks are not open on the cylinder as you can get a split or could crake the cylinder.    

Driving Pins:- Driving pins are on the rear wheels connected to the axle. If the pin is removed a winding drum can be used as a winch. 

S.C.C :- (Single Crank Compound engine) This only has a single crank on the shaft which in turn give the engine two strokes each revolution.

D.C.C :- (Double Crank Compound engine) these have a separate connection rod from each cylinder, which then has two cranks set at 90۫ to each other. Which then giving four power strokes each revolution each time the crank turns.