The button below links to a video showing Clive and Roger starting the National Gas engine. 

The National Gas Engine has one cylinder which currently runs on regular mains gas with spark plug ignition. Starting it is a complex procedure which uses compressed air to turn the engine over, there isn’t a starter motor. 

This is the sequence, most of  which you can see in the video:

• Turn on the cooling water
• Release the compression, so that the engine can be turned by hand
• Turn the flywheels by hand to get the engine to be just over top dead centre
• Engage the governor
• Turn on the gas supply
• Reset the engine stop switch
• Connect the spark plug
• Set the ignition to retard for starting
• Close the compression valve
• Open the compressed air valve in short bursts to turn the engine over. Timing is crucial here, if the valve is open for too long the air will tend to stop the engine. 
• Once the engine is running advance the ignition for optimum running.