Volume Two - The Era of Optimism, Investment & Development - Penarth's contribution to coal exports . . .

The proper method of firing is to fire little and often, especially when using very small coal. To avoid the emission of black smoke from shunting engines, it has been found advantageous to fire alternative sides of the firebox; by this means one half of the fire is kept in a bright state and consumes the smoke emitted from the fire on the other side.

Various quantities of air are required according to the thickness of the fire, and should be regulated by manipulating the damper and firehole door. Air will not flow freely through banks in the fire and combustion at these points will not be satisfactory. Large quantities of air will pass through the thinner parts of the fire and the unburnt gases may not receive a sufficient supply of air to enable them to be burnt, thus allowing gases to pass into the tubes in the form of smoke. (see Diagram No. 3 - left). Every Fireman should be aware that the passage of air through the damper and firebars causes rapid combustion of the heated fuel which gives off gases. These gases have to be supplied with air, which enters the firehole door and is directed under the brick arch by the deflector. The brick arch prevents the gases from escaping through the tubes and chimney in the form of black smoke, doing no useful work and choking up the tubes.

There are certain engines which require firing in a way peculiar to themselves. Some engines with horizontal firebars require a level fire; others require the fire a little thicker at the back end; engines with sloping firebars have a tendency to draw the fire towards the tube plate, and great care must be exercised by quickly turning the shovel and directing the coal into the back corners and under the firehole door. If the fuel is allowed to be drawn off the fire shovel as it enters the firehole door, it will result in an accumulation against the tube plate, as shown in Diagram No. 4.

It is inadvisable to commence firing when leaving a station. The Fireman should first satisfy himself that the train is following in a proper manner. When the engine has started the exhaust will begin and liven the fire, which had settled down after the regulator was closed for making the stop, and then is the time to start firing. A distinct advantage is gained by waiting until the engine is notched up, in order that too much cold air is not admitted to the firebox through the firehole door, as would be the case if firing was taking place when the engine was in full travel."