Firing Small Coal Fired Locomotives
by John Shawe,
Shawe Steam Service, Ltd.
13 Lindsay Avenue
Hitchin, Hertsfordshire S94 9JA
This article is about the coal firing of small locomotives, small in this context being locos running on 32 or 45 mm gauge track. Many garden railway men seem to consider coal fired locomotives of these sizes to be rather problematical and possibly within the realms of black magic. Indeed a well known contributor to the model press once told me the considered such small coal fires to be almost contrary to the laws of nature, and those that practiced the art benefited from "special dispensations"! Although this attitude is less prevalent than it once was, many engines dismissed as failures are in fact taking the blame for their firemen. I shall therefore attempt to provide a few pointers to enable any fireman to gain this "special dispensation", assuming for the moment that there is nothing fundamentally wrong with the locomotive itself.
Firstly, the tools of the trade should be assembled: a shovel, pricker and electric blower. The shovel and pricker should be tailored to the engine concerned to allow firing to be as easy and comfortable as possible. If every shovel full is a feat of balancing, firing becomes very tedious. The chief use of the pricker on my footplates is not scratching the fire to death at every opportunity (often literally in my experience!), but for flicking open the fire door, fending off signalmen, in fact anything BUT poking the fire. The blower should have enough suck to pull the flame of a match vigorously through the fire hole door.
In order to light the fire I find charcoal soaked in paraffin the best; although meths can be used, I find it remains alight on the shovel and then in turn sets fire to the charcoal tin; a slight inconvenience! The charcoal should be broken up to about the size of baked beans (smaller for a very small fire boxes), and it should be noted that there are two types of charcoal available; genuine wood charcoal and a form of briquette apparently man-made for barbeque. The latter may cook an excellent banger but is useless for our purpose..
A supply of coal will also be needed, broken to the same size as the charcoal. Personally I always use anthracite grains pinched from the central heating boiler. It is the ideal size as supplied, produces plenty of heat and burns reasonably slow. This last feature becomes an important consideration when the fireman cannot travel with his engine and tend the fire on the run.
Before lighting the fire, check that the smoke box and tubes are clean and the smoke box door forms an airtight seal. Water level should be about half a glass. Finally, a quick poke around the fire box with the pricker to ensure the grate is its proper place and there are no remains of the previous fire, and we are ready for action. At last I hear you cry!
Lay the fire with charcoal soaked in paraffin, covering the grate evenly and filling the fire box to about half way up to the fire door. Drop the electric blower into the chimney and switch it out, light a shovel full of "wet" charcoal and pop it into the firebox, shutting the door behind you. Only a few seconds later, all will be ablaze and more charcoal can be added until the firebox has been filled up to door level. The last shovel full should be alight before adding the next. All now looks rosy, however the crucial moment is now looming when the paraffin burns away there will be no more flames and it is quite possible the top of the fire will appear black and very unhealthy, most disconcerting for a fireman trained on a meth burner. Confidence is now all important and the trick is to do nothing, shutting the door and allowing the fire to burn through; honest, it hasn't gone out!
Shortly, an even, orange glow will greet will greet you on opening the fire door. Now, the time to feed some coal onto the fire, ensuring that each "round" is alight before putting any more on top. If your blower is exceptionally feeble (as mine often is due to the antiquity of my batteries) you may have to continue with charcoal until there is enough pressure to use the steam blower.
Once pressure has risen to about 20 psi, the electric blower can be removed and the steam blower turned on. Continue to build up the fire with coal and by the time working pressure is reached all of the charcoal will have burnt away. The fire will consist of the, now red hot coal that you've been busily shoveling in since taking the electric blower off. Don't forget to keep an eye of the water level, and use the hand pump as required.
The engine is now ready for the road and can come off shed and back onto its train. With a good thick bed of hot coal you will find it possible to completely fill the firebox before departure, allowing a longer run before more coal is required. As soon as most this new coal is alight and small patches of red are showing through the top layer, the fireman can leave the footplate and the train depart. Whilst in theory the blower should not be needed on the run, it is often helpful in the early stages of the run to live up the still black fire.
The length of the run achievable on one firing can only be determined from experience, however on an engine with no mechanical pump, the run is likely to be governed by water level than the fire. Either way it is surprising just how much a fire can be blackened with fresh coal and brought back to life ready for the next trip, providing of course that a good level of really hot fire survives. Of, the time takes to refill the tender with water is sufficient for the fire to recover, enabling very slick station stops to be achieved.
On railways requiring a less hectic train service with more frequent station stops, or interference from the signaling department, the fire can be fed a shorter intervals and kept at a more constant level. In such cases the need to stuff the firebox to overflowing would be eliminated.
The process of run, build up the fire, refill the tender, run, may be repeated as long as required, although firemen with particularly good stamina may find the fire suffering from clinker and "dead spots" eventually. With these small fireboxes it seems to be more effective to drop the fire and start afresh, rather than attempt to "clean" the fire.
Well, that's all there is to it, and its now must a case of practice makes perfect. I must apologize for taking up such an inordinately amount of space in describing what is after all only a small part of garden railway operation. I make no claims that the above is the only modus operandi for small coal fired locos, but is it a reliable base from which to develop one's firing technique. Apologies also to the experienced firemen, if any of you have stayed with me this far, who will either have been bored still, or enjoyed comparing their own technique with mine.