ALL PHOTOGRAPHS BY DAVID PINNIGER
Coal firing can be the most rewarding or frustrating way of operating small scale steam locos depending upon the design of the loco and the fuel available. As readers may know from my review of John Shawe's Black Adder' in the first issue of Garden Rail Magazine, I am totally hooked on coal firing and have been lucky enough to have had the pleasure of operating 10 different G and l6mm scale coal fired steam locos over the years. All of the locomotives have had very different characteristics and most have generally been much more difficult to operate on the first few runs and tend to be very unforgiving of a tentative beginner. However, once you get to know an engine and begin to understand it's good and bad points, loco performance picks up and your enjoyment increases in direct proportion. This, combined with a supply of good clean coal for the first few runs will usually get you off on the right foot. It also helps to have a locomotive designed by someone who knows about coal firing in the smaller scales as the larger sized passenger hauling steam locos are generally much more forgiving and cannot just be scaled down to 32 or 45mm gauge. Most people recognise the advantages of a deep grate and the need to keep the fire as far up to the fire door as you can so that it does not burn through. The problem with a small thin fire is that you need to burn clean high calorific anthracite but if you burn a hole in the bed of coals the air will go through the gap and it is then very difficult to keep the fire burning. Some model locomotive designs like John Shawe's Black Adder' have deep fireboxes which are much more tolerant and therefore when I was offered the opportunity of running the big Shawe/Roundhouse Sandy River 2-6-2 I was very keen to see how this compared to the other engines which I have operated. Many readers will be familiar with the gas-fired version of the Sandy River 2-6-2 which is the flagship locomotive of the Roundhouse range. It is a big engine and even when scaled down to run on 32mm or 45mm gauge track it is an impressive machine. The prototype was built in 1919 by Baldwin for the 2ft gauge Sandy River and Rangeley Lakes Railroad in Maine USA and weighed in at a hefty 45 tons. It survived right to the end of the railroad's life and was the mainstay of the motive power in the last few years before the Sandy River Railroad closed in 1935. Although some of the Maine 2 foot Forneys survived, sadly the 2-6-2 was cut up for scrap in 1937 two years after the SRRL closed and can only now be seen in action in the superb archive video `Ride the Sandy River' or in model form. The Shawe Steam services version uses standard Roundhouse components for such items as the frames, valve gear, cab and body details but has a completely new coal fired boiler designed and built by John Shawe with associated boiler fittings. The loco is also fitted with an axle driven water feed pump and bypass valve. The tender is made from standard Roundhouse parts and holds the coal and water supply with a hand pump. Although at first glance the coal fired version looks very similar to the standard gas fired version, a closer look reveals many detail differences. The first time I had a chance to operate one of these locos running was on the occasion of a visit by John Shawe and Roger (Roundhouse) Loxley to John Chambers' Boyn Hill Railway. The engine in question had been built by John Shawe for Roger as his own personal loco although it was identical to others built for other customers. Roger raised steam with paraffin soaked charcoal and it was clear that a lot of lumps were needed to fill the firebox up to the firedoor. Within a few minutes the electric blower was removed as there was enough steam pressure for the loco's own steam blower. Roger gradually started to add hard steam coal to the fire and the safety valve lifted at 50 psi after only five minutes from cold. When all the charcoal had been replaced by coal and there was a very hot deep fire in the box, Roger cleared the cylinders of condensate by operating the reversing lever to set the engine backwards and then he ran forward and then backed onto the train.
The cab roof of No 24 raised to show the controls, the water pump bypass valve is on the cab floor
Smoke in The rain! No 24 with a claggy runpast on the Boyn Hill Railway
We started with a consist of 6 Bachmann passenger cars modified by Don Mason for his Beaver Creek and Stoney River Railroad. The locomotive ran extremely smoothly at very low speeds and one run past for the video cameras was so slow that it is tedious even on fast forward! The most impressive thing about the operation of this locomotive was how little attention it was given by Roger, in contrast to some coal fired locos which seem to need adjusting and fiddling with every few minutes, this one ran for periods of up to ten minutes without any attention. The very deep firebox on this engine means that you can load it up with coal and leave it alone for ten minutes. The locomotive was very quiet and hardly noticed the load and so we added 3 more heavy cars which increased the volume of the exhaust note. After running for about half an hour, in true summer style the heavens opened and we had a torrential downpour which put over half an inch of water in the gondolas. Although our spirits were a little dampened, we hid under a tree and just let the Sandy River prairie plod round for nearly 15 minutes without any attention. In my experience this must be close to a `hands off the fire' duration record for a l6mm coal fired loco. After a break for lunch and to dry out our underwear, Roger asked if I would like to have a go at raising steam and running the engine. Having watched Roger and John Shawe operate and drive the locomotive in the morning I was fairly confident of going solo. I started again from scratch with a clean grate and piled in the prepared charcoal up to the fire door. John's tip for lighting was to set light to a piece of soaked charcoal on the shovel and then simply place it in the firebox. The hinged cab roof lifts upwards and forwards and allows easy access to the firedoor and all the controls. With my locos I normally spend the next few minutes filling the lubricator with steam oil and filling the water tank in the tender. I was just starting to oil round the motion when the safety valve lifted after about two minutes! Steam coal then onto the fire for the next few minutes until the charcoal was replaced and there was a deep hot fire. I have never had an engine raise steam as quickly as this and it says something for the balance of boiler design. Driving the loco was very easy as there is a large regulator handle which was easy to reach and operate even on John Chambers' ground level line. However, I did find the positioning of the handle with the off at 6 o'clock rather got in the way when you were firing. When I mentioned this to John, he told me that Roger had altered this because he preferred it that way but all the other engines have the closed position offset from the firedoor. This idiosyncrasy is now known as the Yorkshire regulator! Once I got the feel of the engine it was easy to set the regulator for very slow running. With a light load a slight crack on the steam blower was needed to maintain pressure at slow speeds. But as soon as we hooked up to 6 cars pressure was maintained without any steam blower and the safety valve started to lift. When we added the additional 3 heavy cars the boiler made more steam and the safety valve was blowing nearly continuously. With the 6 car train the axle water pump delivery exactly matched the consumption of the engine with the bypass valve fully shut but with the heavier train the engine was blowing off continually.
Peter's No24 on a thirteen car consist
It was necessary to watch the glass and occasionally give a top up with the hand pump when adding coal to the firebox. John Shawe's advice is to open the firedoor a crack to pull cold air in over the fire if the engine is blowing off too fiercely. Although I was not familiar with the engine I could safely leave it alone for 5 to 10 minutes without any attention to the fire. After driving for 45 minutes I felt very happy with the engine and reluctantly passed the token back to Roger while I took some more photos before the light failed. All in all it was a very enjoyable introduction to the locomotive and it fulfilled all of my expectations based on my previous experience with Black Adder'. With the Sandy River and many other coal fired locos it is easy to get carried away when they are running well but it is important to remember that after a 30 or 40 minute run the ash and clinker can start to build up on the grate and a quick and careful rake with a fire tool can work wonders in livening up the fire. Do not be too enthusiastic with raking a thin fire or you may make it burn right through and put the fire out. If you use really rough and smelly coal you will need to sweep the tubes clean after a run and you may also need to break up and get rid of lumps of clinker before they weld onto the grate bars. It is also not wise to leave old ash in a smokebox for any length of time as it can be pretty corrosive and always remember to make sure that the smokebox door is well sealed when it is replaced or the fire will not pull properly next time you light up the engine and use the blower.
The saga of coal fired Number 24 does not end there as having seen the superb performances turned in by John Shawe's engines, our friend Peter Spindlow decided to fulfil a lifelong desire for a coal fired engine and ordered a Sandy River prairie for his line. The engine comes with a driving lesson and was delivered to Peter by John and I was lucky to be invited to the inaugural steam up. Peter has recently completely rebuilt his formerly ground level Gloucester and Wiltshire line to an elevated line so that he can more easily operate his locos. This mammoth task was only just completed by delivery day with a simple circuit of track without points laid around the circuit. Despite Peter's reservations over his inexperience with coal firing, he raised steam under John's guiding hand and the engine was soon heading round the line with a very heavy GWR train in tow. The deep firebox is a testimony to easy operation as the engine ran perfectly and looked splendid running over Peter's impressive girder bridge. Both John Chambers and myself have now run Peter's number 24 on a number of occasions and on one memorable afternoon on John's Boyn Hill Railroad we hooked up a massive train of 13 cars which the Sandy River prairie pulled with consummate ease. We also used some of our Manx coal given to us by Selwyn, the driver of `Loch'. This is wonderful stuff which looks and smells incredible and fumigates the entire neighbourhood. Number 24 thrived on this cordon bleu coal as the big firebox did not become rapidly clogged with clinker. We also used this coal on the evening when I had my midsummer steam up on the Burnham and Berkshire and in the twilight watching the intense glow from the firebox and savouring that wonderful aroma from the coal smoke hanging in the air we were about as close to l6mm perfection as I reckon you can get.
© 1999 Roundhouse Eng. Co. Ltd.