I wrote this article, originally, for the "Friends of Summerlee Newsletter" with, therefore, a largely local (Scottish) target audience. Many readers may not be familiar with some of the Glaswegian dialect so I have provided a glossary at the end.
Three loves have dominated my life from early childhood: music, mountains and steam. Involvement in steam was mainly passive until a few years ago, when I discovered the Summerlee Heritage Trust. Summerlee is an industrial heritage museum in Coatbridge, a few miles outside Glasgow. Having moved to Scotland, back in 1987, I found Summerlee almost by accident. On my first visit I was so impressed I picked up a Friends of Summerlee membership form on my way out.
Membership of the Friends enabled me, among other things, to play with, restore and (dream of dreams) drive steam engines. When I was asked if I was interested in being properly trained as one of the pool of drivers for the Fowler steam roller I jumped at the opportunity. This training culminated in my passing of the group G driving test. Until I moved away from Scotland, in 2000, I took my turn looking after the roller on special events, holiday weekends, gala days, steam fairs, etc. A typical day might go something like this: -
I arrive at Summerlee at least two hours before opening time. Few people are surprised that it takes longer to start a steam engine than it does a petrol one. However most, used to starting their car in a few seconds each morning, are mildly shocked to learn that it takes two to three hours to get a steam engine going. (They are often horrified at the thought of doing this every working day before the boss arrived.) The first thing I do is remove the haps. This exposes an austere looking black and grey painted machine. On closer inspection it can be seen that not all of the black and grey colouring is paint! Nowadays, steam engines on show to the public tend to be vigorously cleaned and lovingly polished by their proud owners. One of the delights of Summerlee is that it tries to portray the past as it was. There were a few conscientious drivers who kept their charges in gleaming condition, but they were few and far between. It must be remembered that, three quarters of a century ago, steam engines were everyday functional objects with no glamour attached to them at all; especially road rollers. (Railway engines were slightly different in that they had a P.R. role to play.) Needless to say, Summerlee's 1928 steam roller is authentically covered in oil and soot. However, most users, for their own sakes, keep the controls and other frequently handled parts reasonably clean. Rags are never far from your hand on a steam engine.
Most people tend to think that boiler pressure must be the most important thing to keep watch of on a steam engine. However, since the invention of the safety valve (at a very early stage) excessive boiler pressure is not really a problem. In the bad old days when boiler explosions were common, they were rarely caused by over pressure: they were usually caused by low water level. If the water level falls below the top of the firebox or tubes then these rapidly overheat and fail; usually catastrophically. There is a fusible plug on the top of the firebox, which, if it is exposed, melts and extinguishes the fire. It's pretty reliable but is a hell of a job to replace if it goes. For this reason, anyone in charge of a steam engine is constantly thinking water, water, water. This obsession starts right at the start of things and continues, as will be seen, right up until the last moments of putting the machine to bed at the end of the day. After removing the haps, my first concern is to ensure that both the boiler and the water tank are full. There is a dip stick for checking the water level in the tank but, at this stage in the proceedings, I don't bother with that. I lift up the lid of the filler. If I'm lucky and the previous user has topped up the tank before going home then the surface of the water is clearly visible. If not (which is usually the case) I have to fill it up with a hose. It is a large tank and takes a fair time to fill, so I make sure the hose is securely wedged in and get on with other things. The boiler water level is indicated by a sight glass. This is a glass tube connected to the boiler via short pipes and stop cocks. If the previous user has done his job properly, the level will be about two thirds the way up the tube. However, a leak or other problem, or an inexperienced previous user, may leave the water level dangerously low. If so, the boiler must be topped up with the hose through an emergency filler plug on the top. To be doubly sure, the sight glass itself can be checked using the stop cocks. There are three of these: one between the top of the tube and the boiler, a similar one at the bottom of the tube, and one open to fresh air. The tube is isolated from the boiler by closing the first two and then drained by opening the third. The visible water should disappear. Then the drain cock is closed and the other two opened. The water will be seen to reappear at it's original level, thus proving that all passage ways are clear. A most reassuring sight!
Having assured the water supply, I can now start thinking about the fire. As any school boy knows, fire needs three things to exist. It needs fuel (coal in this case), oxygen (air) and a source if ignition (a match). If there is coal in the bunker, fine. If not then this must be man-handled from the coal store. Fortunately, it is stored in sacks (usually plastic, nowadays) which can be easily transported in a wheel barrow. Unfortunately, the bunker is several feet off the ground and, at this stage, there is usually no assistance around. If possible, I make do with what's left in the bunker for now.
Air, despite appearances, is not so freely available as the fire would like. It has to follow a tortuous path from the damper, through the ash pan to the grate and the firebox, along the length of the boiler through narrow fire tubes, via the smokebox and the lum to the atmosphere. This whole path must be clear. To make sure I remember everything, I follow the entire path, but in reverse order. The top of the lum is usually covered by an ingenious contrivance called a lum cap: consisting of a lump of wood held in place by a house brick! Being high up out of sight and out of mind, the lum cap is easily forgotten. This example of amnesia is invariable discovered, most embarrassingly, when the fire is lit. The lum itself is so large in diameter that it is no problem. Any accumulated soot is blown away by the exhaust blast as soon as the engine is started. (Nobody in their right mind should be around Summerlee wearing a new white shirt.) To a certain extent, the same applies to the smokebox, but this has to be opened anyway to gain access to the fire tubes. In this case, as with most rollers, the smokebox door is tucked away neatly, but inaccessibly, behind the front roll. It is held closed by two nuts, which must be removed. First find the right spanner! The open door reveals the front ends of the 23 fire tubes. These tubes are about an inch and a half in diameter and the length of the boiler. Each and every one must be swept clean. This is achieved with a special wire brush on the end of a long handle. With assistance this is just hard work (especially with a new tight fitting brush): single handed, you soon discover how difficult it is to get the far end of an eight foot long springy steel rod into the end of a 1½" tube, especially when your view of the target is obscured. You soon learn the routine of balancing the rod on the front roll, walking to the brush end to insert it into the tube, walking back to the handle end, pushing it down the length of the tube, pulling it back out again and repeating for the next tube; trying to remember which tube you did last! After all 23 tubes are swept; I check that the resulting pile of soot in the bottom of the smokebox is not covering the bottom tubes and then re-secure the smokebox door. Next in line is the firebox. Opening the firebox door, down in a dark corner of the footplate, reveals total blackness. Hoping there are no black cats sleeping in there I thrust the long poker into the black hole until I feel the grate at the bottom. A few scrapes at random soon disturbs the thin layer of soot just swept from the tubes and the white ashes become visible, as if someone has switched on a light bulb. Now I can see what I'm doing it's comparatively easy to rake the ashes though the grate into the ash pan. If the roller is being taken out onto the road, it's usually advisable to keep some ashes in the ash pan to spread under the rollers if they loose grip on a steep gradient. However, today I'm not leaving the museum site so there is no excuse not to rake out the ash pan. This is done, despite the intervening rear roll, using the long hook ended poker. Everything seems to be obscured by something else on this machine. Ergonomics? Never heard of it!
Coal is the fuel used by this machine but, as any old-fashioned housewife will tell you, you can't light coal with a match. My next problem, then, is finding a source of dry wood. This, remember, is Scotland so any wood found outside is guaranteed wet. Hopefully, I can find a small amount in the workshop. This, liberally seasoned with paraffin, should burn long enough to light the wet wood. I arrange the wood, criss-cross fashion to ensure a free air flow, on the grate. The top layer (the dry wood) is soaked with paraffin. I then take an old oily rag, place it on the shovel and soak it, also, with paraffin. This is the point when the panic sets in because the matches have gone AWOL. Remembering that they are in the pocket of the jacket I removed half an hour ago, the panic subsides. I light the rag on the shovel and, after a few seconds when it's burning well, maneuver it on to the middle of the pile of wood. At last, nearly an hour after arriving on the scene, I have a fire in the box.
The elation is short lived because the wet wood refuses to catch. Another rag and plenty of paraffin does the job this time. After a few minutes, when the wood is well alight, I add a few small lumps of coal. To start with it's best to add coal little and often so as not to choke the fire. From now on, until I have full steam, I check the fire every few minutes and add coal as necessary. Once a good head of steam is obtained, the damper can be closed up and coal added less frequently.
Working with steam engines, I sometimes wish I had shares in an oil company. Not only do they consume large quantities of paraffin but also lubricating oil. In a car engine, the oil is circulated by pump from a sump to all points needing it and it drains back into the sump. Most steam engines are different. All the moving parts have to be oiled by hand; at least daily. (The important bearings have to be done two or three times a day.) There are two types of oil used for lubrication. Cylinder oil is thick, almost like treacle, at room temperature and is used in the cylinder lubricator and any other points that get hot. General purpose lubricating oil is much thinner and is used everywhere else (except the king pin on the top of the front roller which is provided with a couple of grease cups). I've never counted the lubrication points and it would be a bit pointless if I did. As often as not I find a new one every time I steam up. Steam Engineer's Rule #1 applies - "If it moves, oil it (if it doesn't, paint it)." Again, as an aid to my ever fallible memory, I work methodically from the front of the machine to the back; first with the cylinder oil and then again with the lubricating oil. The main problem with this is the main roll bearings. As the oiling points revolve with the rollers, on average, half of them will be pointing downwards at any one time. Those have to be seen to after the machine is moved forward a few feet. All through the oiling process I am frequently checking the fire and the water level. As the water heats up it expands and, if anything, the level should rise slightly. However, as the pressure builds up, any leaks in the system will show up as a falling level. Therefore I must watch the sight glass even though I'm not using steam at this stage.
When the oiling is all done, by this time, the boiler pressure is usually just about "off the pin" (the zero end stop on the gauge). The "blower" can now be used to increase the draught through the fire if necessary but, even so, it will be quite a while before there is enough pressure to move the engine. At this point there are two alternative courses of action. Some people take this opportunity to open the Brasso can and start polishing the brass. I (see above) take this opportunity to put the kettle on and have a cup of tea. Apart from regular checks on the fire and water, I can only wait patiently for the pressure gauge to creep slowly up towards working pressure. Technically, the "working pressure" is the point at which the safety valve blows, marked with a red line on the gauge (200 psi in this case). However, in practice, the engine will run quite happily at anything above half this. In fact the engine will tick over, in neutral gear, at a surprisingly low pressure. It's advisable to do this at an early a stage to "warm through" the cylinders and pistons. This helps prevent water condensing in the cylinders later on. Unlike steam, liquid water is incompressible. Therefore, condensation in the cylinders is potentially disastrous. For this reason, each cylinder is provided with two drain cocks; one at each end. These must be kept open for the first minute or two of running until only dry steam issues from them.
Soon, the first visitors start trickling in. (Have I really been here two hours already?) I can almost guarantee to answer the question "how long does it take to get it going" at least twice before I do get it going. The other "standard" questions - "how old is it?" (1928), "what fuel does it use?" (coal), "is it your's?" (no), and many others, are all answered easily without thinking. There is always the odd question that stumps me, though. Some are very odd questions, like the person who once asked me what was the chemical composition of the boiler treatment compound we use! Not even the experts knew the answer to that one.
Eventually I have enough pressure to start running. I close the blower valve, close the fire damper about half way, stop the engine and put it into low gear. Many people are surprised that you have to stop the engine before engaging the gears. Steam engines provide full torque all the way down to zero speed so there's no need for clutch or synchromesh. The only disadvantage with this is that it is impossible to change gear while the engine is moving. On approaching a steep hill in high gear, the driver must first stop the machine and then change gear (a process that takes 10 - 20 seconds; no racing gear changes on a steam roller!). Before pushing the reversing lever forward I remove the washer placed there deliberately to remind me to disengage the hand brake. A short, somewhat disappointing, warning blast on the whistle (the first toot of the day is always a bit "watery" due to condensation) and we're ready to go. Gentle operation of the throttle is impossible with this particular design of engine, especially with a good head of steam, so it jerks into life noisily. Using low gear and with the drain cocks open for the first few yards, progress is a generally clamorous affair; amply justifying Summerlee's advertising slogan - "Scotland's Noisiest Museum". Steam engines themselves are inherently quiet; it's the well worn mechanical gearing that makes the noise, especially in low gear. Also the steel rolls on a rough road surface contribute somewhat. The museum's other big attraction, the Sentinel steam wagon, which has no gears and a direct chain drive from the engine to the pneumatic tyre'd wheels, is so quiet as to be dangerous.
I have no problems with visitors being unaware of my approach. On the contrary, everyone is looking in my direction and the words "what...", "how..." and even "why...", in both young and not-so-young voices, are clearly audible above the noise of the engine. I head off towards the area near the main entrance at the front. Past the Foster portable and the "Fire Queen" steam boat; round the side of the main building and the uninspiring temporary offices; past the enormous South African Garret (built just down the road in Springburn); along the front, alongside Scotland's only working tramway; past the Albion truck and down to a small clear area next to two steam cranes and a large iron barge. Arriving at my chosen spot, a quick check of the water, fire and pressure show all to be satisfactory. The exhaust from the engine has brightened up the fire so I close the damper completely. The pressure has risen to just below the red line and the safety valves are beginning to blow.
The water level is about half way down the glass; perfectly acceptable, but no harm in using some of the excess steam to bring it up a bit. Water is injected into the boiler, not with a mechanical pump, but with a steam injector. This seemingly impossible device uses steam at boiler pressure to force water from the tank into the boiler against it's own pressure. This is a bit like pulling yourself up by your own bootstraps, but it works. I won't bore the reader, with the scientific principals of it's operation, mainly because I don't fully understand them myself. The working of the injector has caused the pressure to drop significantly and the safety valves have stopped blowing. Apart from the crackling of the fire and a slight hiss from the drain cocks, I am sitting in blissful near silence. I put the gear into neutral and let the engine tick over with only a small increase in noise level: a far cry from the noisy modern diesel engine. This is the time when, if the weather is bad, with roasted feet and frozen face, I begin to think "why am I doing this?" However, today, the weather is fine and there's nothing more relaxing than the sound of a steam engine gently ticking over.
"Hey, Big Man, gi'us a shot!". A rude awakening from my reverie. My response to this request depends on many factors. The policy of Summerlee is to encourage youngsters and to let them get a hands on experience of the past in all it's glory; but there are safety issues involved and, also, if I give this "Wee Man" his "shot" I know from experience there is likely to be a queue waiting on our return. However, on this occasion, it's not busy and I'm in a good mood. I give the lad a few warnings about what not to touch, take him for a short run and back and he goes away happy. The anticipated queue has not materialised and I can settle down to answering more questions. Nothing tricky today. "how fast does it go? (about 10 mph flat out down hill with a good head of steam and a following wind - if you dare); "how much coal does it use?" (depends on how hard it is working, but a couple of hundredweights a day is typical).
About mid-day I take the machine round to "the Bothy" and stop for a snack. The Bothy is a small portacabin round the back of the main museum building, which serves two purposes. It is Trevor's office and, more importantly, it serves as an unofficial general purpose shelter for the staff (hence it's name). There's invariably a kettle on the go. On special event days organised by the museum they usually provide a meal ticket for use in the canteen. Today, however, I make do with a poke of crisps and a mug of tea. I can't stay long: steam engines need constant supervision. For later on I stock the Fowler's tool box with more crisps and cans of ginger. Today, my ginger is Irn-Bru.
I top up the water tank before moving back into the public eye and more questions. "where did it come from?" (Ireland); "why is one cylinder bigger than the other?" (it's a compound engine; the larger cylinder being fed by the exhaust from the smaller one); "what's that round brass thingy do? ... and so the day goes on. To relieve the boredom of a particularly quiet period I roll the gravel on one of the roads around the site. This has been done many times before and there is little improvement. The showing off of a steam engine like this to the public tends to be a bit of an anti-climax after all the preparation. At steam fairs and the like there are often parades of engines to provide highlights to the day. Today, the next highlight is at closing time.
About half an hour before it's time to pack up, perhaps surprisingly, I build up the fire and open the damper. At around five o'clock (the museum's official closing time), with a good head of steam, I take the roller round to the yard and back her into her accustomed parking space. Reversing lever into neutral, gear into neutral, drain cocks open, hand brake on (moving the washer back onto the reversing lever), damper closed. Then I open up the injector and leave it open, ignoring the sight glass. When the boiler is full to the top the injector stops working automatically amidst a cloud of steam. The water level is now way above the top of the sight glass and it would be dangerous to try to run the engine in this condition. This is done because, as the water cools down overnight, it contracts and the level drops down to a suitable level for firing up the following day. We are back where we started: water, water, water. When the boiler is full I get out the hose again and fill up the tank for the benefit of the next driver. The Glasgow area has an admirably soft water supply but, even so, some solid deposit forms in the bottom of the boiler (probably peat, I would guess). I dispose of this by "blowing down". This simply means opening a cock on the bottom of the boiler for a few seconds. This releases large quantities of high pressure steam, along with the sediment, aimed at the loose oily gravel at foot level. Needless to say, you don't do this wearing your Sunday best shoes! I replace the lum cap and the heavy haps and finally collapse in an exhausted heap. At this point, invariably, someone comes along and offers their help. I avoid the temptation to swear at them and suggest that they put the kettle on for a cuppa.
Roly Williams
First written Oct 1993
Minor revisions somewhat later
hap - tarpaulin
lum - chimney (stack)
Big Man - a general purpose honorific
gi'us a shot - give me a ride
wee - small
poke - bag
ginger - any soft drink
Irn-Bru - a popular local brand of soft drink