Large and Small locomotive economics, ex-West Somerset Railway developments

When considering boiler and loco size I would have thought the key factor was the rate at which water can be turned into steam.
To heat water to it's boiling point (which depends on the pressure in the boiler) only requires ~4.19 kJ/kg/degree (so even raising it
To boil the water to make useful steam requires 2270 kJ/kg.
So the heating of the water is a trivial user of energy compared to the energy required to make the steam.
As has been mentioned it's the quantity of steam at a given pressure that's needed to move the load. So clearly a bigger boiler with a larger grate can put back the energy lost to creating motion more easily. This is why, logically, that limits are set on locomotive load depending on boiler and grate size and to some extent gradient profile.

 

INCONSPICUOUS CONSUMPTION

PS. I am really not sure how this got here.

Firing a Severn Valley train

Mick E. Mouse


During my time on the footplate, perhaps the most frequent question I have been asked by visitors, is “how much coal do you use on a journey?” I have usually replied “about half a ton”, qualifying that with observations about the size of engine, length of train, and, of course, what the driver does.


Last Thursday, 27th October, 2005, I was working a service train and had a young cleaner, Michael , on the footplate, observing what was going on. In an attempt to de – mystify the whole job for him, I had told him that I would fire the train to Kidderminster and we would keep a count of where, and what, I fired. This article, an account of the journey, will attempt to answer the above question.


The train is the 1605hrs. ex- Bridgnorth and consists of 5 L.M.S. and 1 B.R. Mk. 1 coaches for 189 tons tare. It is well – loaded. The engine is 5164, bunker – first and is being driven by my fireman, Chris. In his mid – twenties, Chris has been coming with me since he passed out for firing and I consider myself extremely fortunate that he continues to do so as he is a first – class fireman and an accomplished and careful driver. This, of course, means that I am free to enjoy my firing, or to supervise others without worrying about what he is doing.


For some years now we have been blessed with excellent coal, which catches very quickly, so it is that at about 1600hrs, I begin to prepare the engine for its journey. Firing methodically, I place 12 shovelsful of coal on the fire, firing from front to back, thus: - three across the front, left corner, middle, right corner, three behind them, a little further back, three behind them and three in the back, one in the left corner, one in the right and one just trickled over the firehole ring. I should mention here that the front of the firebox is always the chimney end, regardless of which way the engine is facing and the reason I start firing at the front and work backwards is that, if you do it the other way round, the first shovelful immediately obscures your view of the rest of the fire with smoke, so, not only can you not see where you need to put the coal, you can’t see where it’s landed when you have fired it.


Use of the blower keeps the smoke down and the injector has kept the engine quiet. We are also steam - heating the train; on the smaller tank engines this can make significant inroads into your water consumption and needs to be watched. Dead on time, Chris eases the train out up the short, steep climb to the Cleobury Road bridge and then chuffs steadily up the easier gradient to Oldbury viaduct where there is a 15mph speed restriction. During this easy work, whilst keeping a lookout, I also watch the chimney; pure white exhaust would mean I had missed somewhere and there would be a hole somewhere in the fire letting in excess cold air. This is an opportunity to repair the damage. The smoke is grey, however and the safety valves start to sizzle as the blast livens the fire and heats the firebox rapidly. On with the injector as we drift across the viaduct, then off again as Chris opens up for the main part of the bank. The pressure remains “on the mark”, so, just before the summit, on goes the injector, replacing what has been used and keeping the engine quiet during the long coast down through Eardington station to the 5mph restriction at Sterns. At Sterns, on goes a second “round” of twelve shovels, as before. At this point, particularly during warmer, drier weather, I would be using the slacking pipe to damp down the coal dust in the cab and bunker, as I would at each station stop. There is no need today, earlier rain and the cooler temperature means dust is not a problem. A pleasant canter through Little Rock cutting and along Waterworks straight follows, pressure again on the red line, a white “feather” at the safety valves and the injector on a few moments before Chris shuts off, at or about the Up distant, before starting to brake for the Home signal, a few hundred yards away round the bend. We know this will be at Danger, as the Distant was on and we are timed to pass a Down train here.


At a stand in Hampton Loade station, we can relax and have a brew; there is no point in putting any coal on until the Down train is in view. If it were late, we would just sit there, blowing off. As the Down runs in, I am firing my third round, pausing to exchange cheery abuse with the other crew; another dozen shovels on to a still bright fire starts the safety valves sizzling. It is a fairly noisy sizzle; what the churlish might call blowing off. The injector gets a grip of it, then, with the timely arrival of the token, we get the rightaway and spare my blushes. From just outside the station limits there is a continuous climb through Alveley Woods, steepening past Country Park Halt, round the reverse curves and the summit by the old Miner’s Halt for the colliery across the river; all landscaped now of course. With a straight run, my fire would have sufficed, but, as we are stopped by request passengers at the halt, I quickly fire three hefty shovelsful into the back corners and under the doors. This takes us happily over the summit, although, as the pressure has come back to 180, I conclude that the extra chuffing to restart the train has pulled a bit of a hole in the fire where it was thinner.


At Highley, I repair the damage with another round of twelve, my fourth, which puts us in good shape for the run to Arley, my favourite part of the line. Chuckling along Kinlet then over the border into Worcestershire, the engine is again feathering with the injector on; steaming freely on a thin, bright fire, an absolute peach to work on. At Arley, dead on time, I am a little premature putting my fifth round on to a hot fire and even I have to acknowledge that the engine blows off convincingly. So, sue me; nobody’s perfect. We amble down to the 15mph permanent restriction over Victoria Bridge and Eyemore Cutting, then Chris opens up again, as the line climbs through the cutting, to a summit by the tall building at the Arley end of Trimpley pumping station. Continuing to accelerate down the slight gradient the other side, we are at line speed by the crossing from the woods to the reservoir and Chris shuts off, letting the railway drive the train around the curves past Folly Point and the Elan Valley pipeline bridge. Here the gradient, rising again, slows the train naturally round the check – rail curve, bringing it down to 10mph for Northwood Crossing without having to brake. As we approach the warning board, I am firing the front portion of my sixth round, pausing to keep a lookout as we approach the light – controlled road crossing. We know we are going to stop at the Halt as the guard had advised us at Hampton Loade that we had a couple of passengers to drop off, so, with the crossing safely blocked by the train, I finish firing and just nip the injector on in time to stop the safety valves lifting. As the stop at Northwood has chopped a minute or two out of our time, Chris blasts crisply away up the rising grade, towards the stables crossing and Orchard Cottage, where an early sighting of the Banner Repeater signal informs us that, as expected, the Bewdley Outer Home round the bend is on and he shuts off. We coast over the slight summit and down past where the Tenbury line used to diverge, braking to check the train. The injector has been on since just before the regulator was closed, but, as we pass the lineside location cabinet, marking the start of the Bewdley track circuit, the signalman, alerted to our presence, pulls off the signal and I shut it off. Chris uses the ejector to blow the brakes off, then opens the regulator to take us on again. It is much better if the signals are off as we can then coast all the way into Bewdley on the falling gradient from Orchard Cottage, using no steam, however signalling regs. mean that, if a train is approaching from the Kidderminster end, the signalman has to check Up trains at both the Outer and Inner Home signals unless the other train has come safely to a stand. (something like that anyway, ask the S & T. I once heard a group of them talking about signalling stuff in the pub; the only words I understood were, ”Whose round is it?”)


As we approach the Inner Home, it comes off, followed immediately by the Distant for Bewdley South which is underneath it, which means the signalman has already offered us to Kidderminster and been accepted. We coast into Bewdley, injector on and, as the train comes to a stand, I put my seventh and final round on; fifteen shovels this time, three extra in the back as a fair bit of chuffing is involved from Bewdley to the summit the other side of the tunnel. As we get the rightaway, I turn the injector off and Chris takes us smartly out, intent on a right time arrival at Kidderminster. I leave the fire doors partly open to keep the smoke down until we have cleared the houses, closing them as we cross Sandbourne viaduct. Six coaches does not require the Prairie to work too hard for its living and line speed is comfortably maintained past the Rifle Range, through the tunnel, the needle only coming off the red line before the summit, (where I turn off the steam heat to allow the fittings to cool before we need to uncouple at Kidderminster) again indicating the blast has probably pulled a small hole in the fire. As we coast down towards Falling Sands, I have a look and repair the damage; one shovel on the hole in the fire, three across the front and three in the back end, as I know Chris has to chuff off the viaduct, up round the bend past the housing estate on the site of the old loco shed. We sidle, comfortably on time, into Kidderminster, injector singing, 190 on the clock, half a glass of water and a thin fire. Easy, innit?


So, how have we done? I make that six rounds of 12 shovels = 72, one of 15, = 87, three extra at Country Park and seven at Falling Sands = 97 total. Assume between 10 and 15lbs of coal per shovel and that gives you between 970 and 1455lbs in total, so half a ton, (1120lbs) wasn’t that far out after all. I also noted that we used approximately 900 gallons of water. These things are not cheap to run, are they? On the upside, we were carrying at least 300 people, so that’s just over 4 lbs. of coal and 3 gallons of water each, which sounds much better. For those of you who can only think in metric, use your own calculators, I can’t be doing with it. This was not meant to be an instruction course in firing; everybody does it differently, it just worked for me. At the end of the day, only the man, or woman, wielding the shovel knows how much they have thrown in and where they have thrown it. To make life more interesting, every trip is different! All this talk about shovelling has made me thirsty; I’m off for a pint. See you.

Look, without malice aforethought and apropos of nothing concerning theory/mathematics/physics, etc, I will attach a little article I put together about 12 years ago, for one or two cleaners who were approaching their passing - out tests on the Severn Valley.

It was never intended to be a "masterclass," just a breakdown of an actual run. For those reading who are footplate crew, this may be of interest, for comparative purposes; for those who are not, it may shine a little light on the operating side.

I have a vague memory of posting this in the "Bullhead memories" section some time ago. It just seemed appropriate to the current discussion.

I would be delighted to read similar stuff from other crews.

Regards,

jtx

 

Further to my last, I have been unable to add the Word Document. My apologies, I have no idea why.

 

What a brilliant post and many thanks for taking the time to put it all together. For us "armchair" enthusiasts it gives us a real insight to what goes on at the "sharp end" Having had 2 footplate trips, NYMR and WSR I have seen what goes on but of course the crews were too busy to explain everything. Once again many thanks.
Paul.K

 

Fascinating, our traction inspector would be apoplectic if he reads it though. He is adamant that you must not fire in stations (except termini during the run round.)
Also "12 at a time" would give him a fit. ( I hope he's not reading this or I'm in trouble next time he sees me for sure!!)
However I'll try to produce a similar record next time I'm on a turn if we have a fooplate passenger to help keep count.

 

I expect there is a simple explanation but this "armchair enthusiast" does not know it but why is your traction inspector adamant that you must not fire in stations (except termini during run round} ? Thank you
Paul.K

 

Because that's what the Black Book says. It actually says that, when the regulator is closed, no firing should be done and, by definition, when the loco is stationary, the regulator is closed. However, if that was followed to the letter, you could never build up your fire before a journey or when descending long gradients. It is meant to apply when you are on the journey as, if you fire in a station when the fire is very hot, the volatiles contained in the fresh coal will be rapidly given off and there may not be the air to combust them unless you turn the blower on hard, which you don't really want to do. Insufficient air will lead to black smoke, which should be avoided, as everyone knows (but frequently ignores.) Once the loco is on the move, the blast of the exhaust will draw significantly more air through the fire enabling the volatiles to be properly burned.

 

Many thanks for that, now I know a little bit more.
Paul.K

 

I expect it's different strokes, aldfort. Some people have very firm, fixed ideas of what is and isn't right, obviously based on what they were taught. As I said, the article was not intended to be a "masterclass," it was what worked for me at the time. It would not work today, as the SVR has adopted Welsh steam coal, which has very different characteristics to the hard coal we were using at the time I wrote the piece.

In Bridgnorth, if you don't build your fire in the station, you will not get out of the station, or, at least, not very far. As for the rest, you fire as necessary to keep water and steam. "12 at a time," was right for that engine and load and the work it had to do then. That equated to a layer of coal all over the box, a "thin, bright fire." It's hard to see what anyone would fall out with, since the engine steamed like a witch and the job ran to time. At the time I wrote that, I had been on the footplate 23 years and a Driver for 7, so it wasn't "cobbled together." I did actually know what I was doing.

I'm not getting at you, by the way, but I'll happily defend myself to your Traction Inspector!

Regards,

jtx

 

At the other extreme - I was thinking today about recent trips with a P class. Generally, if you put more than three shovelfuls on the fire at once while on the run, you'll initially lose pressure quite rapidly, so you definitely have to fire "a little and often". (It takes about 15 (small) shovelfuls to cover the grate). I reckon I'd probably fire about 20-25 shovelfuls at Sheffield Park building the fire up, then around 30 on the "up" trip (roughly three shovelfuls every mile); about 15 coming back. You have to be pretty on the ball though mentally though. That's with Welsh coal.

The bunker takes 1/2 ton and you can just about do two trips (ignoring what is used lighting up) with a two coach train, so 1/4 ton per round trip, during which I'd reckon you'd probably use about 400 - 450 gallons of water - hard to say exactly as we always take water at East Grinstead, but the up trip tends to use a bit more than half the 500 gallon capacity, say 300 gallons, and I reckon you'd use about a third to half that coming back.

On the Autumn Tints service, that meant 100 seats; allowing 1/4 ton for a 22 mile round trip, it equates to 4 ounces per seat-mile. On occasion, I've taken the SECR 100 seater and birdcage which, with a higher seating capacity, gets you down to about 2.5 ounces per seat-mile. Getting close, but not quite reaching, the near mythical 2oz per seat-mile allegedly achieved by the Stroudley Terriers in the 1870s on the South London Line - though I suspect modern passengers wouldn't take kindly to the level of "squeezing them in", nor the rather spartan (non-existent?) upholstery on those carriages if you tried to replicate the same today!

Tom

 

Very interesting to read that, Tom. It will probably surprise non - footplate people, but it is much harder to fire a small engine well than a big one. You have to be much more on the ball, as you don't have the reserves that you do with a bigger engine. You have to shovel more on a bigger engine, but they are much easier to keep in equilibrium.

Regards,

John

 

Definitely agree with that. Firing a Double-Fairlie on the Ffestiniog on 8 cars is reasonably easy going. Firing Linda on 8 cars is quite different!

 

That's definitely true, but it took me a while to realise! Our P's start to blow off above about 150psi, but really start to labour with a heavy load on our gradients below 140psi, so the "happy area" is pretty narrow! Plus 323 and 178 require a rather different approach to water level on account of facing in different directions relative to the major changes of gradient.

If it's of interest, I'll write up a fuller account tonight?

Tom

 

Not saying you're wrong and not saying I always follow the "rules" either.
I tend to build up a decent back end on any western engine (depending on loco size and load) and leave BL with a full glass. Three down the front just before the right away (different from leaving MD obviously) So that the loco comes quickly up onto the mark during the early phase of the climb then just keep the injector on enough to keep the boiler topped up and fire to keep the pressure on the mark until we approach Crowcombe. Usually no more than 3 shovels at a time, middle then front then wherever it needs it. My aim is to have a level fire by the time we reach Crowcombe. I start re-building the back end during the decent to Williton with a view to having a full glass and a good back end and the pressure on the mark as we leave Watchet. Then fire as before on the climb to Washford. From then on it's just a case of doing enough to keep a thin bright fire and a reasonable amount of water for the run to MD such that you arrive with half a glass and good pressure but perhaps 10lb to 20lb off the mark and not making too fast. That's the theory anyway, some days it even works like that. Other days the fire appears to be like a hungry elephant eating buns and you can't shovel them in fast enough.
The comments about bigger engines being more forgiving are of course quite right. Smaller engines on their load limit are by far the biggest challenge followed by loco's who are feeling grumpy and having an off day ( aka in need of some tlc).

 

As you said aldfort "on any western engine" you are starting of with a great advantage. Pity all those footplate crews who don't have the benefit of a Swindon's best. ( I hope I'm not taken too seriously )
Paul. K

 

Absolutely mate. I have been on one or two pre-Grouping engines with 160psi boilers and I know the "sweet spot" can be very narrow indeed. I had a week on our wonderful Jinty a few years ago, (175psi boiler). I needed my wits about me, but what a fabulous week! 8 Mk1s, steam heating, went like a rocket, effortless poke and ran like a deer. I realise it's quite a bit more powerful than the machines you are talking about, being 3F, but, to most enthusiasts, it's just a little shunting engine. Wrong!

It's always interesting to me to read about other people's work and how they deal with it. (on the engine, I mean!)

Regards,

John

 

Likewise Firemen / Drivers.

 

Agreed, Neil. I've done a bit with "The Linda," Hugh Napier and Lyd, plus some with no. 87 on the "Caernarfon Branch."
Bottled the Fairlie, (it was my first trip) Did OK on 87 the first time, but overcooked the job a few months ago. 87 was easier that the smaller engines. Had some fun with no. 19 too.

 

As a footplateman working on both the SVR & WSR I have to say that I am following this exchange with some interest!

I don't recognise the style of trip first described by JTX on the SVR but then we are all different and it must be said that firing with the welsh coal is certainly not the same as the previously used Scottish or other hard.
My own view is that there is far too much "boiler dodging" on some heritage railways where some firemen appear to only fire when in stations rather than firing when the loco is working with the obvious necessity for firing in terminal stations being kept to a minimum.

 

OK, here goes. For the terminally bored, the condensed version: We got there. We got back...

I should say that this is what worked for me – I’m sure other people do things differently!

Firstly, a few general points. A P class is a small loco, just 28.5 tons and about 7,800lb TE. Relative to the more famous Stroudley Terriers, it is more "crew friendly" (with a steam reverser and much more user-friendly injectors) though possibly a bit less powerful. The boiler pressure is 160psi, though in practice the safety valves start to feather about 150psi and the loco is blowing off hard at 160, so my preference is to keep the pressure below about 150 – 155. Water capacity is 550 gallons. It is the custom of most drivers to aim to fill the boiler while still on the water column, so you start with both a full boiler and full tanks (rather than coming off the column with say half a glass, and being 50 gallons down in the tanks even before you start the journey by time the boiler is filled). That maximizes water capacity, but makes building up the fire trickier as there is minimal water space to play with.

As with our other SECR locos, the injector is reliable but slow – one injector on its own won’t keep up with the steam consumption when working flat out. There is also a big “lift” of water level when the regulator is open. When running forwards uphill, if you can see the water in the glass, the level is probably getting too low! As this trip is on 323 “Bluebell” (which faces south) that will be an issue on the return journey, but not the outward journey, where - with regulator open running uphill - the indicated level is about the same as the true level. Firing 178 is a different challenge, since at the end of each bank, the gradient changes are “knife edge” and the water drops as the regulator shuts and then runs to the front of the boiler as you change from uphill to downhill. So you get a big change in level, especially on exiting the tunnel and at the summit in Imberhorne cutting.

The train we are on is the lunchtime Golden Arrow. This is 3 Pullmans and a 6 wheel van, 136tons tare, and the haulage is both P class locos coupled bunker to bunker, so effectively 68 tons each. The duty is one and a half trips; 178 has previously shunted and heated the stock, so we just need to couple to 178 and then the train before departure. On 323, we will be inside for the up journey, and leading for the return.

The timetable calls for a non-stop run of 9 miles to Kingscote, mostly uphill at 1 in 75, in 28 minutes, where we cross the service train, before continuing the final two miles to East Grinstead. The run round is allowed 15 minutes (which includes taking water for both locos) and then a return which is scheduled to be non-stop all the way back, though that depends on the service train being on-time at Kingscote: if it is late, we will be held there.

There is a map and gradient profile here http://www.bluebell-railway.co.uk/bluebell/map_grad.html from which it can be seen that the up journey involves about 8 miles of climbing, mostly at 1 in 75 or steeper, including four miles of constant climbing between Tremains Crossing and West Hoathly. The final climb to East Grinstead involves about ¾ mile of 1 in 75 and a final half mile at 1 in 55. The return is generally downhill, though there is a short section of 1 in 60 after leaving East Grinstead; about 1.5 miles mostly at 1 in 122 between Kingscote and West Hoathly, and about a half a mile of 1 in 150 between Horsted Keynes and Sheffield Park.

So the trip: by time we had both taken water and coupled to the stock, there was about twenty minutes to departure. The Welsh coal we use takes quite a long time to light (and also swells up as it burns), so with about 15 minutes to go, I start to build the fire up. At the point we couple to the train, I have a thin fire across the grate, a full boiler and about 140psi pressure. I start with about 9 shovelfuls across the back – three in each corner and three under the door – then about three down each side, leaving the middle thin, as I don’t want the pressure to race away. The pressure drops quite quickly to about 135psi due to putting so much cold coal on the fire, then starts to recover. I leave the door open to keep the smoke down, the back damper half-open and the blower cracked. As we get closer to departure, I dribble a few more shovelfuls in where it looks a bit thin and the pressure rises towards 150psi, so I put the injector on and fill up the last ½” of water space.

Bang on time, the guard waves his flag. “Green flag, right away, you have the starter and the token” and, after an exchange of whistles with 178, we set off, while I close the doors and open the back damper fully. The pressure drops very quickly to 140psi, but then starts to rise again, and I put my first three shovelfuls on, filling the thin middle of the fire, as we pass the advanced starter. The pressure continues to rise on the easy climb out of the station, and when it reaches 150psi, I put the jack (injector) on. As we past Ketches Halt, the 1 in 75 of Freshfield Bank starts, so I knock the jack off. The pressure sits at about 145psi for a while, then starts to fall, almost imperceptibly, so I add my second three shovelfuls. From now on, firing is in threes across the box, either front, front middle, back middle or back as required, but never firing to the same place twice in succession. The pressure starts to rise and again, at 150psi, I put the jack back on as we continue up hill. When the pressure starts to fall, I turn the jack off: if the pressure then rises, the water goes back on; if the pressure stabilizes or continues to fall, the loco needs more coal. All the time, the intention is never to allow the pressure to fall below 140psi, or rise much above 150psi.

The third round goes on about ¼ mile before Town Place bridge (which marks the end of Freshfield bank), and the injector then goes on ready for when the driver shuts off. We crest the top at 140psi, but with steam shut off, the pressure rises fairly quickly, so I shut the back damper a notch. When the pressure gets to 150psi I ask the driver to put his injector on to control things; this has the desired effect and knocks the pressure back quite quickly, so we turn the second injector off at 140psi and just leave mine on. Pressure has risen nicely to 150psi at Tremaines Crossing, at which point driver opens up. I open the back damper fully, leave the injector on until the gradient steepens to 1 in 75, then the rhythm of either firing a round, or running the injector, continues. Two more rounds go on between Tremains and Three Arch Bridge outside Horsted Keynes. I put the injector on at the outer distant at Caseford Bridge, confident that the pressure won’t fall significantly between there and Horsted Keynes. At Horsted, we run straight through platform 2 at 5mph. With the regulator shut and the gradient level, I get my first true indication of the water level, which is ¾ glass and pressure 145psi – all is well!

Once clear of the platforms, the driver opens up and pressure falls to 140psi, then starts to rise again. I’m occupied exchanging tokens and watching for signals through the station, so the next round goes on once we are past Leamland junction; another about Vaux End and the last about Black Hut. As we enter the tunnel, water level is about half glass and pressure about 145psi. Apart from shutting off through Horsted Keynes, the regulator has been wide open for about the previous fifteen minutes since Tremains Crossing. As we leave the tunnel, I watch out to check the foot crossing is clear, then the driver shuts off, with pressure about 135psi, water below half a glass and the injector running.

While the injector runs, I build the fire back up, especially at the back, with about six more shovelfuls. The cold coal and injector keep the pressure down to about 130psi, so when Kingscote Box comes into sight about half a mile before the station, I shut off the injector to allow pressure to come round a bit before the short sharp climb from the signal box into the platform. When we stop, I put the injector back on, and then check the water level in the tanks using the tap on the end of the tank – water comes out, so we still have at least half a tank, and no need to take water from the emergency supply at Kingscote. Meanwhile, the pressure builds up and the loco starts to feather from the safety valve. With the down train already arrived, we collect the token from the signalman's agent, and set off for East Grinstead. The 1 in 75 starts immediately at the end of the platform, so once again pressure drops rapidly to about 140psi before starting to rise again; at the advanced starter, it gets to 150psi and I put the jack on for a short while to stop the loco blowing off. Once the pressure starts to fall, I fire my final round of three shovelfuls and knock off the injector: the pressure stays rooted to 145psi all the way to where the gradient steepens to 1 in 55, a bit less than half a mile from the summit. The gradient starts to take its toll and the train starts to slow, so I hold off the injector as long as I dare (easier on Bluebell than 178!) but it goes on at the first bridge as we enter the cutting. For the first time since leaving the tunnel, pressure starts to fall quickly, and it is down to about 125psi as we go over the summit. Once safely over the top, I open the doors, close the damper to half and leave the injector on until we reach the level, where we are at 130psi and half a glass. We run over the viaduct to stop in the station on time. There is fire across the grate but the thick back end we started with is all gone. Anticipating the climb out of the station on the return, I put three across the back then go and uncouple.

After uncoupling and taking water, I walk forward with the token to operate the ground frame while the driver runs round. The other fireman couples up, and we have only a few minutes to departure. Pressure has come back to 150psi, so I fill the boiler back to about ¾ glass and fill any holes. We are now the lead engine running chimney first, so gradient changes work against us and I want a reasonable water level for the change from 1 in 60 up to 1 in 55 down at the summit. Once over the summit, it is time to build up the fire for the climb out of Kingscote: about six across the back and a couple down each side and a couple lengthways down the middle while the driver controls the speed on the steep descent from Imberhorne Lane. Theoretically, we should be non-stop through Kingscote, but we are probably a bit early and the up train is a bit late, so we are held in the station and, the loco blows off as pressure reaches 160psi. Fortunately we are off soon, but the loco is still blowing off at the advanced starter, so I shut the damper a notch and open the doors a few inches until the pressure falls back below 150psi. One more round of three goes on between Kingscote and West Hoathly, with the injector controlling the pressure. Once we clear the tunnel, pressure is 140psi and water half glass indicated (so probably a bit higher if we were on the level) so I shut the damper to half (a P class is very sensitive to damper position) and control the pressure with the injector. We run non-stop through Horsted Keynes and, once past the advanced starter, I fire about another six small shovelfuls in anticipation of the short climb after Tremains crossing. Pressure hovers around 150psi and the water has recovered to more or less full glass by time the driver opens up. I wait until a bit before Sloop bridge (where the gradient changes from up to down), then put the injector on; once I am confident of the level on the descent, I knock it off and we roll down Freshfield Bank with the doors part open, the damper half-open and the pressure about 140psi, controlled by the injector. As we go past Ketches Halt, the home signal comes into view signalling us in to Platform 1; when we come to stand, pressure is about 145psi, water about ¾ and a moderate fire: probably in retrospect about three shovelfuls too much as we sit for ten minutes feathering before things calm down. There is forty minutes to take water and run round, then we are off to do it all again…

Tom