Bluebell Motive Power

You've every right to disagree but I don't think anyone actually had it is mind to take an existing Black 5 and supercharge it, which is what I was referring to. AFAIK the 5AT project (and I've not really paid any attention to it) was to build a new loco to see what could be done. It bore no resemblance to a Black 5 other than a wheel arrangement. Fair enough, if you can gather together the finances for such a special project but any idea that it would be anything other than one built simply to satisfy a dream is pie in the sky.

 

I avoided the expression first time round so not to discomfort the religious but Jesus wept!! Modified draughting would be fitted to ease the use of indifferent fuel, reduce the consumption thereof and make performance more reliable. As important for a 25mph railway as a main line. It can be applied to both saturated and superheated machines. As stated before it does not have to mean the destruction of traditional outlines and one successful application involves camouflaging the new arrangements behind uber traditional copper cappery.

It's a great less complicated than either compounding or superheating. Harrumph you not gentlemen.

PH

 

I didn't mean to imply that the 5AT would be a modified version of the existing Black 5. It would of course be a completely new design, intended to be more compatible with the modern railway than existing designs, preserved or new build.

The main advantage of improved draughting on an existing design for use on the main line would be to use less steam for the same amount of power and thereby to have a greater range between water stops. The only putative disadvantage would be less sound. But some designs (e.g. Gresley and Peppercorn pacifics) are already quieter than others (e.g. most LMS and GWR designs). And some French compounds (e.g. 241P) are significantly quieter still, and that doesn't make them any less impressive.

 

Now I like Victorian locomotives just as much as perhaps everyone else. They could be seen as stepping stones on a long journey but sadly few if any managed to get to the other side, to the journey's end. Does it end? No, there is always something new to test out. The 5AT project could be seen as the type of locomotive that could have been built in the late 1950s. It is not the most complicated machine though it does require an attention to detail not found on BR. It is no use stating that the improvements achieveable amount to fractions of a percent. Better to show some realistic numbers.
Some strange things happen when improving locomotives. They can end up using more fuel and not less. What a disaster! Well, maybe not. They produce more power. They produce more power than the unimproved locomotives when working at identical fuel consumption rates however they can burn even more fuel and produce far more power if required. This is a price sometimes paid to have trains run to time. You can modify preserved locomotives with very little obvious change in appearance. You probably would not want to. However it may well come down to a financial consideration. Which preserved line does not want to reduce running costs? It is not all about fuel and water either.
Running on the national network, preserving steam as a spectacle on the mainline is another matter. What would you choose to have to "mix it" on the modern network? We complain about modern traction assists, long journey times due to poor schedules. Network Rail would want mainline steam to go away. An engine available that represented the best that could be reasonably achieved. It could prove useful. But there again I am quite satisfied with Bellerophon and looking forward to 231E41. There is more to steam than UK mainline running.
If a locomotive is quieter it usually has a better exhaust system offering a higher power output against a lower back pressure. However though they can offer a fuel saving they can also drive the fire very hard when required drawing a significant amount of fuel in an unburnt state through the boiler. Or, in the case of A4s going very hard, launch some real flaming missiles out of the chimney. A high output exhaust system is thoroughly recommended but it is not the full solution.

 

While we're in Cloud Cuckoo Land, if I'm honest I'd rather see 'Leader' given another go than 5AT built.

 

But you are suggesting a solution to a problem we don't have, while not solving one we do have!

Our locos can haul the loads we set them, which is limited effectively by their size, but in many cases, even on our gradients we are limited by platform length, not loco size (and that is even more true for most other heritage railways). Our locos also have no problem steaming, as anyone who has had a day on an SECR engine will know - they steam like mad. Coal consumption is more effected by the number of heating and cooling cycles, than the actual coal used once running, so even a 5% improvement there would have far less impact than careful attention to loco rostering. Even so, the coal bill only represents about 8% of a third class ticket, and even less percentage of the revenue budget of the railway, so the capacity for actual cash revenue saving is very limited simply by making the locomotive more efficient.

We do have a problem with workshop capacity - space, money, manpower.

So putting on a modern exhaust on a 100 year old engine, even if "done within the traditional outline" solves the non-existent problem of "how do we get the H class to steam?" (answer: put a candle in the firebox) without answering the question "where would the money and capacity to make the modifications come from" and entirely ignoring the question of "are we preservationists, custodians for future generations, or just playing trains?"

There seem to be lots of groupies out there with an unrequited love affair for Porta, Chapelon et al. Which is lovely to see but all those mods will have more or less zero impact on the economics of heritage railways, which exist for an entirely different purpose and with a fundamentally different economic model.

Tom

 

I just don't see to what end a 5AT would be for other than to satisfy a technical curiosity, yes it would be better at mainline working than traditional steam, but where's the appeal ?, it's not preserving an element of the past so much as a quirky one off experiment for the hell of it, a class 91 is significantly better at East Coast Express work than an A4, doesn't mean there's as much affection for it or desire to ride behind it on railtours, in any case on classic (ie non high speed) main line, capacity is likely to be the big issue in future rather than speed.

I suppose the question is, do the people love steam of any sort, or because it is a reminder of a bygone era, of which the 5AT is not ?.

 

So Tom, the Bluebell needs locomotives that require less mechanical attention. The pool of preserved locomotives it currently has at its disposal are too difficult to maintain at a reasonable cost. If they required less attention then by extension you would not need such a high level of staffing and would cost far less to run. They would not have to occupy the works quite as frequently either. So what can you change that would bring about the desired improvements? Do a type by type break down if you like.
Yes a class 91 is better at East Coast work, but only when it has the wires to draw on. There is no present of something for nothing, it is always a trade off. I suspect GS understood this.

 

The vast majority of people are too young to remember the P2's so they have no affection for their lost youth with it. Therefore, it could be argued that the P2 and the 5AT are on equal playing fields in the 'love steam' stakes. However, I wonder what the outcome would have been if the A1 team had opted for the 5AT instead of the P2? I doubt it would have got very far.

 

You and I met once unwittingly when you had just finished putting out a very nasty fire that was within a touch of getting into the tree line. One of the advantages of re-draughting is that it enables a truly effective spark arrestor to be fitted without affecting steaming qualities. I used to travel many miles behind one locomotive that steamed beautifully but required a lookout to make sure the scenery was not set alight on a dry day. She would not steam when an arrestor was fitted but when re-draughted went back to her old form , burned less fuel and did not set things on fire.

Forgive me for being tart but it is not at all amateur to look into re-draughting possibilities but it can be argued that it is just that to ignore possible advantages just because one "doesn't hold" with something.

Renewed apologies,

Paul H.

 

But look at the significant repairs we have done even in the last fifteen years or so: two complete overhauls from Barry condition (1638 and 34059); new frames (9017); new driving wheels (72); extensive boiler repairs (323, 178, 541 in progress). I'm not sure how any of those would have been alleviated by fitting a Giesel ejector! Likewise, the looming issue with a number of locomotives is life-worn cylinders (those fitted to 592 were probably fitted during the 1940s, for an item that the SECR and SR would have considered a consumable). I'm not sure what protection from wear and tear Lempor-ising the front end would make to that situation.

If you want to build the 5AT, then fine. You'll discover, £10million later, that nostalgics don't like it because it doesn't look like a "proper" steam engine (unlike Tornado, or the P2, equally modern though they may be). And the practical railway operators on Network Rail don't really like it either, because to them it is still basically a steam engine that needs long, awkward to schedule, stops to take on water and it still waggles around near platforms and bangs the track quite unlike a modern engine. Meanwhile, those who like nostalgia can see genuine 100 year old engines doing the work they were designed for and largely unchanged for future generations to enjoy - and they can get there on nice modern reliable electric trains...

Tom

 

There are some features of the P2s that can account for the appeal of building a new one: the handsome appearance of the first one, which the new build is to copy; the fact that they were the "most powerful" design ever to run in Britain (according to some criterion for assessing power, though one could also say that Tornado is exactly as powerful because it has the same boiler); and the fact that after only a short time in service they were rebuilt into such an unattractive form instead of having their poor dynamics sorted out but otherwise remaining as built.

Maybe a 5AT mark 2 would have more appeal if it looked prettier.

 

For someone who spends a large amount of time telling us all that we don't need big locos on heritage railways to suggest that we now should consider modern design steam locos to give us increased power and economy seems to be a total about turn.

As for locos needing better draughting to overcome spark arrestors, I believe it is a fundamental of all locos operating on Network Rail that they are fitted with an effective spark arrestor and I know of no complaints about the ability of any of them to produce steam. (And generally produce more steam than they ever had to in their heyday.)

 

There have been a number of fires recently that were ascribed, rightly or wrongly, to steam hauled excursion trains. If this is correct there must be some ineffective spark arrestors around! Whether we are dealing with large (by necessity) motive power on Network Rail or small (ideally) locomotives on heritage lines, fire raising is not really a desirable characteristic.

Also you have not read what I have posted quite accurately. No-where have I said anything about modern design steam locomotives. Merely we should examine means whereby operating efficiency of existing machinery can be improved at modest cost and without aesthetic penalty by a gentle application of not all that new know-how.

.H.

 

Most fire sources seem to emanate from the ashpan, rather then the chimney, in my experience. Granted the ashpans themselves should have adequate protection but they are notorious for warping.

In terms of modifying locos to improve performance, this is something that happens quite a lot on the narrow gauge where they seem to be more inclined to modify. The FR with their Fairlies, and Ladies, which are nothing like their original incarnations, are two that spring to mind. The TR has also vastly modified most of its locos over the years if you look closely. The same doesn't generally apply to standard gauge locos though, except where it has become mandatory, such as spark arrestors, TPWS, etc. There'll always be the exception to prove the rule, though.

 

Certainly I would agree that ashpans can be a source of fire but whether the are more significant than hot coals out of the chimney I don't know.

I was once told that "yer average" narrow gauge locomotive tends to have a better steam circuit than a standard gauge one so blast pipe improvements are more likely to prove beneficial to the former. Again I could not say if this is true. As the efficiency gains arise from reduction in back pressure, clearly, if the rest of the circuit is poor, there is little likelihood of just freeing off the blastpipe increasing available horsepower or improving fuel consumption.

The whole of the principle fleet on the W&LLR has been re-draughted and was subject to "before and after" comparisons. Martyn Bane's Steam and Travel pages gives some more info. on this topic generally

 

Well Tom the locomotives you state as being equally modern as the 5AT are in truth no such thing. The A1 could have been but a replica of a 1940s design was produced instead.
There is no doubt about the fact that a great deal of work has been done on the Bluebell. As you should be aware best steam practice is more than about exhaust systems. Steam locomotive lubrication was once described as the kingdom of railway stupidity. You can either address the issue or live with the financial implications. In France TIA brought about the closure of many boiler repair centres because repairs were not needed. So if you find yourselves carrying out large numbers of boiler repairs, check your water treatment. If you are not sure what a high efficiency exhaust system will bring to the table think about the impact of high back pressure on not only the economy of the engine but also its mechanical well being. No body is asking you to carry out an irreversible process. As Mr Hitch writes much can be done at modest cost and with little aethetic penalty. There is no escaping the fact that as locomotives get older the costs of keeping them running just keep on rising. You would want to take action to minimise this rise. I also suspect that the railway management would not turn down a locomotive with welded bed plates, Franklin wedges etc. all contained within a recognisable Victorian outline.

 

i think that generally the Bluebell has an excellent fleet of well designed locos regardless of their age, and which (apart from in my own personal view the Bulleid pacifics) are ideal for the line. ok i accept the extension imposes new demands. i also accept that unlike many UK narrow gauge railways which have made considerable 'improvements' to the efficiency of their locos, in fullsize this hasnt been the case in the UK.
FR BLANCHE was rebuilt 1972 with new piston valve cylinders and superheating. the FR are now fitting monoblock piston valves cylinders to the Double Fairlees (single Fairlee Taliesin having tried them out). all sorts of draughting experiments have been tried out. all the locos except PALMERSTON are superheated. but such improvements are a matter of scale and cost and necessity - the locos being worked far harder than in pre-preservation days. the same doesnt apply to the standard gauge preserved lines with a linespeed of 25 mph plus much greater size and consequent increase in costs in any potential improvements to the basic machine. as tom quite rightly states, careful rostering reducing the heat cycles on the boiler probably has far more to do with prolonging boiler life and reducing costs than anything else. my only concern is that the non availability of good quality steam coal in a few years is going to have a huge effect on all steam railways.
i think at some stage in the future the Bluebell is going to have to think about reducing the gradient on the extension. the Talyllyn Railway has now had 2 goes at reducing the gradient between Wharf and Pendre.
cheers,
julian

 

I think they had little option but to accept the gradient if the extension was to stand any chance of being opened. However it is a classic case of "short term gain, long term pain"!

PH

 

I should have added that when the W&LLR rebuilt "Joan" the "diamond stack" spark arrestor was but a dummy, the real arrestor being inside the smokebox in association with the Lempor arrangements. The new boiler has a smaller firebox but I understand retains the free steaming abilities of the former one. Additionally the firebox is so designed to facilitate experiments with producer gas firing methods at a future date. None of this is apparent to the outside observer.

P.H.