Castle Class rebuilding in the 50s

I know that a lot of work was done on some early Castles . Anyone got any thoughts?

4090 for instance sounds like more or less a new build ,classed as rebuilt to satisfy the Accountants.

 

There's a reasonable case for saying 4073 had two rebuilds (come on folks .... that was quite a bit more than a 'cosmetic makeover' before preservation!) ..... it hasn't pulled any trains as a result of that of course, but looks pretty damned good all the same!

 

Mentioning 4073, stumbled across this the other week....

 

Every heavy general overhaul resulted in the locomotive being stripped down to the frames and almost any part could be replaced by a different one. Certainly any part that required overhauling itself. So if the frames happened to need replacing then its quite possible that relatively few of the parts that left the works were the same as the ones it went into the works with. However if they are almost all refurbished secondhand parts it hardly seems logical to describe it as a new locomotive. I'm coming to the opinion that how a locomotive was held in the books is really the only satisfactory definition, because ultimately its gets futile to try and draw lines in the sand and say grandfather's axe was new again when it got a new handle, but not new again when it got a new blade.

 

no that's not what I mean. 4090 was a very early Castle and was rebuilt with (at least) new inside cylinders, new frames and crucially a 4 row superheater boiler and double chimney. Virtually the same spec as the last few castles built in 1950.
I'm not talking about a loco being overhauled in the normal course of things, this was virtually a new loco, rebuilt to the latest spec. There were others too in that early series rebuilt . Others such as 5043 received some degree of re-building, but 4090 on particular seems to have been almost entirely renewed

 

Just out of interest how many of the earlier Castles had their joggled frames replaced by straight ones like 4090? Did any of Star rebuilds get them (their frames being older might they have needed replacing sooner)?

 

Duplicate post deleted

 

Maybe, but think about what the options were. AIUI if new cylinders were required - and they were that sort of age - on a joggle framed Castle then the frames had to be replaced with dished frames. So frames and cylinders have to be replaced or scrap the locomotive. And if you've got a new set of frames and a new set of cylinders why on earth wouldn't you put a 4 row superheat boiler on if there was a choice in the boiler pool? One shouldn't be thinking about 4090s boiler or 4073s boiler. Swindon simply didn't think like that. By this stage they were about a third of the Castle boiler pool and they hadn't built any two row superheat boilers since 1940, or any 3 row ones since 1950. You see it all over GWR maintenance policy. If new parts were required then the current design was fitted if at all possible.

[Late Edit] I now think it likely the WR retained the capability of manufacturing new sets of cylinders for joggle frames. Pendennis Castle has, I am told, has three sets of cylinders and retains joggled frames, so one assumes the last set must have been fairly late. So new frames must have been fitted because new frames were required: it wasn't because of a cylinder swap.[end]

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Star/Bear Conversions
111, 4009, 4016 and 4032 were scrapped in 1950/53.
4037 received straight frames. Not sure about 4000 or 5083-92. Nothing in RCTS.

 

I'm no expert on the finer points of Swindon practices, so please forgive me if any of the following is wide of the mark.

Without heading for the axes or brooms, beyond like for like replacement of individual components, what precisely were the principal developments applied to the "Big 40's" across the 27 year construction period? Are we heading into trying to define what constituted a "rebuild" vs a "renewal" vs a straightforward "heavy overhaul"? I ask as I'd normally understand as a "rebuild" to result in a machine (hopefully) transformed, but in the case of the 'Castles', the only imperative seems to have been some less than earth shattering tweaks to an already decent design to keep them fit for exactly the same duties they were already performing, just doing so with greater economy.

I'm aware Hawksworth introduced a higher degree of superheat, but am foggier on how widely this was applied to earlier machines as they passed through the works, but the work appears to be on nothing like the scale of his redesign on the "Halls". Develoments on the draughting front look as if they had to wait for BR mods .... albeit a bit late in the day.

What other developments were included (and when) over the years? Were earlier and later spec machines worked turn and about? Or were duties allocated according to at which design revision (hope the term is acceptable) a loco happened to be?

 

I think it's simpler than that,I think Swindon wanted to build new Castles and found a way to do it. Bear in mind the first Castle was withdrawn in 1950, seven years before and the fleet was aging fast at this stage with quite a few withdrawn.
I don't believe it's the case that the GWR did as you suggest Jim, otherwise 28xx would have been renewed as 2884 class and early 45xx rebuilt as 4575 class. None of them were.

 

Well, look at surviving tenders: there are loads of "Churchward" tenders left, but not so many that don't have later style straight springs, or post 1936 design frames, or replacement tanks or...
If we consider the 42s, when they required new cylinders they received the different footplate outline and 19in cylinders and were effectively upgraded to 5205 spec, early 28s too have received 19in cylinders, curved frames and outside steam pipes.
Increased superheat boilers were widely circulated amongst earlier Halls (but apparently not 28s, which is interesting in itself).

 

it just shows what a complex subject it is, but I'm sticking with my conspiracy theory

 

At the end of the day the number of Castles doesn't increase. and its inevitable that the number of 'original' refurbished components on a design nearly 30 years old would be by this time quite low. If you are saying that 4090 was brought into works prematurely to have a number of components which we're manufactured solely with a view to rebuilding 4090 in particular to the latest spec. I think I would be saying Swindon did not work like that...

 

i'm saying 4090 may not have been brought into the works at all, just bits of it. Seems to me they didn't use much more than the outside cylinders and motion and the wheels. If it were a 43xx rebuild, they'd have called it a Grange.

 

Surely the point is that they started and finished with the same number of Castles carrying the same numbers. So that's a heavy overhaul in my book - nothing more.

No doubt each individual component repaired or replaced would have been set out; hours logged, and a total repair cost calculated, which in turn would have made its contribution both to the annual Swindon repairs budget and, more generally, to the per-mile repair costs statistics for the Castle class locos.

Tom

 

I still think you're looking for a distinction that wasn't there. Every hundred thousand or so miles 4090 and every other locomotive was brought into the works, completely disassembled down to the frames, and put back together with some of the same parts, and other parts, notably the boiler, replaced from a pool of components made ready. It would normally be known what parts would need replacing, and new ones would be ready and waiting. In this particular case it seems probable that the locomotive needed new cylinders and in the particular case of the early Castle it seems likely that this also meant new frames. I wouldn't be surprised if the new frames, probably with cylinders, were sitting there waiting, as Swindon had a system of predicting what would be needed and having it ready. So the locomotive came into the shops as normal, was disassembled as normal, but instead of the old frames being checked and repaired if necessary they were simply craned out of the way and the new set put down. Then the locomotive would have been reaasembled as normal, with refurbished parts from the pool or the locomotive as was convenient, had the replacement boiler from the pool fitted, and went back into service.

I'm quite sure the object of the exercise was to avoid scrapping the locomotive, and Swindon aimed to turn out locomotives "as good as new" after a heavy general overhaul, so yes, there's a sound argument to suggest that the difference between a major overhaul with a lot of new parts and a new engine could be somewhat notional. Perhaps the most extreme example is the so-called 31st King, the 'new' 6007 built after the Shrivenham accident incorporating, it seems, much of the frames, the boiler and many other components from the "predecessor". Do you have a copy of Cook's Swindon Steam (recommended) ? If not its worth reading as a first hand account of how things were done in the factory. What might be interesting to know is whether 'new' locomotives were normally erected with all new parts, or whether, as with the Granges, Manors, Dukedogs and 72s, there would be a substantial percentage of parts from the spares pool.

 

don't you find it odd that a practically brand new Castle would be built next to Class 42s being built (introduced 1958 so I'd guess they were in production in 57)

the Shrivenham accident was in 1936 and you'd expect the King to be rebuilt, but to be rebuilding Castles, not just overhauling them, as late as 1957 and later is odd I think. I'd imagine that the new inside cylinders would be necessary to fit the double chimney boiler?.

 

I think you may be right to say that a certain amount of "creative accounting" was involved. We have already mentioned a number of Stars which were rebuilt as Castles, keeping their old names and numbers. However my understanding is that Castles 5083-5092 incorporated the frames of Stars 4063-4072 (forgive me if I am mistaken)...yet they were given new names and numbers and officially regarded as new locomotives.

Ultimately I'm sure that the classification of a locomotive as a new-build or rebuild was decided on the basis of whether it was more convenient to charge the work to the capital or revenue account. We all know of famous examples of "rebuilds" which incorporated literally nothing of the original engine (e.g. Vale of Rheidol No. 9).

 

Question: How many surviving 'Castles' don't contain the odd component stamped with a different loco's number?

As @MuzTrem's post says, much was a case of satisfying the accounts books. Back in the day, all locos which entered stock were merely tools of the job .... even the 'celebrities'.

 

You don't need to change the cylinders, the blast pipe casting that bolts to the cylinders (and to the saddle that contains the exhaust from the outside cylinders) is different. As someone involved in the new outside cylinders on 6024, I can see why the frames might be changed when the inside cylinders are renewed. Many of the kings had their inside cylinders changed fairly late on (some say all, but 6024s weren't) together with the section of frame from the front to the motion bracket that supports the outside slidebars. Trying to fit new cylinders to the old frames is difficult, particularly the inside ones, getting the old ones out, as they are hard between the frames, and will be corroded in, and then having to line them up and ream out the fitted bolt holes oversize is a mission. Our new slim cylinders go about a ton and a half, so the inside ones (a single casting which incorporates the saddle) must be at least twice that. Far easier to make up a new section of frame with the new cylinders in and then weld and rivet up, and much less time in the erecting shop.

Rob