Castle Class rebuilding in the 50s

[QUOTE to fit the double chimney boiler?.[/QUOTE]

No such thing. The smokebox is different, but that's just rivetted to the boiler. The boilers are different for different superheat layouts, but that's mainly in the tubeplates. I suspect when a boiler needed renewal it would have been replaced with a new one to the latest spec. Unless the shell and firebox were in very good shape renewing the tubeplates would not be economic. According to Cook boiler life extended as water treatment improved, to the extent that a loco would need between 1.5 and 2 boilers in its life. It would though have had several different ones in that time.

Rob

 

double chimney implies double blast pipe and all that entails.

 

All the first of the Castles withdrawn were those rebuilt into Castles from the Star class. 100A1 Lloyds was a very early withdrawal, as was North Star

 

conversely some of those rebuilt from Stars lasted until very late in the day. I wonder how much Star was left in them.

 

5083-92 kept the same names as 4063-72, unless you consider the addition of "Castle Class" a change. It is not clear from Locos of the GWR whether there was any difference in accounting treatment of the Abbeys and the other rebuilt Stars, as it refers to the former locos both as rebuilds and "new engines". Other things being equal, the capital budget for new locos was probably closely negotiated and controlled, whereas I imagine a "rebuilding" was lost in the normal costs of overhauls so was a preferred route.

 

There were/are a lot of 'Star' parts in every Castle, since a good number of components are the same on both classes. The last surviving Star conversion was 4037, which had had new cylinders and frames. The Castles seem to have lasted better than expected, since RCTS says that 4073 and 4074 were originally scheduled for condemnation in 1955 on an age basis, and in the end were in service until 1960 and 1963. Of course it is feasible that the WR took a look at the situation and decided that it was better to keep the Castle class complete until diesel traction was satisfactory: in 1955, if they had withdrawn the early Castles, then all they might have got to replace them would have been Britannias.

 

This is well covered in Cook's "Swindon Steam". The Abbeys were rebuilt with money from the renewals fund, which was the budget set aside for replacing life expired locomotives. The justification was that as Castles they would be lighter on boiler maintenance than as Stars. The other Star rebuilds were financed from the maintenance budget - revenue. However there is evidence to suggest that renewal fund rebuilds were more thorough than general overhauls: we can observed how the 5111s rebuilt as 8100s lasted much longer than those that weren't rebuilt, and the Dukedogs much longer than either Dukes or Bulldogs.

 

There are references galore to various 'accounts' to which work was chargeable. I've come across mention of 'capital', 'maintenance', 'renewals' and 'revenue'. Were there any other sources within GW finances?

In the interests of clarity, what specific terms were used for accounts (perhaps we'd best stick to the GW ..... or we'll be O/T before you can say "Castle Cary Cutoff"!). Specific charges seem to have followed some labrynthine internal company reasoning, but did any of these accounts change their name over the existance of the GW?

It's all terribly convoluted!

 

4074 is a case in point, rebuilt with a 4 row superheater boiler and double chimney. Preferring Castles to Brittanias is what i think happened too.
Mention of 100A1 reminds me that this loco was withdrawn before 7037 was built.

 

From what my old man tells me most drivers would have preferred to have kept the Saints over the Britannia's!

 

I'm sure its all perfectly logical if you're a trained accountant with an interest in the history of railway finance. I'm not!

My current understanding, doubtless over simplistic and naive is that:-

Capital is theoretically the money raised from shareholders. Expansions to the locomotive fleet must be made from capital.

Revenue is the daily income from running the business. There is a budget for maintenance which is supplied from revenue.

Renewal is the process by which capital assets are replaced as they depreciate - eg wear out. The renewal fund was an allowance ring fenced from revenue so that when a locomotive (or anything else) needed replacing there was money there to do it.

So if the locomotive fleet needed expanding it was done from capital.

If a locomotive needed repairing it was done from revenue.

When a locomotive needed replacing it was done from the renewals fund.

Back in the 19thC, when just about every locomotive was six wheeled, this was all very easy. When an 0-6-0 was clapped out a new one (to a current design) was built from the renewals fund, and this is what is described as a renewal. It might be that some usable secondhand parts were incorporated in the renewal, but basically the word renewal meant replaced with new, not repaired as good as new.
By the 20thC it got a bit more complicated. If you wanted to replace 10 0-6-0s with 10 2-8-0s, then the renewal fund would only supply the value of 10 0-6-0s. The rest of the money was considered an expansion of the fleet, and had to come from capital.However if you could replace 10 0-6-0s with 7 2-8-0s, maybe the numbers would balance.

What also makes it complicated is authority. The CME had a maintenance budget, and seems to have had a lot of freedom to do what he wanted with it.
Renewals seem to have had to be approved by the Locomotive committee.
I believe capital expenditure had to be approved by the full board, and I have the impression they were reluctant to do so.

Another complication is that all the funds may not be healthy at the same time. In the 1930s times were of course hard, and the maintenance budget was being cut to the bone. At the same time though there was a healthy supply of money in the renewals fund. This meant that there were a whole bunch of major rebuilds done on the GWR that were treated as renewals.

Now I think of it it seems possible this was also behind the large scale scrapping of Dean and Armstrong 0-6-0T classes in favour of large numbers of new 57s. The old locomotives were surely expensive to run and maintain, and they were very keen to cut maintenance. The new 57s could be bought out of the renewals fund, and would need little maintenance in their early years and be generally cheaper to maintain with improved engineering design, greater interchangeability of parts and all the rest of it.

 

thing is any class of steam locomotive that has had a long service life will receive modified components over its life better design of super heating, double chimneys, etc, all to reflect the changing world around them, any steam locomotive is just a collection of parts from the works, over time things change, in engineering nothing stands still, where a design might remain unaltered, its because either there is no need to improve it, or there is no way it can be easily improved,
take the design of midland axlebox for example ,prown to running hot but as far as i know it was never improved on later builds to eradicate its short comings,
An early castle may look from the outward, the same as a later batch, but thats as far as it goes, every class of engine received modifications at some stage , the A1, became a very different engine as an A3, even the southern maid of all work , the Maunsell Mogol, recieved new front frames and cylinders ,

 

@martin1656 My guess would be that to solve the infamous 'standard Midland bearings' issue would have meant such a substantial re-engineering (or outright replacement) of the mainframes as to render complete replacement the more cost-effective solution, with older locos already earmarked for the chop under the Stanier/Stamp scrap and build policy and in the case of more recent locos, as long as they worked after a fashion, there'd have been less unwanted awkward questions from the board involved in just letting sleeping dogs lie.

From what I can glean, modified Halls aside, most of the alterations to GW locos centred on the boiler .... the area that Churchward had done the most tinkering with, both before and after the basic group standards were laid down.

 

Not sure you can say that. Under Collett Cook records a lot of work on suspension and riding qualities and a lot of work on bearing design and especially lubrication.

 

I think this whole issue was complicated even more in the 1930s by the Govenment offering money for capital works. It may then have worked to the railways advantage to class some work as new builds when they were nearer to rebuilds. Working in industry I found the best way to proceed was to ask the acountants what the rules are and then adjust what you were trying to gets funds for accordingly. What is classed as revenue this year might have been capital last. I read somewhere that Swindon built 2-8-0 tanks between the wars, put them into store, then converted them into 2-8-2 tankss before they went into service

 

Cheers for that. Did any of Collett's work in these fields become subsequently incorporated in his own earlier classes, such as the Castles?

 

What I can say is that the Black 5's built under the Ivatt regime had been significantly re-engineered resulting in a more robust machine

 

Interesting comment, in what ways were the Ivatt 5s "more robust"?

 

All of it really, when applicable. If you go and look at Caerphilly Castle you'll see, for example, that she has connecting rods with large rectangular integrally machined oil reservoirs at the small ends, no equalisation gear in the suspension and broadly triangular rather then crescent moon main springs, all of which differ from the original GA drawing. No doubt there are plenty of other changes I'm not knowledgeable enough to spot or aren't externally visible. Cook records differences in the way axleboxes were machined, for instance, which made a significant difference.

 

The Black 5s were evolving from day 1. Were any two the same? 1", 1-1/16" and 1-1/8" thick frames. The later locos were fitted with manganese steel liners on the axleboxes and horns as well as Horwich style horn ties. The springing was modified. Possibly, the comment "more robust" can be deemed as being correct.