JimC

Oh yes. if you want to get an idea of the variety of subclasses of boilers take a look at the end of my GW standard boilers web page here: https://www.devboats.co.uk/gwdrawings/gwrstandardboilers.php#prefix I was lucky enough to have sight of a couple of GWR documents which listed boiler prefixes - as the GWR called the two letter code - and combined the information and published it there. Its not a complete list, because some types were extinct by the time of the documents.

Perhaps overstated for the GWR. If there was a significant operational or maintenance advantage then they would most definitely retrofit. Perhaps the most obvious example is the rate at which Churchward had superheaters fitted to the existing fleet. I believe that by WW1 the GWR had more superheated locomotives than all the other lines in Britain combined. And fitting superheaters is not a minor change as the whole tube layout is different with the flue tubes. Presumably with top feed the advantages weren't so marked on the small tank engines as it was on the taper boilers where it seems to have been retrofitted quite swiftly. I don't believe the Frenchmen had top feed. I think you'll find the arrangement that looks superficially like top feed is in fact external steam pipes. I think it depends on your background. The key point to the GWR seems to have been interchangeability. They certainly didn't let standardisation preclude necessary improvements: indeed you could make a case that continuous improovement - to some extent anyway - was GWR policy. An example is in tenders, where one can see a mix and match approach where later design parts would certainly be installed if necessary/desirable. With boilers its important to be aware that there were sub classes, and with the most numerous types there were quite a number which weren't strictly interchangeable with different fittings for tank and tender engines and the like. I don't think, for example, that 2721s ever carried the 200psi boilers with two flue tubes used on 57xx. The number of P class boilers was large enough that they didn't need to be pooled between the pre group and Collett classes with P class boilers

The other problem with this on my 1920x1200 Huawei tablet is that the downward creeping banner hides the notifications, so I have to tap repeatedly and quickly to grab them before they are hidden. If I'm too slow only thing to do is hit refresh and try again. This obviously does not help site performance one little bit. Also at the moment I am largely typing blind since blank top ad, video and on screen keyboard cover about 85% of the screen. I refuse to use ad blockers for moral reasons, but this is not a user friendly experience... NB Its only an issue on the tablet, its usable on 720 x 1280 phone and on PC.

GWR Goods wagons has dimensioned weight diagrams for similar types which should help. Unfortunately b/w scans so dimensions are difficult to read. O39 17'01/4 inside body, 8'0 body width, 8'7 over ironmongery, 7'3 height off rail, 3'51/4 solebar to top of body. Anotated 040/042 same except brakes and W iron type. V36/7 were 20'6 over buffers, 17'6 over headstocks, 5'0 and a fraction door entry clear, 11'81/4 total height, 6'0 9/16 door entry height clear. Both 10' wheelbase.

A number of classes were given rear frame extensions for more coal and water capacity and the bunker could also go higher, so maybe those changes were made after a bit of experience with the prototype?

Perhaps I can be of assistance? Does this help? And for non-fictional GWR 4-6-0s may I recommend the link in my signature?

The current "going Loco" blog at Didcot features Pendennis Castle's record card. https://didcotrailwaycentre.org.uk/product.php/78/going-loco. To my surprise she appears to have twice been fitted with the relatively rare flush tank (=Collett) 3,500 gallon tenders in the 1930s after having had 4,000 gallon tenders.

I'm not sure there's a good answer to that request. There was a feature in the Great Western Study Group Magazine Pannier, issues 17 and 18, which isn't bad, and the GWSG will supply reprints. There's some information in RCTS part 12 which is only available on the second hand book market, but I don't think its one of their best pieces. There are illustrations at the end of the Russell books, also only on the second hand market, but no significant written content. There's a chapter in my book, but its only seven pages and I could do better now as I've had sight of some significant archive material since then. There's probably a book's worth of material if one were to cover the subject in good detail, but how many people would buy a book on GWR tenders? I can't imagine the author making enough to cover the cost of some reasonably thorough research. Even though I say it, the web page I wrote the shell of and @Miss Prismhas considerably expanded at http://www.gwr.org.uk/no-tenders.html is probably not the worst piece on the subject.

For @Mike 84C...

But, but, its always shown in the down position on GWR GA drawings. Who am I to argue with their conventions?

According to the GWS Web site 6998, which worked the last steam hauled service on the WR in Jan 66, was transferred to them the same month, and later moved to a GWS site running under her own steam, which would suggest there was nothing significant missing. Frilford Grange had been withdrawn at the end of November 65.

This is the source. https://www.steamindex.com/gwrj/gwrj5.htm#39-417-rh Apparently in a letter published in GWR journal no 39 by a gentleman named R.F. Hill the writer notes that 6815 Frilford Grange had been selected for preservation as it was in good condition, but that 6998 Burton Agnes Hall was selected as it was cheaper (it contained less non-ferrous metal). As I said I don't understand how there could be a significant difference, or indeed whether the anecdote is actually true.

I've heard it said that when the GWS had the choice of purchasing either a Grange or a Hall from BR they picked the Hall because it had a less non-ferrous metal and thus was cheaper to buy. I've never understood how that could be, but if Halls were cheaper to build for some reason I suppose that might explain the choice.

It would be interesting to know the relative costs, manufacture and running, of the GWR implementation of two sets of gear plus rockers against three sets of gear. Its hard to avoid the conclusion that boiler and front end design was not an especial strength of the LMS design team, but on the other hand its said, I don't know how reliably, that post WW2 Swindon redraughting wasn't as effective on 3 cyl types as on 2 and 4, so who knows.

Ultimately nearly all GWR locomotives, except the Kings, were used for some freight duties so its hard to draw a firm line, but apparently the raison d'etre of the Granges was that the running department wanted a bigger boiler and a front bogie on the 43s.

There you go, a Castle boiler on a 5'8 4-6-0. Sort of a County equivalent really.

A Castle boiler would be a better bet for weight. Actually....

I enjoyed doing the "Churchward Grange" more than I expected and couldn't resist doing some more work on it, and have produced two versions, one pre war and the other post WW1. For pre war I've removed the raised foot plate over the cylinders and replaced it with a cover as per Churchward 42xx. Its imagined to have been built in 1906/7, so short cone boiler, not superheated, no top feed, no Holcroft curves etc, and carries a 3 digit number as per other Churchward prototypes. I also picked a fish name nearer the beginning of the alphabet. This imagines the class introduced post war, alongside the 47xx which it has much in common with and hence the number 4800 which would have been the logical next series. The running plate is slightly higher, the same as the 47xx, so no cover over the cylinders. If successful these would surely have been built instead of Halls and perhaps also instead of the later lots of 43xx too, so one can imagine it being an exceedingly numerous class..

Apparently when the running department wanted more 47s Collett decided to build Castles instead as being more versatile. But a Collett 47 is easy enough to imagine. Side window cab and fire iron tunnel!

Something like this I expect. Grange with a 47xx cab (slightly *shortened* to my surprise), a tall safety valve cover, no fire iron tunnel and inside steam pipes. I've called her Salmon because Churchward was much keener on natural names than Collett's buildings, he was an outdoors type and he'd already used birds and flowers...

Amazingly though, the last one being withdrawn wasn't the end of the story. See this thread for the second life of one (or part of one) of the class. https://www.rmweb.co.uk/community/index.php?/topic/156057-identification-of-a-mystery-outside-framed-engine/ Also https://www.flickr.com/photos/14581588@N05/4735888892 and http://www.historywebsite.co.uk/articles/Railway Gazette/OWWR.htm

Bit of a veteran this time. These are technically absorbed locomotives. 248 (upper sketch) is one of a class of five delivered to the Oxford, Worcester and Wolverhampton Railway in 1854/5. They were an E.B. Wilson standard design. 253 (lower sketch) is one of seven more, with differences to the frames, were bought by the the Newport, Abergavenny and Hereford Railway. These lines merged into the West Midland Railway, which in turn was taken over by the GWR to form a significant part of the narrow (=standard) gauge Northern Division. They were much rebuilt over their lives, acquiring larger cylinders and other changes – even in some cases new frames – but don’t seem to have been officially renewed. In RCTS the 253 frames are described as G.N.R. pattern, and the 248s as being N.E.R. pattern. In the E.L. Ahrons sketches I've used as the chief basis for these drawings I also seem to see some differences in the inside motion arrangements and some other more obvious variations. Although the first was withdrawn as early as 1877, and all the 253s by 1881, the last survivor of the 248s was withdrawn in 1907, but not bearing too much resemblance to this sketch by then. Livery is a complete minefield for something as early as this. I've just chosen an approximation of Wolverhampton colours with the lining left off.

I was mulling over the 15xx in a blog post. There are some surprising dimensions. If only one could talk to the people who designed it and know what they were doing in detail. Here's a chart of some of the measurements of the 15 against vaguely comparable types. Do they altogether make sense when you look at it as a dedicated dock shunter? Weight: Why did they put such a big boiler on the 15xx? A P class boiler like the 57 would have been perfectly adequate for short distance shunting work. It was basically a bigger boiler than the ones on the Austerity and USA tanks. The big boilers on the GWR locomotives make sense when you consider their traffic duties. Wheelbase: Its arguable whether the 15xx is in the same ballpark as the Austerity and 08 - 10% longer than 08, 25% longer than the USA. I have doubts about enthusiast second guessing on technical design matters, especially when its me(!) but I think there's a case to be made that the 15xx wheelbase was as long as it could be without having the locomotive fall on its nose because of the weight of the big cylinders. Its interesting that there's a known study of an outside cylinder 2-6-0PT with a P class boiler and 14'6 fixed wheelbase. I wonder if the longer and rear heavy (because tapered) Std10 boiler was chosen because it aided the weight distribution?

I have a not very well founded suspicion that enthusiasts tend to exaggerate the practical benefits of outside cylinders and outside valve gear. The trouble with this sort of thing is that few of us are trained steam locomotive designers, and I wonder how sound some of our deductions are. I've found it very easy to construct a cloud cuckoo land castle of theories that seem completely logical, only to have it come crashing down when a new bit of evidence appears.

You're correct, the long rail does seem to have been a GWR addition. Goodness knows where I got that from! I've altered the original post.