JimC

Running through Lyons quickly, the only GW turntable sheds with a separate turntable were Wolverhampton Stafford road and Cardiff Canton, both of which had considerable straight road accommodation as well as the turntable shed. However the vast majority of straight road sheds of any size did have turntables. I know nothing about facilities on other lines, but as was said above, economy. It's hard to believe that GWR policy was to turn locomotives off site at the biggest sheds and on site at smaller ones. Off hand the only example of a turntable not associated with a shed that I can think of is Ranelagh, which is a special case.

It seems to me that the wide firebox Atlantic solves or at least deals with a number of the ten wheel design problems evident in the Johnson pastiche photo. The short wide box over the trailing wheels means that the boiler length is kept down, and trailing wheels under the firebox helps the overall length. So what the designer achieves is a locomotive with a considerable boiler capacity increase over the 4-4-0s. To my mind it's very analogous to the successful Pacifics, where the wide box, together with a combustion chamber to increase firebox heating surface and reduce tube length, also enlarges the boiler capacity without the length of the locomotive getting out of hand. An expansion of the Churchward 4-6-0 type into 4-8-0 as a twelve wheel type, on the other hand, would I think run into a raft of problems with firebox, ashpan and so on. I must take another look at Dusty Durrant's flights of fancy to see how a Swindon trained man handled it. [Later] A quick skim of his book and I haven't seen that Durrant sketched of a 4-8-0 with wheels in excess of 6'0, which means a vital few more inches for grate and ashpan. His long firebox 4-8-0 has two axles under a part sloping grate. And a very long firebox it is too - a good bit longer than a King. Not, I suspect one to find favour with the firemen's union.

Maybe one aspect to this topic is that it can highlight design problems that exercised the minds of designers back in the day. Clearly this extension of a reasonable 4-4-0 has produced an unreasonable 4-6-0, but should we ask why? I'm of the opinion that the turn of the century transition from eight wheeled to ten wheeled locomotives went badly on some lines, and this illustrates to me the issues. An eight wheeler, be it a large wheel 4-4-0 to a small wheeled 0-8-0, was a fairly straightforward proposition. There was room for the firebox between the last pairs of wheels, a reasonable sized boiler fitted on top, the wheelbase was under control, and we see this in all sorts of reasonably successful locomotives from different lines. Enlarging this into a ten wheeled locomotive most especially with driving wheels north of 6'8 or so, was quite a different proposition. I think we can see that here. If we have the same firebox position and drive to the leading wheels, as was customary, then what we get is something like this Johnson pastiche. I got a very similar result when I tried to enlarge a Dean Atbara. The whole locomotive gets so long that the boiler is ridiculously long, it won't steam, the weight distribution is up the chute, all sorts of evils. And we can see that when designers tried it previously competent design teams produced some very mediocre locomotives. So I think you have to look at the photo edit and say, well that's how it could have gone even wronger, but what would have been needed to make it right? How do you get 3 sets of 6'9ish driving wheels and a sensible boiler? What did the draughtsmen in the drawing offices have to consider? And if you do that, maybe you can do some imaginaries around how some of the designers that failed to get to grips with the ten wheel era should have gone about it? (Even if the answer is "copy Churchward"!).

Is that a general opinion? If the occasional what if of standard parts I post is unwanted then I'll go away.

Station layout is very much not my field, but how about something like this? Move the crossover round the corner and it can be trailing, plus a trailing access to goods that's accessible to trains coming from both forks. Enough platform for short branch trains, plus more length for main line trains. But how realistic it might be is beyond me. It does assume that there wouldn't be through trains from branch to stations to the right though, that would need another crossover, but in practice wouldn't most branches have a shuttle anyway and go no further than the junction?

I think the trouble is that when you change from a shunter to a trip engine everything changes. The Austerity has a much smaller boiler than a locomotive required to run trips like a GWR pannier tank. I've heard it said the draughting could be improved too. Then if you're not going to be running on hastily laid uneven track with harsh curves, then the wheelbase can be increased a bit and it will ride better and the hornguides etc last longer, and before you know it you've changed everything but the space between the wheels.

It was inevitable, though, that with a a complete traction change, some locos would run a short life. And with steam locomotives being relatively cheap to build and expensive to maintain it might not need a very long life for it to be cost effective to replace rather than repair. In the 30s the GWR was spending about half the cost of a new locomotive on major third party overhauls of absorbed classes. If your new locomotives are running say 30% longer between overhauls and the overhauls are cheaper too, plus the advantages of no longer having to hold consumables for obsolete types then I don't think it would take that many years for replacement to be cost effective.

Yes indeed. Formal trials were run, and a Dean Goods tactfully prettied up in Riddles LNWR lined black to make the comparison, at which it came out well ahead. However it should be remembered that a 1950 Dean Goods was a very different beast to a 1890 one, reboilered with superheater, belpaire firebox and increased pressure, and, judging by dates on drawings, having had front end design work as late as the 1940s.

I've produced a sketch of the as built condition. It took an awful lot longer than I had hoped. A lot of it was not finding it very congenial to work up, and a lot more was having a very detailed but very indistinct works drawing to use as a source. Livery is largely guesswork. I have a black and white shaded drawing which gives some clues, but little more. I'm choosing to believe that it was painted up something in the style of GWR Wolverhampton, the S&C having been the foundation of that line, but that's completely and utterly a guess. I'm still unsure of some constructional details, and cannot make sense of @billbedford's comment re valve gear above. I don't think it really matters for the sketch though. I do remain unconvinced that they would have stayed in this configuration for all their twelve years of service, but there's no evidence otherwise in any source available to me, it's only surmise. Its so easy to construct a grand theory, but I'm all too aware its easy to construct grand theories that then get utterly demolished when subsequent evidence comes to light. Update: 5/11/2023. I've found a more detailed description of these locomotives in E.L. Ahrons. The early Great Western standard gauge engines, The locomotive magazine No 260 1914, which amongst other things states the dome was painted, so I amended the sketch. Ahrons is quite positive about one of the oval boilers having been reconstructed with a circular profile in 1866, which would seem to torpedo my theory about an earlier reconstruction, although these were events from before Ahrons was born. As a light hearted aside, whilst talking about another ex S&C locomotive in the same piece, Ahrons' dry sense of humour is evident. He records that the locomotive in question "had but a short career, the chief incident in which appears to have been a collision with an itinerant horse, as a result of which, No. 32 sustained damage to the extent of one broken split pin on the outside valve gear. Structural alterations subsequently required by the horse were not stated.". Thanks to Steamindex for the extract.

Interesting. Unsurprising that larger locomotives = longer trains = increased receipts per locomotive mile. An interesting question is whether there had to be infrastructure upgrades like longer refuge sidings to cope with longer trains. At any point there must have been limiting factors. The practical problems of managing a loose coupled train have been mentioned above, and presumably the longer the train the greater the challenge, especially on an undulating route if some parts of the train are going uphill and some down. One also suspects that longer trains of indifferently maintained PO wagons would be more likely to experience delays from hot boxes etc, but OTOH fewer trains would need to be run.

Given the British loading gauge and other limitations really one has to see Garratt types as the right solution for steam super power in the UK. Axle loading, boiler diameter, no need for larger turntables, it ticks all the boxes.

There were, I understand, studies for the Counties that included outside walschaerts gear. Weight limitations seem to have been a big issue. A Std 1 would presumably have been smaller than was wanted, and little advance on the Hall, so presumably the choice was between a high pressure version of the Castle boiler, or to take advantage of the tooling kindly supplied by the government.

I suppose, going back to the OPs question, the answer is pretty much yes, they were about as big a step, but in both cases the new designs, although they superficially look rather different, were really evolutionary, not revolutionary and so the steps not as big as one might think.

According to the drawings list the NRM publish work was already in progress on the 15xx design in January 1944, (and, it seems, possibly before the 9400) and so Hawksworth can't possibly have noted what the Southern were buying in 1946! I wrote my opinions up in a blog piece last year - see here https://www.rmweb.co.uk/blogs/entry/25226-gwrwr-15xx-class-1948/ but suffice to say that looked at in detail the 15xx is a very different beast to the S100 in spite of the superficial external similarity. Its certainly not remotely a Swindonised S100. In particular the wheelbase on the 15xx is some 30% longer than the S100. My basic premise in the blog is that given the outside cylinders and the boiler size the wheelbase is as long as could be managed.

FWIW we have this in "Next Station" , a 1947 GWR publication: "The new method now being applied on an increasing scale avoids the use of separate floor framing in the body; the side pillars are secured direct to brackets welded to the underframe, which becomes the floor of the finished coach. It also introduces partial prefabrication on jig tables laid out in conjunction with the assembly line. On these tables are built twelve prefabricated frames wich, when assembled, form the complete side walls and end walls of a coach." I don't know enough on the subject to comment.

There was a joint GWR/LMS buckeye trial in 1945, but the GWR at least considered it didn't justify making a change. There must have been something fairly different about the Hawksworth coach construction, because there was a lengthy inter-union demarcation dispute on an aspect of the construction which delayed their introduction. Think it may have been getting on for a year. I've seen a letter from Hawksworth to the board claiming it's not that big a deal since instead he'd been able to make excellent progress in refurbishing carriages suffering from war time neglect. One shouldn't forget that it was Hawksworth's job to sort out that sort of thing, and to my cynical eyes it read an awful lot as if that was all spin, even if not called that yet. For the youngsters, a demarcation dispute occurred when there were separate unions for different trades. Each would claim that a particular job came under their trade and therefore should be reserved for their members. They could be long and very disruptive. Now most sites are single union at best such things are very rare.

Could you enlarge on that please? I'm having trouble working out what you mean. As far as I can see there is maybe a few inches, no more between the cylinder and the axle, so I don't see how there could be any kind of central piston rod or yoke external to the cylinder - I don't see where it can move. I've sketched my interpretation below, please could you clarify what I haven't understood. It seems to me as if the valve (red in front elevation) is about 30 degrees off horizontal, as well as sloping downwards on the plane of the valve rod (very faint pink), so pretty much below. The cylinder is in green, and I don't see there's room for any kind of yoke. We've certainly got the two round bars top and bottom, but my interpretation had them as piston rods. I think I see bearing surfaces for conventional slide bars on the crosshead (red)

I posted a link to the sketch on the GWR Elist and a fellow member suggests that the drawings show two piston rods per cylinder, one above and one below the axle, and (bearing in mind the possibility of pareidolia) I now reckon I see that too. Besides how else can it possibly have worked? But it doesn't seem to me that this setup would have worked, presumably adequately, for twelve years under Joseph Armstrong. I think it reinforces my (utterly without evidence) conjecture that they must have seen a significant rebuild fairly early in life, maybe even in S&C days, into something more conventional and more in the style of their renewals. Maybe even a smaller wheeled long boiler 0-6-0? But I don't know what sources there are for this era, what RCTS drew on for their research. And even if anything does exist in some register in one of the archives, can I face working through pages of impenetrable victorian copperplate handwriting to find it?

Reading RCTS more carefully and looking at the Vulcan drawing the original 34 and 35 had the exceedingly unusual feature of an oval section boiler. This boiler had the long dimension vertically, which one supposes explains why there was room for railings round the footplate, otherwise only seen on the broad gauge. I'm tempted to speculate that perhaps these oval boilers didn't last very long, and that some time before 1866 these locomotives had been rebuilt with more conventional boilers, and when Armstrong came to rebuild the chassis he retained the replacement boilers, which would have been of more recent and more conventional construction. If boiler and at least some motion components could be retained then the reconstruction looks rather more sensible. Just about everything in the chassis must have been discarded with even the wheels of a different size. I'm still struggling to fully understand the Vulcan drawing, but I'm also coming to think that at least the valve rods ran under the front axle rather than above. I'm really struggling with the drawing as regards the piston rods. As far as I can see at the moment the pistons are directly in line with the leading wheel axle, which is surely impossible. I'm increasingly tempted to believe that the locomotives had a major reconstruction that hasn't been recorded, because I find it hard to believe that something so very unconventional ran for 12 years.

Numbers 34 and 35 seem to have been reserved for oddities! Later there were a couple of Dean 0-4-4Ts. The original GWR 34 & 35 were a pair of locomotives built by the Vulcan Foundry which the Shrewsbury and Chester Railway bought off the shelf in 1853, and one may suspect at a bargain price. They could be described as long boiler 0-4-0 tender engines, but the drive was not to either wheel axle, but to an intermediate crank axle, somewhat in the position that the middle driving axle of a long boiler 0-6-0 would be. An original works drawing of these oddities is available here on this excellent site of Vulcan Foundry locomotives . Presumably they must have been reasonably competent since they ran for twelve years before they were taken out of service. This drawing is from Ahrons "The British Steam Railway Locomotive" but was clearly originally published in "The Engineer". Anyway long out of copyright, so I'll break my normal habit and include it. In 1866 George Armstrong took these weird contraptions in hand and reconstructed them. They reappeared as long boiler 0-6-0s, the only ones of this configuration to be built by the GWR, although a fair number of others were taken over in the early days. They were definitely not in the general Armstrong style. and one may speculate how much of their predecessors was reused and why. RCTS claims that the boilers were of the same design as those of the Vulcan Foundry originals, but the surviving Vulcan foundry drawing shows a dome as does the above illustration. There's very little other information about them, and they were withdrawn in 1888 and 1889.

There's more inside at least the GW tanks than one might expect. This page is mainly about promoting the tech the company used to repair the tank, but there are excellent photos of the interior. The MR ones might have done without all the internal bracing, I don't know. https://www.corrolesseastern.co.uk/tank-lining-and-protective-coating-didcot/

Didcot is certainly covered.

That's a very good point, it hadn't occurred to me, but I think you're right, it was the classes with drum head smoke boxes that had supports to the footplate at the front end. Hence 94 and 15 . The usual GWR exception seems to be the 1366, which had brackets to the running plate but not a drum head box. I can't think of any drum head boxes with the support brackets though.

According to Ken Cook, GWR Works manager in the 40s, his predecessor, Hannington, was known to swim in a water tank from time to time. Apparently he also took a cold bath each morning in a pond in his garden, breaking the ice if necessary! In the end his love of water was his undoing as one day he dived head first into a 5 foot deep swimming pool at his daughter's school and fatally hit his head on the bottom.