JimC

In "Chronicles of steam" Cox talks about testing in the 1930s with "the 17mph average running speed of the working timetable" and some experimental runs at 23mph with a lighter load.

If the pit under Caerphilly at Swindon is any guide then its far deeper than a working pit would be. In fact it would be quite useless for doing any work on the locomotive!

I wonder just how big the GWR route map including everyone's fictitious lines would be [grin] Salisbury shed closed in November 1950 according to Lyons.

But maybe not as much fun? There's probably more than might be thought to "back reving" a 57xx. The shorter front overhang of the pre group classes is quite distinctive, and the valancing under the footplate needs quite a lot of extra material added.

The S class were four powerful and heavy shunting engines, delivered by Hudswell Clarke in 1908. They bore a definite family resemblance to the R class 0-6-2T, with the same coupled wheelbase but a shorter boiler, a round topped firebox and smaller driving wheels. Their original boilers were replaced with A class boilers by the grouping. They joined the GWR as 608-611. In 1930, all were rebuilt with superheated Standard 10 tapered boilers and new GWR style larger bunkers. They were renumbered 93-96 in the 1946 renumbering and all survived to British Railways to be withdrawn in 1953/4. The first sketch is intended to show the class as delivered, with the round top firebox and the short lived oval number plate. This sketch should be treated with caution, since I didn't have a good drawing to work from, just a particularly rudimentary weight diagram, although I did have a good official photograph. There was particular difficulty in reconciling the proportions of cab and tank between the photograph, the weight diagram, and drawings of the class after reboilering with a GWR boiler, and I just crossed my fingers and hoped for the best. The reboilered version of the S class is covered in this entry.

I'm reasonably confident the forward chimney position is associated with superheating. Whether it was moved back again after superheaters were removed is another question, but that's not your problem. I believe the pipes along the boiler top and into the smokebox are all or at least mostly lubrication runs.

These were essentially updates of the S class (qv), slightly longer and with larger bunkers, and based on A1 class 0-6-2T design features. They also had a slightly larger boiler with a Belpaire firebox. They were delivered in 1920 by Hudswell Clarke. They were numbered 604-606. Plans to reboiler them with Standard 10 boilers were never acted on, although one did receive an enlarged GWR style bunker. They did acquire GWR safety valves and covers and some additional tank fittings. They were renumbered 90-92 in the 1946 renumbering and were all withdrawn in 1954. The S and even more the S1s were large and heavy for 0-6-0Ts. At 56 tons 8cwt and with 19tons 10cwt - the GWR red route limit - on two pairs of driving wheels they were heavier than their eventual successors, the GWR 94xx class. One may compare 46 tons 10cwt for the USATC tanks and 48tons 5cwt for the Riddles Austerities.

Or "What if Gresley had been succeeded by Bulleid?" [grabs coat, runs for the door]

Presumably its a shallow grate and a somewhat convoluted ashpan. A challenge for the fireman and a very complicated layout of dampers I expect. We are after all in the realms of imagination. I'm sure that plenty of the imaginaries I've posted here, if examined by a trained steam engineer, would turn out to have some comprehensive flaw to render them inoperable.

I believe just about all of the tales in the original books had a foundation in real events. Sadly once the TV companies started on their own plots that was lost.

Or another Hecate?

If we rework the question to "what locomotives would the GWR have used on my fictional branch" , then gradients are going to play a significant role, I suspect even more important than water capacity. I suppose in a dream world you might produce a gradient profile for your fictitious line and then compare with other GWR branches, but then you maybe need to design your route and civil engineering which all gets a bit out of control if you just want a credible model. And to complicate there were plenty of branches that were not run with auto trains, but used standard tank engines, and these might even be turned at each end. So I think I might look at it from a different direction. What is my planned coaching stock? If its going to be auto trailers then 45s can be ignored, it will be a 14 if there are one or two trailers and not too steep, or a 64 if up to four trailers and/or more gradients. Auto fitted 45s were a specific BR era usage in S Wales, you can ignore that option. If you don't want trailers then the choice is wider and includes 57s as well as 45s, and they might even be turned at the terminus. And if you consider your terminus has a small turntable you can even add 2251 or Dean Goods to the mix.

You'd have to draw up all the internals really to work out weight distribution. Shape of the tanks, shape of the coal space, internal dividers... Water pickup gear when that started to be fitted must have complicated things too.

Especially as it would surely not have been finished until the state of the art was much more advanced.

Yes, although the 56s did have piston valves rather than silde valves. They also had an all new motion design which AIUI those that understand such things regard as being theoretically superior to the older style layout that continued to be used on six wheeled classes with inside cylinders.

I doubt it. Russell vol1 has a late 2721 diagram, which shows 6'6. But its just another example of the compromises Hornby had to put in to make the existing chassis work. The Hornby designer did a really good job of making it look like a 2721 when you consider all the dimensional handicaps he was saddled with. That LMS wheelbase is just so damned long. I was looking through Russell absorbed earlier these evening, and not one 6 coupled locomotive I could see in there had a wheelbase as long as 8' + 8'3. But it is what it is, and I think what the OP is up to makes a lot of sense in the circumstances.

We're confusing you I think, with a digression onto other types. A 2021 is a considerably smaller Wolverhampton built tank. A 16xx would be a dreadful candidate for a 2721, 1854 or similar - better off with the Hornby chassis! An alternative for the saddle tank would be to fabricate it from plasticard. Multiple layers of thin plasticard glued together hold their shape, and you could to advantage readily simulate the overlapping panels of the original with, well, overlapping pieces. Find a metal or glass jar the right size, tape the plasticard over and soak in hot/near boiling water and it will hold a curve. Do two pieces and cut one up into the actual panels and glue them on and you should be able to get something not a mile away.

Yes that's the P class (only one by that date) and a very useful looking photo when I come to it. I believe the Rhymney locos rarely went to Swindon, and that they were the best maintained fleet at the grouping. Very much in RR condition there still with pop safety valves.

The last of the outside framed classes had been delivered to the Rhymney in 1900, and from then on the locomotives took on a much more modern appearance. The first were what was later to be called the M class, and the detailed design is usually credited to Robert Stephenson & Co. All subsequent locomotives for the Rhymney, other than a pair of locomotives which started life as railmotor units, bore a distinct family resemblance. These locomotives form a complicated and rather incestuous group, since around 17 variations on the 0-6-2 theme can be identified, all sharing a common 7ft 3in + 8ft 0in + 6ft 0in wheelbase which was also seen on similar locomotives for other lines and even the GWR's 56xx class. Within that there are three basic themes: 4'6 wheels with larger boilers (M, R), 5ft wheel with a smaller firebox (P), and 4'4.5 in wheel also with the smaller boiler (A). There were subclasses with round top and belpaire firebox boilers, and some experiments were made with boilers swapped between classes. When the GWR introduced their own boilers the Ms and Rs received Std 2s, and the Ps and As Std 10. It's also helpful to consider the S and S1 class 0-6-0T when looking at the RR locomotive development. The actual construction order was M, R, S, P, A, A1, P1, S1, AR/AP, and its helpful to keep this in mind tracing the development between classes. The original boilers on the Ms, which had Belpaire fireboxes, were considered unsatisfactory, and by the grouping all were running boilers of the design first used by the R class. The GWR tended to treat the Ms as one class with the later Rs, albeit with subclasses represented with different diagrams. They were numbered 33 and 47-51. This first sketch represents what was temporarily known as the Mr Class, being the M class fitted with the R class boiler. Once all had been converted the r disappeared again. The Ms received R class cylinders in the 1930s. One was rebuilt with a Standard 2 boiler and GWR style cab, but otherwise they had few changes beyond safety valves and larger bunkers. The second sketch is intended to show the one M, no 47, that received a GWR boiler - a standard 2. The resemblance to the GWR 56s is surely no coincidence, but in point of fact the conversion wasn't carried out until after the 56s had been in service a few years. Two Ms were withdrawn in the 1930s, but the rest survived the war, three getting to British Railways and the last going in 1951. The dark Brunswick green I've chosen to approximate (with lining missing) RR paint tends to hide detail doesn't it. I shall have to think about that.

And, ideally, the dome and maybe other fittings. It might be an interesting thing to try with a scrap/damaged body. Must be plenty about.

Unfortunately RCTS doesn't give any dates. The precise wording is "Top feed was fitted at times to..." and I submit its a reasonably safe bet that locos noted gained and lost top feed as boilers were rotated. RCTS mentions a few 1813s, 1661s and 1854s as having had top feed at some stage in their lives too, so one may guess it was a matter of a handful of experimental boilers circulating round the fleet.

Yes, converting from a large type pannier )1813/1854/2721/5700 to a small one (850/2021) would mean changing just about everything. A Bachman 64 would be a better candidate for a 2021 conversion (revering history), although the wheels are too large.

RCTS says top feed was found on 2734/54/61/85/6 and possibly others. Curiously all but 86 were in the minority that were never superheated.

The S2 boiler with pannier tanks was a rarish beast. The dome is a good way forward of where it is on the Hornby model. Bit smaller too possibly.

A good point. There's nothing particularly unusual in a client putting forward a specification that looks impossible in the hopes that the supplier will know more than they do. I recall in my brief industrial chemistry days my employers were asked for a chemical stripper that would remove nylon coating from aluminium zip fasteners so that those that failed QA could be recoated. I wasn't allowed to send out my proposal to dissolve out the aluminium and recover it from solution... Mind you who knows, 40 years later maybe that's possible.