JimC

5 hours ago, Jim Martin said:

Did companies do the same thing with locomotives?

The early GWR system certainly worked like that. Renewals, which were replacements for existing locomotives containing at least 0% (!)  of the parts of their predecessors, were given the numbers of the locomotives they replaced, but additions to the fleet were added on at the end of the list.

5 hours ago, Andy Kirkham said:

I'm sure I remember people referring to "The Concorde", as if there was only one of them.

But more often without an article at all, which is even wierder.

15 minutes ago, Compound2632 said:

I think it gets a bit messy with the 0-6-0STs?

Very messy as Dean had to introduce a second block and small wheels (eg 850/1901/2021) were separate from larger wheels.
So there are 0-6-0Ts under 1300 in the sequential series, 1501-1900, 1901-2160 (small wheel) and 2701-2800 in Dean's  blocks, and then the later classes under Collett. And note how Hawksworth reused 15xx and 16xx, but starting at 0 not 1.
I worked this out in some detail in my book (see sig - shameless plug!), which has over 2,800 words on GWR numbering! Its all in RCTS in one place or another, but it was quite a bit of work to try and bring it all together in a (hopefully) logical form. 

3 hours ago, Compound2632 said:

A curiosity: once the block numbering of locomotive classes had set in, numbering started at 0: 2800, 2801,

More complicated than that! At one stage post grouping the GWR had at least four different numbering schemes in use concurrently!

In Gooch and Armstrong days locomotives were pretty much numbered sequentially, with complications for renewals. Most of these were never renumbered.

Dean introduced blocks for wheel arrangement, but with no attempt to separate classes, instead each lot followed on sequentially. These blocks started at one eg 3201 - 3500 was passenger 4 coupled, and started like this:
Numbers              Class

3201-3205           Stella (2-4-0)

3206-3225           Barnum (2-4-0)

3226-3231           3226 (2-4-0) (built 6 of these which complicated things!)

3232-3241           3232 (2-4-0)

3242-3251           3232 (2-4-0)

3252-3253           Duke (4-4-0)

3254-3261           Duke  (4-4-0)

3262-3272           Duke  (4-4-0)

3272-3291           Duke  (4-4-0)

3292-3311           Badminton (large wheel 4-4-0)
Some of these (mostly 4-4-0s) were renumbered to bring classes together in 1912

Churchward we know about (blocks starting 0, second digit indicating wheel arrangement, classes kept together where possible )

And then the absorbed classes at the grouping were ordered in wheel arrangement and power reusing available numbers below 2000.The arrangement by power was particularly odd because it split up locomotives of the same class which had derated boilers, and that got even odder when they were reboilered with GW boilers and the numbers not changed.

Or just twenty eights. There don't seem to have been hard and fast rules. A variation I've seen in some WR documentation at least is to refer to a class by the most recent number range, eg Castles as 70xx, 57s as 36xx, 28s as 38xx.

2 hours ago, rodent279 said:

2 questions.

 

1. How does the Std no.10 boiler compare with that fitted to 9351, the 51xx converted to a 2-6-0 tender engine by the WSR?

2. What would a similar exercise using a 45xx as a basis look like, and would it be a useful engine?

1. On boilers I have a web page: https://www.devboats.co.uk/gwdrawings/gwrstandardboilers.php
9351 has a Std 2 boiler. Compared to the Std 10 its 9 inches longer in the barrel and a foot longer in the firebox, so an appreciably bigger boiler - 1349 sq ft total as opposed to 1248 sq ft. 

2. I have drawn a 45xx based 2-6-0, probably somewhere back in this topic, or on my fictitious locos web page https://www.devboats.co.uk/gwdrawings/fictitious.php

I've heard it said that 45s were regularly seen at 60mph, so it probably doesn't need 5'2 wheels. I think you could just about squeeze 5'2 wheels on, at least with some brake reworking , and it might benefit from some more adhesive weight. Sadly I'm not competent to do a weight study and see how the numbers would come out. The 44/45 boiler is the standard 5. The Std 3 had the same firebox as the Std 2, but a shorter barrel like the Std 10.

The big drawback of the 2251 was that the bigger and heavier boiler compared to the Dean Goods took it out of the unrestricted weight category, and hopefully this wouldn't be restricted. The WR managed to get away without an unrestricted Dean Goods replacement, but presumably one could also have been contrived with a 57xx boiler on a 2251 chassis.

I have sketched up such a beast, and it looks, well, horribly anomalous with a side window cab stuck on the back of what is otherwise pure 19thC. I included a 3,500 gallon tender, which didn't help, looking biger than the loco!

1 hour ago, AlfaZagato said:

There may have been some desire for the additional sure-footedness associated with 'all-driver'

I don't suppose the significantly lower capital cost did any harm either. Work on the design seems to have started in 1928, before the great depression really bit, but times were still difficult.`

This came out of the how common were outside cylindered 0-6-0 tender engines thread. The question was "supposing Collett had elected to build the 2251 class 0-6-0 as an outside cylindered 2-6-0?". The premise seemed simple enough: basically a 2251, so the short Std 10 boiler and with 4575 cylinders bored out to 17.5in.  How hard can that be? Well, when I started trying to assemble parts, getting in as many standard components as possible, the answer - at my skill level at least - was "very hard". Nothing fitted!

After rather longer than I might admit to I gave up and rethought the thing completely, and I believe this makes for a reasonably credible concoction. The boiler is still the Std 10, and wheels 5ft 2in, as that was the point of the exercise. The cylinders are still 4575, but I had to lengthen the slide bars and piston rod in order to meet the standard connecting rod. I have my doubts about whether this would be a good engineering option.  Thereafter the chassis is basically 4300, but shortened at the back with the third driver set moved forward in proportion to the shorter firebox of a Std 10. The smokebox is extended backwards slightly for the shorter boiler than the Std 2.  The cab is the same size as the 2251, and the tender is a flush tank 3,000 gallon. It would readily be turned on a 55ft turntable.

As a slight aside, I've been trying to sketch up an outside cylinder 2-6-0 version of the GWR Collett 2251 and it's a surprisingly difficult task unless I accept large numbers of new design non standard parts. The theory seemed sound enough. 4575 front end with cylinders taken out to 17. 5in, extended smokebox, job done. But when I get down in the detail nothing fits. Not only is the small prairie connecting rod too short for the larger wheels, the large prairie/43 etc rod doesn't fit either because of the wheel spacing. Alter the wheel spacing, non standard coupling rods and problems locating brake gear, the difficulties pile up...

With regards to the Bulleid Q1/Maunsell Q, I understood it was a minimally changed Q chassis with an oversized boiler and much weight saving to permit the boiler. As little new design as possible to save time. 

I suppose money? On the GW side if you compare a 2251 to a 43, even a baby 43 as produced by the WSR, then the latter is a considerably more complex and expensive locomotive. Even if scaled down further, say roughly a 2251 with a 4575 front end, (must sketch that) then it's clearly a more expensive piece of kit to do the same work. So perhaps the question is whether the 2-6-0 would be sufficiently kinder on itself and the track to make maintenance savings enough to compensate for the extra first cost and extra parts to maintain? 

4 hours ago, Flying Pig said:

Speed means power, and power needs grate area and heating surface so there would be a limit to what you could get out of a Manor boiler, however many cylinders you had sucking steam out of it.

I tend to agree. I suppose if we imagine the original 14.25 in Star cylinder size and Sam Ell's refinements to the Manor draughting it might just about work on a route with opportunities for mortgaging the boiler and recovery. Anyway it was quick and easy to draw like this. Star chassis, slightly shortened, Manor boiler and cab.  I've drawn it with full size (6'8) wheels which would bring the power down, but maybe reduce the steam required a little at any given speed. It would also bring weight problems, so there would probably have had to have been a lot of weight saving. I narrowed the footplate valances and gave it County style continuous splashers in that vein (and to try and make it look a bit different), so we assume it was 1947 built.  Its not, I fear, a very inspiring creation, being something of a universal GWR 4-6-0. It was however rather quick and easy to draw. The tender is a mythical Hawksworth style 3,500 gallon tender I drew up for another project.

4 hours ago, The Johnster said:

 So, this is a pleasant but rather irrelevant discussion, as 4MTs held the fort until the arrival of dmus; what would bigger tank engines have been for?  This is borne out by the experience of the 1938 31xx 'superprairie'; there was actually very little work for them.  .

This is pretty much what went through my mind when someone suggested the concept of a twelve wheeled GWR tank. The Churchward locomotives and their derivatives somehow seemed to manage with smaller boilers and larger cylinders than their LMS/BR equivalents. The extra pair of wheels could only really be justified by a bigger boiler, but there seemed no need for one. Still, it was fun assembling the parts into that form, and a bit of fun is after all the point of the exercise! 

The 2-6-4 will have much more water capacity in the bunker under the coal space than the 4-6-2 don't forget. To give you an idea this the graphic is the back tank and coal space from a 42xx, which is also quoted as a nominal 3.5 tons of coal.
 

But yes, I admit I haven't scaled the tanks. Perhaps I should let's see.
Roughly speaking . The 2-6-4.

The bunker will be about 8 feet wide and 7 feet long at the top, so 3.5 tons of coal, if I have my sums right, would be a coal space 30in deep (it wouldn't be that shape of course, but it makes the sums easier.
That leaves about 8 feet by 6 feet by 3ft6" for the back tank, which would be about 1050 gallons.

I've drawn side tanks that approx to 17ft * 4ft4" I reckon. The barrel casing on a Castle is 6ft wide. So the tanks will be about a foot wide at boiler centre and above, and wider below.  Lets say an average of 15 inches. I make that 540 gallons. So total water capacity I've drawn is 2,130.  [Redacted] me, how on earth did I get that close. 

The Manor tank, by similar crude estimates comes out slightly larger, but not much, about 2,300 I think.  The back tank is small, only about 300 gallons, but the side tanks, as well as larger lengthwise and height, are also a bit thicker with the smaller boiler.

Remember though, these are really little more than finger in the air estimates. Very easily be 10% and probably  more out. I must admit, though to being excessively self satisfied that my drawn by eye tanks are in the right sort of ballpark.

BTW they scale just under a foot longer than the BR tanks. Aesthetics, well we all have our own preferences!

[Later] what I should also have mentioned was that the small side tanks on the 2-6-4T were very much about weight. I remain concerned that were I enough of an engineer to do a weight study it would come out over heavy on the driving wheels, so I wanted as much as possible on the trailing bogie, hence the long bunker giving room for a substantial back tank.

10 hours ago, rodent279 said:

Not a very exciting one, maybe it's been done already, but how about extending a large Prairie into a 2-6-4, creating a GWR version of the BR Std 4MT?

A BR 4MT has 3.5 tons of coal and 2,000 gallons of water and a large prairie in final form has, you guessed it, also 3.5 tons and 2,000 gallons. So the difference is presumably that the 4MT has a bigger boiler.  But although the Prairies, especially in Std 2 boiler form, were anything but overboilered with the boiler feeding 18*30 cylinders instead of 18*28 on the 4MT, in practice it doesn't seem to have been a major issue for the duties they had.

But anyway, what that leaves us with, to justify a 2-6-4, would be a need for a larger boiler than the Standard 4. Next up from a Std 4 is a Manor boiler, and after that a Standard 1. A Standard 1 won't play I don't think. A standard 1 on a tender locomotive like a Hall and Grange is already red route, so if you add water tanks etc. then I doubt it will make the weight limit for anything but double Red (King) routes.  So either a new standard boiler, which is what I drew for a 2-6-4, or a Manor boiler (which is basically a narrower Std 1 length barrel with a new firebox). I don't recall all my thinking, but I think my reckoning was that a Manor boiler is too long for a Churchward Std based 2-6-4. On the standard types I reckon the firebox is pretty well immovable in relation to 2nd and 3rd driving wheels. So that left me thinking that a Manor boilered 10 wheel tank engine would be better as a 4-6-2 than a 2-6-4. Although I greatly fear that until Sam Ell had sorted out the draughting in the 1950s it would have been little better than a 3150. 

For a 2-6-4 it would need a boiler with much the same length barrel as the Std4, but a bigger firebox. So I figured pick the biggest that might have some chance of making the weights and that was the Castle box with a shortened barrel. The alternative would be a Std 1 firebox, but in that case the barrel could be no bigger than a Std 4 barrel, so the difference between my 2-6-4 and a 3150 might be a bit marginal... Of course if I were a real steam locomotive designer there would be about a thousand and a half factors to consider, but I like to think my Manor tank would have put up a fine show on heavy suburban traffic out of Paddington, Cardiff and Birmingham once Sam Ell had sorted it out.

Anyway, here they are, so feel free to vote on which is more impractical!

8 minutes ago, Steamport Southport said:

Mostly dock tanks though. Something to do with the short wheelbases making them unsuitable for the inside cylinders/valve gear.

A very good point that hadn't occurred to me before. As well as space for the eccentrics and expansion link, the connecting rod needs to clear the axle of the first wheelset, so the shorter the wheelbase the steeper the cylinder inclination and the higher the boiler must be pitched. I've been thinking that outside cylinders tend to encourage shorter wheelbase, due to the balance issues, but it seems its also true that shorter wheelbase tends to favour outside cylinders.

3 hours ago, The Stationmaster said:

the big saving was on prep time and that was carried out by an expensive Grade - Drivers - so savings there would feed back in improved productivity and reduced costs.  

But on the GWR at least wasn't prep a piece work task with two rates/allocated times, for large and small engines? That would mean no saving at all without renegotiating with the unions. 

I've heard it said that one advantage of the Churchward 2 cylinder layout was that a lot of shed maintenance tasks could be performed without disturbing the valve gear. 

3 hours ago, D7666 said:

I would apply Occam's Razor in that the simplest explanation is the most likely.

Indeed, but what is the simplest explanation? Is it that designers who were innovative with all sorts of other configurations suddenly became conservative when faced with an 0-6-0, or is it that an outside cylinder 0-6-0 may not work very well? Inspired by this discussion I drew up the chassis for the GWR 94xx (inside cylinder) and 15xx (outside cylinder) 0-6-0PT, (on my Blog post about 15xx if interested) and it was very striking how much various heavy components have to move forward relative to the driving wheels.  One thing that struck me while I was drawing it was just how unbalanced the chassis would look without the back half of the cab and the bunker. Now I'm not a locomotive designer, and I'm probably speculating way beyond my actual knowledge of the subject, but it seemed to me that an outside cylinder 0-6-0 would have to be effectively a long boiler type, or close to it, with the firebox largely behind the last driving wheels in order to counterbalance the cylinders.  So the result, I reckon, would be a very short wheelbase, fine shunting the docks at 5mph, but probably not what the PW side would welcome at 30mph on the mainline!

Are you aware of the ex Cornwall Mineral Railway tanks converted to Tender engines for the Lynn and Fakenham Railway?
https://rogerfarnworth.com/2019/11/16/the-lynn-and-fakenham-railway-part-1/ 

There's some other links on my blog page about the GWR history of the locomotives. https://www.rmweb.co.uk/blogs/entry/25405-gwr-13921393-class-0-6-0t-ex-cornwall-mineral-railway/

21 hours ago, The Stationmaster said:

.  And look what happened when they did use the arrangement on a short wheelbase engine where the Western 15XX 0-6-0Ts were very prone to oscillation unless they had a heavy load behind them to steady them.

There's also a weight distribution problem. Inside cylinders can overlap the driving wheels, so can be getting on half a wheel diameter nearer the first axle than outside cylinders. Effectively the leading wheel set is forced back and the locomotive becomes front heavy. It's evident when comparing 15xx and 94xx. 

13 hours ago, RJS1977 said:

I suspect too that preservationists tended to go for the biggest locos they could afford, because of the higher perceived prestige. Much as how now it's the "high spec" modern classic cars that tend to be preserved rather than the once more numerous lower end models that are the real social history.

I'm not sure that's true. If you look at the early history of say Bluebell and Dart Valley they were very much geared to tank engines. I recall some surprise when the Dart Valley bought a Manor, because what use would it be. There are non enthusiast related distorting factors, one being Dai Woodham's purchasing policy, and another what survived in service very late - Industrials and Black 5s!

As regards classic cars, build quality is a big distorting factor in survival. 

9 hours ago, Schooner said:

While I'm adding pictures, the other RTR pannier tank I'd really love to see is the rebuilt 795

which, like the 850 class, I think would sell as an industrial/generic

Its a shame that the original locomotive was an unusual type... Worth noting that 795's sister, 921, still a saddle tank, has survived into preservation, and that the builders, Brush Electrical, still survive in business under the same name. Indeed until fairly recently they still owned the factory in Loughborough where the pair were presumably built. The reason for the unlikely sounding Brush Electrical as a builder of steam engines is that they had taken over Falcon Engine & Car Works.

7 hours ago, DenysW said:

 except the Kings and the Night Owls - too heavy for most routes.

I think, from looking at WTTs etc, the restrictions on the 47s were at least as much about clearances as weight. Something of a moot point though. An interesting (to me anyway) observation is that Duchesses, A3s and even LNER V2s would have been just as restricted on the GWR as Kings. The LNER had a far higher percentage of RA9 routes than the GWR had double red. By published figures the Kings were much the same sort of weight as a V2. Some, at least, of the LNER constituents and the LNER itself must have had quite a programme of increasing RA. I do know that the LNER actually went as far as enlarging a few tunnels which presented particular gauging problems

Should you be considering maintenance costs more? Cook tells us the GWR upgraded Stars to Castles because they calculated that there would be a saving on maintaining the boiler. Similarly would a new 48 with all the advances in detail engineering run greater mileages between overhauls and need less attention than a 40 year old 2-4-0?

Trouble is knowing what we don't know... Cook tells us that after he had the works put together 3265, the prototype Dukedog, the running department where it had been sent said "Send some more like 3265". Now I can see that the factory would much prefer to have stronger and somewhat newer frames on Dukes rather than weaker frames approaching end of life, but in my ignorance of the day to day graft of running a steam locomotive it's not so obvious to me why the running side had indicated a strong preference. 

Coal consumption was a key overhead and given a lot of attention at board level, but so was maintenance expenditure. It's clear the GWR didn't value large wheel 4-4-0s since they scrapped them all in the 30s when presumably they were due for new cylinders and the rest of the sort of mid life upgrade other standard classes got, but it's less clear to me why. 

[Later - I wonder if it was a factor that if the GWR scrapped a County then a substantial percentage of the locomotive would go into the maintenance pool rather than be cut up. I have picked up hints that nominally all new locomotives might be fitted with refurbished parts, even boilers. I suppose if its good enough to run until the first heavy general then why not. It's not as if the components are going to stay with the locomotive it's entire life.] 

3 hours ago, melmerby said:

Hawksworth's 15XX was a big departure, apparently inspired by the USATC S100 tank 

I don't think that claim really stands inspection. The GWR designers could have seen an S100 when they started work on what became the 15xx in 1944, but perhaps little more than that.

I did write a blog post on this, which I shan't duplicate, it's here if anyone's interested. 
https://www.rmweb.co.uk/blogs/entry/25226-gwrwr-15xx-class-1948/

To summarise though here's my list of similarities and differences. 

Similarities

No footplate
Outside cylinders with prominent steam pipes

Outside Walschaerts gear

Wheel size 4'6 v 4'7.5

Differences

coal capacity (1 ton , 3.25 ton)

parallel/taper boiler

driven wheel

wheelbase (s100 as short as possible, 15xx longer and arguably as long as was practical)
boiler proportions (much bigger boiler on the 15xx)

For whatever my opinion is worth I think the similarities are mostly convergent evolution - what other configuration could you use for an 0-6-0T intended to be serviced without need for a pit. The main exception, the lack of a footplate, could just as easily be an idea pinched from Bulleid's Q1. 

1 hour ago, corneliuslundie said:

"Welsh Railways records Volume 1: Rhymney Railway drawings" by Nigel Nicholson, Trefor Jones and Mike Morton Lloyd (Lightmoor Press with the WRRC, 2010).

Which is an excellent volume, firmly recommended, and was invaluable when working out my RR sketches. Sadly, though, no drawing of the pannier tank version.