JimC

Yes, its easily forgotten that Churchward's early superheated locomotives had higher superheat. The first installation on 2901 had 3 rows of 8 flue tubes in a Schmidt superheater arrangement with 308sq ft heating surface, and 2922's first had 3 rows of 6 in a Swindon designed arrangement for 275 sq ft. The std Swindon superheater for the Std 1was 2 rows of 7 flue tubes for around 260 sq ft (330 for one group with 8 elements per flue rather than 6). Oil consumption was such a big item that it was reported to the board.

So perfect for a tail chasing oval then [grin]

Some 2721 saddle (later pannier) tanks were built with piston valves from Feb 1901. RCTS records that "piston valves had been experimented with from 1899", but I haven't managed to identify the earliest fitment. It seems well established that they weren't fully satisfactory until Churchward introduced the semi-plug type from the US.

I have heard that the loading gauge used on the Cornwall railway was significantly smaller than the main GWR broad gauge one. This must presumably have been height, since the rail to platform clearance must have been standard to within an inch or too, and as you've noted broad gauge carriages and wagons seem only rarely to have penetrated the upper reaches of the gauge. What one might call the eaves height is more significant, and it wasn't all that high on the GWR broad gauge. If you have loading or structure gauges for the Cornwall or anything else I would be delighted to see them. Incidentally I think I've succeeded in adequately reading the scale on the larger drawing. Assuming I'm correct then here is the shed opening against the gauges. The two marks do indeed specify the position of standard guage rails, but the platform to wagon clearance is much greater than I imagined. As you can see the opening is sufficiently large for broad gauge stock.

Interesting. Its a shame the scale isn't visible. There are two vertical lines at ground level on the elevation which one would think were rail positions, [Later. I found and I think managed to read the scale. The drawing below appears to be comprehensively wrong and all my conclusions struck through below utterly invalid!!] but when I line them up against GWR loading gauge drawings (narrow and broad) they don't seem to make any sense. I think its possible that the drawing represents filling in the end of an ex broad gauge shed for standard gauge vehicles, but that's highly speculative without a scale. The attached assumes that the cross beam is about the top of the post WW1 GWR loading gauge (green) which is a very big and unjustified assumption. Orange is a GWR broad gauge loading gauge. This sort of comparison would be much better done against the structure gauges rather than the loading gauges, but alas I do not have them.

What was your G/Grandfather's job in the 1920s? Its an odd grouping, since assuming they are all working men they appear to be all in Sunday best with the exception of the men standing extreme R & L with caps. The chap on the R at least appears to be in footplate overalls.

Can you read the lettering on the board? Might give some clues.

Not at all sure I can agree with you. Wasn't 833 a 517? Do you mean the 850s? The 2021s were basically an 850/1901 with a longer firebox and wheelbase, so they were very similar. The 2021s U class boiler was of similar dimensions to the Std 16 on the 16s, whereas the Std 21 on the 54/64/74 was significantly larger. And the 16s had the same 4'1.5 wheels as the 2021s. There were 158 850s/1901s and 140 2021s, so I submit that 115 54/64/74s weren't enough to replace them. If you add 80 16s the numbers start looking more reasonable. I submit that the 54/64 was a replacement for all the pre group autofitted 0-6-0s of various classes, the 74s were a replacement for all pre group types lighter than the 57s, which again wasn't just 2021s but a mix of 4'7.5 and 4'1.5 wheel types, and the 16s were a replacement for the rest of the small types. We shouldn't forget that the route mileage of lighter coloured routes was decreasing with upgrades and closures, especially during /after the war.

There's certainly no record in RCTS of the 136x or 16xx being autofitted. There was probably no need for the 16s to have the gear, with the 54s and 64s replacing autofitted 2021s on those duties. Only a small minority of the 2021s were ever autofitted. Interestingly the autogear seems to have been regularly swapped on and off pre group classes, and all sorts of locos were fitted from time to time, including small numbers of 4'7 wheel tanks - mostly though the earliest and least powerful.

The 48s were very much an updated 517 with a very similar boiler. I suppose all else being equal you want the cheapest locomotive that can do a particular job, and arguably the Metro sized niche was filled by the 54s and 64s. The 54s and 64s were straight developments of the Wolverhampton 2021 class, and the 48s had a lot of parts, motion especially I believe, in common, whereas a Metro derivative would presumably have had much less in the way of standard parts.

I didn't find one. Picture something like an Armstrong goods with the dome on the front ring, and the cab off GNR single no 1.

She didn't look remotely like that by the end of her working days though, with a small cab and a GWR boiler.There's a photo in RCTS volume 3, no C65.

And in case its not already obvious from the foregoing, the first "Collett" 3,000 gallon tender was built in 1940. The easiest way to distinguish the later style tenders is that the coal raves continue at half height round the back of the tender, whereas on the earlier ones they stop before the back. Swindon being Swindon though, tenders were mixed and matched and updated, so various combinations of features can be proved to have existed that were never built new!

Yes Tuplin's embellishments server only to make the tale less credible. I've heard it said his lurid speculation about the locomotive slamming into full gear plain couldn't happen on a piston valve locomotive and was a phenomenon restricted to slide valves, although I don't know enough about the engineering detail to know the truth.

Tuplin is always a dubious source, but the story also appears in the much more reliable Ken Cook's book (and Cook knew Churchward). Professional locomotive engineers seem to have had a low opinion of Tuplin, so it seems unlikely Cook would use him as a source.

Its widely reported with varying numbers!

I find it very hard to be sad about the demise of deep coal, its a horrendous industry that destroyed people. The failure was in not finding alternative employment, but time to stop before getting into too much politics.

You could, I reckon, get 13ft wheels to fit in the Broad gauge loading gauge, which would give room for a more substantial boiler.

Fowler, knowing he was not a steam locomotive designer, deferred to Anderson, who had been. Normally that wouldn't be a mistake.

Well, if it means your locomotives are 20 years behind the state of the art then it might be...

Its also been my experience that how good a senior exec was at doing my job when they were younger bears no relationship to how good they are at doing their job now.

Taff Vale rail motor No 1, 1903, at Cardiff West Yard.

If you mean fig 360 in Russell I'm pretty confident those are 10 spoke. Whilst one may not post full images, scanning the book photos and posting them cropped down to the wheels only would be within the fair dealing clauses.

No, but if you find something better than a weight diagram please let me know.

I think you need to supply some evidence for that, since everything I know is to the contrary. The GWR started a policy of rebuilding bridges to a 22 ton weight limit at the end of the 19thC. Introducing the Kings on the tight timescale was only practical because enough bridges on the key routes had already been upgraded that the rest could be done quickly. To the best of my knowledge the policy continued, which is why the Kings were able to be used on more lines after WW2. As for imaginary wide firebox GWR atlantics, I sketched this one a while back. Its a shortened version of the Bear's boiler on a Star chassis. Goodness only knows what the axle weights would be, but probably King territory.