[Boilers with flue tubes but no superheater elements.]

I would have thought that too, but apparently not. I've got a scan of the  drawing "Arrangement of tubes Standard boiler No.7" in front of me, (59502, June 1920) and whilst the arrangement is basically the same, they are definitely spaced differently at the firebox end.

 

I've just spent some time trying to understand the drawing - in the past I've given up, frustrated!
As well as the position of every tube at 3in to the foot scale it has insets at full size showing arrangement of small tubes at each end around the centre. At the smokebox end it shows hexagonally packed with horizontal spacing of small tubes 2 3/8in and vertical spacing of 1 3/8 in. At the firebox end it shows 2.33 in horizontally and 1.45in vertically. And yes, it does have that mix of decimal and vulgar fractions! First time I can recall seeing decimals on a GWR drawing. As I'm sure you all know without me telling you the vulgars work out at 2.375 and 1.375.  Which means that the firebox end tubes are spaced narrower horizontally and wider vertically compared to the smokebox end! When you go over the whole drawing it gets even more complex. The top couple of rows of tubes are horizontal at the smokebox and arched slightly, following the inner firebox profile at the other end. The bottom rows at the firebox end are stretched down towards the grate. The whole arrangement is immensely complex and very difficult to understand in words or even on the drawing! It seems to me that immense effort must have been put into optimising the layout.

[Errors/Inaccuracies etc]

Its all very weird though. Freezer must surely have seen umpteen 94s. How did he get the idea they had screw reverse, and where did the other tales come from? Offhand I can't think  of any GWR classes that converted from screw to lever reverse in the right sort of timespan that the tales could be confused with. 2251s went the other way I believe.

[Errors/Inaccuracies etc]

94xx reversing gear. I've been pointed at drawing 122690, which is for Lot 365 and is of reversing lever and quadrant. That's an October 1945 drawing for lot 365 , the Swindon build, so I'm pretty reasonably confident they were all lever reverse.

[2-4-0s, and the Armstrong era in particular]

23 minutes ago, Compound2632 said:

 

By which I take it you mean new frames (were there changes of wheelbase?) and / or new cylinders?

Yes (all of them on one or other!)

There were all sorts of combinations of frame setups, some of them quite eccentric to my eyes.  Quite a few of the 2-4-0s had inside frames for the driving wheels and outside frames for the leading wheels. Maybe it made for more room round the cylinders. Actually, you've got me wondering now, what were the cylinders fastened to on a locomotive with just outside frames?Must look that up.

And you remind me of an excellent point. I need to make very sure I've distinguished (correctly) between outside frames and double frames (or even part and part!)

[2-4-0s, and the Armstrong era in particular]

Here's another little in progress vignette. I thought I should make myself a list of 2-4-0 builds and renewals so I can get a bit of a track on what I should be documenting. This list doesn't include a myriad of boiler variations, it just new builds and renewals and rebuilds which had significant chassis changes!
Its a working document for me, so excuse the formatting and the crude layout, also the screenshot because I couldn't be bothered to format text for the web forum, but I was so struck by the variety I thought I'd share it.

 

My next job is to list which I have done sketches of, which I have enough info to make sketches, and which, for I fear there will be some, are going to stump me completely!
 

 

[A Missing Link?]

On 13/09/2023 at 20:30, crompton said:

"It is a capital mistake to theorize before one has data.” Sherlock Holmes

Maybe so , but it can be great fun. The massive beartrap waiting, though, is to be so pleased with one's highly logical and plausible theory that you attempt to hold onto it after contradictory evidence comes to light.

 

Been there, done it, hopefully metaphorically slapped myself round face and instructed self not to be so daft.

[A Missing Link?]

The words "Thus the six-wheel engines for the seven-feet gauge, as those on the Great Western Railway, belong to class A"  are interesting. I should have thought that choice of words at  their least imply that there were other Class A engines. I'm away from my library, but what was the situation with other broad gauge lines that early? Were any operational? I just had a reasonable scan through RCTS broad gauge, and I don't know how thorough it is on locomotives that never made it to the GWR. Mind you a contractor's locomotive is also a very viable possibility I would have thought.

[Tender Drive - a convenient short-cut]

I note that many of the GWR 2-2-2s had the same size leading and trailing wheels. That causes  me to idly wonder, not having much anything in the way of skills in this area, whether one could drive the carrying wheels and leave the driving wheels running free. Given double frames, perhaps the driving wheels could sit independently on short axles, leaving a gap between them for mechanism.

[Errors/Inaccuracies etc]

54 minutes ago, MikeOxon said:

On the few occasions where there are photos, however, I have found frequent discrepancies from the drawings. 

I suppose if no battle plan survives contact with the enemy then perhaps no arrangement plan survives the first general overhaul!

[Errors/Inaccuracies etc]

One could have a spot the difference here! Feel free folks, especially if you can spot something I'd otherwise miss when I come to my sketches. I was thinking that these two variants on the 79 class were so alike as not to be worth illustrating, but I've decided there's enough change there that it should be highlighted.

These are the Ahrons drawings, from the Holcroft Armstrong's book, of the 2nd Goods (1857) and the 4th Goods (1861). The thing that particularly struck me was the apparent lack of a sand box on the 79. I suppose there could be a tiny sandbox between the frames, (I've found what appears to be one such in "The British Steam Locomotive" but its a bit odd. The actual pipes are clearly different, Ahrons is not tracing his own drawings. It could be an error I suppose, even Homer nods. 

I'm beginning to find this early stuff rather fascinating, but always the way I suppose. I fear I lack the skills and perhaps more importantly the determination to follow @MikeOxon into modelling the period though. I will admit to being happy to have little in the way of locomotive breaks (we are in the 19thC here, breaks is correct) as I find them a particular pain to get right.

[Errors/Inaccuracies etc]

Well, it would seem so. Its not impossible, I suppose, that some were screw fitted initially, maybe the first lot, but bearing in mind that screw reverse needs to interact with the firebox casing if not the tanks I can't imagine fitting it would be a shed job, even f the factory would supply the parts. I'll ask on GWSG. Someone there should know.

[Errors/Inaccuracies etc]

That seems to be the case, yes. Certainly neither 9400 or 9466 have it now.

[Book Format for Locomotive Development]

Annotated drawings is a good thought. I did something like that for GWR valve gear because I had trouble working out what all the bits were, and especially as the GWR occasionally uses different terms to other lines. 

http://devboats.co.uk/gwdrawings/GWStephensonGear.php

 

I've also done a page of reversing lever arrangements

http://devboats.co.uk/gwdrawings/GWReversingArrangements.php

 

I'll have a thought what else might be useful. Suggestions welcome. Just don't expect me to explain how an injector works!

[Book Format for Locomotive Development]

Absolutely. The images have to be in strict date order, otherwise what's the point. 

[Book Format for Locomotive Development]

Running numbers and Lot numbers... How important to list these do you think. Lot numbers seem rather arcane, but are really rather important because changes were normally introduced with new lots. Running numbers are really rather less unimportant in development, but rather important if you are trying to work out what you are looking at. 

At the moment I still don't know if I like the format. Its rather cool to be able to page down, look at the sketches and see how the general style changed from domeless Gooch, early small dome Armstrong and when I get that far various dome positions under Dean, plus inside frames outside frames, sandwich etc. 

But on the other hand it feels as if the average entry could be something like:

 

XXX Class 2-4-0 1866
[image]

Lot ZZ, numbers 456-499 and 1024-1037. 
14*24 cylinders and 5ft driving wheels. This was the first XXX Lot to have bushes rather than cottered bearings on the connecting rods.
See p13 for earlier class members, page 22 for the next batch built and p45 for the 1878 renewals.
 

or alternatively (see discussion below)
For the previous Lot ZQ see P13, for the next Lot AAB see P22, and for the 1878 renewals see P45. 

 

Well maybe not quite as bare as that, but you get the point. But as Mike said with RCTS available again there's little point in going for RCTS levels of detail, but I think the consistent series of sketches has something to offer...

I've also been playing with indices, having figured out a peculiar bug/feature in MS Word which was stopping me creating multiple indices. At the moment I'm playing with Illustrations, Classes, Year/Class, Lot, and CME/Class. It occurs to me, as a thought, whether rather than having all the class numbers in the text it would be good to have an index of class number. Ferocious bit of work, and you'd end up with multiple entries for some numbers, but it would be a useful thing to have even if some entries looked like

149-163 - page 75

157-164 - page 13

157-164 - page 35

159 & 159 - page 82

Easy to end up with a volume that had ten pages of inexes at the end though! 
What do folks think would be useful? Also what about cross references like the "see P 13" in the example. It seems to me vital that one can readily follow a class through this annal format which does mean lots of Xrefs. Having that based around Lot numbers might be helpful, as in the variant above.
 

[Book Format for Locomotive Development]

15 hours ago, MikeOxon said:

Their biggest weaknesses in those books are the very small illustrations and very little about constructional developments and details,

Yes indeed, I'm looking at developments as much as I can for the 19thC developments, injectors, cabs, all that sort of thing. If the idea comes off it should be possible to page through and see the design progress in successive illustrations. In an ideal world I'd combine my profile sketches with a good selection of photographs, but the trouble is I find the cost of library photographs quite prohibitive, and all the older stuff is with Locomotive Publishing Co collection at the NRM. I wonder at the economics of books full of photographs.

[Book Format for Locomotive Development]

So at the moment I'm thinking that maybe I should mark boiler capacity in the "too difficult" column and omit it. After all it would need something quite extraordinary to be able to distinguish poor steam generators from good ones by dimensions.

[Book Format for Locomotive Development]

Yes, I too have bitten nails in frustration over boiler diameters... I think realistically the amount of data you need to do a proper job for modellers is beyond my capabilities. Typically one of my profile sketches takes two or three days, depending on the level of detail I have in sources and the number of components I already have available. At one extreme I can do a fictional locomotive from the GWR parts kit in a couple of hours. At the other extreme if I have a hazy GA drawing with lots of detail but nearly impossible to read, and want a better level of detail than something weight diagram sourced it can be days. But if I was trying to do something for a modeller... (None of this will be news to Mike)

Of course the first problem is sourcing data, You need elevations and probably sections.  If the drawings are available they're probably in the NRM collection, and at £7.50 a scan it soon adds up - I have done something in the region of 200 sketches for the book, and if you were to budget 20 or 30 quid for NRM files for each then it starts to hurt!  And then the amount of work in getting end elevations. Profile photos are relatively common and useable (and I can count the number of spokes!). When really desperate I've tried de-perspectiving (there'll be a word for that) 3/4 or at least 7/8 photos, but its hard work. Getting elevations from photos, well I find the thought quite intimidating. I would think its got to be weeks not days to produce a three view drawing.
 

Anyway, yes, thanks for that, it all helps crystallise my thinking. 

[Book Format for Locomotive Development]

Boiler dimensions...

The last book had a big table of leading dimensions for each class, Builder, Dates Built, Number Built, Route Colour, Power Class, Tractive Effort, Driving Wheel Size, Cylinder Dimensions, Wheelbase ,Front Overhang , Rear Overhang, Boiler Class, Dates Withdrawn (overhangs mainly/only 0-6-0 classes where it differentiates between classes and was often altered). Now all well and good, but the big tables distract from readability and I'm trying to give this a bit more flow, and also in general make it a smaller volume*. So I was thinking that just driving wheel size, cylinder size and some measure of boiler size in the text would be enough to get the picture.

So I thought it would be a good idea to quote heating surface of the boilers as a measurement of real size and to illustrate capacity increase. I'm realising, though, that in the mid 19thC they were really cramming tubes into some boilers, to the extent that a new built 645 had a deal more heating surface than a 57xx, and very nearly as much as an unsuperheated 94xx, which was a far larger boiler. I've read, too, that these had the tubes crammed in too much to be optimal. So I guess I have to abandon that measure as being misleading.  The question is what to substitute. The best measure of boiler capacity of course is to list the whole damn lot, physical size, heating surface, the lot but that's getting into the dense lump of numbers I was trying to avoid.  I suppose barrel diameter and length and firebox heating surface might be the closest to a simplified measure, but that seems to be a nasty mix of measurements. Would barrel L & D plus firebox length be too simplistic? Or am I still getting over buried in numbers, and it would be better to skip the boiler data completely? But if I say OK, let's have a table at the end, effectively that's repeating the RCTS Boiler Appendices. and even if one simplifies its still a massive body of data and pretty damn indigestible. With RCTS now readily available on line at moderate cost it seems somewhat pointless to replicate a sub set of it. 

 

Any thoughts, suggestions?

*which as I seem to be doing a fair number of extra sketches may be doomed to failure

[2-4-0s, and the Armstrong era in particular]

The Birkenhead Railway was 'vested jointly' (which I presume means taken over and split up) in the GWR and the LNWR on 1st January 1860, and the GW and LNW got 21 of their locomotives each. Their main routes ran from Chester to Birkenhead and Chester to the LNWR near Warrington and became a joint line of the two companies.

[2-4-0s, and the Armstrong era in particular]

Here's a bit of fun, and probably some procrastination as well. This is the current contents of my 2-4-0 sketches directory. There are a good few more to come I reckon, which is rather intimidating. The main takeaway, of course is how all GWR locomotives look the same... 
I think at the moment I like the appearance of the 111 early best.

[2-4-0s, and the Armstrong era in particular]

Yes AIUI the straight footplate on the 824 photo above was a Swindon rebuild. I seem to have given myself a project and a half to sort all these 2-4-0 variations out.

[2-4-0s, and the Armstrong era in particular]

On 09/11/2023 at 10:27, Mikkel said:

Somewhat similar to the 717 class (I have a couple more photos of that class, if you're interested).

And now I've got to the 717s, and hey ho, what is there?
That's a super clear profile photo, and will be a big help getting the frames because it doesn't seem as if they were much altered, but without the big Giffard injector on the side of the firebox, a polished dome, enclosed splashers and a cab that has got to be a good few years on. There's another 717 photo in RCTS, which must be a bit earlier as it has the Giffard injector, but its still cab and polished dome. It has both splashers open and a narrow cab, but RCTS is suggesting that originally they had a large side panel covering the trailing wheel splasher and only the leading one was open.  
I don't think I'm going to do much better with the 806 series either. There's a slightly earlier photo of one in RCTS, but we are now getting past the days of completely open locomotives, and I'm not clear whether the vestigial sides to the weatherboard as per photo D68 in RCTS and the photo of 442 above were from new or added just a bit later with these classes. At the moment its feeling as if each successive class is more hassle to sketch, and gosh I'm glad that I skipped over them in the previous book. 
Trouble is I don't think I can skip here in this format, its a significant era.

[Book Format for Locomotive Development]

Well, I'm progressing through an initial draft of this format. I'm basically up to Swindon 1870. I think realistically I have to get well into the 1870s, maybe 1880s before I can make a judgement of whether I think the format works. It's going more slowly than I might have hoped, because I keep getting stopped because I don't have a sketch of a new class in original form. I'm hoping the drawing list will be more complete a few years on. At the moment I'm listing  Swindon and Wolverhampton separately for 1864-1877 and 1877-1892. That may need to be rethought, because I've just got to the 1076s, and have to note that they appear strongly influenced by the 1016s at Wolverhampton, but at the moment Wolverhampton 1864 is after Swindon 1877 in page order. Another thought is that this might work better as an electronic document than paper. If one has hotlinks on each section to the previous and next entries for each class it would be a lot easier to read the whole history of a class link by link electronically than it would be on a paper equivalent. 'm also wondering if I should use lot numbers extensively in headings and indices. It's a very convenient way of separating successive builds of classes, and its also the way the GWR worked. I tended to stay clear of them in the last book as an unnecessary complication, but with this format it might well help readability and referenceing.

Running by date certainly works in some respects. I'm picking up things that I hadn't really noticed before, introduction of injectors for instance, and the replacement of cottered bearings with plain bushes on the coupling rods. Also spotting things that seem to be missing. RCTS seems very quiet about the changeover from coke to coal, and that was a very big deal indeed at the time. 

[2-4-0s, and the Armstrong era in particular]

1 hour ago, Mikkel said:

Jim, would you say that the digital RCTS volumes reproduce the photos better than the printed books? If so I may consider purchasing some, even though I have the books.

Not really, they are facsimiles of the originals - in other words they've scanned good copies of the books. They haven't gone back to the original photographs. The pdfs are searchable though which is quite handy.