Sir Nigel Gresley - The L.N.E.R.’s First C.M.E.

Source, please, because as far as I can see from my notes, none of that is true.

Yes, which is why I am exasperated that you’re saying something without a citation or reference again. This was the closest thing I could find to your claim.

 

Col. Roger's book. Perhaps you can provide evidence of the claims that you made regarding Gresley and Chapelon, ref. 'Chapelon and Other Matters', posts #132 & #136. You didn't provide an answer, never mind a reference.

 

I have the report for the D49 testing in front of me and it is clearly described as a Kylala exhaust. I can see where other secondary evidences have said Chapelon was involved, but the primary evidence seems to be lacking in this regard. He is not mentioned in the reports.

Point me to the things you want explained and I will happily provide where I can.

 

LNER.info: 'During 1928 trials were performed with 'Kylala' blastpipes fitted to D49/1 No. 251 and D49/3 No. 322. Initial results with No. 251 were good, and No. 322 was fitted with a 'Kylala' blastpipe that incorporated some recommendations from Chapelon.

Col. Rogers' book: 'As an immediate result of his visit (to France at the end of 1925) Gresley decided to fit a Kylchap exhaust to one of classsShire 4-4-0 engines, and, supplied by Chapelon with drawings, a single Kylchap was made and fitted by the LNER'. Page 45, ppb version.

Same story essentially. Since Rogers was a friend/acquaintance of Chapelon and the book was published six years before Chapelon's death, it is quite possible that this information was supplied by Chapelon himself.

Your quotes for which asked for evidence:

'I think (and I say as much in my book on Gresley) that Chapelon's influence on Gresley was more minimal in comparison to Gresley's influences on Chapelon, particularly where the prototype W1 is concerned. William Brown also noted this in his book on the W1 - Chapelon, thanks to the more generous loading gauge and free from the pressures of running a railway, was able to set up his compounds as Gresley originally intended for the W1 and produced excellent results.'

'Streamlining, in fact, and learning from Gresley's work by improving his own. That much is factual.'

 

The Kylchap is not the same as the Kylala and the relevant drawings for the D49 exhaust is found in the relevant RCTS book.

The W1 file at the NRM and Rail 390 and 394, the LNER board and locomotive committee notes. The W1 is a Gresley locomotive incorporating a huge range of experimental developments.

Streamlining - the casing, not the internal passages. Arguably Gresleys most important development in railways, in particular for high speed rail in the years to come. This in my view is a more important development.

He was the first engineer to have his designs tested in a wind tunnel and produce a genuinely scientifically streamlined locomotive. Check the dates, the drawings, and the photographs available from a range of sources (including the W1 file).

 

I'm not sure this really explains the influence of this on Chapelon, though?

 

Look carefully at the casing.

 

Yes, there's some A4 to it in the shape of the boiler casing and valances, and in more than just sense of it being a streamlined locomotive at a time of a lot of streamlined classes. But in your opinion a single streamlined example (not repeated) of an established class constitutes a greater influence than the acknowledged and attributed (by Gresley, to the PO Pacifics) adoption of steam circuit improvements across entire classes?

I really don't quite understand your aversion to any suggestion of Gresley having received influences though, from Chapelon or Holcroft or whoever. Good, even brilliant engineers are allowed to be really good at picking up influences and suggestions and borrowing bits of other designs; it can save an awful lot of time and money. It does not belittle Gresley to say he was excellent at incorporating the developments and ideas of others into his overall vision.

 

Are you sure that is evidence of influence (rather than just convergent evolution, i.e. two independent designers coming up with similar solutions to the same problem)?

There was a massive development of interest in streamlining and associated wind tunnel testing from the 1920s onwards. As an example, in 1920, the air speed record was 171mph; by 1931 it was 407mph and by the outbreak of the war it was up to 469mph. That's like going from "Columbine" to "Mallard" in the space of two decades. Some of that increase in speed came from increasing engine power; some from aerodynamics (which in turn was enabled by better structures). I've got a "boys own" type children's book from the 1930s discussing the Supermarine Schneider Trophy racers that goes into detail of the reduction in frontal area. Not a scientific treatise, but an indication that such concepts had permeated society.

My point being - there was a lot of interest in aerodynamics in the 1920s and 1930s, to the point of percolating down even into children's books. Given that, it's hardly surprising if design teams across the world - and particularly in the engineering power houses of the day, i.e. Britain, France, Italy, Germany and the USA - independently choose to investigate ways to make trains more streamlined. It's possible that designers may have talked to each other (Holcroft spends a chapter of his book discussing a trip by a number of notable British engineers to visit German Railways in the 1930s, including a sustained high speed run at over 100mph behind a streamlined locomotive) but it doesn't feel to me that streamlining locomotives, or using a wind tunnel to do so, was a particularly big leap of imagination in that era.

I think to claim Gresley influence on Chapelon in that area, you really need to demonstrate evidence that Chapelon hadn't considered the idea until talking to Gresley. Two designers both working along similar design directions discussing detailed findings between each other is less significant.

Tom

 

I agree with your basic point, but want to take issue with how restrictively you define "influence". Influence may also be seen in how different people, pursuing the same basic idea (say, streamlining) engage with each other to develop their approaches. That means that the influence may be mutual, and it may be felt in the detail rather than in the broad concept.

 

But a Kylchap is a Kylala modified by Chapelon which is precisely what both accounts state.

Work started on the W1 in 1924, a year before Chapelon had even started working for PO, so perhaps not too surprising. With a bit of assistance from Chapelon, W1 might have been successful! Not really sufficient to claim 'I think (and I say as much in my book on Gresley) that Chapelon's influence on Gresley was more minimal in comparison to Gresley's influences on Chapelon, particularly where the prototype W1 is concerned. William Brown also noted this in his book on the W1 - Chapelon, thanks to the more generous loading gauge and free from the pressures of running a railway, was able to set up his compounds as Gresley originally intended for the W1 and produced excellent results.'

True for the W1 but not much for anything else.

Streamlining on a steam locomotive is of questionable use, since it is only useful after a certain speed has been reached. It also hinders maintenance, which is why it was at least partially removed from most applications.

Given that the speed limit in France at the time was 120kmh, there wasn't much of a requirement for streamlining. Virtually doubling the power of a locomotive together with a substantial improvement in economy made much more sense. For a locomotive, Chapelon realised that internal streamlining was of much greater importance than external!

 

Indeed, there is a continuum of sorts. But @S.A.C. Martin seems to be pushing a line that says that Gresley in glorious isolation hit upon the idea of the externally-streamlined locomotive and refining that design using a wind tunnel; and the influence to other streamlined locos therefore goes all in one way: essentially setting Gresley up on a pedestal in glorious isolation as the innovator in the field. My premise is that such ideas were "in the æther" at the time and hardly a groundbreaking leap of imagination given the general direction of engineering at the time, so it is plausible that they were alighted on independently by different designers. The fact that there was then a level of both face-to-face and journal / learned paper contact with developments in other countries doesn't diminish that.

Tom

 

Broadly I agree but "talking to Gresley" might not've been essential. If Chapelon became aware of something Gresley'd done first; thought about why he did it and as a result applied it to his own work that would be influence - but to 'prove' it you'd need to find something he wrote, or a reliable witness to something he said, to confirm it.

 

Yes, “talking to” might be a bit loose. Could be “Chapelon read a paper by Gresley and as a consequence changed his ideas” etc. But to claim influence, you have to show the influence, rather than convergent evolution to similar ideas.

Tom

 

I thought that might hit a nerve, and I was right.

We have been discussing for days and arguing that Gresley/Bulleid et al were influenced by Chapelon but finding primary evidence has been difficult, however turn it the other way and the immediate argument is a 180 degree turn on Gresley’s influence.

If influence is only one way - i.e. we are arguing that Chapelon influenced everyone else on very small amounts of primary and secondary evidence - then when we reverse it, as Tom has rightly pointed out, we should be saying the same thing.

However that’s not what I am reading here.

I think part of this issue may be (as it has been with me too, incidentally) some ingrained ideas about influence and design.

Perhaps if I may reword the below:

This really needs to be the key principle at the heart of all this, for all of the parties involved (and we can subsequently also apply that to the Gresley/Holcrot dichotomy too).

 

Hi Tom - I do challenge this though. My research has shown Gresley was undoubtedly the first to apply those scientific principles to a locomotive design. His work on the W1’s streamlined casing predates by some margin the Commodore Vanderbilt, which is commonly (but wrongly) known as the first fully streamlined locomotive design.

Yes, streamlining was in vogue by the 1920s - only a few of those streamlined casings are in fact “streamlined”, however, and there needs to be a wider debate about what constitutes true streamlining, and part of that is recognising that some are scientifically arrived at and others are a result of aesthetic industrial design. There is a big difference between the two, even if on a first glance, that’s not obvious.

 

Fair comment. But what then is the pattern of influence of that scientific approach?

Where the W1 (a byway that I know little of, to be fair) is concerned, what surprises me is how little reputation that streamlining has in the evolution of railway vehicle design given the comments being made here.

 

A good question, I don't think we have an answer currently. We are discussing it, which is the first step! I think looking at the papers Gresley put out, together with the other engineers, may be the next step, together with close study of the archives.

What surprised me most going through the archives was just how ahead of its time it was. The W1 front end is multi-functional, with the streamlined casing designed to do several very specific things. The principles utilised in the design can in fact be recognised as still being used in car design today.

It's a very clever design and (in my view) the water tube boiler discussion has overshadowed this far more important development.

 

The water tube boiler necessitated a different shape of outer casing from conventional locos anyway, regardless of either scientific or aesthetic streamlining. What was the logical sequence? Did Gresley (or his drawing office) first rough out something to fit round the boiler, then look at smoke lifting, then decide on wind tunnel testing, and then finally look at minimising air resistance? Or were they looking at minimising air resistance from the outset? Or is clear evidence not there?

 

A very good question. Streamlining definitely came later than the decision to fit the water tube boiler, but the decision to design it in the way that it came out was down to the necessity for draughting, both inside the casing and outside with the smoke clearance. The "minimising air resistance" needs to be understood as being part and parcel of the overall design package, not a by-product, but thought about as part of the overall design process at the National Physics Laboratory.