Edward Thompson: Wartime C.M.E. Discussion

I sense some amusement from winding up the regulars Hermod. I respect your right to hold an opinion and would be interested to get more detail on your interpretation of Gresley.

Could we do it without angering the “natives” please?

 

It didn’t matter - LNER works practice saw virtually all components swapped about in works anyway. Including the frames, which in 4470s case went into the spares pool.

 

Erm, I don't think that was my argument...
I wasn't denigrating Gresley.
I was merely saying that the other railways which tried conjugated valve gear (Gresley or other types) did not multiply it beyond the first few examples. This is true in several other countries and before the exigencies of war, so it seems to be a reasonably objective assessment. The gear was good enough to keep the engines which had it going, but perhaps not good enough to multiply in such numbers, given the disadvantages.
There was lots else which was excellent about Gresley engines apart from the valve gear - the steam circuit for example. Saying that his valve gear was not as good as he thought it was is not denigrating him or his work seen holistically. Like all of us, he was not perfect. He was still one of the greatest locomotive designers in history.
It does however give some important context to Thompson's rebuilding/new build 2 cylinder programme.
Turning to your other points, I certainly do not criticise the Midland for pursuing compounding (albeit they only did for one class of engines). In fact, I think the Smith compound system had enormous potential, and if it has been matched to a modern steam circuit on a powerful loco (say a rebuilt Scot) it might have created a superlative loco. It's just that extensive experience in actual service persuaded the LMS (and before them the NER, BNCR, GCR, LYR, GER...) that the extra complications weren't worth the effort. I think this was partly an inherent British suspicion of complication, and partly due to the British system of footplate crews learning on the job with little engineering training. But I still think it was probably a reasonable conclusion.
I am always ready to defend Webb - partly because he was trying something news which is always risky but someone needs to do it, and partly because, Compounds aside, his overall output as a CME was titanic. But I would tend to say he rather stubbornly pursued something which demonstrably wasn't worth the effort longer than he should have.
I think, to a lesser extent, the same could be said of conjugated valve gear on the LNER. It was worth exploring, it could demonstrably produce world record performance, it could be made to work, but it had drawbacks which perhaps meant it wasn't worth it for everyday service.

 

Whoa, I posted #2818 because that is what I think, it's my opinion, if you don't agree........fair enough, say so, bit I think we can do without the 'dear god' bit.

 

I am increasingly irritated by the rhetoric.

Gresley was a great engineer, but not a deity. He is not immune from criticism. To understand the context of the criticism, we should not attack it for being different to our point of view.

And “hatchet job” this is not.

 

I don't think anyone is saying Gresley is immune from criticism but there's a bit of a steep incline between:

• I don't think 3-cylinders/conjugated gear was necessarily the right way forward in a time of post-depression/wartime austerity.

• He should be sacked

I think one of those is a fair comment, one of those is a tad extreme.

If instead it was all meant for a bit of a laugh, try a doctor, doctor joke. Like it or not, this is an emotive subject. Don't swim with the sharks if you don't wanna get bit!

 

Don't think so Victor but IMHO in order to comment on Thompson you have to compare him to his peer group. Unfortunately the comparison between Gresley and Thompson appears to be demeaning of Gresley but that is because critics fail to understand the simple point that different times call for different solutions - and WWII provided a major shift-change in railway operations.

 

I have literally spent the last seven years putting that last caveat into everything that I’ve done and written on here.

 

Since the main thrust of the argument was centred on the conjugated valve gear I would humbly suggest that the problem lay not so much in the design of the gear but in its maintenance regime. I have previously pointed out that Haymarket followed the maintenance regime in principle but did so at lower mileages than recommended by the CME and this was rewarded with better availavalibity and improved MPC (Miles Per Casualty) figures. These I do not have to hand but I understand SAC has obtained them and has analysed them as part of his research hence my interest in obtaining a copy of his book once published.

In a wider context I suspect the vagaries of many locomotive designs (whether steam diesel or electric) depend on the maintenance regimes. If a design has a specific problem area (e.g. the conjugated valve gear) the depot that understands the problem and develops the skill to deal with it will have a better MPC figure than the depot which simply fixes it enough to keep it running. This is not to criticise either Gateshead or Kings Cross but simply to note that a depot has a mix of locomotives - each with a design peculiarity - hence the maintenance regime has to concentrate on the most important locomotives required for the depot's workload.

In terms of the Thompson argument I wonder how much of his design work was geared to the maintenance element of the locomotives' life and how this compared to the work of Gresley during his tenure of office. Perhaps SAC's book may enlighten us.

 

Isn't there, though, an argument that the required maintenance regime is part of the design? The conjugated gear was not an end in itself: Holcroft tells us he developed his first version in order to design a 3 cylinder locomotive with the valve on the centreline above the cylinder, as he couldn't get an inside gear to fit. Presumably the point of the conjugated gear was some combination of reducing build and overhaul cost with fewer components and reducing maintenance costs on the road, together with avoiding the design problem of how to fit in an inside gear with exactly the same events as an outside gear. If the conjugated gear requires extra attention over and above what a standard gear would receive then that is surely a design flaw. Gresley will not have done the actual design that resulted in components that needed special attention, but he was ultimately responsible for any shortcomings.

 

As the 2 : 1 gear has less components than a 3rd set of inside Walschaerts valve gear wouldn't it be easier to maintain? Not only that but more accessible too.

 

And how many more bloody times must we point out that there was nothing wrong with the Gresley gear per se? The big end was the Achilles heel and a redesign of that along with optical alignment of the frames sorted things out. Plenty of posters here ignore that.

 

It surely depends on the result surely in terms of the consequent trade-off. If the design requires additional regular maintenance but generates a better mileage before requiring works attention (hence being unavailable for traffic) then it may prove a better option than using a "normal" gear arrangement. Whilst agreeing that maintenance should be part of the design the designer is not necessarily familiar with operating conditions at specific depots and therefore I would argue that the CME specifications should be taken as a guide not as a definite hence leaving depots to modify any maintenance regime in the light of operating experience.

It seems to this observer that the nub of criticism of Gresley centres on his continued reliance on conjugated valve gears for his 3-cylinder locomotives and I refer to the previous note re Haymarket Depot and its maintenance regime for conjugated valve gear. I venture to suggest that Steve's analysis might be worth a chapter in his proposed book to highlight whether the conjugated valve gear was as inefficient / ineffective as many critics suggest thus confirming the validity of Thompson's decision to discontinue its use in future designs.

 

As a result outsider (LMS enthusiast) I look at this 140 odd pages with some bafflement. After all, Stanier replaced Henry Fowler with no massive arguments ensuing on forums, and he went in a different direction to his predecessor, same on the Southern re Maunsell replacing Bulleid, further back, on the Western where William Dean was replaced by Churchward.

The issue appears to be the 3 cylinder valve gear which may have been a disadvantage in wartime conditions, but the Gresley locos continued to give good service when running for BR until the 60s so it couldn't have been bad. Thompson wasn't in the job very long and at a difficult time too. His B1 was excellent, but so were Gresley designs. His bogie design was adopted by BR for EMUs due to its smooth running.

Two good engineers with different approaches to some areas of design I think sums it up.

 

There is only one person writing on this thread suggesting that Gresley produced designs that were badly flawed. That person is not Simon. In the 140odd pages of this, he's not once said that he thinks Thompson superior to Gresley

 

That is true. Unfortunately, some have been well and truly trolled and the person responsible will be rubbing their hands in glee! Shame really, it all detracts from the main discussion...but that's Nat Pres.

 

This post raises a question in my mind. How mechanically efficient was a conjugated drive against independent? Did conjugation reduce the mechanical losses from the cylinders, or incur more mechanical losses than a direct drive?


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I'm parading my ignorance here, so I apologise if any of the following is libellously wrong. From what I've read, it appears that in 1923 the management of each of the newly formed big four railway companies adopted a different management strategy.

The GWR already had a very strong corporate image, and many of the new lines had previously been operated by the GWR anyway, so not too many surprises for employees.

The Southern, it seems, just painted “Southern” on everything, changed very little and allowed the various constituents to gradually grow together-lessening the strife and uncertainty for all.

The LMS apparently allowed old rivalries between the MR and LNWR to become somewhat toxic in the new organisation, particularly the Crewe/Derby precedence. I think this lead to some years of strife within the company.

On the LNER, the formation of the company more or less coincided with the appearance of Gresley's pacifics, so rather than one former company stamping it's identity over another, there was a magnificent new icon for everyone to admire and inspire loyalty.

Might that then be the origin of Gresley's “sainthood”. I mean, the A1's were the dogs biscuits-looks, performance, good to work in, on and around. Maybe not as powerful as a Castle, they were absolute thoroughbreds, and the successes just kept on coming. 100Mph, 112mph, longest non-stop service, A3, A4.

In the same way as Alex Fergusson will be ever linked to the success of ManUtd, was Gresley himself an icon of that success?

Did the fitters and staff who were most able to see issues in the conjugated valve-gear maintenance regime collectively overlook some shortcomings, and not allow them to become an issue simply because they were enthusiastic about the locomotives in their care, and felt they were part of the winning team?

If you talk to anyone who works on Ferraris, they all bitch about how stupidly difficult many tasks are, “but its a Ferrari”

Then the war changed everything.

 

FWIW I was only disagreeing with S.A.C. Martin in so far as he claimed Gresley fans couldn't criticise Gresley. Some of us can in fact. There is all the difference however betwixt criticism and blatant, unfounded revisionism. If Hermod is genuine, I feel quite justified in pointing out that his "contention" falls far outside the realms of historical fact. I struggle to think which of Gresley's various actions would warrant instant dismissal.

If Hermod is merely trolling though, I will be the first to admit I just don't understand the purpose of it. Some of us just don't get off on getting a rise out of someone. Different strokes I guess. I would ask Hermod to put such comments in a fun thread or somesuch and not de-rail this very interesting debate.

Back on topic: Was the K5 a missed opportunity? It would seem to combine the best elements of both Gresley and Thompson nes pas? With the success of various moguls elsewhere, surely there was a place for a 5'8" mogul with all the Thompson trimings, a go anywhere, do anything machine if ever there was one?

 

An interesting area of conjecture methinks. Gresley was using the V4 design as prototypes to formulate the final form of his mixed traffic lightweight go anywhere design for which he proposed using the 2-6-2 wheel arrangement (V5 perchance ?). This idea ended with Gresley's death leading Thompson - as the successor CME - to return to basics by adopting the 4-6-0 wheel arrangement as epitomised by the the experience of both Stanier (with his 5MT 4-6-0) and the GWR with its history of 4-6-0 designs. A "what if" discussion on the relative merits of a Gresley V5 v Thompson's B1 might have legs but I suggest is outwith the immediate scope of Simon's proposed tome.