Edward Thompson: Wartime C.M.E. Discussion

8126,

I think you have completely missed the point!

If the middle cylinder with conjugated gear is overunning then one approach is to have a bigger middle cylinder to take advantage of this. In practice, the opposite was tried with the middle cylinder being reduced in diameter to reduce the effect on the middle big end. It is not a good thing to have one cylinder performing far more work than than the other cylinders. Holcroft proposed another alternative by tweaking the conjugated valve levers to reduce the effect of the overunning on the middle cylinder. The paper that I quoted by Holcroft post WW2 many pages ago refers to this. In any event the problem was solved by lots of improvements in smokebox cleaning and adherence to proper lubrication of the conjugated gear post WW2 and so the Gresley gear preformed as well as it did pre-WW2, plus later the Kenneth Cook modifications to the middle big end and better setting up of the frames at Doncaster as per Swindon practice.

Cheers,
Julian

 

Mitigated might be a better word.

 

There's several ways you could do it without needing excess balance - certainly not more than a 2cyl job would need (I'm assuming that if you were designing this hypothetical loco you'd have already discarded two cylinders for loading gauge reasons). Having the two outside cylinders each equal half the power of the inside one would be one.

 

No, it wouldn't. All the solutions have problems, in fact half the problems in designing a loco are dealing with the issues raised by the other half. No piece of engineering is without its stress points, and there will always be a weakest link - at some point the return on investment of continually 'improving' a design ceases to be sufficient. After the Cook developments and the universal application (except for a few A2's) of decent exhausts, all the LNER Pacifics were producing performances which were if anything more than were needed, and were doing so cheaply. At that point the wise engineer stops tinkering and looks to the future, as J. F. Harrison did.

 

Oh, I wouldn't deny it could be done (although I'm imagining the exhaust beat from your hypothetical design there and I think it might be difficult to develop a satisfactory draughting solution - I'd give it four cylinders personally), but your original post said there was no engineering reason for three equal cylinders. I disagreed, three equal cylinders more closely approach an optimum solution in several ways.

The day an automotive manufacturer puts out a V5 with three small and two large cylinders, I will concede the point.

 

Belatedly. Recently read your book on the P2s. Bravo! Even after all these years, the photo of the converted Cock O The North at the head of Chapter Seven ("Thompson Takes Over") still shocks: imagine what the effect at the time must have been.

 

I'm sorry to drag this discussion backwards in time, but I have been away and am only just catching up...... Can someone point me at where I can get a copy of Symes' recollections? I have collected most publications covering the LNER in this period but don't know about this..... thanks in anticipation

 

Hi David,

The Symes recollections are in the HCB Rogers book 'Thompson and Peppercorn Locomotive Engineers' via letters to the author.

Simon is not a fan of this book!

Cheers,
Julian

 

Just catching up with this - no, I'm not a fan of Rogers' book.

With good reason: historical accounts should be fair and balanced, and consider all sides of the story and look at decisions being made in the full context of the time period.

Rogers' book, whilst it contains many excellent sources (Symes included) is nowhere near a balanced account of Thompson's work nor does it fully appreciate the full working conditions of his reign as CME.

Symes' recollections are most useful but Rogers' commentary and personal views are slanted too heavily to be considered a fair source.

The comparison of the Thompson Pacifics to the G&WSR locomotives is, for example, an utter nonsense and just one example of many straw man arguments and comparisons contained within the text.

 

Could be telling as he saw it of course and I'm sure if he had painted ET in a glowing light you'd be quoting him ad infinitum.

 

Absolutely not. That's the entire point of a fair and balanced account. Accepting there are flaws and examining them objectively and where there is praise, quantifying that.

It's about both sides of the story but one historian can do himself and his subject a disservice by only looking to report one side. That's not what I am doing; and I'm by no means being selective in my sources either.

So that insinuation is unfair, if I may so say.

 

Good morning,

A thought occurred this morning that I wanted to put forward and see what people think.

Hypothetical: Musgrove - locomotive superintendent - puts forward 4470 Great Northern for rebuilding. Let us say we believe after this choice is made that the chief draughtsman remonstrates with Thompson over this choice on historical grounds of the locomotive's importance and Thompson does not change this choice.

Let us say for argument's sake that Thompson in this scenario does not have the authority to change the choice of locomotive for rebuilding, but as CME would have had some sway perhaps in persuading someone who could.

What do you feel that says about Thompson, and why?

 

Yes we do know you are writing a book!!

PH

 

Just trying to get a better understanding of the alternate view. Your cynicism is quite unfounded Paul.

Between you and Mr Spamcan I rather think you two have it in for me.

 

Infamy, infamy. They've all got it in for me.

 

The chances of getting people to read the finished work would be much enhanced by fewer "wild surmises" of the kind in Post1332 along the way.

PH

 

I must admit I did smile at that!

The problem is Paul I'm trying to get a fair and balanced view in myself and for my writing. That does involve trying to understand the other point of view. I cannot get inside other people's brains so what would you have me to?

And for the record, it's not so much about the book anymore. I truly do want to consider all the angles. This particular point has been maddening me for ages.

 

I think you ought to drop, if not the whole thing, at least this aspect of it. No-body is likely to know the answer and obsessive guesswork stands the very real risk of damage to health. Take a break from it at the very least.

PH

 

A fair and balanced view would require an explanation of why Col. H. C. B. Rogers' account is not acceptable- you would have to include this in the book, as this shows where your research is coming from. Its good that you are attempting to engage in a historiographical argument, but you still need to say why you disagree with Rogers' opinions of Thompson, using specific evidence to refute his claims- unfortunately in the scheme of things, Mr. Hardy's accounts of Thompson is a case of 'one swallow doesn't make a summer'.

As such, the evidence you seek is probably unlikely to be forthcoming due to the vagaries of time. I haven't seen much in the last 67 pages other than 'there must have been good aspects of Thompson's tenure as CME', or 'imagine if X was in charge'. Counterfactual history is interesting, but doesn't really lead us anywhere in terms of what or why things actually happened.

 

Actually not too sure that's true, although we're getting into the realm of postgrad level history here. Properly handled, with due care and favourable weather conditions, counterfactuals can be really useful in illuminating what did happen and why - particularly when trying to get under the skin of the person that did make x or y decision.

For example, if we posit Halifax vs Churchill for PM in 1940, then the knowledge and working through the strengths/weaknesses/likely policies of Halifax casts light on the strengths/weaknesses/actual policies of Churchill and can really help to understand the *whys* of what he did. Essentially you have to know your ubject really well first, before you go into counterfactuals, but at that point parahistorical flights of fancy can help you to get new insights - it's an intellectual work-out fundamentally. Nial Ferguson's Virtual History from about 20 years ago is the classic in this field.