Edward Thompson: Wartime C.M.E. Discussion

I met Ron Jarvis once and had quite a long chat with him. On the question of the rebuilds, he was quite definite - the policy was to rebuild them all. It was only when the policy changed to eliminate steam that the rebuilds stopped

 

And given the chance what a CME he could of turned out to be. Read the book on him. Definitely a brilliant engineer.

 

I agree with Simon's analysis of the Bulleid Q1s.

They had the same chassis as the Maunsell Qs, despite Bulleid critising the 'Victorian' design. Bulleid used the same valve gear and cylinders, and the outside admission piston valves - with loco links indirectly driven by rocker arms which was a far from satisfactory arrangement - launch links being much better for this layout with far less suspension offset and less die block slip.

This shows that Bulleid didnt understand the basics of Stephensons valve gear. Jos Koopmans has also shown that Bulleid's understanding of the LeMaitre draughting was poorly applied and defective in all the types it was applied to, and can easily be improved upon.

Now, Bulleid was Gresley's right hand man. Recent design evaluation re valve gears and draughting, and that undertaken at Rugby in the 1950s on the original as built MN pacifics shows up the flaws in Bulleid's designs. I would certainly take a punt at criticising Bulleid far more than Thompson - which supports Simon.

Cheers,
Julian

 

Which is what jamessquared said in his post.

 

Tell me, how many locomotives have you designed and put into traffic?

 

Talk about playing the man and not the ball... Is the personal attack really appropriate? I'm sure he's just as qualified to have an opinion as you are.

 

Just asking a question so keep your hair on.

 

I think it's a little unfair to criticize Bulleid's efforts in the drafting area, most of the in depth knowledge has been gained in more recent times with the work and experimentation of Porta, Wardle & of course Jos. With this knowledge yes the LeMaitre can be improved now, but could it have been in Bulleid's time, probably but not without considerable experimentation which there was unlikely the time nor the money to do for a small likely improvement.

 

Now you know perfectly well that was an aggressive rhetorical device and not a genuine question. And my hair, I fear is mostly long gone.

 

I always see the Q1 as an evolution of the Q, with a design brief of producing something more powerful, with the same route availability, cheaply and ASAP. In that context the valve gear simply wasn't (in my opinion) the part of the design most in need of fixing. Improving it would have been a nice-to-have, but that's additional drawing office time and works tooling up time. Whereas what Bulleid's team actually did was take the basic engine of the Q, put on the biggest boiler they could get away with and strip out every non-essential to get the weight back down and save cost. In the context of getting something significantly better into service fast during a war, I'd say the Q1 gets it about right.

 

The operative word being 'recent' design evaluation. Inefficiency is in the eye of the beholder. If you want to time your trains to a schedule and keep the passenger happy, then a Bulleid as designed fits the bill nicely, and burning extra coal and a bit more maintenance is a price worth paying. If you aren't too interested in that, then you've g ot any number of LMS designs and working practices to help you save coal. The upshot was that there was still more to learn from the steam locomotive, and Bulleid's output neatly demonstrates this.

Either way, if a design manages to pull a heavy train and more besides, then no amount of nit-picking over aspects of the design can take away the fact that they mostly did what they were designed to do.

 

It could be argued, though, that delivering an expensive to run locomotive to do a job of work is a lesser achievement then producing an economical one.

 

It could be, but if it still does the job it's supposed to do, then it's just splitting hairs, which also depends on what you want to give weight to. This is why the 1948 trials did not provide an effective comparison as drivers were under orders to either save coal (LMR), or show the prowess of their steeds (SR).

Time and advances in the technology associated with most of their foibles has shown that the originals can be very reliable machines. And the two coach trains they hauled were essentially end of day turns before returning to shed, so if anything, this added to their economy.

The nature of the beast means that running a steam locomotive economically when you are trying to keep to time is an inexact science in any case- some drivers will get close, while others will fall by the wayside.

Therefore, as a passenger, I'd rather a locomotive be expensive to run but as a result has enough in reserve to get me to town on time whoever is driving than marvel at economics of using 1.34lbs less coal and miss my appointment by five minutes. At the end of the day, they had a job to do, and when in fine fettle, a Bulleid did it with panache.

 

Nail on head. Enthusiasts and academics can argue about loco design until the cows come home but all the travelling public want is to arrive on time. And let's be honest, what was up front depended very much where you lived. Somebody catching a train from Salisbury to London wouldn't get many opportunities to compare a Bulleid with a B1.

 

.. "odd"? ... and what are the majority of continental railways building today for regional passenger services? Bless my soul; DoSto's (Doppelstock), based on the development carried-out by the East German works at Görlitz! (OK; They have a more generous loading gauge.)

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Loving the 01.5.

 

Thank you for your thoughts Julian.

Absolutely - and if we follow that logic then the Thompson A2/2s (which were remarkably capable Pacific locomotives) shouldn't get the level of criticism that they do. In fact that could be applied to all of Thompson's Pacific designs.

I feel this is a very good point and worth saying that I feel this was something Thompson always tried to achieve with all of his designs. Whether he succeeded or not is dependent on the individual design but I suspect he succeeded far more than he failed in this regard in comparison with other designers.

 

From earlier today for all you Thompson fans.

Two very practical designs.

Sawdust.

 

I shall keep an open mind Tom.

I accept that, but it is also true to say (and has been said) that the original intention was to rebuild all of them in any event. The point is made that the originals were considered flawed enough to be rebuilt to a more conventional form and in their rebuilt form are rather more comparable with Thompson's Pacifics as a result with three sets of walschaerts valve gear and 6ft 2in drivers. I feel it is significant that Thompson is criticised for his choices yet Bulleids designs which are widely revered were rebuilt to a specification broadly matching his own standards.

I confess a lack of knowledge in this area so I will bow to your views here Tom. I will state that I do consider the performance potential of an original Bulleid to be great; that much is not in doubt. The question is at what cost, and do we really believe that Thompson's Pacifics did their work any less adequately than Bulleid's when called upon?

But significantly Tom, all of the Bulleid portions of the design which are experimental were removed. Chain driven valve gear and the slab sided casing replaced with a conventional outline with three sets of walschaerts. So while they may have kept 90% of the material, the 10% which was removed changed the design and its outline significantly. Thompson's were never rebuilt and worked decent lives by comparison.

I characterised it by the locomotives they have to their name which seemed fairest: and the reboilerings still required some modifications beyond just fitting a boiler. Certainly they were considered enough of a rebuild to be given new categories altogether (O4/8, O1, B2, D Class, etc).

I am happy to add the Nelsons to the mix if this seems consistent and reasonable.

Tom, I did give the caveat that I was aware Bulleid was involved in other work in my original post. I specified the steam portion only as that is what was being compared.

If it would please you I am happy to give Bulleid his due in his DE and Electric work: but that was not the point I was making where the question of how good a steam locomotive designer Thompson or Bulleid was. It is in short a diversion away from the point being made.

I do however take that point and agree with you there.

I don't disagree that the views can be hardened; but in the cold light of day and asking what was needed as opposed what people feel was needed, it is often that we find the view that Thompson could do no right on the LNER and yet the locomotives built, amongst other things, suggest he did a good job as CME in the main as opposed a bad one.

I don't think anyone here is arguing that Thompson might not have inspired everyone or indeed been universally or even liked in the main; but that is used as a crutch to beat him and his engineering reputation down when it should remain separate to that. If the question is was Thompson a good steam locomotive designer, and is the criticism he receives inconsistent with the praise seen elsewhere (Bulleid) then we should be looking at what they actually achieved and not what people state and believe they achieved.

 

Thank you for that - two of my favourite designs right there.