Edward Thompson: Wartime C.M.E. Discussion

Yes it was me - but by your criteria........ haHa!!

 

I don't think aeroplane and locomotive design are necessarily compatible.

In aeroplane design, many of which are typically high-speed designs (at least relative to locomotives), there is a design premium on aaerodynamics. Generally that means the design might be characterised as "sleek", "smooth" etc, which we are conditioned to consider to be desireable properties. So it is hardly surprising that many aeroplanes which "look right" "are right". Even so, it is possible to think of good-looking aeroplanes which, for various reasons, were broadly failures (for example, the Westland Whirlwind - an attractive design, good pilot visibility etc, but let down by poor engines and a flawed "heavy fighter" concept). It is also possible to think of some aeroplanes which were, frankly, pig-ugly but which were very successful in their design role: a classic example was the Short Sunderland which, for various reasons, didn't even have the engines pulling in the same axis as the fuselage! That feature didn't stop the aeroplane being highly effective in its intended role. More recently, ugliness hasn't stopped designs such as the A10 Warthog or Apache helicopter being very successful designs.

With regard locomotives, which generally operate at speeds where air resistance is not a significant proportion of the total power consumption, there is even less emphasis on aerodynamics, so relatively few locomotives could be described as "sleek". So there is even less basis for "if it looks right, it is right". I've already mentioned the Q1 as a successful design that is, shall we say, "aesthetically challenged"; others have mentioned the American cab-forward designs, or the Chapelon loco suggested by ragl.

So I'd say again - basing an argument agianst Thompson on the fact that he ruined the looks of a favourite loco is a specious argument.

Has anyone come up with comparative statistics of, say, coal consumption per ton-mile, maintenance costs per mile, mileage between heavy general overhauls etc, percentage availability, between the Thompson locos and other locomotives of similar size and function. Those statistics would be far more telling than simply saying "his pacifics didn't look right".

Tom

 

I was about to comment on the fact that most US locos are ugly as sin (not all I grant you!)...and as for flying pigs, only a mother (or Ivatt) could love it

 

Except as I briefly mentioned above, the Westland Whirlwind was not "broadly a failure".

 

...and if you read East Coast Pacifics at Work you would know that Cecil J Allen very much does that comparison study a disservice. You are also not comparing like with like: two 6ft 2in locomotives designed for mixed traffic against a 6ft 8in Pacific designed for express passenger work.

Peter Townend is much more circumspect and fair, and when I get a chance tonight I'll quote the relevant passages.

However for the moment you should bear in mind that the A2/2 had larger grate (50 compared to 41.25) and crew familiarity with the new designs compared to the older type was also a factor (regulator type was different, for instance). A further set of comparisons was taken later on the and coal consumption figures were much closer.

The best set of comparisons probably arose from the A1/1 and A4 comparison of 4470 and 4469. Coal and water consumption virtually identical between a streamlined locomotive with conjugated valve gear and a non streamlined locomotive with three sets of walschaerts.

 

you're very perceptive there, Big Al, my tongue was very firmly planted in cheek for that. however, you can see my point.

As for a barrage of Exocets, I would gladly have to fend them off, if only a Chapelon 240P had been preserved; it seems that the French may have a thing about "looks" too - as all of Chapelon's rebuilds were scrapped as they were not pursang, tragic.

Cheers

Alan

 

Allow me Simon, as I have the relevant data under my nose as I type.

There are 2 tests quoted in Peter Townend's book, firstly between 4470 and A4 4466 in November 1945, with each engine working 5 trips between KX and Grantham, results quoted are for coal consumption:

4470 - Lb coal/train ton mile: .081 - .089 Lb coal/mile: 38.1 - 41.9

4466 - Lb coal/train ton mile: .081 - .093 Lb coal/mile: 38.4 - 42.6


The second test was conducted in September 1947 against A4 No. 31 Golden Plover, also by now, 4470 had been renumbered 113. Test runs were between Edinburgh - Dundee and return, results:

113 - Lb coal/ ton mile: .121 and .106 gal water/mile: 36.1 and 30.6

31 - Lb coal/ ton mile .137 and .135 gal water/mile: 40.5 and 38.8

The results speak for themselves.

Interesting points centering on 31's condition on the second test, it had a single chimney and centre cylinder reduced to 17" dia. To save unnecessary conflict, I won't expand on the need to reduce some of the A4 centre cylinder diameters during this period of their lives.

The rebuilt Great Northern went on to achieve about 950,000 miles during it's 17 year life, none too shabby for a one-off, although, Townend does say that it had above average visits to works. Also, as for the comparison with the A4s, we know they were transformed in the 1950's due to changed maintenance regimes and the fitting of a Kylchap exhaust, a pity no further comparisons tests were conducted.

Cheers

Alan

 

The streamlining was an irrelevance after the war.

 

Perhaps I could further quote Mr Townend regarding the tests carried out between A4s with single and double chimneys - The saving was "about 7lb of coal per mile in favour of the Kylchap" The tests were between Kings X and Doncaster in 1957, so I'm assuming a train of say 350 tons, giving a saving of 0.02 lb of coal per train ton mile. Given the first set of figures you quote and the saving I calculate, a kylchap A4(4466 was a single chimney loco) might have used 0.061 - 0.073 lb of coal per train ton mile - a clear advantage for the kychap A4 over the kylchap A1/1.

Now the tests between Edinburgh and Dundee were on a different road, so using the same saving for 60031 is fraught with difficulty but that said, comparing a kylchap loco with a non kylchap loco is questionable at best, given the known advantages of the kylchap. As you say, it is a pity the two types of loco were not run head to head when both were fully developed.

Townend stated that the A1/1 made 29 visits to Doncaster during its 17 year life "which was well above average for even a prototype locomotive" A little more serious than "above average visits to works"

 

This comment seems just a tiny bit daft in view of the fact that Chapelon did not alter the classic de Glehn positioning of the outside cylinders in any way.

.H.

 

Paul, a classic p*sstake doesn't care where the classic cylinders are positioned.

Cheers

Alan

 

Apologies. It had seemed like a classic insular gricer not knowing his de Glehn from his von Borries!

P.H.

 

And so we roll on........

Any good reason to handicap a locomotive? (with regard to the reduction of the middle cylinder on some A4s to 17" bore) it made them weaker where higher outputs were concerned and so they had to be worked harder. What happens when you work a locomotive harder? Makes one wonder about the real motives behind ET's decision.

Yes, paulhitch, most gricers in this country wouldn't know ........... But for most it is a hobby and not an academic pursuit.

The streamlining was a splendid safety feature, let alone energy saver. It served more than one purpose.

One of the problems with the larger grate was that it needed fuel just to keep the grate covered during periods of modest output. So though it was thought necessary pre-war, post war power requirements did not justify more than the standard grate area found on the Gresley Pacifics. A little reminder might be in order here: 4400ihp can be sustained from a nominal 40 sq ft grate area.

It doesn't look as though Simon did contact Mr. Bannister. He could always try Joan Jackson - she took the notes of his memoirs.

The LNE employed the best that it could, it had to, the best tend to deliver and the company was in no position to afford too many failures - financial state and all that. It is all the more surprising that Company ended up with the directors fourth choice. Fourth wins, well, nothing. And so it proved.

 

So all that work and expenditure to produce a loco which was more complex, with zero improvement in efficiency?

 

Maybe Thompson should be judged against the other CME of the time when he was in office to judge what he achieved.

 

Not as far as lifting the exhaust was concerned, an oft ignored function of the streamlined front end.