Edward Thompson: Wartime C.M.E. Discussion

The exception that proves the rule....

 

I really don’t get the “ugly” argument for the Thompson Pacifics.

Aside from the obvious points about wartime austerity informing design constraints (were any of the wartime designs truly beautiful? I love the Bulleid Pacifics but they’re not beautiful. Functional, definitely) there’s really not that much different to the Gresley designs that cane before it.

It uses a double kylchap exhaust, A4 boiler, A4 frames, original flat fronted cab, same tender.

The chimney is definitely a marmite affair whereas the running plate is functional and informed by the cylinder position and desire to make everything more accessible.

I’ve made several models of GN and just find it rather handsome in the NE blue livery.

 

I share the widespread dislike of the "rebuilt" GN on aesthetic grounds, but I am unsure exactly why. I think it is mainly the position of the outside cylinders. For one thing they were even further back than those of the GW 4-cylinder locos and the De Glehn compounds that inspired them (praised for their appearance by PH in post #1988). Also, I think GN was the only British Pacific that had outside cylinders in anything like that position and smoke deflectors, so there is also an element of unfamiliarity. Although the Duchesses and the Peppercorn Pacifics have divided drive, their outside cylinders are not so far back. The stovepipe chimney doesn't help either. It works on the A4s and the few other LNER locos that had the same streamlining, where a fancy rim might look wrong against the sloped front, but I can't think of any other class where it looks good.

 

Some of the Swindonised Welsh tanks were visually 'challenging'

 

I tend to agree. Whilst Peppercorn retained divided drive, he ditched equal length con rods so his Pacifics looked more balanced to me.

 

As first rebuilt, my thoughts were that the aesthetics had been ruined - The small cab looked hideous to me, and the front end looked very odd without the cylinders over the bogie...
But, as further modified with a full-depth cab and with smoke deflectors, I think the looks improved greatly (although not to their full pre-rebuild extent) in my eyes.
The smoke deflectors in particular seem to fill up some of the void around the smokebox area and add some "bulk" to its appearance, balancing the view more.

Richard.

 

It was a principle Express Goods Loco. though, and not restricted to Goods workings either. The KX-allocated members of the class being used on KX-Skegness summer excursions.
I'd love to see one in model form at least, they looked a beautifully proportioned locomotive to me... 5'8" drivers would give them a fair turn of speed too...

Richard.

 

From a historian's point of view, yes, definitely, but its raison d'etre - the flat 'racing grounds' between York and Darlington, weren't going to be electrified any time soon. What else could she do? What else was 1500v DC? She wasn't suitable for rapid acceleration, so not good for suburban services, and she would probably struggle on the impending Woodhead services too. In any case, she was a one-off, and electric control had moved on from when she was built. I wonder, too, how much she was worth as scrap - the country was still short of raw materials as the rebuilding after WW2 was under way.

 

I really don't see the argument re cylinder position on 113. these examples are all very similar

the aesthetic difficulty seems to be the running plate

 

Lines out of Liverpool Street which were 1500v DC?

Needless to say, a white elephant, but nonetheless a pioneering white elephant.

But here is where I think we come full circle - we attribute the rebuilding of Great Northern to vindictiveness/ necessity/ next loco into the works (depending on you perspective) and we could say the same about E1. Just as I don't think people thought about the idea of preserving/conserving Great Northern at the time, people probably didn't think 'this is the pioneering electric locomotive in the UK and is therefore as historically important as Locomotion and should be conserved.'

 

and the one I missed !!

 

Quite the opposite I'd suggest - they illustrate a progression of the relationship between cylinders and bogie: between the bogie axles (4470 as built); in line with the rear bogie axle (6201); well behind the rear bogie axle (60113). So aesthetically they are far from similar. (And at a practical level, the exhaust route between outside cylinder and chimney gets further and further out of line).

I realise fully that form doesn't always follow function; and the design decisions around the rebuild of Great Northern may well have been made for sound, sincerely held, reasons. But I think you'd be ploughing a very lonely furrow to try to make out that, on pure aesthetics, 60113 was an improvement over 4470 as built (sorry, @S.A.C. Martin - I just don't see it...) Just about OK from the cab up to the leading driving wheel; an aesthetic disaster from there forwards. (It might have looked better as a 2-6-2; about five or six feet shorter overall, though maybe that would have put an unacceptable axle loading on the front pony truck and given too small a smokebox capacity).

Tom

 

Like Tom, I'm not sure I'd agree with your assessment of 'very similar'.

The big difference between Thompson Pacifics and four-cylinder divided drive GWR classes (taking the Princess mechanicals as honorary GWR) is that the cylinders are too big for that classical De Glehn compound position outside the trailing bogie wheels (which incidentally is the cause of current gauging problems with Kings and the like) as used on 6201. So instead, the bogie is pushed forward and shortened until it doesn't foul anymore. The Royal Scots (plus descendants) and B17s, which had three-cylinder divided drive long before, use the same arrangement later adopted by Peppercorn, with long outside connecting rods and the outside cylinders between the bogie axles. Notably, the Stanier Pacifics, which had four cylinders and were therefore less affected by clearance issues, had still evolved from the De Glehn arrangement (Princesses) to between bogie axles arrangement (Duchesses) only a few years before, partly in pursuit of mechanical robustness.

From previous discussions on this thread, it seems that Thompson had a fairly high regard for the work done under Stanier on the LMS, certainly enough to use them to back him on the valve gear question, and I'd suggest the B1 implies a certain appreciation for the supreme utility of the Black 5. So I wonder why he went the opposite way to that Stanier's team had decided on, based on their own direct experience.

 

At least he didn't give the leading bogie axle outside bearings.

 

I was not commenting on relative aesthetics , merely , pointing out the similarities in cylinder position to other designs that people don't seem to object to .(leaving aside the P2 parentage.)
the original A1 pic was included simply for its interest . (its a decent pic ) .

if the running plate had been the same as the A2.1 it would have looked a whole lot better .

the exhaust route on the Princess class is similar , as are the GWR 4 cyl. locos . what does that have to do with it ?.

I don't see how you would get an A4 boiler on a 2-6-2, when using the A4 boiler was one of the objectives .

the problem , as always is that 4470 was chosen , not what was done , i for one would rather we had 4470 as an A3 ,in preservation , than 4472

 

Couple of things.

I am not saying that 4470 as rebuilt is more beautiful than 4470 as built. Clearly not. They are both products of their time. Between 1920s opulence and elegance, and 1940s austerity and utilitarianism.

I am simply saying that 4470 as rebuilt isn't completely ugly. I reserve that word for locomotives like the Fell, the Kitson-Still Diesel and similar.

Regarding the bogie position - that was almost entirely necessitated by the fact the Thompson A2s had equal length connecting rods. However Great Northern did not. She had the same layout of divided drive, but the centre connecting rod was actually longer than the outside ones (matching the Peppercorn A1 and A2 setup in ethos if not in the position of the bogie). The question was why - I have not been able to find out anything further about this entirely unique arrangement.

The rebuilt Great Northern was - with respect - a far better locomotive than the A10 she replaced. We would be surprised if she was not, given the components used and the fact there was around 20 years worth of development too. She was the Thompson Pacific with the highest mileage, according to works cards one of the most reliable too (if major attention in works is taken into account against minor attention - all of the Thompson Pacifics seemed to have had more visits than their respective Gresley and Peppercorn brethren, but take up less overall time in works annually) and she was considered the equal of a Peppercorn A1 in terms of ability by several of her regular drivers.

She was not perfect. Like the P2 rebuilds, she suffered some degree of problems with loose cylinders at the front end, amongst other issues (I do not believe frame cracking was quite the issue on Great Northern that it was on the original A10s, A3s and A2/2s).

Withdrawn in 1960, when the trend for some time on British Railways was to withdraw the smallest classes and unique locomotives first, she didn't do too badly I think, for what was effectively the last development of Gresley's A1 class, given her standard A4 components and layout.

Let's also not forget - she was meant to be streamlined. There are some surviving draughtsman's drawings showing this.

There was also resistance from the LNER board to streamline future classes. I cannot say with any degree of certainty but I suspect (given Peppercorn's tenure also had streamlined designs and these fell by the wayside) the austerity of post war Britain and the way in which streamlining was perceived may have put paid to any new Bugatti fronted LNER locomotives (and indeed, bar the A4s, all the other streamlined engines had gone by 1949).

I do feel that if she had been given the Bugatti front end, the animosity of the decision to rebuild her would have been softened rather a lot.

 

Yes, I have made the comparison to Stanier's Princess class before. There is a rather astonishing comparison to be made between Great Northern as built, and one of the Princess schemes which was a virtually identical 3-cylinder setup. I found it in one of the Stanier biographies I perused for material, and I will try and find it tonight when back from work to give the source.

 

All british pacifics and GWR more than two cylinder designs had looked better and used less coal if made the Claughton,Raven that is front wheel drive, way.If made the midland compound way the would have saved so much coal that tender can be two feet shorter to compensate for having 7 feet 6 inch between aft bogie wheel and first driver instead of 5 feet 6.
https://imgur.com/ZQjgKpG

And would track better and be within present gauge

 

Is this where some smartarse unhelpfully suggests the kinetic envelope of the Webb arrangement might suit modern loading guages better?

 

A smartass migth suggest that british railways had been served even better after 1935 by five feet wheeled 4-8-0s and 4 feet six 2-10-0s .
Webb style