New-build steam strategy coordination?

Actually there was a severe shortage of certain grades of steel which did affect quite heavily the railway industry as a whole. A number of grades used pre-war for LNER connecting rods, for instance, was not available during the war and so other solutions had to be found. Copper too was an issue for a time during the war. When we consider that a lot of the heavy industry the railways owned had been given over to building munitions and vehicles for the war effort the need for austerity and careful management of that becomes more apparent.

Poppet valve gear I believe was that originally considered along with Caprotti?

Challenge accepted! No, none of the wartime Thompson Pacific classes were entirely all new. The A2/1s used already manufactured components intended for four V2 class locomotives and synthesised standard parts from the A2/2s to again make what was in practice a new class, but made up of substantially standard components. 4470 Great Northern as we know was rebuilt from the original A10 though in practice so much of the locomotive was "new". It too, utilised a large number of standard parts including an A4 boiler and again standard parts from the A2/2s and A2/1s. The A2/3s were post war, the first all new Pacifics and even then were very closely matching in many details to the A2/2s.

There were only 26 Thompson Pacifics and there were 110 Bullied light Pacifics built and 30 Merchant Navy. On a purely economic level the use of standard parts for the rebuilt A2/2, and the use of existing components for the newer A2/1 and A2/3 designs looks much better in comparison to the total cost of building all of the Bulleid Pacifics with new tooling required.

60 of the light Pacifics were then rebuilt removing the experimental Bulleid valve gear, and the whole Merchant Navy class was rebuilt on similar lines. None of the Thompson Pacifics were rebuilt or modified as heavily. The only big change was the use of the Peppercorn diagram 118 boiler on the A2/2s and A2/3s to make the pool of boilers bigger for both classes and thus fix what was always the A2/2s achilles heel - a very small pool of boilers, hence a lot of their time off the lines and in for shopping in the late 40s and early 50s before this decision was taken.

So I would call building 140 Pacific locomotives and for well over half of them (and a whole class in fact) to be drastically rebuilt after less than a decade's work to be entirely reprehensible. How can that level of expenditure - to build them in the first place - be justified? The level of expenditure to rebuild them seems to have been well enough justified by historians elsewhere.

But all of those rebuilds did re-use existing components, did they not? There was nothing wrong with the Coronations being churned out - these were existing orders placed pre-war being carried out, which is what happened on a number of other railways.

 

In fact - the thought occurs that you could reasonably compare the rebuilding of Gresley's Mikados into the Thompson A2/2s and the rebuilding of Bulleid's Pacifics into their final, Jarvis directed forms. Both Gresley and Bulleid's locomotives featured unconventional valve gear and were causing maintenance problems and had reliability issues as a result of their unconventional formats. Both sets of locomotives were rebuilt into new classes which used three sets of walschaerts valve gear and more conventional outlines for their cladding and smokebox arrangements.

Makes you think!

 

Bulleid had originally ordered the MNs pre-war, had he not? If you're going to bring the Light Pacifics into this, along with the ten post-war MNs, I could go into some of the post-war Thompson Pacifics, and the B1s for that matter too - since the Light Pacifics fulfilled effectively the same role as the B1, albeit in a very different form.

The Jarvis rebuilds could not be justified when all of the Bulleids then had a maximum of eleven years' service left in them (assuming we take 1956 as the starting point and 1967 as the end). Many of the rebuilds ended up serving only about five years. None of the original locomotive's problems were insurmountable, but BR wasn't interested in improving maintenance... and so we got heavier, slower, less powerful rebuilds (or, as many ex-Southern Region crews called them, 'detuned') which couldn't go to Ilfracombe, Torrington, Bude or Padstow (just to cite a few lines in the West Country - there were doubtless others closer to London too).

 

You keep repeating that the rebuilds were inferior when a number of contributors have pointed out that this is not so and I must add that stating such as fact does you no credit in your argument.

It's interesting you compare B1 against the light Pacific and make comment on their work. If I were an accountant looking at the costs of running a fleet of locomotives I wonder if I'd be happier with a fleet of two cylinder, round topped boiler steam engines simple to build and maintain or more experimental, bigger, more complicated Pacifics to do similar work?

As it is I don't think the BoB/WC to B1 comparison is a fair one: but I base that more on the fact that the B1 and V2s proved their worth when sent down south to work the services the Merchant Navys were taken off after the Bibby Line incident!

 

Every Bulleid driver and fireman I've spoken to or read testimony of has made it clear they thought the rebuilds inferior. Quite a few have written of being less than enamoured with the V2, which, while not a bad engine in itself by any means, was nothing like as nice a thing to live with - much more exposed cab, more oiling points etc - and only the performance of a Light Pacific rather than a Merchant Navy.

While the B1s were undoubtedly simpler and thus presumably cheaper to maintain than Bulleid's Light Pacifics, they also knocked seven bells out of the track with their outside Walschaerts valve gear and those two big cylinders. In that respect, they were much more comparable to the S15/H15/N15 family. If you wanted a smooth ride and to be friends with the P-way guys, the Bulleid was the better locomotive - and, for a similar weight, it was substantially more powerful.

 

The rebuilds may have had an economic life of no more than 11 years. But that was as a result of later unrelated policy about the demise of steam: the business case for rebuilding was based on the locos lasting into the 1980s, at which point it looks economically far more sound.

As for the issue about the rebuilds not being able to work West of Exeter, that's true, but even the original locos were arguably too big for the traffic on offer. Accepting that the presence of pacifics on two-coach trains was justified on rostering grounds, it still leaves open the view that, with one or two exceptions, most of the traffic west of Exeter could have been economically worked using locos of about Class 4 size.

Tom

 

Mods: please can all these posts about the rebuilding be moved to the Bulleid Pacifics thread.

Anybody: can someone please find that link to the detailed report that was the basis for the rebuilding.

 

You will need to report a post on this thread if you want to draw the mods attention to it - they don't read every thread/post so it's unlikely they'll see your request above.


Keith

 

Here I think:

http://www.national-preservation.co...s-it-for-the-better.140130/page-6#post-739726

Tom

 

I did once hear an ex-ER driver describing a light pacific as "Just a V2 in a box". I'm fairly sure that he meant it as a compliment.

 

Hardly surprising as Merchant was a Class 8 and a V2 was a Class 7, same as a WC/BB. I suspect an East Coast crew would have a different opinion though.

 

A WC/BB was a Class 7, a B1 was a Class 5. Both good engines in their own right but not really comparable to each other for various reasons.

 

What I find difficult to comprehend is that Bulleid only got away with the 'Merchant Navies' in wartime by describing them (with 6' - 2" driving wheels) as a 'mixed traffic' locomotive, yet the LMS clearly got away with building the 6' - 9" wheeled "Duchesses" in wartime, a design which was clearly an express passenger locomotive.

 

I suppose you could consider Bullied to fall well within the LSWR tradition as a worthy successor to Beattie and Drummond. Bullieds thermic syphons achieved what Drummond was trying to with his firebox water tubes, the pacifics' attempt to break from tradition with chain driven gear can perhaps be compared with Drummonds break from convention with double singles and later using different gears for the inside and outside cylinders i.e. you don't know until you try it!

I do confess that I have never understood the development of Leader. Starting with a sububan tank loco using a Q1 boiler - quite logical; then mounting it on two four wheeled power bogies - geting a bit eccentric; then 80 tons being too heavy for four axles it was amended to 150 tons on six axles - eek, didn't any alarm bells ring; oh and sleeve valves as used on Paget's locomotive - shouldn't the men in white coats have been sent for by then?

 

I think men in white coats should be sent to all of us for the amount of thread drifts on Nat Pres!

 

Yes, when you look it like that, South Western motive power policy certainly plotted a mazy path between (possibly misguided) innovation (Beattie père-et-fils, Drummond); and rock-solid dependability (Adams, Urie), a pattern continued into SR days.

I get the sense that they asked the right question, but each time they didn't get quite the right answer, they seemed to solve one problem by introducing two more, in the process seemingly completely losing sight of the initial question!

The SR lost a lot with the more or less simultaneous retirement of both Maunsell and Walker. One gets the feeling that Walker may have acted as more of a restraint on Bulleid than Missenden did!

Tom

 

I suspect we might be in agreement. The right question was certainly "what do we do about all those ageing tank engines?" It was after that that they started to get the wrong answer...

Agree about the diesels: 10201/2/3 were broadly successful, and Maunsell had already introduced successful diesel shunters, so the experience was there. One wonders what a mid-1940s loco filling the role later taken on by Cromptons would have been like?

Tom

 

It looks as if Bulleid was trying to combine the power of steam E/C engines with the ease of maintenance of the Petrol I/C engine. He seems to have been blind to the fact that the I/C engine is a relatively small part of the vehicle, and can be removed for rebuild or replacement if it fails, whilst the E/C engine is the vehicle itself. Perhaps if he had tried more cylinders, single acting, using a more robust valve gear than sleeve valves, he might have got a better bogie system, but then there was the whole boiler/firebox layout. Even a bayer-garret type with power bogies would have been more logical for the size of loco the Leader became.

How it got that big is another question...

 

Vanity project is one description. Madness is where I would place Leader - and what was the most high profile contemporary to Leader? This:



More fuel efficient, cleaner, more powerful, shorter by 6 whole feet, lower axle loading...

What was Bulleid thinking? Railway enthusiasts criticise Thompson for his designs, Hawksworth is castigated for the County's shortcomings, there's no end to the criticism of such oddities as Webb, Drummond and a few other CMEs, and yet where Bulleid is practically canonised there is this utter waste of resources on his CV:



You couldn't make it up - Leader and LMS 10000/10001 were built around the same time and there's no comparison as to which is the better machine. Forget prolonging steam's life - the above diesel-electric should have shown the Southern that Bulleid was off his rocker with the Leader.