O.V.S.Bulleid - The Southern Enigma

I'm sure as a diligent Assistant (to Gresley) and then CME, Bulleid would have kept appraised of developments by his contemporaries, including Chapelon. But if you look at what he actually built, thermal efficiency doesn't seem at the forefront. Instead, the two qualities that shine through are reducing material costs (important in wartime) and attempting (not always successfully) to reduce labour, not least on the footplate. If you broaden the discussion to modifications he made on Maunsell's locos, the draughting changes were attempts to improve locos known for being shy of steam (LN and Q). (Though I suspect with the Q, the real issue isn't the draughting of the boiler per se, but the fact that it is a bit under boilered relative to the cylinders: an issue that was sorted out definitively by reboilering to produce the Q1, which mated a Q class chassis to the biggest possible boiler that could be carried).

Tom

 

I agree re his work on the LN’s was effective, probably the Qs, not sure about the Schools. Not wishing to be churlish
but does not improving ‘steaming’ normally improve thermal efficiency ?

I think Bulleid actually knew Chapelon rather well. ( I note Apple, or similar, has decided for you
that Chapelon was looking after Bulleid .

Michael Rowe

 

For shunting, they already had an entirely competent 350hp diesel design, and I suspect they just would have continued to roll those out as steam locos needed replacement, no doubt on a less than 1 to 1 basis to allow for higher availability.

There were various design studies (outlined in HAV Bulleid's book) for various tank engine variants based around either the Q1 or more radical. The Q1-based designs included 0-6-2T; 0-6-4T; 4-6-4T and (simplest of all) a Q1 with various adaptations to enable it to be driven more easily in reverse. The fact that none was proceeded with may be an indication that the design process is harder than it looks with each design presenting unacceptable compromises.

Maunsell's proposed designs (no doubt strongly influenced by Holcroft) include the following - the last mentioned is essentially what you suggest - a 2-cylinder 2-6-2T with a new boiler and N1 outside cylinders and motion.

• 1927 - an 0-6-0T shunting tank. This was essentially an updated LBSCR E2, designed to replace LSWR G6s, LBSCR E1s and SER R / R1s. Cancelled due to the dire financial situation; when traffic improved, 350hp diesel shunters were introduced instead.
  
• 1928 - a 3 cylinder 4-4-0 with conjugated valve gear and a shortened Lord Nelson boiler. Essentially a dead-end on the way to what became the Schools Class.
• 1933 - a 4 cylinder pacific with wide firebox Belpaire boiler. That would have been a very handsome design, but rejected by Maunsell on account of high cost and the low number that would be needed. They stuck with the Lord Nelson, despite the patchy steaming.
• 1934 - a mixed traffic 2-6-2. Boiler was similar to the proposed pacific (i.e. wide firebox Belpaire etc) with cylinders and motion based on the U1. This would in effect be a SR version of the LNER V2. Essentially rejected due to artistic differences between the CME and the Civil Engineer ...
• 1935 - Beyer Garrett 4-6-2+2-6-4. I can't believe this was ever seriously entertained by Maunsell; it feels to me like a sales proposal by B-P.
• 1935 - Heavy goods four cylinder 4-8-0, based on the Lord Nelson. Rejected as being too powerful relative to the actual trains that could be worked within existing infrastructure (Sidings, loops etc). The final batch of S15 4-6-0s was built instead.
• 1936 - 2 cylinder 2-6-2T, essentially another variant in the Mogul lineage but with smaller cylinders (the same outside cylinders fitted to the three cylinder locos, but only two of them). It would have replaced elderly 0-4-4T, 0-6-2T and 4-4-0 mixed traffic locos, essentially the same niche that Leader was designed to fit. This got close to being built after the Civil Engineer took advice from Sir John Pringle, (remember - Sevenoaks was only 8 years previous) but the order was cancelled. No reason remains for the cancellation, but it was probably because further electrification was envisaged. In hindsight that was a missed opportunity. Pace @Jimc, the boiler design was indeed proposed to be new. Had it been built in reasonable numbers, there would have been no need for the Leader.

Tom

 

Generally better steaming = better efficiency (because you can work more of the time at a higher efficiency, high pressure regime). However, I'd suggest that the rationale was less about explicitly saving coal as an end in itself, and much more about reducing time lost to poor steaming.

I think his work on the Schools was of marginal benefit because there was basically nothing much wrong with the design in the first place - so not much scope for improvement.

Tom

 

I suppose you can say the same about Bulleid’s adoption of Monsieur Armand’s water treatment regime.
( actually I suspect it wasn’t strictly Armand’s but he was given credence because of his senior position )

Less scaling, longer periods between washouts, less tube failures, but also
less scale better heat transfer,better heat transfer results in higher thermal efficiency.
( less tendency to prime, or carry over, at a given water level is another gain )

Similarly, whilst Bulleid pointed out to the I.Mech.eng, the higher boiler pressure
( 280 psi ) permitted smaller cylinders, it also represented a higher saturation
temperature and with a large superheater a high final steam temperature.
( the higher the steam temperature the higher the efficiency, second law of
Thermodynamics )

I think French practice, ( helped by his fluency in French ) was very much to
the front of Bulleid’s credo.

Michael Rowe

ps I have always thought that both Ivatt’s and Bulleid’s use of smaller
cylinders might well have been right. ( it does of course lose the bragging
rights associated with high TE values .)

 

Liberté egalité eccentricité?

I think there is a strong logical link there, just for a different outcome.

Other British loco design tends towards simplicity to reduce labour costs, Bulleid follows the french approach of technical complexity to achieve his result, but his priority is labour-saving rather than coal-saving.

In plenty of cases, the one drives the other - better water means more efficient transfer of heat, which means less fuel wasted and less man-hours devoted to washing-out, and clearing ash and coaling.

I wonder how much of Bulleid's work on crew conditions was driven by the concern about keeping staff when the war finished?

London has always had a lot more light industrial and clerical jobs, which are much cleaner options than railway work compared to eg mining, steel-work etc.

Cutting down cleaning, oiling-up, disposal etc might be more of a priority where the alternatives for labour were less arduous and dirty?

 

In a way this is similar to the discussion on the Gresley thread about rationale for design choices (in that case, whether particular locos were deliberately streamlined with the objective of reducing air resistance, or whether that was just incidental).

So to take water treatment - it is perfectly possible that using it resulted both in better thermal efficiency through better heat transfer, and reduced maintenance through increased periods between washouts. The question then is which one was the prime objective, and which one an incidental benefit. I tend towards the view that Bulleid was primarily interested in labour saving - and any thermal benefits were incidental - because while it is possible to point to features on Bulleid locos that were obviously about labour saving even at the expense of reduced thermal efficiency, I can't think of anything he did explicitly to improve efficiency in a way that knowingly also increased maintenance overhead.

(Obviously not all his innovations worked. But inasmuch as he deviated from conventional practice, I think you can always trace it back to an intention to reduce material costs, reduce servicing labour, reduce footplate labour or increase utilisation and availability).

Tom

 

Something like the 1928 3 cylinder 4-4-0 was actually built but in 3.5" gauge with a lot of input from Holcroft. It had the shortened Nelson boiler and semi conjugated valve gear. I also had a Chapelon economiser

 

The water treatment seems to have been forced on Bulleid by the use of steel fireboxes. Burrows and Wallace cover this at some length in their paper to the ILocoE in 1958 on the experience with the steel boxes. Bulleid refers to it briefly in his own paper, mainly in answer to a question from E S Cox.

 

I agree that a steel firebox mandated water treatment, as a minimum pH control.

Water treatment of course was a regular routine pre WWII, indeed external treatment, lime softening
plants existed pre 1914. ( later hot lime softening, then base exchange softening by ion exchange and in
the modern era reverse osmosis ), Similarly a requirement for internal treatment, pH control , ideally
reserve alkalinity with either intermittent or continuous blowdown to control total dissolved solids was
general practice pre WWII.

A quote from Bulleid’s 1945 paper ( steam index gives 1946, but this refers I think to an area meeting,
the original was presented December 14 ) may be relevant

QUOTE “The use of steel fireboxes on recent French locomotives with 280lb per sq.in.pressure and
over had been satisfactory and, in fact, the author found the French engineers convinced that for
such pressures steel fireboxes must be used.

The successful introduction of the Nicholson thermic syphon had provided a reliable means of
improving the boiler circulation whilst, at the same time giving added security against overheating
of the crown plate.

It seemed reasonable to expect good results from steel fireboxes provided that care was taken
in the design to allow for the difference between steel and copper, and also that all reasonable
precautions were taken to ensure that the fireboxes were treated with care in service. END QUOTE

It is not surprising I think that the SR elected to use a French proprietary water treatment system.
I believe, as with Alfloc treatment, used inter alia by the LMS, it centred on maintaining a free alkalinity
and a phosphate ( Na3PO4 ) reserve in the boiler water with blowdown facilities.. plus
oxygen removal, anti foaming agents etc.The Armand treatment involved continuous dosing..

Both Alfloc and Armand hid their chemical use under proprietary brand names but the
French system I think offered better control.

Michael Rowe

 

I recommend you get hold of a copy of Burrows and Wallace'paper, which is a fascinating account of the issues which arose. Much of the problem with stay and plate cracking was put down to lack of mandated procedures for cooling down prior to washout. The corrosion due to lack of satisfactory water treatment in the early days was a big issue too (they state that internal water treatment had been practically non-existent prior to 1946).

I personally think Bulleid's use of closer-spaced small diameter plain steel stays in wider than usual water legs, rather than using Flannery-type flexible stays (other than around the syphon bottom flanges), common in most steel boilers was an interesting design feature (although monel was later subsituted for some of the plain stays in the combustion chamber area).

 

Burrows noted that in the early days i.e. pre 1946 there were problems with water treatment which were
obviated once Armand (TIA) was introduced. QUOTE. “ It can truly be said that the introduction of comprehensive
water treatment proved to be the turning point in the history of steel fireboxes” END QUOTE.

AFAIK in 1941 they were dependent on external water treatment. Not sure when TIA was introduced, I
believe asap following the end of War in France. Bulleid had been aware of French developments with
steel fireboxes prior to WWII but obviously the War brought discussions to a halt. ( One of Day-Lewis or
H.A.V.Bulleid might include a date of a French post WWII visit. I will have a trawl ) The LMS was utilising
Alfloc feed water treatment pre WWII I believe. Not sure about the GWR and LNER ?

Burrows states the only mods to the original firebox design were Monel substitution for some of
the stays.

In 1941 they were washing out ( using cold water ) every five days. Post TIA 56 days, with hot water.
Burrows attributed early cracking/corrosion more to the regular cold water rather than lack of
internal water treatment I think. I assume there were indications of what some twenty five years
later we would have identified as stress corrosion cracking. ( when I worked for Babcock and Wilcox) ?

Michael Rowe

ps I have been endeavouring to answer my own query re LNER and GWR. Although the
copy I have of Alfloc “Locomotive Feed Water” is post war and has a plain cover, the
January 1 1938 first edition had a picture of an A4 I find.

My post war copy, I think is essentially the 1938 edition reprinted, i.e. 101 pages as per
1938, has photos from all the ‘Big Four’. The frontispiece is Royal Scot 6168 in
original condition, she was rebuilt early 1946.

 

Were Copper fireboxes a British peculiarity or were they used abroad?

 

My understanding is that, although steel fireboxes had become standard in North American practice in the 19th Century, European locomotive engineers usually employed copper until the 1930s. I attach a commentary by ES Cox ("World Steam in the 20th Century"). Cox's final sentence is alluding to the adoption of steel fireboxes for the Class 52 Kriegsloks, and the continuation of that approach in post-WW2 German practice.

 

The diagrams of Maunsell's proposed Pacific and 2-6-2 in Holcroft's autobiography show round topped rather than Belpaire fireboxes; Holcroft also mentions a three-cylinder version of the Pacific with no further details. Maunsell's 4-8-0 proposal was "around 1930" according to Holcroft who could see no need for such a machine, which would have been the largest freight locomotive in the country at the time except for the Garratts and Gresley's P1.