The LMS's pre-grouping express 4-6-0s - a question

And I would join you in that project! I think they were a superb looking machine. Mind you, you might not like the name I would suggest for it - Mario Balotelli! (football reference, occasional good performance, but erratic, inconsistent and a bit unreliable!!)

 

Sorry, I was!

 

I don't think you were, I think you mean the Rivers: designed for HR, banned by Civ Eng as too heavy (didn't understand hammer blow), sold to CR, ran on HR mainline in LMS days.
Clans were replacements for Rivers, always allowed on HR mainline. Good engines, but Rivers were best of the LMS-inherited 4-6-0s. They influenced Hughes' design of the Crab, via St Rollox.

 

I think you are confusing two different classes. PH is talking about the Highland Castles built by NBL for the Etat company as their 230-321 class. Only three survived to SNCF days, none past the invasion of France: http://roland.arzul.pagesperso-orange.fr/materiel/traction/230.htm
Meanwhile NBL (and VF and various French builders) also built a class of 2-8-0s for the French government administration lf the railways in WW1. These became Etat class 140-101, later SNCF class 140C. These survived very late, and eight are preserved: seven by NBL and one by VF: https://fr.m.wikipedia.org/wiki/140-101_à_370_État_ou_140_C_SNCF

 

Well that's two of us. I really must begin to accept that I'm too old to keep commenting from memory. I have the Highland Railway history book to hand and ought to check these things up instead of being sure of what I read years ago.

 

Front end design in particular I suspect. Poor steam distribution will make less difference on a loco at low speed than at high speed (because the ports are open for a shorter time period at high speed, so getting steam in / out quickly is at more of a premium). My guess is that that explains why the Maunsell S15s were preferred by crews on passenger turns, but the Urie ones were considered good engines on slogging goods turns. Probably also explains why the best of the early passenger 4-6-0s were those by Churchward.

Tom

 

The 'Rivers' did indeed return to the Highland in LMS days, but apart from a change of Chief Civil Engineer, I believe that a certain amount of upgrading of the route - bridge strengthening especially - allowed this.

 

I suspect partly 4-6-0s were a tougher nut to crack than hindsight makes us realise.
They were designed because longer, heavier and faster trains were needed. That meant more power - but with the British loading gauge larger cylinders is not a simple matter, hence multi-cylinder designs. Also there are many more and older bridges (because of the early date of railway construction but in a land already heavily developed), so axle loads and hammer blow are more important that e.g. in the US.
More power to bigger cylinders means more steam, and faster
: hence the front end becomes much more critical and ports and passages start to strangle the loco when they were fine on earlier designs. Here also valve design becomes vital, and apparently small details: many of the sub-standard 4-6-0s were badly let down by wide piston rings.
More steam means big boiler - again a new departure, and the British loading gauge again makes it tricky (and a big boiler means short chimney and may spoil draughting). Superheating was clearly promising, but some of the factors weren't understood, e.g. lubrication was a common 4-6-0 problem. Churchward was fortunate that on the GWR low degree superheat was adequate for their needs, with the good fuel they had available. Others made the right call (e.g. Hughes) having proper superheat but was harder to get right.
Generating all that steam means a good firebox and grate: British loading gauge means you can't go high so grate is stuck down between the frames and hard to get right.
With all these new factors, and trying to keep weights down, etc., some designs were found wanting. The best designs used overseas experience: Churchward did, but so did Hughes: It turned out that some things worked better in translation than others. Churchward's greatness was in spotting which, and in good testing of prototypes. The GWR paid for those; would other lines' management have done so?

 

Agreed - in hindsight, 4-4-0 to 4-6-0 looks to have been much more of a step change in design than that from 2-4-0 to 4-4-0 that in the main was navigated successfully by Locomotive Superintendents faced with similarly rising loads in the 1870s / 1880s.

Tom

 

I think the head scratching was often more with regard to the boiler, particularly the grate, than the front end. Even with 4-4-0s the coupled wheelbase was being stretched to fit bigger grates (or in Drummond's case even un-coupling the driving wheels). Hence the succesful adoption of Atlantics by a number of companies.

In particular the Great Central 4-6-0s had longer barrels on similar fireboxes to their 4-4-0s, whilst amongst other problems the Claughtons' ashpan was too shallow over the rear coupled wheels.

The cylinders of succesful Atlantic and large 4-4-0s were of a similar size to many 4-6-0s yet were free running and well regarded.

I presume the Castles and Clans had a bit more space due to smaller coupled wheels while the Manson and Holden 4-6-0s were significantly less ambitious than the Drummond and McIntosh giants. (The freight version of the Great Eastern 1500s was an 0-6-0 whereas the freight version of the Great Western Saints was a 2-8-0!)

 

I have a great fondness for the handsome Manson 4-6-0s. But they were only 3P, not powerful enough for heavier trains Carlisle line even when built (although probably fine for the normal Carlisle trains). You can see why the LMS Compounds (4P) were welcomed, although the Black 5 (5P5F) or even Jubilee (5XP) was really what was needed.
I have often thought that the GSWR 4-6-0s might, if rebuilt with smaller drivers, improved front end and the saturated ones superheated, have made a good loco for secondary lines in the Manor/Std 4 mould. They were similar size and weight.
But the LMS wasn't that kind of railway. And anyway, in the late 1920s they had plenty of old 4-4-0s on those trains. Funny they never did have a standard light Class 4, though, the Class 4 tanks would have made a perfect basis, as they did for the NCC moguls. The Ivatt 2-6-0 were 4F on the LMS.

 

The J20 wasn't exactly a small 0-6-0, mind you.

Comparing the S69/1500 to the Drummond (LSWR) 4-6-0 classes is interesting. Look where the firebox is. On the Drummond classes, the front and rear of the box is directly over the middle and rear axle. The corresponding dampers are actually between the axles, so air to the ends of the grate comes in the damper, does a neat U-turn, packs any ash in the shallow space over the axle, and then might make it to the grate.

On the S69, the firebox straddles the centre axle; it is for all the world as though somebody has taken a fairly shallow box 4-4-0, cylinder arrangement and all, then shoved an extra coupled axle in the middle. But both the front and rear of the grate get unrestricted airflow, and the middle gets fed from both ends, making choking rather less likely.

The Urie classes, including his Drummond rebuilds which kept the shallow box, do things a bit differently again, with the box entirely behind the middle axle and overhanging the rear, and a rear damper behind the rear axle to ensure good airflow there. With the sloping grate variants, it's actually very similar to the layout on Drummond's D15 4-4-0, which successfully broke out of the cycle of bigger 4-4-0s that didn't have any more grate than a T9 because nobody dared lengthen the coupling rods again. So oddly, Drummond's last, successful 4-4-0 showed how the grates on his unsuccessful 4-6-0s should have been done...

This is all a long way from pre-grouping LMS 4-6-0s, but I wouldn't be surprised if some of the issues were similar.

 

I think this is in part bad history written by the victors, "GWR good, everything else bad". Whilst there were some issues LNWR wise, many of these performed very well over a number of years including the whole WCML, including the WW1 years. I feel this is a great historical malappropriation. The GWR was ahead in design at the time but not that ahead. Post grouping, some of these designs became very successful. But look how well the Castle beat the A1, but which was better in 1963, and does it matter? But after 1927 the GWR became the most slow to progress, due perhaps due to its earlier supremacy...how do you improve on perfection?

 

As a died-in-the-wool Southern enthusiast, far be it from me to comment on matters GWR, but I've been educated by the likes of @Jimc to maybe see GWR loco progression in a more benign light (Nurse! Nurse! the smelling salts, I think he has come over all funny...) If you look at the headlines, they were seemingly building Castles for quarter of a century without progression. But a 1950 Castle was not the same as one built in 1927; and the fact that basically the two had the same class name, leading dimensions and looked the same disguises quarter of a century of incremental improvements, some obvious, some not.

I think you do also have to see that, pre-WW1, they were a long way ahead of most other British companies; and ultimately the Churchward school influenced all of the other post-grouping companies: on the Southern via Holcroft; on the LMS via Stanier and on the LNER from Gresley learning from what he saw.

Tom

 

Well, they barely saw any LMS service anyway!

 

As another non-Swindonian (I'm Horwich and Crewe by preference) it is simply true to say that in terms of large engine design pre-WW1, Churchward was streets ahead of anyone. He got there by learning assiduously from the US, France, Germany, Belgium, etc. incorporating the best bits (taper boiler, superheat, Belpaire firebox, Walschearts gear on some locos, large ports, etc.) and testing carefully. He was simply a brilliant engineer. His basic designs served all the GWR's needs for half a century, with suitable modernisation.
Hughes was also a good engineer, and made sound individual detail design decisions, but the sum total simply did not come together well. Details like smokebox vacuum leakage and piston rings let the whole thing down badly.

 

That description of Hughes might equally, or even more accurately, be applied to Bowen Cooke.

BTW I do wonder, given the commonality of details among Crewe designs whether the well regarded George Vs would have been even better performers with better smokebox sealing and American type piston rings.

 

A lot is made - rightly - of the GWR influence on other British railways, but it is often forgotten that each railway all had influences on the others, with the exception of the GWR. Engineers and draughtsmen moved freely form one railway - and one private builder - to another and took the latest thinking of his former CME with him.

George Hughes was well imbued with the needs of the L&YR and his engines were excellent for the needs of that line. But as said earlier, when he became CME of the combined LMS he tried, to a limited extent, to use these same machines over the entire system. They were not the answer to these different needs, any more than the Midland engines imposed by Anderson via Fowler were to be when they also tried to impose Midland conditions across the entire LMS.

 

For my own interest, I developed the attached graphic showing the various types and "families" of 4-6-0s (and related types) in Britain, and their various influences. Hope it is of interest. Caveat: was done quickly and not very carefully!