Castles, Nelsons and Royal Scots

So not an L1 boiler then and my Conversion of a Triang L1 to a D1 many years ago wasn't as good as I thought it was!

 

No, though probably acceptable for the Triang era of railway modelling!

To be fair, the SER / SECR 4-4-0s are a bit of a minefield to disentangle, with the Sirling B / F very closely related (and the rebuilt B1 / F1 are essentially identical); and similarly the Wainwright D / E (and therefore the D1 / E1). Essentially, an E is a D class with a Belpaire firebox and very minor dimensional changes to accommodate the different firebox; the D1s then arose because it was realised that the new boilers and cylinders designed for the E --> E1 rebuild would fit without modification. With the second series of D --> D1 rebuilds done at Ashford, the workshop wanted to provide new frames with 2" longer wheelbase, which would in effect have made them uniform withe E class; that was rejected on cost grounds, since the original frames were still in good condition, but it goes to show that the notion of locomotive identity and where the dividing lines are between overhaul / rebuild / renewal / new loco can be quite fluid.

Tom

 

James Clayton brought the shape and similarity and a very good Walschaerts valve gear which he first put into the S & D 2-8-0. As a result he was able to use this gear successfully on the Woolworths. He took the Midland wheel spacing of 8 foot 8 foot six, and it transferred from the midland and ended up eventually on the Q and Q 1. This had been a Midland standard from the 19th century and transferred to the southern. As far as the LMS 2P being a poor locomotive, it was of its time and perhaps shouldn't have been continued by the LMS from 1928. In its defence, it was able to pull 6 coaches unassisted across the mendips and up the Parkstone bank. A feat that a greyhound struggled with, even though it could run down hill like the wind. I agree that the L1 was a wonderful locomotive and had the better long travel valves, which would have been beneficial on the 2P. As far as the Q, Peter Smith didn't find it better than a LMS 4F despite its improvements in valves. So not everything was hunkydory.

 

The popularity of the Midland / LMS 2P 4-4-0 was that they were very cheap to maintain. I recall being hauled by a few and they were fine on about four coaches. Odd really, because the scaled-up version, the Deeley 999s, were pretty much a match for the compounds and it is claimed that they could have surpassed them if the esoteric Deeley scissors gear for the valve system had been amended. One thing about the Scots, and this compares favourably with modern practice, is the short time between NBL being authorised to build them and their delivery. True, the promised schedule slipped a little but it did illustrate the output ability of NBL compared with many of the railway companies' own workshops. In their original form (which I never saw for real) they did look rather box-like, verging on the ugly, but their rebuilding with taper boiler and a less angular Belpaire firebox made very handsome engines.

 

This of course was one of the reasons James Anderson gave for their perpetuation as an LMS Standard class. The reason for their mechanical longevity was that it was impossible to work them hard. The valves' location below the cylinders required a very tortuous and restricted path for both the live and exhaust steam. Basically, it couldn't get in or out of the cylinders fast enough to do much work!

 

An extremely short lead time may have resulted from the fact that most of the design work had already been carried out by a third party. Perhaps from an existing operational locomotive!

This basic design could then have been simply tweaked. Substituting Midland standard components for the third party's own items. Slide bars were mentioned, of course it makes sense to fit your own design rather than the 3 bar type fitted. This philosophy would have been followed all over the locomotive in order to make use of existing tooling and patterns rather than making new. All this resulting in a similar looking locomotive with considerable design diffences able to be built very quickly from a basic proven design.

 

Which 'basic proven design' did you have in mind? It was nothing on the LMS and details only were carried over, except for the 2-6-4T valve gear, and minor standard fitting such as injectors, ejector, etc. And the differences between the Scots and Nelsons rule out the latter. Going from a four- to three-cylinder layout involves far more than a change of the middle cylinder block. And there were other major differences elsewhere.

 

I was indeed thinking of the Nelson as this is the popular thinking for as long as I've been interested in railways. The 3 cylinder piece is interesting, maybe this was a major redesign from Derby taking time to complete. It would be good to know what had been drawn by Derby and what was carried out in house at NBL, even comparing these to Eastleigh archives.

What we have here are statements from respected draughtsmen, one saying it definitely wasn't based on Lord Nelson the other stating that there was some collaboration. A quickly designed and built express passenger locomotive leads me to think that it isn't quite as clear cut and that some collusion did indeed take place. As to the extent I have no idea. It would be fascinating to find out but I don't think that'll happen on here!

 

I'm not sure I'd agree with the 8' - 8'6" standard spacing transferring wholesale to the Southern. It may have made it onto the Q and Q1 (and certainly a Q could hardly look more Derby if it had been designed there). However, unlike the Crabs and Fowler tanks, for instance, the N class had 7'3" - 8'3" and the K class tanks were 7'3 - 7'9", which was subsequently inherited by the U class. Fortunately the S&D 2-8-0 gear didn't make it wholesale over to the Maunsell classes, or they'd have been rather hamstrung by its short travel. Eric Langridge wrote about having to persuade Herbert Chambers to allow long lap gear for the Fowler 2-6-4T, ironically by using the K class as an example that the sky would not fall in, when instructed to use the S&D 2-8-0 as a basis.

Harold Holcroft also wrote that T.S. Finlayson, of the Eastleigh drawing office, managed to talk Clayton into accepting a lot of South Western mechanical design practice after the grouping, particularly in the case of the Lord Nelsons and Schools, when Holcroft was pushing for a more Great Western influenced approach. I get the impression Holcroft was torn between irritation and grudging admiration at being outmanoeuvred.

 

Hello Don,

Great post, goes some way to acknowledging the vital input of the whole of the drawing office staff in the research and design of locomotives. Just one thing tho', the Royal Scot taper boiler was based on the boiler fitted to the rebuild of "Fury" when it was also renamed "British Legion" in 1935.

Cheers,

Alan

 

Getting back to the ex SECR D1s and E1s just for a moment, the only way to easily tell them apart was that the D1s had plain coupling rods and the E1s had fluted ones.

 

Apologies! You are quite correct in that the boiler was first used as a Fury replacement.
Unusually, Henry Fowler had the final say on the valve gear on the 2-6-4 tank after a meeting advocating the use of long travel valves. He visited the drawing office and confirmed that long travel valves would be used. The result was an excellent locomotive and was accepted by Stanier as one of suitably modern design along with the Scot, Baby Scot and Crab. A driver who, over the years drove every permutation of 2-6-4 tank barring the Northern Irish loco, said there wasn't a jot to choose between the Fowler, Stanier or the BR standard. It was a shame that he didn't cross the office and do the same to the 2-6-2 tank. The Fowler version was appalling and not much improved by Stanier. It wasn't until the Ivatt that a decent class 2 2-6-2 tank was made by the LMS. I have often wondered why the Northern Irish 2-6-0 and its sister the 2-6-4 tank never had parallel boilers when Stanier was using taper boilers elsewhere. They appear to have more to do with Crabs and the Fowler 2-6-4 Tank even though the latter was produced under the CME ship of Ivatt.
I had only meant that the 0-6-0's of the Southern of the Q and Q1 had the Midland spacing not all 6 coupled locomotives. So apologies for the mis-understanding.

 

You mean they never had taper boilers. The reason is explained in a RPSI article that was linked to on another thread. Give me a minute and I'll find it.

Edit. See http://www.steamtrainsireland.com/FFT/FFT28.pdf (article near the end of that issue).

 

NBL had a lot more design experience to base the Scots on that just British 4-6-0s, they built large numbers of locos for far more demanding clients than the LMS - overseas, mostly the colonies. Although some required quite different approaches due to local conditions, many elements were common.