Locomotive Superintendents

If considering unconventional locos then of course there were Churchwatd's own railmotors. British builders had also been using Walschaerts gear on some double Fairlies for export.

Dean tinkered with outside valve gear (with inside cylinders) when first looking at using 7'8" wheels on the narrow gauge ( Stephenson in that particular case) and next proposed Joy valve gear before moving the valves to beneath the cylinders, possibly to give sufficient room for the expansion link (I wonder if he considered reverting to Gooch motion?).

 

That engine was a one-off whose valve gear apparently baffled the staff who were meant to maintain it!

The next use of Walschaerts gear in the British Isles appears to have been by Bowman Malcolm in the 1890s on the Belfast & Northern Counties, inside on the broad-gauge engines but outside on the 3-foot gauge S-class tanks.

https://en.wikipedia.org/wiki/BNCR_Class_S

Outside Walschaerts gear was used quite early in British Colonial engines, for example in some of the standard designs for India in the early 1900s. It was also by that time in widespread use in Continental Europe, for example the Prussian S3 express 4-4-0.

https://en.wikipedia.org/wiki/Prussian_S_3

 

I suppose since I am frequently critical of Drummond, I should mention this example of a two cylinder loco with outside Walschaerts valve gear from as early as 1906 ...



Source: http://1920slocomotives.blogspot.com/2014/02/

(There was a little phase around that time for railmotors, and rail motor tank engines, several of which had Walschaerts valve gear).

Tom

 

When I look at Drummond and Webb's later designs, I am constantly reminded that it was very fashionable to consume opium in the late C19.

 

The oldest surviving British locos I can think of with Walschaerts' gear are NG. The oldest is T&DLR No.5 2-6-2T Hunslet 1892 (related earlier 2-6-0T design dated from 1889, extinct 1959) and of course, W&LLR Nos.1&2 0-6-0T BP 1902

Other than the Fairlie mentioned earlier, the earliest British example which comes to mind was (again NG) Schull & Skibereen No.4 Erin an 1888 Nasmyth Wilson built 4-4-0T which lasted until 1954

 

Tri-angs famous Nellie:
http://4.bp.blogspot.com/-2xvSoDcb8jQ/U2DoSo9hjqI/AAAAAAAAEDI/eZJhzFLsYCc/s1600/P1070240blog.jpg
Pat

 

DHR class A from 1881

https://i.pinimg.com/originals/a0/61/21/a0612120a3cc6b1eb19c39b7ddd3272a.jpg

 

I do believe that the trip to Europe that you are referring to actually occurred in May 1934 and was arranged to attend the trials of a metre gauge Sentinel locomotive on one of the Belgian secondary lines, CMEs from the UK and European railways attended. The Sentinel was part of an order for a railway in Colombia. On the back of the trials, Gresley instigated the ordering of a similar locomotive for the LNER, but this order was later cancelled.

The Sentinel locos bound for Colombia were indeed very interesting machines, running two high-speed, compound geared engines on two 6-wheeled power bogies with steam supplied by a 550psi Woolnough boiler, power output was 600hp. Looking at a photo of this loco and you must wonder where Bulleid got his idea for "Leader" from.........



Cheerz,

Alan

 

And with equal success, or rather, a great lack of it.

 

Didn't the prototype Star have "scissors" gear, avoiding the need for any eccentrics at all on the driving axle? That would necessarily have been inside the frames, with rockers for the outside valves. Although Churchward then changed to conventional Walschaerts, the general layout of the valve gear remained the same, complete with the cranked rockers which I believe do something clever for the valve events, though I don't understand the geometry.

 

Yes, you are completely correct. Thanks for the correction.

This is what you get from reading wikipedia...

So in wikipedia it reads as follows:

"A brief period working for the Board of Trade followed from 1910, arranging exhibitions in Brussels, Paris and Turin. During this time, he was able to travel widely in Europe, including a trip with Nigel Gresley, William Stanier and Frederick Hawksworth, to Belgium, to see a metre-gauge bogie locomotive.[1] In December 1912, he rejoined the GNR as Personal Assistant to Nigel Gresley, the new CME. Gresley was only six years Bulleid's senior."

https://en.wikipedia.org/wiki/Oliver_Bulleid

Footnote 1 takes us to Steamindex which says the following:

"He started an apprenticeship under the equally devout H.A. Ivatt at Doncaster on the GNR in 1901. In 1908 he left to join Westinghouse in France. He married Ivatt's youngest daughter Marjorie on 18 November 1908. He then worked for the Board of Trade at the International exhibitions in Brussels in 1910 and Turin in 1911. This gave him a knowledge of European languages which enabled him to join several parties of senior engineers on their forays into Europe (see for instance his visit to Belgium with Gresley, Stanier and Hawksworth to see the demonstration of a bogie metre gauge locomotive for Colombia). In December 1912 he bacame [sic] Gresley's personal assistant, but left to become the CME of the Southern Railway in 1937."

https://www.steamindex.com/people/bulleid.htm

So it looks like whoever wrote the bio on wiki misunderstood that the visit to Belgium with Gresley, Stanier and Hawksworth was part of the 1910 exhibition in Brussels.

Once again, a reminder that no single source should ever be trusted. Although I did read the steamindex story at the time I didn't read it as taking 25 years apart. Not the first time and not the last time I am sure that I will need to revise my thoughts in the face of new evidence.

 

Yes, and yes. The scissors gear would have been very hard to implement outside the frames. The cranked rockers and specific lengths of the components are supposed to compensate for the effects of angularity described in posts above. Its covered lightly on Don Ashton's pages here, http://www.donashton.co.uk/html/more_cylinders.html but I shan't pretend I understand why and how. Its interesting that these subtleties were completely missed on the LMS Duchesses, presumably demonstrating quite different design priorities.

 

And yet the Duchesses were extremely satisfactory despite not having perfect valve events....
Makes you think, doesn't it?

 

Indeed. I can't think any other loco Nellie could have been based on, though obviously lengthened to suit an already existing chassis and obviously outside Walschaerts valve gear was not going to feature on Tri-ang's bottom-of-the-line loco. Which my parents bought me when I was 4 and Tri-ang track was s still series 3.

 

As I have said regarding other classes, the perfect steam loco was never built, and could probably never have existed, because the beast was a compromise between unreconcilable goals. I'd list the Gresley A4's, the Peppercorn A1's and the standard 9
F's as best of the UK breed, but also up there are the Castles, the SECR/SR moguls, the Stanier 8F's and many another close contenders. IMHO the UK could have used best of breed to go another decade with steam (like Germany) and not wasted so much on poor diesel designs, but ultimately the steam engine was doomed - if not least because it needed too many unacceptable jobs to keep it cleaned, fed and watered.

 

Yes number 40 had scissor valve gear. However the Midland heard that number 40 had scissor valve gear, and started proceedings to take the GWR to court for breach of patent. However the representatives from the Midland, were invited to Swindon, and were showed the mock up, which predated the patent. Churchward having proved this, decided that scissors valve gear was a technological back water, and decided not to proceed with development. North Star kept her Scissor valve gear, until being rebuilt into a Castle

 

There are a number of versions of the scissors valve gear story, but there are details there I haven't heard before. Please could you tell me your sources?

 

The scissors gear seems elegant and simple, but Churchward was no fool, so he must have had a good reason not to stick with it. It would be interesting to understand exactly why he abandoned it.

 

Just as an aside, Martin Evans wrote of No. 40 and it's scissor valve gear in his 1961 book 'Atlantic Era' He gives the story regarding the Midland patent Much as in post 96.

 

Has anyone got a drawing / picture / description of scissors valve gear? I've found lots of reference online, but can't find a good description. As much as I can tell, the valve on one side of the loco is driven by the crosshead on the other.

As an aside, I did find this showing the valve gear layout on a GWR four cylinder 4-6-0, but I don't think this is what is being discussed - a development from, it sounds like.



Tom