Valve Gear Varieties

I was trawling through Google Patents for some information on some of the more obscure valve gear varieties and I had a fair bit of success. I thought I'd post my "finds" here and hopefully start a discussion on these also-rans and why they didn't take off like Walschaerts.

Bryce-Douglas (tried out on Caley 124):
https://patents.google.com/patent/U...1&after=priority:18860101&oq=link+motion+1886

Isaacson (E&WJR 17 & 18):
https://patents.google.com/patent/US915224A/en?inventor=Horace+Sanderson

Morton (GER G14 644):
https://patents.google.com/patent/US281548A/en?q=morton&q=valve&q=gear&oq=morton+valve+gear

J. T. Marshall (both turn of the century GNR & LD&ECR:
https://patents.google.com/patent/US714213A/en?inventor=James+Thompson+Marshall
...& later of SR N class 1850 fame):
https://patents.google.com/patent/US1760952A/en?inventor=James+Thompson+Marshall

W. M. Smith compound valve gear (+ some other Smith patents):
https://patents.google.com/patent/US736889A/en?inventor=Walter+Mackersie+Smith

https://patents.google.com/patent/U...oq=inventor:(Walter+Mackersie+Smith)+cylinder
https://patents.google.com/patent/US662578A/en?inventor=Walter+Mackersie+Smith

Younghusband (NER):
https://patents.google.com/patent/US703885A/en?inventor=Samuel+Smith+Younghusband

I also found all sorts of weird & wonderful valve gear variations. A list of highlights follow:

https://patents.google.com/patent/US1749408A/en?q=benton&q=valve&q=gear&oq=benton+valve+gear

https://patents.google.com/patent/U...ar&inventor=blanchard&oq=blanchard+valve+gear

https://patents.google.com/patent/US1582877A/en?q=elliot&q=valve&q=gear&oq=elliot+valve+gear

https://patents.google.com/patent/U...gear&inventor=hathaway&oq=hathaway+valve+gear

https://patents.google.com/patent/U...gear&inventor=hathaway&oq=hathaway+valve+gear

https://patents.google.com/patent/US1748844A/en?q=valve&q=gear&inventor=kupka&oq=kupka+valve+gear

https://patents.google.com/patent/US1801752A/en?q=mueller&q=valve&q=gear&oq=mueller+valve+gear

https://patents.google.com/patent/US1249534A/en?q=smith&q=valve&q=gear&oq=smith+valve+gear

https://patents.google.com/patent/U...gear&before=priority:19500101&sort=old&page=1

https://patents.google.com/patent/U...ity:19370220&after=priority:19370201&sort=old

https://patents.google.com/patent/US2416982A/en?inventor=dekle&before=priority:19500101&sort=old

https://patents.google.com/patent/U...gear&before=priority:19100101&sort=old&page=1

https://patents.google.com/patent/U...ity:19330101&after=priority:19320101&sort=old

Hopefully these are of some interest.

 

Well if nobody else is going to start, then I will - I would suggest that few if any of these "alternative" valve gears showed any significant advantage over the conventional types and this is why they were not generally adopted. Another point is that long-term testing has always been a problem with steam locomotives - somebody invents a valve gear, or other improvement, persuades a railway company with great difficulty to give it a try, and when the experiment does not produce brilliant results straight away, the idea is abandoned.

 

The Marshall valve gear on N 1850 apparently worked well at low speed but a knock was noted at speeds of 50 to 55 mph. When the loco was tried on a semi fast train the RH valve gear disintegrated. This information is from D L Bradley's book

 

Ahrons was of the opinion that the excessive coal consumption of the first British loco with Walschaerts valve gear' was probably due to inaccurate setting of the valves by running shed fitters to whom it was a complete novelty.

Any alternative valve gear would likely cause similar maintenance problems.

 

I know it won't fit, but a Gresley/Caprotti hybrid on the P2 would be .....

 

I think the nail has been hit on the head with the above points with experiments not producing quick results and novelties on shed seeming to have been short-lived.

I have to confess that J. T. Marshall gear is a bit of a guilty fascination of mine.

Regarding the J. T. Marshall gear on 1850, I have read that the failure mentioned by RLinkinS wasn't immediately fatal to the endeavour but the untimely death of Marshall was. Whether this was because of legal issues regarding the patent or because Marshall was no longer on hand for technical support as it were, I have no idea. Possibly both?

While on the subject of J. T. Marshall gear and the Southern, I have seen it written that the Maunsell Z class had a "custom" gear on the inside cylinder and some (T. H. Shields in his "The evolution of locomotive valve gears") have described this as Marshall gear. Certainly the description of the gear in the December 1930 Locomotives Carriages Wagons etc. Shields references would fit the description of Marshall's 1901 gear and the diagram of the Z class within shows a gear not at all dissimilar to the drawing of the Marshall gear fitted to LD&ECR No. 26 that is available at the NRM. The cylinder inclines are similar, 1-in-8 on the Z & 1-in-9 on 26.

I could very well be mistaken. There is a fair bit of drawing in the way on the Z class inside cylinder and the gear settings are different but the resemblance is striking.

If my assertion is correct, could the success of 1901 (there is also a similar 1907 patent) J. T. Marshall valve gear on the Z class have led Maunsell to consider giving the 1926 variant a go on 1850?

For clarity, I use the year the patent was filed as that was when it was in the bag as it were, rather than the year it was granted.

ETA: Both Holcroft & Bulleid commented on Shields's paper and neither refuted his claim that it was fitted to the inside cylinder of a 3-cylinder 0.8.0 of the Southern. Surely they would know?

 

Apropos of nothing and completely off topic, I found some interesting patents from Whitelegg of LT&SR/G&SWR fame that may be of interest:

https://patents.google.com/patent/US1734508A/en?inventor=Whitelegg+Robert+Harben
https://patents.google.com/patent/US1564390A/en?inventor=Whitelegg+Robert+Harben

 

The inside gear on the Southern Z class (and on the 3 cylinder Moguls) was basically Walscheart's but with a second eccentric to drive the combination lever as there was no space to drive it from the crosshead. This is clearly not the same as the JT Marshall gear fitted to the outside of no. 1850, which may have had two eccentrics (or return cranks) but it also had a conventional combination lever. I would like to know more about it, but I have never seen a good drawing or explanation.

I would have thought that the knocking and breakage of the gear in service could have been overcome with a bit of development - it is the sort of thing which happens on prototypes, and suggests a design fault. Marshall's death must have been a factor.

 

Sorry, to clarify, my assertion is that the Z class was fitted with the 1901/1907 variant gear (as shown in the link below) not 1850's 1926 variant. The two are very different and have separate entries in the Shields paper I mentioned.

https://patents.google.com/patent/US714213A/en?inventor=James+Thompson+Marshall

 

OK if anybody thinks I'm infringing copyright, please, please feel free to tell me & I'll take this down. The following has been (crudely) cropped to only show the relevant sections.

Z class diagram (source: Locomotive Magazine and Railway Carriage and Wagon Review, December 1930):

Z by Matthew Palmer, on Flickr

 

From what I can make of it, on the Z class the piston valve was alongside the cylinder which resulted in the piston rod/crosshead assembly being some distance away from the valve spindle. This I believe to be the reason for the 2nd eccentric to operate the (much shortened) combination lever.

Edit. Was this same arrangement used on the 3-cylinder N1 and U1s when converted from Gresley 2 : 1 gear to 3 sets of Walschaerts?

 

Matthew,

Many thanks for posting the excellent diagrams. I have just found my copy of Shields...

The Z class uses 1 eccentric to drive the expansion link and a second to drive a short but fairly conventional combination lever. The 1901 gear uses the second eccentric to oscillate the expansion link trunnion, so the two gears are not identical, though similar in principle. The other two drawings seem to be versions of the 1901 idea, but with swinging links instead of a sliding trunnion.

The gear used on SR no. 1850 was different. This engine had separate inlet and exhaust valves with the aim of improving efficiency, and the valve gear is basically Walscheart's adapted to control the two sets of valves independently, hence it has two expansion links.

 

What did Gresley have to do with it?
Designing a better valve gear and getting rich on the royalties seems to have been a 19thC dream. We may note the classic Churchward quote after inspecting Holcroft's first model of his conjugating gear, which IIRC was on the lines of "Now young man, all you need to do is work out a way of using one set of valve gear on a two cylinder locomotive and your fortune's made."

 

PoleStar, many thanks for the clarification!

While we are on the subject of constrained 3-cylinder valve gears, does anybody have or can point me to a diagram of Stanier's 3-cylinder 2-6-4T valve gear arrangement?

 

Just for reference, here's the 1850 diagram. Edit: Removed.

 

'Fraid not. Just because its been posted on the web doesn't mean its fair game.

 

This thread made me try to look up a valve gear I experienced many years ago on an OL49 called Tropanoff I think?
Anyone else come across it or have any links to information please?

Whilst driving you would coast in full gear and upon stopping, you had to wind into mid gear, snap open and shut the regulator to “reset” the valves before winding back into full gear to get underway again. Quite labour intensive.

 

Wasn't that the type of valve rather than valve gear?

 

Trofimoff.