Lee
Involved Member
Posts: 95
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Post by Lee on Sept 21, 2006 8:07:46 GMT
Hi All Can anybody provide me with the name or information on the unusual valve gear on this neat little Loco engine built in the UK by R & W Hawthorn in 1880 evidently it was based on a steam tram engine. I would like to find a bit more about how the valve gear worked.  I found this engine on Colin Usher's web site Ken Swan is building a 7-1/4 gage version of it but the page hasn't been updated for a few months. Lee |
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Post by baggo on Sept 21, 2006 10:48:16 GMT
Hi Lee, there's a website I found recently by someone else building a model of this loco. I'll root it out and let you know. John Hi again Lee, it may be the same one that you have already found: www.homepages.mcb.net/howe/LocoinBuild.htmIt describes making the rocking beams but doesn't give any details of how the valve gear actually works. Just studied the photo again and there appears to be a vertical lever connected to the connecting rod which disappears behind the tank and I would hazard a guess that the valve gear is Hackworths or something very similar. |
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Post by Tel on Sept 21, 2006 20:21:27 GMT
Now blokes, I don't want to stick me nose in where it ain't wanted, BUT - that rocking beam is part of the main drive, not the valve gear
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Post by baggo on Sept 22, 2006 0:23:23 GMT
Hi Tel,
I must admit I had to do a double take as I first assumed that the rocking levers were part of the valve gear! As you quite rightly say, the levers are part of the main drive. That's when I looked more closely at the picture and saw the vertical lever which is obviously the drive for the valve gear,
John
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Post by Tel on Sept 22, 2006 1:28:17 GMT
...... which leads me to believe that it's Hackworth gear hidden in behind there
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Post by Shawki Shlemon on Sept 22, 2006 9:53:01 GMT
Hi all  I would like to put my two cents worth on this !!! though I am not sure . I think the large vertical levers are part of driving gear. The small vertical rod connected to the coupling rod at the rear end drives an eccentric which drives the valve gear similar to slip eccentric system. |
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Post by greasemonkey on Sept 22, 2006 11:37:17 GMT
Hi All
That small lever at the rear is connected to the Con Rod and so would describe a diffrent motion than if connected to a crank. Can Hackworth gear be made to work from that style motion?
Andy
Andy
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Post by baggo on Sept 22, 2006 16:26:20 GMT
Think I may have cracked it! Searching back through my Model Engineers I've found an article by R M Tyrrel ( Volume 143 Issue 3553) that describes some unusual valve gears. There is a photo of a small 0-4-0 loco with Brown valve gear that looks exactly the same as Neptunes. Charles Brown was an Englishman who was the works manager at the Swiss Locomotive and Machinery Factory at Winterthur ( S.L.M. Winterthur). In 1878 he came up with the idea of splitting the connecting rods into two sections connected by the large rocking lever. This was because the majority of the Swiss locos had very short wheelbases to enable them to negotiate very tight curves and it was difficult to fit a conventional outside valve gear. In another article on Hackworth valve gear by J N Liversage (Volume 76 Issue 1885) mention is made of the Brown valve gear which eliminated the problem (with Hackworth's) of angularity of the radius rod affecting the valve displacement. I can only assume from this that Brown's gear is an improved form of Hackworth's. John Just found this as well which has another couple of photos of locos fitted with Brown's valve gear: irsociety.co.uk/Archives/27/CL_2.htm |
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Post by greasemonkey on Sept 22, 2006 17:14:41 GMT
Hi John
Think you might be right, the overall style is the same with the rocking lever. I would like to see more details as to how it all works. What has Ken used in the design?
Andy
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Post by GeorgeRay on Sept 22, 2006 20:59:09 GMT
Is this the loco on the cover of the latest issue of ME. |
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Lee
Involved Member
Posts: 95
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Post by Lee on Sept 22, 2006 22:29:35 GMT
George
We are about 6 issues behind out here in Oz. I hope it is I would like to see a modelled version of it'
Lee
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Post by baggo on Sept 23, 2006 0:28:30 GMT
George,
Yes, it is the same loco. I hadn't realised until you mentioned it and I had another look at the cover. Hopefully more details will follow in the next issue.
John
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Lee
Involved Member
Posts: 95
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Post by Lee on Sept 23, 2006 6:28:25 GMT
John
Thanks for solving this you have done really well.
Lee
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Post by steammadman on Sept 24, 2006 17:20:11 GMT
Yes guys ,but , I don't think KEN SWANS version has the same valve gear
or motion layout as in the pic at the top of this thread.
I have seen Ken's model and i am sure he used stephensons gear.
I stand to be shot down in flames though, the old memory is not what it
used to be .
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Post by chameleonrob on Oct 13, 2006 10:56:57 GMT
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Post by baggo on Oct 13, 2006 16:49:55 GMT
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