[Rail-Rider]

WALSCHAERT'S VALVE GEAR ANIMATION

Acknowledgements to Robert A Booty, 2nd trumpet in the Oshkosh Brass quintet, under whose totally unrelated web page these great technical drawings and animations reside.
Robert appears to have several VERY diverse strings to his bow!

Robert's engineering site (updated link)
provides some more lovely animations, very nicely illustrating how this fascinating and almost unlikely mechanism does its job.

More than half my pleasure in watching a steam engine operate is in simply gazing at the hypnotically relaxing motion of this valve linkage and I think that pleasure is an almost universal feeling. Inside valve motions tend to produce very boring looking machines, by comparison! I still haven't figured out the differences, if any, between Walschaert and the Heusinger named linkages usually assigned to German locos, or what look to me like terribly similar setups, with other names on other locomotives.
Perhaps someone here can clarify this?

Considerably more Walschaert's detail is available via links on the site and yet other illustrated 'tutorials' are provided too. It's a great resource for the scientific/engineering mind. But, for me, this single one is an absolute classic.
Feeling stressed out?
Just watch Walschaert's in action for a couple of minutes and it all goes away!

 

[Dennis David]

 

[John Webb]

Very neat! But I've a sorry feeling there is a slight error. It would appear that the exhaust is from the centre of the valve chest as there appears to be a pipe heading from there towards the chimney. So steam would have to be admitted from the outer ends of the valve chest. But the combination lever (the link from the crosshead to the valve rod and radius arm) is set up as if steam were being admitted at the centre. The differences are described in the 'Handbook for Railway Steam Locomotive Enginemen' published by the BTC in 1957 and reprinted by Ian Allan in 1977, pages 102-109.

Regards,
John Webb

 

[dwb]

If I remember correctly the Science museum in London had model valve gear with knobs you could turn to adjust the operation.

Wouldn't it be great if there was a DCC controller which had all these knobs and levers on it and then the rate of coal and water consumption depended on the settings?

David

 

[Rail-Rider]

Sorry chaps - I made an error with the link to Robert's Engineering Site

The one I originally posted actually links to the the latest beta of Windows Media player 11!
Interesting and useful in itself, but not in this place!
Probably why Dennis has a screwed up face in his post!
Sorry Dennis!

The new link above is now correct and maybe one of the mods could edit my earlier post with the proper, corrrected link, please?

Once you get to that page, there are more options available on it which might bring some clarity to the diagram above. Other options show the steam and exhaust flows, full naming of all the various parts and including the ability to select reverse gear yourself, plus several more diagrams of other bits of a locmotive that one isn't normally able to see. I just wish the speed could be reduced slightly as it can be a bit difficult to follow everything. But nonetheless fascinating - for me anyway

 

[Makemineadouble]

I had'nt realeased there was an upgrade for windows media player so thanks for that !

 

[Rail-Rider]

G'morning, MakemineADouble (may I abbreviate that to MAD?)

Bear in mind that WMP 11 is only a beta at this point, not the finished product.
I'm a great believer in letting other people have their PCs screwed up before plunging in myself and I might add that you must always be extremely wary of Microsoft's Digital Rights Management (DRM), high-handedly refusing to let you play your files because it decrees that you don't have the legitimate licence to do so - they are famous (notorious) for that, the £%$*@#~s!!!

Better get back on topic, quick, though I know Doug is always interested in the software we have to use in order to make the most of our digital communications here