Alco 3rd Cylinder Valve Linkage

[jkimberln]

I thought Gresley's conjugated valve gear was rather fiddly and prone to wear with all those levers. I have a 3-cylinder Schools Class locomotive that has inside Walshaerts valve gear and it is just like the outside except that the return crank is an eccentric. It's a Henry Greenly and Earnest Steel design.

[Asteamhead]

3 cylinder engines can be done in every scale from 3/4 " and up
They were more comon in Europe and were produced in big numbers. For example, the Decapod class 44 903 was the very last steam engine to run in revenue service as late as october 1977 here in Germany. Their triple sound will not easily be forgotten
There are serveral models of different types running reliable as the prototypes did
For an example please look at the attached photos. This model has a complete 3rd walchaert gear with a cranked axle instead of using an exenter disk.
Start and try, it*s fun!
Wishing a better new year 2022 to all of you!
Asteamhead