Re: Walschearts Gear with Slide vs Piston Valves . . .

Earl Wrote:
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> Officially that form of Walscheart Valve gear
> is called "Indirect Motion".  It is "indirect" be-
> cause in motion the eccentric rod from the ec-
> centric crank to reversing link is moving in the
> opposite direction of the valve stem.  You see
> this set up on lots of locomotives with Walsc-
> haert Valve gear and slide valves, like #26.


OTOH, on ex-S.P. #18, when in 'rods down' position, the eccentric crank is angled to the rear to accommodate the outside-admission slide valve (and the valve stem is attached to the combination lever above the radius rod rather than below it as on a typical inside-admission piston-valve setup).  As noted, this is more common for a road engine vs a switcher.