mrwalsh85 Wrote:
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> On a related note...
>
> It was my understanding that piston centerlines
> should be aligned with the centerline of the
> driving axles. If the T12 was straightened out,
> and as such, higher than the CL of the driving
> axles, this could be problematic, correct? I could
> see some "waddling" of the locomotive occurring
> under power.
Right Mr. Walsh. Here is my assumption and, my not being a mechanical engineer means I AM assuming, but most locomotives have the piston on the same level as the center of the drivers. On the T-12's the center-line of the cylinders is raised above the center-line of the main driver's axle. This is possibly due to clearance problems for the 4-wheel lead truck. So to create four equal power stroke events per revolution I think the cylinders would be angled downward to align the piston rod with the main driver's center. Setting up the valves to get four equal strokes would seem to be difficult if the components weren't aligned.