Dave Boyer Wrote:
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> It's interesting that the Glenbrook and #5 are
> on their own narrow gauge tracks and don't
> share a standard gauge rail.

Rader Sidetrack Wrote:
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> Note the tracks are leading up to the turntable.
> A turntable with three rails is not practical, so
> there needs to be a conversion to four rails
> before the turntable.

Dave Boyer Wrote:
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> Thanks, it makes sense that an engine has to
> be centered left and right, front and back, as
> much as possible on a turntable.


It's not just a matter of balance, Dave -

As Rader pointed out, a dual-gauge turntable with just three rails isn't practical.  It might work to put engines onto different tracks leading into a roundhouse, but when it comes to turning an engine around it's not merely impractical — as you can see in part 2 of the following simple diagram, it just won't work — at least not without some misalignment:


The third part of the diagram shows how a transition from 3-rail dual gauge to 4-rail dual gauge and a 4-rail dual-gauge turntable allow turning of both narrow- and standard-gauge locomotives.  For further information see Roosso's post at [ngdiscussion.net].

- Sincerely, Willie  (Wm. Claude Johnson-Barr III, Esq.)  
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Edited 2 time(s). Last edit at 06/25/2022 01:13PM by Johnson Barr.