Re: Spirals and track precision on narrow gauge lines

I seem to recall a system used in haul road design that allowed the use of simple curves but used extra superelevation to compensate for the lack of transition. IIRC, the superelevation actually began on the tangent just prior to the point of curvature and the general rule was to be at about 1/2 of the max. superelevation by the time the curve began. The idea was that the inward pull of the partial superelevation would ease the vehicle into the curve naturally.

Could some narrow gauges or logging roads have used a similar system?
The earlier portions of the SVRy were built primarily as a log/lumber hauler, but the Austin-Prairie City extension was built as the first part of a long-range connection to the Nevada-California-Oregon RR at Lakeview. The first part of the extension, out of Austin was on former Oregon Lbr. Co. right-of-way, I wonder if the change in curve design corresponded to the point where the new extension began and represented a change to a somewhat higher standard of engineering for the long-range line?

Jes speculatin',
J



Edited 1 time(s). Last edit at 03/31/2008 08:11PM by Jeff A..