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Re: (erielack) Superelevation - cant deficiency



There are several ways of superelevating curves on model RR's. Probably the 
superior way is to use spline subroadbed and superelevate that. Since most 
of my RR sits on plywood sheets, I use stripwood underneath the outside 
rail, sanding down each end to achieve easements. With easements applied 
also to the curvature, the whole effect is quite pleasing. On my EL the 
superel is a scale 4", which is very noticable. Since we tend to use much 
sharper radius mainline curves than the prototype, higher superel 
disproportionately increases the risk of stringlining, which is 
proportionate to % upgrade, degree of curve, length of car, C of G, rolling 
resistance and length of train, and inversely proportional to weight of car 
(more important for light cars at or near the head end). So Erie/EL's 7" 
maximum may be too much for your pike. The prototype also encounters 
stringlining, particularly as you might expect with long cars (TOFC, 
autoracks) on the headend of trains operating in mountainous terrain. It's a 
big issue in the Tehachapi's and Cajon Pass, and was a major reason behind 
the 1972 realignment on ATSF at Summit, CA. Frequently, operating rules 
stipulate that 89' cars be placed on the rear of the train on such upgrades.

Paul B

2. For modelling purposes, from my own calculations and drawings when I was
in the construction phase, the prototype # of inches of superelevation is a
close parallel to the actual geometric # of degrees off-level. A prototype
5" superelevation, for instance, is close to a 5-degree incline off-level as
measured by a protractor or equivalent. Protractor measured angles are much
easier to work with than scale inches when modelling, especially when
computing algebraically and cutting intervening angulations as in the
transitons to and from tangents.

Joe Braun 


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