07-29-2010, 10:24 AM
Elevation of curves, from "The Mechanics' Handbook " Dec. 01, 1903:
" The best authorities on this subject place the maximum elevation at one seventh the gauge, or about 8" for standard gauge of 4 feet 8-1/2 inches. The gauge on a 10 degree curve, elevated for a speed of 40 MPH, should be widened to 4 feet, 9-1/4 inches.
All curves, when possible, should have an elevated approach on the straight main track, of such length that trains may pass on and off the curve without any sudden or disagreeable lurch."
At the end of the paragraph......"It is a striking fact that experienced trackmen never elevate track above 6 inches, and many of them place the limit at 5 inches".
8" = 0.091954" in HO scale.
6" = 0.0689655" in HO scale.
5" = 0.0574712" in HO scale.
Anyone who has knowledge of mechanical engineering will understand what "moments" are, and those do not scale. The moments of scale model trains, are such that even at a scale 80 MPH, no elevation is required to "counteract the centrifugal force developed when a car passes around a curve". ( and in fact, the "non-scale" amount of drawbar pull, more than compensates for centrifugal force, actually pulling the cars into, not out of, the curve )
The weight distribution of model rolling stock, is that radically different from the prototype.
Superelevation in model trackwork, therefore is strictly "visual", and should be kept to a bare minimum, even when operating at scale speeds. and most that I've talked with about this recommend no more than 0.020" for the height difference of the outer rail.
There are curves on the club layout, that I cannot run any autoracks on, at any speed, because of the "stupidelevation"..............they always fall to the inside of the curve!
It may look neat, but it doesn't work in scale anyway near the way it does in full size.
" The best authorities on this subject place the maximum elevation at one seventh the gauge, or about 8" for standard gauge of 4 feet 8-1/2 inches. The gauge on a 10 degree curve, elevated for a speed of 40 MPH, should be widened to 4 feet, 9-1/4 inches.
All curves, when possible, should have an elevated approach on the straight main track, of such length that trains may pass on and off the curve without any sudden or disagreeable lurch."
At the end of the paragraph......"It is a striking fact that experienced trackmen never elevate track above 6 inches, and many of them place the limit at 5 inches".
8" = 0.091954" in HO scale.
6" = 0.0689655" in HO scale.
5" = 0.0574712" in HO scale.
Anyone who has knowledge of mechanical engineering will understand what "moments" are, and those do not scale. The moments of scale model trains, are such that even at a scale 80 MPH, no elevation is required to "counteract the centrifugal force developed when a car passes around a curve". ( and in fact, the "non-scale" amount of drawbar pull, more than compensates for centrifugal force, actually pulling the cars into, not out of, the curve )
The weight distribution of model rolling stock, is that radically different from the prototype.
Superelevation in model trackwork, therefore is strictly "visual", and should be kept to a bare minimum, even when operating at scale speeds. and most that I've talked with about this recommend no more than 0.020" for the height difference of the outer rail.
There are curves on the club layout, that I cannot run any autoracks on, at any speed, because of the "stupidelevation"..............they always fall to the inside of the curve!
It may look neat, but it doesn't work in scale anyway near the way it does in full size.
We always learn far more from our own mistakes, than we will ever learn from another's advice.
The greatest place to live life, is on the sharp leading edge of a learning curve.
Lead me not into temptation.....I can find it myself!
The greatest place to live life, is on the sharp leading edge of a learning curve.
Lead me not into temptation.....I can find it myself!