Re: Steepest train/tram line

[G.Lambert@unsw.edu.au (Geoff Lambert)]

krel4203@netconnect.com.au (Krel ) wrote:


>On a similar subject - Is there anywhere apart from North America that
>measures curves by degrees instead of distance for sharpness. I don't
>understand how a right angle curve could be described as a 2 degree
>curve :-).

>Surely radius, in yards, metres, chains, feet, anything makes more
>sense.

Similar reasoning applies here as to grades: the measure of grade or
curve resistance can be made (more or less) proportional to the
measure of gradient or curvature if you measure the latter two as
fractional/percentage and as degrees turned while advancing a certain
distance (in the U.S. case, 100 feet), respectively. Formula existed
for calculating curve resistance as a direct function of the "degree"
of the curve.  Had it been in terms of radii, they would have had to
divide by something- they didn't like that.

In essence, one can calculate the total resistance on a curvy hill by
adding the two (with appropriate scale factors) only if grade is in %
and the curve is in degreee terms.

Geoff Lambert