Terry Simpson wrote ln USMA 26370::No. A grad is not a grade. A grade is the rise in height divided by the road distance travelled expressed as a percentage. A 100% grade = 45 degrees.
If a 100% grade is 45 degrees, then a grade must be the rise (or fall) in height, divided by the horizontal distance traveled, not the road distance traveled (which would be along the hypotenuse of the implied triangle).
Bill Potts, CMS
I believe that a cartographer would refer to it as a 100% grade, but a railway civil engineer would call it a 41% grade. It is matter of tangent versus sine.
Terry Simpson defined the railway grade, but then gave an example of the cartographer's grade.
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Joseph B. Reid
17 Glebe Road West
Toronto M5P 1C8 Telephone 416-486-6071
