Grades and curves

I offer to respond to specific questions sent to my address, on these two subjects. To the left of this keyboard is Railroad Engineering, Wm. W. Hay, University of Illinois, 1982.
Very critical is the combination of grades and curves. Ask any locomotive engineer. It is common to reduce the grade around a curve. Listen to the locomotive and observe the speed as it passes into, around, and out of a curve. A properly compensated curve can't be seen or heard. Not always the designer's practice.
Consistency of grade, curvature, and grade compensation in curves are essential to the economical operation up a hill. Horsepower or tractive effort per ton are how trains are set up for hills.
Study the chart on page 10 of C&TSR System Timetable No. 3 for the local empirical method. The eastbound ruling grade is about three times the westbound ruling grade, but the westbound ruling curve resistance is about four times the eastbound curve resistance.