If the ruling grade is 1.1%, it is actually 1.1% compensated, as used in tonnage rating charts. This is universal.
No railroad grade is completely steady. There is always some vertical curvature which causes small variations. Curvature is the main factor in compensating an ascending grade for tonnage rating purposes. The Engineering and Mechanical Departments run their numbers and the tonnage rating is produced for each class of locomotive, and sometimes with variations for train length. Then it has to rub up against helper placement rules, long car/short car rules, train tonnage placement rules, etc. in order to get a train over the mountain, and you know how that works, since you do it daily.
I suspect that the curves are more numerous, or tighter, or longer -- or some combination of the three -- on opposite sides of the crest of your grade. Is there a difference that you can detect? It only takes one 10-degree curve to change the rating for that whole side of the hill.
