The reason it seems like it is a lower grade is the curve measured with the calipers is going to be measured in small straight segments which will be shorter in overall length than the actual curve, thus the track is actually longer than measured and the incline is less.
When stepping off the distance around the curve, the divider is taking "shortcuts" by measuring the straight-line distance between points, not the curved track distance between the points. The curved line of the track is longer than the straight line of the divider. Therefore, yes, the piers on the curve are spaced farther apart (by the path the train will take), than the piers on straight track. The longer the track distance, the larger the denominator in the slope (rise/run) formula. The larger the denominator, (for the same numerator = step in pier height) the smaller the slope. Hope this helps.
Ah ha, now I understand it and it all makes sense. Question: Using the factors in my post (a 2" rise over a 112" length of track with 28 piers every 4" using the divider), will the lengthened spacing of the piers on the curve affect the total rise in elevation at the end of the grade? In other words, at 112" will I be at 2" or something different? This is just a matter of curiosity, not a critical factor. Thanks again for all of your help with this.
Does Kato's No. 2 Wye Turnout have the same selectable power routing features as their No. 4 Turnout?
You will be at +2" elevation at the last pier. That will be 112" from the start of the incline, measured start to pier to pier to pier..., but slightly more than 112" when measured along the track centerline (the path the train takes). How much the difference is depends on the average radius of curvature along the path. The sharper the radius, the more the difference. This should not create any operating issues if your curve radii are reasonable. Keep in mind, curves induce their own drag, not related to straight line drag, or climbing. This is due to two wheels, fixed on the same axle, rolling the same amount, though the outer wheel on the curve will travel farther than the inner wheel (something has to slip). This is why curves amplify (or add to) the effect of grades.
Excellent. This is such interesting stuff. Though I was never an Engineer, I often worked with Electrical, Mechanical and Civil Engineers in my career and always enjoyed being involved in their projects, though some of their coolest achievements took place at 2AM when the plant was down and they'd adapt a mismatched part or make a repair to a circuit board to bring us up.
Some of my best ideas came when I relaxed in bed, with my head on the pillow. Followed by a sleepless night of mental gymnastics, and an early rise in the morning to get started implementing it! Occasionally they occurred while I was actually at work, but there were too many interruptions there for really imaginative improvements. But they all started with: "What if we..."
If trains were pushed rather than pulled, the tapered wheel surfaces might compensate somewhat, but pulling trains pulls the cars to the inside of the curve, for which the wheel taper works against it (putting the larger circumference section of the wheel in contact on the shorter length inside rail of the curve.) This is why you see "flange greasers" installed on sharp turns, because the inside wheel's flange is hard up against the rail. Tapered wheels reduce wear on the wheel flanges over the vast majority of trackage that is straight, by keeping the trucks centered between the rails, and the flanges away from the rails as much as possible.
