The state plane requirement on a large pipeline in an earlier thread is most likely needed for Control, Layout and ROW purposes. And not a real concern in calculating to over all length of pipe. Though the over length will be different in grid vs ground, it not much of a factor in construction when considering the other tolerances involved here. The pipe lengths will be computed in ground distances, along the slope distance at center of pipe on the shop drawings from the Engineers plans. This is very common in pipe industry and DEP.
Just wait until you have to recompute 30 miles of alignment and convert from stationing along horizontal distance to stationing along slope distance along the pipe centerline. There is no software for this, that I know of. I had to create my own.
We face a similar issue on Tappan Zee Bridge project also. When talking with the structural engineers it is clear that the grid to ground scale factor is marginal compared to tolerances in joint placement, steel expansions and other variables per section of steel placed.
For example we have 0.92' difference in grid to ground on TPZ in the 3.2 miles of bridge. Brake it down per section of bridge span to be installed. Each span is about 400ft or less , with the main span at 1700'. Over the 3.2 miles, that's just 0.02' per span in the grid to ground scale factor.
Lee Green
It would make no sense to ignore something that can be used to improve accuracy. Keep the error budget for things you can't control.
Another way of saying that systematic errors are cumulative.
All That 0.92' Error Can Be Psuhed To One Span
Then you do have trouble.
But then again there should be a few 1' expansion joints designed in.
Paul in PA