Apparently there was a problem with the underground feeders and they decided it would be cheaper to go over the roof. When we proposed a repair the customer's reply; "No, we haven't had any problems so lets wait until we need to make the repair." 408V 3P Parallel feeders. They must have decided a straight line was not a good idea.
I get the feeling that the roof is newer than the wacky run. I may have been straighter before the roofers pulled it to one side for thier work, and never put it back. The other stuff on the roof being a bit more rigid, they just lifted up, splid new roofing under, and put it back down. The very slinky PVC they just dragged around, after all, whats it gonna do? Leak?
I will eventualy fail, that guys just hoping its after he retires.
Mark Heller "Well - I oughta....." -Jackie Gleason
Judging from the corrosion on the straps, that "emergency" repair has been there a long time.
I don't think you can blame the PVC itself -- a properly cemented joint is as strong as the base material. (It says here on this can...)
It looks like maybe the S-curve might actually have been intentional, to mitigate the expansion effects. I wonder how much curvature you'd need to eliminate expansion joints? Would the wood sleepers eventually rub their way through the roof?