Interesting photos Alan.
Some plastics are made for exposure to sunlight and some aren't.
That flexible conduit looks exactly like the type of conduit here called Cobra-flex.
It melts away before your very eyes in sunlight.
Catenaries are the easiest way to support cables for over-head spans, especially where the cable(s) would not support thier own wieght.
Looks like the PoCo should have used better quality cable ties and going by the second pic, the PVC cement had run out as well.
I use Ty-Rap branded ties and I've never had a problem with them so far as long as you use the black ones and not the white (indoor) type. [Linked Image]