A neighborhood near me has old creosote utility poles. Among the standard primary and secondary power, cable, fiber, and phone, there was a crossarm mounted near comms height carrying a telegraph conductor. Bare copper wire on glass insulators. Every few spans the wire was broken, with the wire just hanging loose.

This is nothing new, I have seen this before around here. But what I found interesting is what they did with the telegraph line when replacing a pole. On of the poles along the length of the telegraph wire was brand new, a car probably hit it or something, idk. But they kept the telegraph line. They mounted a crossarm at comms level (just like before), and used a new polymer primary insulator to hole the telegraph wire.

Why would they do this? They could have just cut the wire (it was already broken in several places). But they went through the effort of mounting a crossarm and using a new insulator to mount it. Has anyone seen this before? Why would they do this?

One potential reason is that if you own the telegraph line, you likely own the right to put other cables on it too. So this means that you can buy a dilapidated telegraph line for cheap in the late 90s, do just some cosmetic work to keep it in non-deserted state, and whenever your telecom company decides it's time, use that right of way to put fibre on those poles (which is of course much cheaper than digging, and you already have the permission to have those cables on that area of land).

@Laurens
That is a very interesting possibility, there isn't a whole lot of telegraph line there but that could be the case.