Interesting. Seems like a good idea. It makes them much safer when they start getting worn out.

Yeah it is a good idea, mounting a plastic signals on a hanger like this puts a lot of strain on the top sections, most newer installs use a plumbizer instead.

In fact I've seen a 12-12-12-12 here with external reinforcement too.

Here this style mounting method is used for new mast arm installations. There are the odd few intersections that use spanwire though I think they're trying to steer away from span wire installations after Hurricane Irene badly damaged a couple of spanwire intersections. I like this style best, though it's not used anymore. All three methods were used for all these years but now it's just the first method I showed, which appears to be the strongest.

Ahh, the Astrobracket we use those to if there's more than one signal head mounted on a mast arm here. My personal favourite is the hanger with double guy mast arms.