[Synchrodyne]

In respect of twisting, as I recall from observation of NZ telephone poles and wires many years ago, a given pair would alternate amongst four insulator positions forming a “square” on two cross arms. Short crossarms accommodated a square on each side of the pole; long crossarms accommodated two squares each side.

So for example, starting with the two wires respectively at TL (top left) and BR (bottom right) on the square, at the next pole that would move to TR and BL respectively, then to BR and TL, then to BL and TR, then back to TL and BR. It was easier to see this when a single pair extension was made down a road. Then the poles had two short crossarms (two insulators each side) to enable the twisting, even just for the one circuit. Open wire subscriber drops were not usually twisted, parallel pairs being used, although somewhere around 1960 give or take, it was more usual to see twisted cable drops from open-wire streetside lines. I am not sure if the trunk lines followed the twisting pattern. They had larger insulators (often cream-coloured it seemed) on longer crossarms.

Cheers,