Interesting the differences between the UK and NZ.
We use in NZ the two phase supply or the SWER (single wire earth return) system. (washing line)

In the second case the 11 or 6.6 kV single wire is taken off an 11/11 or 11/6.6 kV isolating TX to avoid having the feeder trip on earth fault. The secondary voltage is 230/460 or 240/480 Volts.

But on the first photo of this thread, it looks like a SWER system set up.

The product of rotation, excitation and flux produces electricty.