May 18th – I’m hoping a linesman or electrical engineer can help me with this one, I’ve never noticed it before.

Approaching Anglesey Basin on the canal at Chasewater, electricity is supplied to the dam cottages by single phase overhead lines. one of the last poles in the run has an anchor cable staked to the ground to stop the change in cable angle pulling it over. The anchor cable, bolted to the top of the pole, isn’t electrically connected to any part of the system, yet has a two to three foot long insulating piece fitted, with a pair of lightning bypass probes to create a safety arc gap. 

Why would they do that? Is is a current limiter to stop lightning melting the anchor or what? Never seen an arrangement like this before.