On Mar 13, 10:06 pm, Chris J Dixon wrote:
Matty F wrote:
The old insulators have had a hard life. If you are very clever you'll
know what they are and why they are broken!

Well, from your other post, I would guess that it is part of the
overhead electrical supply system for a tram.

Here's the arrangement for holding up the wire on a corner:
http://i43.tinypic.com/fvzbsz.jpg

The clamps on the left hold the wire. The insulator is held within the
brass casting. The brass cap on top screws down on the insulator,
keeping it rigid. An earthed steel cable is attached to the brass
casting at the same height as the wire so that it does not twist.
The wire is 600v DC potential.