Twenty years ago when I was working for the Central Electricity Generating Board, I was briefed there was a problem with salt build up on the insulation of transmission towers in the Plymouth Area, causing flash-overs.

So off I went to try to photograph the problem, they were unable to tell me where the towers with the problem were, and I was given a map of all the towers in the area.

I spent the night pointing my camera at towers with the shutter open as long as I dare to before fogging the film, hoping to catch a good flashover.

This is the result, when they saw the picture they told me that as far as they knew it had never been photographed in the wild before, and this was the first time outside a laboratory.