Sidenote: these images were so hard to get. Getting detail on the underside of a wire on a bright sunny day was like:
*adds a stop of overexposure*
still no detail
*add another stop*
still no detail
(repeat until they chuck you out because its closing time)
Please do post corrections and additions, I could do with some trolleyphiles to improve my understanding of this very weird - to me anyway - system.