I think you might be talking about the “High Line” – see picture below.
http://news.bbc.co.uk/1/hi/uk/3723124.stm
The winch wire is in the Winchman’s hand. Just below his hand is the winch hook attached to which is the nylon ‘high-line’ which you can just see looping down to the guy at the front end of the tower. This speeds up returning the hook and strops for multiple lifts and can often prevent swings developing during transfers.
There may well be a metal static discharge wire (about 6-8 feet in length) attached to the hook but that would be out of picture.