I got a call today from an old friend with a Valiant 47. The harbor had alerted her that there was a problem with her boat--someone heard a loud
noise and the backstay was broken.
I went down (in the rain) and checked things out. Turns out the
boat has a
Harken power winch, which is used for the main
halyard and mainsheet. The
boat was put away with one end of the main
halyard hooked to the stern pulpit, and the other end around the
power winch, in the self-tailer.
Did I mention it rained? Well, as best as I can figure, the rain got into the
cockpit control switches of the power winch and activated the low speed. It pulled on the halyard until something gave. The first thing to give was the stern pulpit, which is now a stern arch. The second thing was the halyard turning block at the base of the
mast, which is in some pretty spectacular pieces. After the turning block blew up, the halyard no longer had a nice lead into the
mast exit plate, and ripped through some stainless and the
aluminum mast. Fortunately, the rip was sharp enough to cut the halyard, which ended the carnage. Unfortunately, the pulpit was sucked into the (no longer available) Navtec hydraulic backstay cylinder and bent the piston rod.
The winch breaker did not pop, but the winch had stopped by the time I got there. I pushed buttons and the winch still worked and shut off when I stopped pushing. I set about to finding ways to turn off the winch. First, I turned the house
battery switch to off. Not only did the winch still run, it didn't turn off for about 10 seconds, which gave me my my final clue.
I gave her my estimate of about 5 big boat bucks for the damage, and we had a discussion about turning off the breakers to windlasses and power winches when you leave the boat. It doesn't take much
current through a
windlass or winch switch to turn on the controller, and they are both powerful enough to do a lot a damage.