Marine Shackles

Marine Shackles. Want to make sure the clevis pin stays in the shackle? Then mouse it closed. Mousing, pronouncedmouzing* according to wikipedia is “the application of safety wire, called mousing wire in this use, to secure a threaded clevis pin to a shackle. This is done by passing a couple of turns of mousing wire through the hole provided for this purpose in the unthreaded end of the clevis pin and around the body of the shackle’s hoop.”

They also go on to say that you can use zip ties instead of wire to mouse a shackle closed, which is what we actually use on ZTC (we use black zip ties as they are reportedly more UV resistant).

A shackle properly moused shut.

Why bring this up today? Because there was only one shackle on our entire boat that was notmousedclosed. Guess where it is now? At the bottom of Hermitage Bay. 

On our anchor bridle, there are two shackles which connect the chain plate to the bridle lines. One never gets opened so it is moused closed. The other is removed each time we raise anchor. Because that one goes on and off so frequently, we don’t mouse it closed, our thought being that the vibration or movement that would be required to unscrew the clevis pin couldn’t possibly happen in the short period of time that our boat would be stationary. And we have been right about that, until now!

One of those two large shackles was recently sacrificed to Poseidon.

During Rebecca’s workout on the bow yesterday morning, she happened to look down at the bridle and see that it was hanging strangely. When she pulled it in to inspect it, she could see what had happened. The unsecured shackle had somehow come unscrewed and had fallen off. Fortunately we had planned ahead and purchased a replacement for it, as it’s a particularly large one, a bit uncommon on a boat this size. But now that our spare is in use, we’ll have to try to purchase another one to take its place in the rigging kit. And we’ll also need to make sure that we check that thing every few days as we stay at anchor because we sure don’t want that happening again.

Do you have any shackles on your boat that are not moused closed? If you want them to stay that way, closed, you might consider mousing them closed. Yes, learn from our mistakes… it’s less painful that way.