Launching a P15K with a crane?

[Tollerowner]

I posted before about launching my P15K in shallow water.  Well, I got a better solution!
A facility a half mile away has a crane they use to launch their motor boat.  They have agreed to use it with my boat.  Since their boat must be 3 times as heavy, I am thrilled.

The guy who sold me the boat gave me piece of gear that is a ring with 4 ropes coming off it.  There are carabiners that attach to loops (don't know the technical term) where the side stays attach in the front and to two loops near the transom.  I asked him how to use it; he had no idea, the yacht club put it in and and out for him each time he used it using a crane. I didn't expect to ever need it, so I let it go at that. So, questions...

1) There are two long ropes and two short ones.  I presume the short ones go to the front, but want to make sure.
2) I would think that the mast has to go up after it is in the water; otherwise the mast would hit the crane.  But I can't imagine the yacht club puts the mast up and down each time, so maybe not.  Any idea?  I have put the mast up in the water the last 5 years so I can certainly do it again, but it is not fun.  (the ramp I used to use had overhead power lines)

Thanks much.

[tjspiel]

I'm not sure I quite picture it but it sounds like two attachment points for this harness would be the chain plates that the shrouds connect to and there are two other attaching points somewhere near the transom?

I don't know that you'd want to lift a boat by anything attached to the deck. It might be OK with a smaller boat, I just don't know.

The only way I've seen it done is with large straps running underneath the hull. And yes they can do it with the mast already stepped but I suppose it depends on the crane.

[David B.]

What you have is called a lifting bridle. It's exactly what you need to launch from a crane. At my club, we launch over a sea wall using fixed Derrick-style cranes and lift the boat from the trailer to the water, and we all use bridles for the job.

Yes, the shorter lines should probably go to the forward chain plates where the side stays attach, and the longer lines will run back to the eyes near the transom. The center of the lifting bridle (where you attach to the crane) should be directly over the boat's center of gravity, which should be somewhere between the mast and the fore-aft centerline of the keel. You may need to take the boom off while you're doing the lifting operation, but, maybe not.. try it both ways if you have time.

[Tollerowner]

This is a gantry style crane.  A winch rides on an I-beam.  I am thinking the mast would be in the way of the I-beam. It was 6 years ago, but I think the yacht club had a derrick style crane.  I guess makes a difference.