Ron,
I finally found a way to download a picture and sketch of Dol Fyn's mast lowering system and have attached them with this email. Not very good ones. But I can get more accurate if people are interested. I also rewrote the description - below, hopefully a bit clearer than my earlier submission, but feel free to edit away!
Thanks,
Mark
Here is an account of unstepping mast for first time.
I found this description of the mast unstepping procedure on the web, but could not find the site later. It made sense to me because it was less subject to wind and wave, could be done with a non-pivoting/ hinged tabernacle, and could safely be done with two/three people (I suppose one person could do it in a pinch.)
An A frame that is slightly longer than half the mast, straddles the deck either side of tabernacle, and is tethered from the top fore and aft so that it is stationary, stable, and can bear the 150 lb weight of the mast from a pulley at the top. This forms a "mast crane." (also see Windswept too's version)
First I'll describe how it should be done, and then how I did it, and what I learned the first time. For the Dolphin, the A frame should be about 18 feet tall and made of 1 1/2" conduit pipe or equal stiffness pipe (2X4's joined perpendicularly to each other would also work, but get heavy). The crucial part is the joint of two 10 ft sections, which can be stabilized with a 3-4' splint of right angle iron and hose clamps. The apex is simply joined with an eye bolt which is bolted through the top inch of both pipes and allows lines to be tied both fore and aft securely once the A frame is hoisted.
Also, from the apex, a pulley is suspended through which a line leads from a noose under the spreaders to a winch in the rear. This allows the mast to be lifted 2-3" out of the tabernacle and lowered slowly. The actual noose needs to slide up and down (when stepping the mast). This can be accomplished with a small line tightening the noose attached to a cleat on the bottom of the mast. Procedure is to set up the A frame on the deck, with the fore and aft lines attached to the apex with its pulley and a line noosed around the mast and threaded through the pulley. The two ends face forward and the apex of A frame points aft (this allows it to be raised behind the mast – if the apex points forward, it will end up in front of the mast, as I mistakenly did).
Two people walk it up so it sits on wood blocks on the outer deck and the top is just aft of mast. A third person can assist by pulling the line at the bow to pull the apex forward once it is halfway up. This is the trickiest part, requiring you get it past the rigging. Fore and aft lines are secured and the noose is persuaded to slide up the mast and tightened just under the spreaders which are slightly over halfway up the mast. The lifting line is given friction by leading it around a winch (an appropriate tackle may be needed to direct the line onto the winch). This means once it is suspended, the weight of mast will hang from this noose and not topple (which is the problem with other unstepping / stepping schemes). Then all rigging can be loosened (it can be partially be loosened before so you just need to slip out turnbuckle pins at this point.)
As one or two people lift the mast and then hold the bottom of the mast and walk it back past the cockpit, one person lets the line lower the mast down from its midpoint which is easy with winch friction. The weight of the mast is mostly carried by the line from the apex of the A frame. The mast can be swiveled to ease the spreaders past the fore support line. Once the mast lies on the deck, the A frame can be lowered the same way it was put up (again the line from top helps to ease the weight of the A frame as it is lowered.) If this is unclear, I would be glad to write out instructions in steps.
My mistakes: I made my A frame out of four, 10 foot sections of 1" conduit pipe (wanting to cut down on weight), cutting 3 feet off to use as a splint for the joint, making it 17 ft tall. I would make it a bit taller. And the 1" wasn't stiff enough, it started to bow with the mast weight, and I ended up attaching pipe to 16 ft. 2x4's to keep it straight. (I have since bought four 1 ½" sections, but I haven't tried these out yet. I'm worried about the weight of A frame.)
I also forgot to raise the A frame behind the mast. With it in front, we had to walk the bottom of the mast to the front of the boat instead of to the cockpit, letting the spreaders descend behind the A frame. But two people easily carried the mast. I used a small jack to make sure the mast could get free of the tabernacle to start, since it had not been unstepped in some time. (Again, this procedure allowed me to unstep the mast without a pivoting/ hinging tabernacle.)
It was hard to explain the arrangement to the marina worker, but he was impressed how easy it was once it was set up. Earlier, we had abandoned trying to unstep the mast by hoisting it with his travel lift, because it would have been attached way below the halfway point and I was afraid it might topple (which the marina fellow said only happened "if everyone didn't follow their p's and q's"). With the A frame "crane," it felt safe and could be done slowly with little danger of it getting out of control.
