Stepping keel mast

Moderator: GreenLake

Stepping keel mast

Postby jritsema » Tue Apr 16, 2019 8:27 am

Greetings, I am a new DS3 owner, the boat built in 1992, having a keel stepped mast. I would appreciate any guides to accomplishing both stepping and dropping the mast, particularly any apparatus that can be used to aide in this. My preference is to retain the keel step if I can manage it. I am experienced in using hinged mast steps but not confident about how to raise the keel step setup, whether I am able at age 71 to muscle this. I appreciate any feedback very much.
Jeff
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Re: Stepping keel mast

Postby GreenLake » Tue Apr 16, 2019 3:26 pm

My boat came with a clever solution to that problem by a previous owner.

See pictures here.

Unfortunately the link to the full writeup is currently dead. Some issue with my webhosting ISP. But perhaps these images are enough to get you started?
~ green ~ lake ~ ~
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Re: Stepping keel mast

Postby jritsema » Tue Apr 16, 2019 8:36 pm

Thank you Green Lake. Interesting device. Will study this further.
Ironically, I will be sailing this boat on a lake near Grand Rapids, Michigan, named GREEN LAKE.
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Re: Stepping keel mast

Postby GreenLake » Wed Apr 17, 2019 3:47 pm

There's one in every state (or nearly).

The device is easy to construct. It has four parts. A circular base bolted to the deck. A gate hinge bolted to the base. A wooden block and a sheet-metal sleeve. Both base and sleeve are from aluminum. The block is about 6"-8" long. It's shaped on one side to fit the curvature of the mast (approximately). The sleeve is formed into a U shape and screwed into the wooden block. The fourth side of the wooden block is where the gate hing is screwed into.

When I refurbished mine I couldn't source a gate hinge that fit, so I used a normal hinge but added a T iron to take up any twisting loads.

The sleeve should fit snugly, but with just enough slack that the mast can slide easily if aligned.

I push the end of the mast into the sleeve, then step into the cockpit and lever up the mast. There's enough pressure on the sleeve that the mast will not slide in or out at this stage. At some point, the bottom of the mast will also rest on the edge of the deck opening until it is straight enough to go in. The mast has to be very well aligned to slide down into the opening - that's a feature, because it helps you control the descent. I can manage that from within the cockpit, but some people might like to have crew stand on the deck facing backwards and help steady and lower the mast at that stage.

Because the mast tends to bind if not aligned, the one critical step in assembly is to make sure that in the raised position, the sleeve aligns with the deck opening, same for the opening in the base.

In principle the base is optional, you could simply laminate a small platform behind your mast partners onto which you bolt the hinge - with a good backing plate under the deck. Mine came with the circular base and I've used it to locate other hardware on it, like fairleads for spinnaker halyard and downhaul. However, it does leave a gap in front (because it sits above the desk due to the raised mast partners) and I had to fit a small aluminum strip there to keep the jib sheet from catching.

Lowering the mast works in reverse. If you are tall enough, you can push the mast up from the cockpit until the bottom just clears the deck and then tilt it down from there. Again, it is not necessary to secure the mast bottom in the sleeve, if the sleeve is not too loose.

Finally, I fitted a U-bail through the bottom-aft corner of the wooden block. This works well as attachment point for my vang.
~ green ~ lake ~ ~
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