Keel stepped vs. Compression post

[rickinnocal]

Hi all, I posted this in "Motorsailors", but I think this might be the better forum.

My new project, a 54' Calkins motorsailor, has never had a mast stepped. She has chainplates, and was drawn for a sailing rig, but it was never installed.

The original drawings call for a mast of 50' above deck level, stepped on the keel, so about 57' total. My local yard, where I'm having the boat hauled soon, has a 48' wooden mast from a wrecked boat available. Were I to cut a hole in the deck and keel step this stick, it would be only 40' above deck level - a lot shorter than is called for. However, a couple of people have suggested that, since there is no hole in the deck, I should keep it that way, and mount a steel compression post from the keel to the underside of the deck, bolted through the deck to a mast step.

Some googling has led me to a number of discussions of the alternatives, and I see very little downside to going this way. Do any of the designers on here see a major problem of any sort with it?

Richard

[Paul B]

Originally Posted by rickinnocal

My new project, a 54' Calkins motorsailor, has never had a mast stepped. She has chainplates, and was drawn for a sailing rig, but it was never installed.

Richard

I suggest you contact Doug Peterson in San Diego. He worked for Skip Caulkins and may have knowledge about the boat, the construction, and the possibilities.

Doug owns 2 Caulkins 50s.

[rickinnocal]

I have talked to Doug via emails, but he doesn't remember anything about the conversion project at all. Until I found design drawings and correspondance from Skip, I think he suspected someone else - maybe the builder himself - had done the conversion drawings.

I didn't know Peterson owned one. He didn't mention it. I already knew he owns 1/3 of Sabrina with Skips son (also Skip) and another owner.

Richard

[Paul B]

Originally Posted by rickinnocal

I have talked to Doug via emails, but he doesn't remember anything about the conversion project at all. Until I found design drawings and correspondance from Skip, I think he suspected someone else - maybe the builder himself - had done the conversion drawings.

I didn't know Peterson owned one. He didn't mention it. I already knew he owns 1/3 of Sabrina with Skips son (also Skip) and another owner.

Richard

Too bad Doug didn't have any good input for you.

Doug and Chris have owned Cathleen together, and also Sabrina. Last I knew they still had both, in some form of partnership or another. I think Ed Reynolds is also involved with one or both boats.


To address your initial question, a deck stepped mast needs to have much higher moments. If the mast you have sourced is not stiff enough you will be seeing a gravity storm at some point.

[rickinnocal]

Thanks, I'm going to have a rigger check it out. It's a pretty heavy section for a 48' mast, but I'll see what he says.

Richard

Edit.... This magazine article about the restoration of Cathleen is from May last year. http://articles.dailypilot.com/2009-...san-diego-boat

[gonzo]

A mast stepped on the keel can have a smaller section because it is pinned at two points. You can always add the extra section with a factory made sleeve and step in on the keel.