P22 #16

[Antony Harvey]

At last some progress. I made some changes to the foredeck for an external anchor well. The diaphram action of the mast / tabernackle is taken by both the remaining foredeck and the floor of the well. I also took the option of the open #2 bulkhead to get  internal access to the space under the bridge deck. While I was at it I made a sliding cupboard that gives access to the rest of the galley.

[Norman Colter]

Another beautiful boat!

Thanks for the update, do you have a launch date?

Norm

[Garry]

Nice work. Interesting details. Good job!

[Greg Luckett]

This is the first time I have seen an anchor well on the foredeck without a hatch cover....interesting idea.  I take it that on the PS22 there is not much foredeck rigging work that would cause crew to be stepping into the well?

[Charlie Jones]

basically none Greg. Nothing to do up there once the mast is swung up in the tabernacle and that happens from aft. Also little room to stand up there even with a solid deck.

[Howard]

For a slightly different twist on the tabernacled mast theme.......

This is a Bolger AS29. Bottom of mast is weighted to counterbalance the weight of the mast. Bottom of the mast goes through that slot in the bow where a stem ought to be. I'm not fond of the aesthetics (typical of Bolger boats), but that does allow a longer mast section below the pivot point of the mast.

One thing about the tabernacled masts I've often wondered about is how much stress does it place on the un-stayed mast? There is not much mast below the pivot point on the main of the Princess boats....about as much as you see above the deck on this boat. With such a long lever, it seems like a tremendous amount of strain....on both the mast and tabernacle. Seems to me like Graham might have done something similar to this slot arrangement for the main on Southern Skimmer with a slot in the fore deck where the anchor sprit might have been.

But as for the original post, Antony has got himself a gorgeous, well built boat!

[Designer]

Howard,

The mast on the Princess has enough bury in the tabernacle for strength. The mast transfers the load to the tabernacle which goes all of the way to the keel. The Southern Skimmer tabernacle would not have enough bury above the deck which is why it goes down into a self draining well similar to Antony's anchor well. A few skeptics voiced concern about the drain holes allowing the well to fill up but during our hard driving it stayed empty.

I knew an owner of an AS29 who built a drop-in slide because that open front did act as a scoop.

[Greg Luckett]

For a slightly different twist on the tabernacled mast theme.......

This is a Bolger AS29. Bottom of mast is weighted to counterbalance the weight of the mast. Bottom of the mast goes through that slot in the bow where a stem ought to be. I'm not fond of the aesthetics (typical of Bolger boats), but that does allow a longer mast section below the pivot point of the mast.

................

Howard, all I see is a big empty box and your text.  Should I set something differently (somehow?)?

Thanks 

[Charlie Jones]

As I've said before- built to plan I'd have absolutely zero concerns on the strength of the Princess 22 tabernacle

Note the heel on our boat, from which this picture was taken, and the heel on Pilgrim. The luff in the main is because she was driving over a wave. Pilgrim had JUST shaken out her reefs and we SHOULD have had one in;D

[Howard]

Greg: Let's try this........

http://photos1.blogger.com/photoInclude/blogger/5608/867/1600/Picture%20135.jpg

On the mast bury, after again reading Graham's explanation of it, I do recall seeing a picture of the tabernacle/mast setup, on one of the Princess 22's, a view looking inside the tabernacle. You don't normally see it all, but there is a lot of "structure" in there that mates up with the mast. I keep thinking of a long lever like the mast and thinking all that force is applied to the few feet of bury (assuming the top of the tabernacle is the fulcrum point of the lever.....and imagining the force it must take to heel a hard chined, ballasted boat of this size).

But if all that force transfers to the tabernacle, that is essentially a keel stepped mast....several feet deep and not even an issue to worry about.

[Greg Luckett]

Thanks Howard!

[Antony Harvey]

Strength of the tabernacle:

I know it is a case of "belt and braces" but I made the tabernacles out of Spotted Gum. It has a strength grade of F27 ++ (it goes off the dial) and as a comparison, Douglas Fir is rated F11. The performance of PILGRIM is very reassuring. Thank you all for your replies, it is nice to know there are so many of us out there.

Regards

Antony