Mast Tabernacle Design

Triton 185 · Post by **Triton 185** » Wed May 23, 2007 1:50 am

I?m planning to make a mast tabernacle and really don?t know how to proceed. The mast is deck stepped (on a Triton) and I have two things I would like it to do. One is to raise the mast myself and the other is to be able to lower it while under way on canal systems. (I?m not sure if I am out of my mind on the later idea.) Does anyone know if there are plans available? I?m thinking aluminum or stainless?I think this rather depends on the design.

(As a footnote......I still have to replace the mast deck beam)

Thanks for any info you can provide me.

Cheers,

Stephen, Triton 185

Ceasar Choppy · Post by **Ceasar Choppy** » Wed May 23, 2007 10:11 am

Have you looked at the MIR pages on the Triton Web site?

Try here: http://www.tritonclass.org/mir/TABERNACLE.htm

Robert The Gray · Post by **Robert The Gray** » Wed May 23, 2007 11:51 am

The lowering the mast for canals with a boat that has the triton's small fore triangle may be difficult. For one thing when the mast gets down near the height you need it extends way beyond the bow. Using the boom as a lever can help control the descent but it is best done tied to a dock where there are no wakes. I think it might be kinda hairy to do at anchor along side a channel with any kind of boat wakes. You could easily be looking at your mast hanging down into the river murkiness. The boats that have lowerable masts have quick release systems at the ends of the shrouds. To lower the triton mast one perhaps might remove the mainsail, de-tension the shrouds, set up boom and main sheet to facilitate lowering. Set up crutch on the fore deck to support the mast when down, engage in the lowering process, pray, detach mast from step, tie shrouds to mast to avoid fouling the prop, move mast back so as not to extend 25 feet beyond the bow, store boom along the side decks, store sail below. motor under bridge, reverse process with the additional step of retuning the rig to the proper tensions. Might take a while. Having a tabernacle step does let you drop the mast without a crane to work on the mast or the mast step but as a system for traveling through areas of low bridges I feel that it has some real draw backs. Just my thoughts.

r

Triton 185 · Post by **Triton 185** » Thu May 24, 2007 1:31 am

Thanks for the replies. Ceasar, I had a few reads of the MIR pages on the tabernacle ? I had forgotten to check there.

Robert, I have never used a hinged system to raise a mast before. Seems like it would be a bit precarious if praying were part to the system. Perhaps I will just remove the mast for a trip on the canal.

With a tabernacle setup with one hinge pin ? does the weight of the mast and all the compression loading rest on the pin, or is there some other arrangement?

Thanks again for the info.

Stephen

The Good Goose · Post by **The Good Goose** » Fri May 25, 2007 8:26 pm

Stephen

There are some pictures of my tabernacle on the MIR section. they are under the heading of Good Goose's Blade in the sails section. My Mast step was aluminum so I removed it and had 5/16 aluminum sides welded to it. I had a piece of angle welded to the bottom for attaching blocks. I had a piece of flat stock welded just below the pivot pin to help strengthen the sides. I made my pivot point up high so the mast could pivot astern.

My plan was to use the spinnaker pole attached to the mast with lines running from its outboard end to each of the shrouds. A halyard attached to the outboard end and a block and tackle . The block would then be attached to the attachment point for the fore stay. This setup gives the angle needed to allow the mast to be lowered all the way to the deck. If you just use a Hayard or the stay when the mast gets most of the way down the forces on the halyard are in the wrong direction and the mast becomes difficult to controll.

There is a second bolt lower down that is used to keep the mast from moving when it is up. I ground off the protrusion from the heel of the mast that interlocks with the mast base. Be sure to make the top hole oblong to allow the mast to pivot over the length of the base.

Unfortunately I didn't have the guts to try it out. There was a crane just below Albany at a boat club so I rented it instead. Most of the major canals have mast stepping facilities nearby. I felt like I would want about three or four people helping me the first time I tried it. I think once I had done it a couple of times I would be confortable with two people. the thought of that big stick crashing to the deck made the crane fee seem a lot more reasonable.

If you get serious I can send you dimensions and more pictures. Maybe I'll get brave and actually try it. I'd like to go up the Richelieu to the ST. Lawrence so it would be good to know if it works.

Brock

Rachel · Post by **Rachel** » Sat May 26, 2007 12:06 pm

This may be too nerdish - or my understanding might be just plain wrong - but I believe a mast tabernacle is actually where you have a couple of long "ears" of tabernacle coming up from the deck and then the pivot pin is at the top of them. The mast runs all the way down to the deck, so the result is that the pivot point is partway up the mast, not at the bottom. I think the other arrangement [with the hinge/pin at deck level] is more of a "hinged mast step. Of course a hinged mast step might just fill the bill for what you have in mind, so this is nothing against the concept.

I always think of Irving and Electa Johnson's ketch "Yankee," when I think of mast tabernacles. Not that you'd probably rig something like this for a Triton, but it shows the tabernacle arrangement:

One last photo, of a Nimble Kodiak's tabernacle:

Okay, I'd better run before this gets any more Nerdery-ish...

Rachel

CharlieJ · Post by **CharlieJ** » Sat May 26, 2007 2:03 pm

Yep- I concur with Rachel. I was gonna say something earlier, but decided against. But she's correct. What we mostly have on the boats we sail are hinged mast steps, not true tabernacles.

Another point- in a true tabernacle, the mast is almost never unbolted- it just pivots back. On the 22 foot cat ketch I built for a man in Okla in 2004, both masts are in tabernacles and both fold- the main aft, the mizzen forward. All you have to do to rig the boat is pivot the masts up and insert a pin. Both masts are free standing and depend on the tabernacle for strength.

On the 20 footer I'm currently building, the main will be tabernacled. The mizzen is light enough to pick up and stab into the mast partners.

Rachel · Post by **Rachel** » Sat May 26, 2007 4:32 pm

I don't mean to hijack the thread (perhaps the fact that I'm posting photos will excuse me somewhat), but I wanted to show you all "Pilgrim," which is the boat Charlie's talking about just above. She's a Princess 22, designed by Graham Byrnes of B & B Yacht Designs, and built by Charlie J.

I hope you don't mind, Charlie, but it really is a neat boat and I bet everyone here will be interested to see her. One shows the build in progress - where the bow curves had to be cold-molded - and the last one shows the mast tabernacles (by the way, these photos have all been posted/linked to in a public forum already):

CharlieJ · Post by **CharlieJ** » Sat May 26, 2007 5:52 pm

lol- nope Rachel- Don't mind at all. She IS a pretty boat, and a pretty fast sailer also, particularly off the wind.

Hirilondë · Post by **Hirilondë** » Sat May 26, 2007 10:04 pm

She is a very pretty boat (Pilgrim), Graham does a great job with designs for owner-built trailerable cruising boats, and dinghies too. The builder had something to do with the looks as well I bet!

CharlieJ · Post by **CharlieJ** » Sat May 26, 2007 11:19 pm

Well, I did make a few mods for the owner. He's got a pair of bad knees ( both have been replaced) so when I did the interior I raised the settees one inch to make them a bit more comfortable for him. I also raised the cabin top one inch to regain the lost headroom. Additionally I gave the cabin top a very slight camber fore and aft, to carry that headroom as far forward as possible.

He's trailered the boat all over the place and is extremely pleased with it. And happily, as are all the people I've built boats for so far, he's still a friend.