Mast Hinge or Tabernacle

[Brian C.]

I have been thinking of putting a hinge in the mast of my gaff-rigged sloop to make it easier to trailer the boat if I want to. By hinge I mean a hinge that is about 12-18" above the gooseneck and not a hinge at the mast step (this is a gaffer after all). After doing some searching on the net, I have not found anything compatible with my mast (5" round with a wall thickness of .125"). The nice hinge made by Marshall Marine will not work, unfortunately. I would prefer a hinge to a tabernacle as I am not fond of how most tabernacles look. So, I am thinking I may have to have something custom made.

First, I am open to any hinge design ideas anyone may have. Second, I am open to suggestions for outfits that could make such a hinge for me (I am located in Maine so the closer the better). Finally, if anyone has any suggestions for a tabernacle setup that does not make the bottom 15% of the mast look boxy and bulky, I would love to learn more about it.

Thanks.

[CharlieJ]

Dwyer sells one all ready made- all you have to do is cut the mast and rivet the hinge in place. Fit's up inside each half. I believe it's exactly like what the Suncat uses.

[radicalcy]

Brian,
What size boat? What height mast? Why not at the mast step?
Larry Wilson

[Brian C.]

Larry:

My boat is a Herreshoff Eagle which is 22' LOA and 18' LWL. The mast is 32'6".

I want the mast to hinge at 12-18" above the gooseneck so that the hinge is above the gaff throat jaws and mast hoops when the main is down. That way, I can drop the mast using the hinge and haul the boat using the trailer without having to remove the boom and gaff or undo the multiple halyards and sheets (this boat has a main, jib and topsail so there are a number of lines).

Brian

[radicalcy]

Now I understand. I have a mast hinge setup on my Columbia Saber, but it's at the deck. I can see how that wouldn't be practical with your setup.
Larry Wilson

[CharlieJ]

OOPs - sorry- I just re read your first and saw your mast size. Dwyer may not have something like that. But I'm betting a competent metal worker can build you one outta stainless.

[Tim]

If you can't find someone local (and I don't know anyone offhand--which definitely doesn't mean they don't exist; it just means I don't know), I suggest Metalmast Marine. Custom work is their bread and butter, and they'll build anything for anyone. Excellent quality work,too.

www.metalmast.com

[Robert The Gray]

I am not sure how your mast is stayed, but perhaps you might also look into a sleeve type connection. this would entail you lifting the mast off the section that stays on the deck, as opposed to hinging it down. Most of the time with a tabernacle the mast extends waaay out in front or behind of the boat and has to be removed and centered for trailering any way. a 32 foot mast mounted amidships on a 22 foot boat, would extend 20 feet beyond one end. of course your mast must be forward of the midline, but it seems to still entail disconnecting the mast some how to center it's length on the boat.

this link will take you to a eagle site with a boat pictured on a trailer

http://home.earthlink.net/~gmayhak/eagle.htm

The sleeve could be internal to the mast section or like a collar on the outside.

R.

[kendall]

obtain a short section of 5.5 inch mast section, possibly two foot or so long, at the approximate center point, cut just less than half out for about 4 inches, then step in to halfway, cut your mast at desired height at an angle tapering towards the direction you want it to tilt, cut the upper section flat, slip it into the short sleeve, and bolt together (several short bolts just through mast and sleeve work as well or better than a couple long bolts completely through the mast and sleeve) place 'stub' in the cradle formed where you cut the sleeve, and drill and bolt the stub at the small 'ears' (~4inch section) use a crush sleeve inside the mast stub, and a couple thin washers between the mast and sleeve on each side for a bearing. lower bolt is the pivot and shoud be used for you height measurements. the cradle adds a bit of strength back to the mast, keeps it from overcentering, and stiffens it up nicely. use either a bolt or a collar to lock it in place

if the cradle is in the way of the gaff jaw and hoops, you could likely set it so the sleeve is mounted on the stub, and the mast swings into the cradle. either way though, you may have to hand guide the jaw/hoops over the collar bolts when taking it down (carriage bolts may eliminate the problem)

when making the cuts, keep all corners radiused and file/sand them smooth to eliminate stress risers.

also, could get a longer section and completely replace the lower part of the mast with the sleeve

try it out with drinking straws and pins to get the whole thing down before hacking on the mast though....

Made the same setup when I was into radio using two sections of 4" aluminum irrigation pipe very strong, held a 10 meter yagi for a few years

ken.

[hesper]

Hi Brian.

Well, I just finished a great reply(beleive me, it was brilliant) then I hit the "back" button and erased.....

Why won't Marshall's rig work? I'm guessing the mast section on an 18 is very close to yours. The 22 would be a little bigger I think. Could the Marshall hinge be turned down a little on a lathe or built up a little?

Anyway, check out this page about 1/3 down.http://www.shallowwatersailor.us/swsman ... index.html
I would suggest a slighlty larger bottom section could be got from Marshall (they sometimes have a broken mast hanging around) as I beleive the Eagle mast is slightly smaller diameter than a M22(that's what we have). You should still have room for wedges etc.

Scary to cut an otherwise good mast but in the interest of science, I think it's a worthwhile exercise. For what it's worth though, I'll stick to the old fashioned bridge-removal/installation method.

Good luck

Jim
Marshall 22

[Brian C.]

Jim:

Thanks for the link. That is really the kind of design I need and I had not found that page in my previous web browsing.

I love the M22 and did speak with the folks at Marshall when I was last in South Dartmouth. They were very helpful but they were certain from prior experience that I would need to replace my mast in order to use their hinge (I forget why right now).

Brian

[hesper]

Brian-

Glad it's helpful.

Geoff Marshall and John Garfield and friends would certainly know if their socket would work. They also would not sell you something they didn't think it would do the job. I just wonder if it could be replicated/sized up or down by a machine shop???

Anyway, good luck!

Jim

[hesper]

Why not beat a dead horse?

How 'bout this little beauty...
http://users2.ev1.net/~fshagan/masttab.htm

Looks all too easy. You sure you wouldn't rather just launch near a bridge?

Jim