My Tabernacle

[Dave R1]

This is a picture of my tabernacle arrangement. Sorry it's not better. The strap up the side of the mast has a mate on the starboard side and they are joined by a 3-1/2" wide band that goes around the front of the mast. The straps are attached to the stub mast with carriage bolts threaded into coupler nuts embedded in the stub. The carriage bolts aren't totally seated in the picture but will be once final assembly is started. The carriage bolts reduce the possibility for mast hoop hang ups.

Currently there is just a bolt shoved through the mast to hold it up. I'm planning to use carriage bolts there as well. With a provision for four bolts in the mast, I figure there is quadruple redundancy.

[Florin {VACATIONER}]

That's looking pretty good Dave.

It looks pretty strong too. I like the idea of the coupler nuts. That rig should work swell. What hapens to the steel bands on the sides of the mast when the mast is folded?

Cheers

[Dave R1]

Thanks Florin. The steel bands stick up above the stub all the time. I suppose I could remove a pair of bolts and fold it down as well. We'll have to see about that.

[Barry Pyeatt]

I'm curious as to why you feel that you need all the additional material when the hinge is to fold the mast and the mast itself is supported by the shrouds and the forestay when raised. :? I'm not being critical, just curious.

[Dave R1]

It was designed and built when the plan was to simply cut the round mast at the hinge point. I needed some sort of hinge and didn't think the gate hinges would work well on the round mast. Besides, I'm not thrilled with with the gate hinge on the front as it tends to catch mast hoops or lacing for the mainsail.

The original plan didn't include the gate hinge at all. I was going to have the lower pin for the mast set in short slots in the straps so that once the upper pin was removed the mast could be lifted about 1/2" and folded back, pivoting on the lower pin. By putting the lower pin in a short slot, I could avoid having to bevel the edge of the mast thereby having two large mating surfaces when the mast is up. Now, I still get the large mating surfaces and I don't have to lift the mast to fold it down.

I decided to go ahead and use the thing even after switching to a 4x4 for the stub mast. It should be reasonably smooth when completed so hopefully I won't have to fight the hoops or lacing up the mast when raising the main.

I imagine this year the main will get laced on. Over the winter I'll probably make hoops.

Like I said once before, This thing is probablt a belt and suspenders sort of thing but I like the idea that it is probably strong enough to support the sail even if all the shrouds and forestay parted.

[TexasPhil]

You could turn the hinge around, so the pin is on the inside. This would require a little trimming of the mast, but it would no longer be protruding to catch your hoops.

I am curious if anyone has determined how much force is placed on the shrouds and mast at various wind speeds?

I would tend to think that the force the shrouds can withstand is far greater than what the mast, by itself can. Therefore, if the shrouds fail, I would want the mast to fail gracefully. Gracefully in this case is that wood remain intact, and the tabernacle fails. I figure it would be easer to replace the tabernacle.

The tabernacle only needs to be strong enough to hold the force of mast stepping and un-stepping, and the lateral force of the full sail.

Phil

[Dave R1]

Phil, as to turning the hinge around, I thought of that but the hinge won't go much more than 90