BYYB Forums

I've noticed on my yet to be launched Weekender that when the shrouds and forestay are not connected, my mast is a bit "wobbly" around the tabernacle joint.

Part of this might be due to my extra heavy-duty hinge that I used but even when I have the forward hinge setup, there's still a bit of play. When I first assembled the mast, there was a bit of a gap between the top and bottom, but I've fixed that.

Additionally, when I set up my test shrouds and stay (rope) I can cause the mast to lean to port or starboard and also affect the rake of it a fair bit. Once the tension is on the stay and shrouds though, the mast seems rigid.

My question is - do I need to worry? Should I do more to make the tabernacle joint rigid?

Door and gate hinges have wobble in them so there isn't much you can do. Not a big deal if you have a forestay and shrouds. The other option is to ditch the hinges and go with a more traditional tabernacle setup pictured below. About as easy as a hing to setup as well.

Tabernacle details:


Mast on boat:


On this boat the goosneck attaches to the mast above the tabernacle and you can still fold it. Only thing different is you need to take the gaff jaws off the mast before folding. Mast is held up by a pin through a hole until I can get the forestay hooked up.

A tabernacle is intended to hold the mast upright or in the lowered position. It's doesn't have to do so rigidly, just enough so this is reliable or predicicable. The standing rigging (wires) will firm things up, once tensioned properly.

Scott, I have been thinking up all kinds of complicated and fancy ways of doing exactly what you have done. Thank You for the idea.
Brian.

No problem. Just make sure you do the 45 degree cut on the mast at the tabernacle. This is what makes everything work.

Paul is correct, btw, about the shrouds and stays doing most of the work. However, on the PC I ended up getting rid of the shrouds because they were impacting sail shape when running with the wind. On the boat pictured the mast is too far forward (catboat rig) to give shrouds and the forstay the angle they need to work and still clear the rigging. The mast setup pictured is no more because, while it held up to 12+ mph winds, the mast had too much bend and I was still a bit nervous about the bend in the tabernacle as well. Now, I have a thicker birdsmouth mast with no tabernacle trading off setup time for confidence on the water. Stays and shrouds certainly eliminate a lot of concerns regarding sturdiness of the mast.

New mast in place:

Thanks everyone - I'm a bit more reassured. I know it's too late to do it now, but I wonder if it would have been more rigid if I'd done the joint at 45 degrees like Scott did. My heavy gate hinges certanily would have stood the strain.

A free standing mast requires a sizable difference in mast wall scantlings, compared to a stayed stick. As in Scott's case and common among cat rigs, or any boat (like some schooners) where the pole is in the "eyes" of the boat. You just don't have enough "base" to spread out the shrouds for a decent angle. Generally if the shroud angle is less then 10 degrees (viewed from front or back) then you'll have difficulty holding the stick up. Sometimes this can be corrected with spreaders, but properly located spreaders on a gaffer with jaws is impossable. Cats at the turn of the century where often seen (especially the racers) with huge V shaped jumper struts above the jib tang on the mast and runners were used to tighten the jib luff when on the wind. All of this is an effort to hold the stick where you want it and keep the jib luff taunt.

The angled cut on the bottom of the mast is very important, as Scott points out. It doesn't have to be exactly 45, but it does need to be there. I usually set tabernacles to have much less angle, just enough to permit the mast to swing in and out of the tabernacle, without binding (the whole point of the angle cut thingie). It's also wise to set it up to receive a wedge or two (dirven into the angled cut area), so you can "load" up the mast/tabernacle assembly, before you tension the rig. This makes the whole thing a single compression column, which is all a sailboat mast is.

I was concerned abot the "wobble" factor too. My thinking was that it was inherent in using those hinges. If they have play in them....well, there's nothing to be done about that. I assumed that the shrouds and jib cable (fore???????-can't remember the term) would tighten that up. Apparently my thinking was right about that.

Fore and aft strung wires are stays and those attached to the sides of the boat are shrouds or runners. The hinge thingie is a cheap way to get it done, but by no means a good solution, with many reported issues concerning the hinge arrangement. It will get you on the water and it does work. I used a modified, galvanized, chain link fence, gate hinge as a gooseneck years ago and won races with the set up.

As you gain experience with the boat, you'll surly have modifications and upgrades you'll want to incorporate into your yacht. This is normal and part of the illness (one of the classic post build symptoms of the continuing disorder), get use to it. Many changes you make will be to ease your burden underway and make life easier aboard. Others will be blatant plagiarisms of other builder efforts, because it seems like a good idea. Don't be bashful, it's done all the time and the whole point of a place like this.

It is never to late. If you want your mast on a 45 get 1 more 4X4 and make your stump 4" longer cut your 45 on the stump and mast. your mast will still be the same as before. Bud.