Tabernacle for CS 20 Main Mast -- Any Thoughts?

[Don Silsbe]

7 hours ago, Reacher said:

I was able to construct the new bulkhead in one piece so that was a plus.

I won’t have that luxury on my 17 mk1. I’ll need to make it in two pieces, and use the aft side of the tabernacle as a butt block.  If I can’t get each piece into the hatch, I’ll need to cut an insertion slit in the bulkhead to the rear, and patch it up afterward.  Good times!

[Reacher]

21 hours ago, Don Silsbe said:

I’m having a hard time visualizing what this looks like.  How about taking a photo of it?

This is the prototype. A 3/4” stud placed 3” from the foot of the mast is the “key”. It rests against the lip of the swivel collar until the mast is upright. Then the mast is rotated and the key goes down the slot and the mast goes through the collar and into the mast step.

[Don Silsbe]

Ah, I see.  Thanks.

[Hirilonde]

It's going to be a while before I can give my swivel collar a proper test. My arthritis is getting worse, and it looks like a hip replacement is coming soon.

[Reacher]

I’ve used the boat a few times with the mast pivot improvements.

 

The main mast tabernacle is a winner. The only thing is that I have to look for someone at the dock to attach the nut to the hold down bolt while I prop it up. The lift is so easy and controlled.

 

The mizzen mast swivel is also a winner. Just as easy to lift as a tabernacle. I would not use a mizzen tabernacle on a Mk1 boat because the pivot bolt would have to be unpinned each time to position the mast for travel and storage. And lifting from the back is better than from the front IMO.

 

Regarding the “huge stresses” on the swivel, there really aren’t any. I figure there is about 25 lbs of upward pressure on the swivel when starting the lift about 5.5’ from the foot of the mast. That rapidly decreases as the mast goes vertical. When lifting the mast out, the foot is always contained in the swivel. The effort required to do a controlled lowering doesn’t compare to freehanding the mizzen.

 

I’m sure there are other ways to make the swivel work to allow the mast to slide through into the step. The keyhole works well enough for me. 

 

 

[Hirilonde]

And it looks perty. 

 

Surgery for me in Aug.. Hopefully get to try mine out in October.

[Docpal]

OK, similar issue,different solution.

I wanted a mast step which I could use to assist in the actual mast hoisting process, and then still give me the freedom of rotation I really enjoy on this rig.

(Because of my trunk cabin my pivots are taller than most would need).

The "mast clamp" is simply PVC and a piano hinge with a couple of bolts to hang it from;

My solution to how to hold the mast in place when it's upright was to make this small detachable "stirrup" I could slip on the outside of the clamp when it's in place;

As you can see from the first picture above I set the stirrup in place before hoisting the rig;

 

So that when I get the mast upright, the forward PVC tabs act as temporary "stops", and then I just pull on the line attached to the "stirrup" and the mast drops into place.

And when I'm done stepping the rig I can then take everything off the mast itself;

I will add that I also run twin topping lifts and in the hoisting process I keep them attached to deck cleats on either side, in the event of an unexpected wind event.

With no wind i can walk the rig right up, if I'm fighting a breeze I use a 4:1 block and tackle to help me get her off the cabin,, and also act as a safety brake.

 

[Reacher]

Thanks for posting another way to help step the mast. Good pictures.

[Don Silsbe]

I’m going hard core, and cutting a tabernacle in after the messabout, according to the plans. 

[Reacher]

The good thing is you have plans. I wasn’t aware that there were tabernacle plans for the 17.1. You will be satisfied when you are done. 
 

The 20.1 plans had a critical dimension for leveling the boat for setting the tabernacle and rake of the mast. For a 20.1 the boat is level when the bow is 10 5/8” higher than the corner of the transom. I expect that the 17.1 has a similar dimension. Once the new bulkhead is plumbed to vertical the placement of the tabernacle and the rake of the mast follow nicely.

 

Alan Stewart also provided plans for a mizzen tabernacle for a 20.3 that could be adapted. Don, are you thinking about a mizzen tabernacle? 

[Don Silsbe]

Reacher— I don’t think it’s necessary on the 17.  I had no difficulty stepping the mizzen on PadrePointe’s 17.3.  A 20 might be a bit more difficult, though.  Stepping the main is a bit more precarious, though.  I might change my mind in a few years, though.

[Paul356]

Nice idea.  I like that it's all above deck and doesn't require cutting into the deck and making a new watertight compartment or worrying about forward swing, bury, etc.  

[Don Silsbe]

A friend of mine devised this simple system for stepping his mast.  It’s more of a funnel than a tabernacle, and there are no moving parts.  

 

 

This is so simple and easy, I’m gonna give it a try.

 

[Reacher]

What I like about this one is that it is scuffed up. That shows it has been used so it must be working.

 

The “shelf” is critical to control the foot of the mast, especially during lowering.

 

This method still requires the user to lift the mast clear of the hole, which can be a problem, but once clear it makes for a controlled lowering. Raising looks good.

 

I’d say it’s worth a try before going to the work of retrofitting a tabernacle. Thanks to you friend for sharing.

[Mike Vacanti]

Is that a Gilles Montaubin design?

[Don Silsbe]

Sorry for the delay.  I had to check my facts.  It is a Wabi 17, designed by Gilles Montaubin.  In our cruising club, the WCTSS, we call it the Red Rocket. She is fast.  The plans were hand drawn, and in French.  Montaubin didn’t want to sell my friend a set of plans at first, until he learned that he was fluent in French.  The writing on the plans also  used some antiquated terminology (in French).   In spots, Montaubin’s hand lettering was illegible enough that my friend had to call him several times (in French) for clarification.  The entry at the bow specified contains a compound curve.  When he quizzed Montaubin about how to do this in plywood (it is impossible).  Montaubin’s answer was “you know how”. My friend finally figured it out— he needed to switch to the strip-built technique for that section.  He did a fine job of blending the two.  
 

He has two rigs for her, one large and one small.  This photo is the small rig.

 

Would I ever consider building a Wabi 17?  HELL NO!  But she sure is pretty and fast.  

[Mike Vacanti]

Thank you for the confirmation. I recognized it by the shape of the bow, his designs all share that shape. 

[Don Silsbe]

By the way, my friend has two rigs for this boat.  They’re both cat-rigged,  but this is the smaller one.  He has a larger rig, too.

[Don Silsbe]

I’ve been using a variation of my friend’s system long enough to know that it works.  I wanted mine to be less bulky than his.  All it really needed to do was position and hold the mast over the hole.  And I didn’t want any of that stuff remaining on the deck while sailing.  I might switch to a full-blown tabernacle next building season, but this works, and that is a major tear-up.