I have to have a pedestal made - why not a tabernacle?

[rslifkin]

Originally Posted by Chotu

Still, while I’m already getting a pedestal fabricated, might as well get it done like a tabernacle and just not use it yet until it seems like a priority

Unless you can find a way to make the structure of the pedestal do double-duty for some other purpose, that sounds like the right plan to me.

[NevilleCat]

But Chotu I had the impression you were going to return halyards and sheets to the interior forward helm position a la Gunboat etc?
Building the pedestal might give you some opportunity to incorporate sheaves or whatever is necessary to assist this as well as perhaps divert some potential water ingress down halyards etc, will converting to a tabernacle still make this practical?

[Chotu]

Originally Posted by rslifkin

Unless you can find a way to make the structure of the pedestal do double-duty for some other purpose, that sounds like the right plan to me.

Thanks!

[Chotu]

Originally Posted by NevilleCat

But Chotu I had the impression you were going to return halyards and sheets to the interior forward helm position a la Gunboat etc?
Building the pedestal might give you some opportunity to incorporate sheaves or whatever is necessary to assist this as well as perhaps divert some potential water ingress down halyards etc, will converting to a tabernacle still make this practical?

Yes, definitely.

I didn’t envision this having an effect at all on the routing of the halyards and sheets to the inside sail control table.

I’m glad you brought up a possible concern.

Can you share with me how you see there being an effect?

In my imagination, I’m seeing the halyards coming down externally (at least at by the time they reach the point of mast attachment) and going to some swivel blocks at deck level and into the deckhouse.

[NevilleCat]

I got you now.
For some reason I was envisioning the pedestal being almost part of the deck house structure, with exit blocks leading into the deck house at bench height for your jammers and winch.
Don't know if it would make a difference any way when the mast was rotated down.

[Jdege]

I can't speak for any particular design, but my boat has mast tabernacles, and the work I've been doing to restore her had been great easier than it would have been without them. Being able to raise and lower single-handed makes a lot of things easier.

On mine, the booms are on tracks below the hinges.

[MicHughV]

Let me get this straight.....this 60 something foot mast will be supported only by a line from the masthead to a gin pole and the pivot point. In other words the entire mast will be supported only on the two outer ends during rotation ?? Additionally, the support line from the masthead is not going straight up, but at a pretty pronounced angle towards the pivot point. This is going to result in quite some lateral load at the tabernacle, and if the mast does not stay inline with the centerline of your boat, substantial twisting load on top of everything else.

The mast will have it's spreaders, shrouds, etc, still attached to it. ie, it will be quite heavy, and still only supported by the outer ends during any planned rotation.

I see a lot of potential issues here from several angles and before you jump into anything, my suggestion would be to enlist the aid of a professional structural engineer or nautical architect to assess your goals and requirements.

[Scaramanga F25]

If you change the mast length you should change the spreader height too.

[thataway41]

We successfully tabernacled a 60' mast. The pivot point was near the boom gooseneck, so the mast was laid into a crutch, then the mast was also in a crutch when fully down. We used a 12,000# capacity Holmes tow truck winch. We did have the upper shrouds with a pivot point at the same place as the mast pivot point. The mast was keel stepped, but we put the stub pivot point 7' off the deck. You could do similar, making the permanent part the pedestal you mentioned. The 7' section below the pivot point was cut out and the fulcrum for the winch. The mast laid aft, and the lower 7' were forward, and had the sheave for the cable from the winch at its bottom. You would have to do some engineering, and modification of the attachment of the lower 7' to the mast-but it would give you the extra height you want. We did have to be lined so we were going straight upwind or down wind, and in wind no more than 10 knots. It was a one person job, with a wired remote to the winch.

[Happ]

Originally Posted by Chotu

I have a mast that is approximately 5ft too short.

There is no way to get a mast section for this extrusion, so I have to add a pedestal at the base of the mast.

While I’m having to get something custom fabricated, why not make that custom thing in such a way as to be able to raise/lower the mast, if needed, for inland/ICW?

Question: is there a mast raising/lowering system that can secure the mast from moderate lateral forces when it’s being lowered other than carrying special shrouds and supports to line up perfectly with the pivot point?

I see this as a fair weather operation. Nothing to be done in a chop or overly windy conditions. Early morning calm is when this would be attempted. Not like the videos you see of people sailing up to a bridge, dipping the mast and raising it again. It would go down to transit the entire ICW. Or to go deep inland through rivers or canals. Or to stay in one anchorage that’s height restricted for a week or two.


Also, how much mast bury do you need below the “Jesus bolt” or pivot point? Some designs have none, others have quite a bit.

Is just a hinged mast step on top of the pedestal good, or do I need a full tabernacle? What’s the difference?

Thanks! This should be the final mast thread

A mast for a 50’ Catamaran? Are you kidding? The mast weighs 100’s of pounds! I’m quite sure you and another person couldn’t lift it. So how are you going to move it around on deck to position it? Tabernacles are used on small boats. Like 27’ and 28’ boats. The largest mast I’ve seen that came be raised is on a Dragonfly 32. I’m pretty sure it is Carbon Fibre as well. I think you will find it won’t work. If you really need to add 5’ you may want to talk to a mast builder and just have a new mast tube made. Transfer the bits from the original mast to the new one.

[Jdege]

Originally Posted by Happ

A mast for a 50’ Catamaran? Are you kidding? The mast weighs 100’s of pounds! I’m quite sure you and another person couldn’t lift it. So how are you going to move it around on deck to position it? Tabernacles are used on small boats. Like 27’ and 28’ boats. The largest mast I’ve seen that came be raised is on a Dragonfly 32.

The boat I pictured above is 37', but it's a ketch and the masts are relatively short - 28'4" and 24'6". I'm not sure what they weight, but I can lift one end at a time and shift them around.

[MicHughV]

my first boat was a home built ketch.

the main mast was 40', with absolutely nothing on it, two people could barely lift it.
once the rig was on, spreaders, etc, it took 4 people to move it.
it took a crane to mount it on the boat.

my mizzen was 30', and off course, a smaller section, even fully rigged, I was able to manhandle this with a friend.

a 60' stick is another matter altogether.

[ben2go]

Originally Posted by Chotu

I have a mast that is approximately 5ft too short.

There is no way to get a mast section for this extrusion, so I have to add a pedestal at the base of the mast.

While I’m having to get something custom fabricated, why not make that custom thing in such a way as to be able to raise/lower the mast, if needed, for inland/ICW?

Question: is there a mast raising/lowering system that can secure the mast from moderate lateral forces when it’s being lowered other than carrying special shrouds and supports to line up perfectly with the pivot point?

I see this as a fair weather operation. Nothing to be done in a chop or overly windy conditions. Early morning calm is when this would be attempted. Not like the videos you see of people sailing up to a bridge, dipping the mast and raising it again. It would go down to transit the entire ICW. Or to go deep inland through rivers or canals. Or to stay in one anchorage that’s height restricted for a week or two.


Also, how much mast bury do you need below the “Jesus bolt” or pivot point? Some designs have none, others have quite a bit.

Is just a hinged mast step on top of the pedestal good, or do I need a full tabernacle? What’s the difference?

Thanks! This should be the final mast thread

Have a look at Dutch sailing barge tabernacle set up. They raise some fairly substantial wood masts with little effort. Also, a lot of them have a square mast base. I wish I could be of more help. I'm considering a similar set up on my next boat for cruising in the EU. I've even considered going over and buying a sailing barge just to cruise the area.

[Rjstutch]

All this mast discussion reminded me of a boat sailed to Sydney, Australia from Amsterdam where I believe it was built. It was a micronesian proa designed and built by the owner at the time. This proa could change direction (the bow and the stern reverse, starboad becomes port and visa versa) and used a mast that moved back and forward on a track but could also pivot. I am still dumbfounded how the mast of this 71 foot proa catamaran has the strength to manage all the pressures the main would bring, yet still easily moved on this track system. Maybe this might spark an idea? You see a side view of the reverse direction change then a cockpit view of the mechanics of it at 2min 30 seconds in!
https://youtu.be/iS270ousYwg

[NevilleCat]

Originally Posted by Rjstutch

All this mast discussion reminded me of a boat sailed to Sydney, Australia from Amsterdam where I believe it was built. It was a micronesian proa designed and built by the owner at the time. This proa could change direction (the bow and the stern reverse, starboad becomes port and visa versa) and used a mast that moved back and forward on a track but could also pivot. I am still dumbfounded how the mast of this 71 foot proa catamaran has the strength to manage all the pressures the main would bring, yet still easily moved on this track system. Maybe this might spark an idea? You see a side view of the reverse direction change then a cockpit view of the mechanics of it at 2min 30 seconds in!
https://youtu.be/iS270ousYwg

https://yachthub.com/list/boats-for-...proa-71/271980