Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 13-01-2013, 17:14   #1
Registered User
 
Bluefuss's Avatar

Join Date: Apr 2010
Location: B.C. Canada / San Carlos, Sonora
Boat: Tayana 37
Posts: 168
Keel stepped, deck stepped, tabernacle?

What are the advantages, disadvantages, or reasons for choosing one over the other?
For the sake of this discussion lets assume it apply's to a 35 to 40 foot heavy displacement cutter design.
Cheers
__________________

__________________
When we remember we are all mad, the mysteries disappear and life stands explained.
Mark Twain
Bluefuss is offline   Reply With Quote
Old 15-01-2013, 22:29   #2
Registered User

Join Date: Sep 2012
Posts: 4,924
Re: Keel stepped, deck stepped, tabernacle?

Surely this has been discussed before...keel step, stronger, might be able to save the mast if a stay breaks, probably leave you a good stub if you were rolled and lost the mast, ..down side, leaks inside most of the time. Deck stepped, lose a stay, lose the rig. Upside no deck leaks. Needs a proper compression post.
Reality most offshore sailors prefer a keel stepped mast but a well executed deck stepped mast is just fine.
__________________

__________________
robert sailor is offline   Reply With Quote
Old 15-01-2013, 22:35   #3
Registered User
 
Bluefuss's Avatar

Join Date: Apr 2010
Location: B.C. Canada / San Carlos, Sonora
Boat: Tayana 37
Posts: 168
Re: Keel stepped, deck stepped, tabernacle?

Yes I did read a lot of former posts and i guess I did not phrase my initial post well. It is mostly the Tabernacle that I most wonder about. Is it weaker but handier? etc
__________________
When we remember we are all mad, the mysteries disappear and life stands explained.
Mark Twain
Bluefuss is offline   Reply With Quote
Old 15-01-2013, 23:11   #4
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
Re: Keel stepped, deck stepped, tabernacle?

Tabernacle?
Larger boats (>30') don't normally have a Tabernacle, unless it were specifically requested and designed.

But yeah! If one would want one it can be designed into the rigging. And it would have to be extra heavy duty and have other rigging for getting the mast up/down.

Smaller boats are usually trailerable and require some sort of Tabernacle, and can be manhandled fairly easy.

But still not sure what you're really after here?
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote
Old 15-01-2013, 23:18   #5
Registered User
 
Bluefuss's Avatar

Join Date: Apr 2010
Location: B.C. Canada / San Carlos, Sonora
Boat: Tayana 37
Posts: 168
Re: Keel stepped, deck stepped, tabernacle?

Most of what I have read about tabernacles has been on pocket cruisers, but I recently saw one on a Tayana 37. Knowing very little, or nothing, about the subject I asked about this in reference to boats of that size, displacement etc. Any idea what they might have been thinking, what are the possible pitfalls or advantages compared to standard deck stepped or keel step (besides being able to drop the mast without a crane)?
__________________
When we remember we are all mad, the mysteries disappear and life stands explained.
Mark Twain
Bluefuss is offline   Reply With Quote
Old 15-01-2013, 23:33   #6
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
Re: Keel stepped, deck stepped, tabernacle?

Boats that desire to go up rivers or canals with bridges would need a tabernacle setup to save costs and time traveling.

As for off shore it shouldn't be any less strong then a standard deck stepped mast. One just needs to watch their fittings carefully while raising/lowering the mast. Too many times I've seen kinked cable (shrouds) in the process.

I once made a yoke for a trailerable that worked excellent. But on a larger boat it would be more complicated and heavy.


.
Attached Thumbnails
Click image for larger version

Name:	frontboom.JPG
Views:	191
Size:	87.1 KB
ID:	52934  
__________________
Faithful are the Wounds of a Friend, but the Kisses of the Enemy are Deceitful! ........
A nation of sheep breeds a government of wolves!

Unprepared boaters, end up as floatsum!.......
delmarrey is offline   Reply With Quote
Old 16-01-2013, 03:01   #7
Registered User

Join Date: Feb 2012
Posts: 2,441
Re: Keel stepped, deck stepped, tabernacle?

Tabernacles, if well designed, can tip the balance in favour of deck stepped even for the extreme expedition-yacht end of the offshore toughness spectrum, IMOThey can take the thrust from the main boom/gooseneck, leaving the mast tube entirely free of that.And if they snugly encapsulate the mast (like a deck collar) or have a well engineered pivot point, (with the mast tube beefed up suitably at that locale), the bottom panel of the mast is that much shorter. It's like moving the keel step up to the deck, and the deck collar up to or even past the gooseneck, in terms of the bending moment and shear force diagrams, and that's all good. The only point against this is that it will weigh more, and that weight will be higher. IN the scheme of things, I think that's a reasonable price to pay. For an expedition yacht, not having a hole in the boat with a great big lever stuck into it, is a big attraction.
__________________
Andrew Troup is offline   Reply With Quote
Old 16-01-2013, 03:37   #8
Registered User

Join Date: Jul 2012
Location: Switzerland
Boat: So many boats to choose from. Would prefer something that is not an AWB, and that is beachable...
Posts: 1,241
Re: Keel stepped, deck stepped, tabernacle?

Quote:
Originally Posted by robert sailor View Post
Surely this has been discussed before...keel step, stronger, might be able to save the mast if a stay breaks, probably leave you a good stub if you were rolled and lost the mast, ..down side, leaks inside most of the time.
What if you were to have a tube around the mast, so that any leaking goes directly in the bilges?
__________________
K_V_B is offline   Reply With Quote
Old 16-01-2013, 15:22   #9
Registered User

Join Date: Feb 2012
Posts: 2,441
Re: Keel stepped, deck stepped, tabernacle?

Hmm .. leaking does pretty much go directly into the bilges anyway

(most of it's down the inside of the mast, generally) ...

to anyone who's relaxed about that, then one of the issues which some people greatly dislike about keel stepping becomes a non-issue.
__________________
Andrew Troup is offline   Reply With Quote
Old 16-01-2013, 15:46   #10
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,342
Re: Keel stepped, deck stepped, tabernacle?

Seems to me an unstayed rig, whether deck stepped or keel stepped is fairly equally at risk from failure. Most the masts I've seen bent/broken are well above the deck either way. A longer beam in compression is more likely to buckle without intermediate support than a shorter one. (called the slenderness ratio) A keel stepped mast gets some support from the deck hole... but it's a longer beam too... Not sure how the real world shakes out... but would guess it's about a toss up personally.... anyone ever seen actual engineering numbers?
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 16-01-2013, 15:50   #11
Registered User
 
Bluefuss's Avatar

Join Date: Apr 2010
Location: B.C. Canada / San Carlos, Sonora
Boat: Tayana 37
Posts: 168
Re: Keel stepped, deck stepped, tabernacle?

Thanks Andrew Troup, thats the kind of info I need. I would suppose that the extra weight, higher, would not be a great concern on something like a T37?
__________________
When we remember we are all mad, the mysteries disappear and life stands explained.
Mark Twain
Bluefuss is offline   Reply With Quote
Old 18-01-2013, 08:35   #12
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Keel stepped, deck stepped, tabernacle?

Quote:
Originally Posted by K_V_B View Post
What if you were to have a tube around the mast, so that any leaking goes directly in the bilges?
Leaks at the bilge are a thing of the past this days, here the riggers everytime step a rig up made a plastic dam , kinda with the form of the interior section of the spar with a short tube to pass wires , the dam is coated with a especial epoxy in the sides and then the dam is moved inside of the spar to aprox deck level, the epoxy expand when cured and form a watertight seal, a drain hole is made it in the deck level to drain rain water , or make a hole and fit a exit for spinaker pole lines etc...

No more water in the bilge , and it work!!
__________________
neilpride is offline   Reply With Quote
Old 18-01-2013, 09:54   #13
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,310
Re: Keel stepped, deck stepped, tabernacle?

I'd avoid a boat with a tabernacle--they are usually made of stainless for strength and you will have serious long term corrosion issues with an aluminum mast. Most boats have aluminum mast steps, which will have their own corrosion issues with stainless fasteners but can be replaced.

If you don't believe me, walk around your (saltwater) marina and take a close look at the bottom of the deck-stepped masts.
__________________
donradcliffe is offline   Reply With Quote
Old 18-01-2013, 10:16   #14
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: UK/Portugal
Posts: 20,189
Images: 2
Send a message via Skype™ to boatman61
pirate Re: Keel stepped, deck stepped, tabernacle?

Never seen an S/S tabernacle... over here they're usually galvanised... and definitely not ally... cheap buga's..
Best one I've seen had a 3/4 backing welded onto the cheeks and a second bolt going through halfway between the deck and pivot bolt.
Gave me a wee bit more reassurance than just the wedge tapped under the foot....
__________________


Born To Be Wild
boatman61 is offline   Reply With Quote
Old 18-01-2013, 10:29   #15
Senior Cruiser
 
sneuman's Avatar

Cruisers Forum Supporter

Join Date: May 2003
Location: Jamaica
Boat: Tayana 37 Cutter
Posts: 3,167
Images: 37
Re: Keel stepped, deck stepped, tabernacle?

I think there are pros and cons to each. I have a deck-stepped and feel a bit more secure with it, as it does offer some substance to the rig. If I were buying another boat, I wouldn't make it a consideration either way, though.
__________________

__________________
Voyage of Symbiosis: http://svsymbiosis.blogspot.com/
sneuman is offline   Reply With Quote
Reply

Tags
deck, keel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 04:08.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.