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Old 21-12-2008, 20:11   #16
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Originally Posted by Celestialsailor View Post
It cost much more in labor and F/G materials to beef up a cabin top, fabricate a tabernacle out of Stainless or Aluminum and build in the wood structure internally for the compression post than the extra 6 feet of Aluminum extrusion of the mast...IMHO.
I was refering to production boats,not custom jobs.And I can assure you your cabin top needs to be just as beefy with a keel stepped mast.With a deck stepped mast the compression post is the vital thing that must be correctly engineered IMHO
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Old 21-12-2008, 20:56   #17
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Quote:
Originally Posted by nonam View Post
I was refering to production boats,not custom jobs.And I can assure you your cabin top needs to be just as beefy with a keel stepped mast.With a deck stepped mast the compression post is the vital thing that must be correctly engineered IMHO
I was not referring to custom boats merely responding to your statement of deck steps being less costly. Merely comparing deck step to keel step. I have been in boat construction long enough to make the statement I did not speculation based on opinion.
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Old 22-12-2008, 02:30   #18
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Deck stepped masts can be lighter in sectional dimensions because they are shorter.

I've had both, currently have keel stepped. I prefer deck stepped, notwithstanding stub remaining after dismasting in the case of keel-stepped. I like the absolute waterproofness of deck stepping. Plus, compression poles tend to take up much less room below than an actual mast. There is lots of visual weight in the interior soaking up space with a mast in the middle.
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Old 27-01-2009, 08:21   #19
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Excellent Thread

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Originally Posted by endoftheroad View Post
I was taught as a kid that to be considered a serious offshore contender a sailboats mast must go all the way to the keel.
With the great offshore reputation of the Westsail 32 I am puzzled why the mast stops at the deck.

What makes this possible when masts stop at the deck?
I always thought the same...and since I'm looking to buy a Westsail it's right on target for me.

Thanks for everyone's input...expecially about the 'kit' boats, since at lease half were of that ilk.
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Old 27-01-2009, 10:48   #20
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A boat with a great reputation for seagoing is the Contessa 26. One of our Forumites has just sailed his across the atlantic.

This has a deck stepped mast.

Boat builders and designers like a deck stepped mast because it does not intrude into the living space.

I like one cause it removes a major source of water intrusion into the boat.
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Old 27-01-2009, 11:05   #21
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No, emphatically no.

A deck stepped mast cannot be a lighter section. It must be a bigger section with increased moments of intertia over a keel stepped mast. Designed correctly each method can be very satisfactory and each has it's own benefits. I leave it up to the client then design/spec the extrusion accordingly.
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Old 27-01-2009, 12:08   #22
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Well there you have then.The score is six for one and half a dozen for the other.
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Old 27-01-2009, 12:44   #23
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The Westsail kit boats that we were familiar with while building ours were way better built than the factory boats. The W32 had two different deck moulds around the era wheh ours was built, 1974/hull #163. One deck mould had more saddle in the cabin top than it was supposed to have. It cut down on the headroom but made for a much better looking boat. The saddled deck mould was dropped sometime after hull #200.

Deck stepped masts need to be larger section and/or wider shroud angles than keel stepped masts for the same height. It's something that is important to a racer but immaterial to a cruiser as it has such a small effect on sailing ability. In the case of the W32, the shroud angles are huge so there is much reduced compression load on the stick. That makes it way stronger than a keel stepped mast with narrower shroud angles. No one would accuse the Westsail mast section of being puny, in any case.

As far as dismasting. If you lose a cap shroud or stay, no matter whether the boat is deck stepped or keel stepped, the mast will buckle at the spreaders. You'll have a stump no matter what the design. If you lose a lower shroud(s) the mast will probably buckle at the deck. In the case of the deck stepped mast it will go overboard probably without damaging the deck. A keel stepped mast could do significant damage to the cabin top and you will have to cut off the stick to clear it from the deck. In any case, you can use the boom or a spinnaker pole to jury rig a stub mast to have some sail area. That's what that French women did who lost her mast in an around the world attempt so she could sail to a port for repairs.

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Old 28-01-2009, 11:01   #24
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I think one major reason we are seeing more deck stepped boats is because they are easier and cheaper to produce.

Not sure where you get that information. That's like saying a convertible costs less and is easier to build than a sedan.

I don't think where the mast steps is a determiner of cost. How the boat is reinforced is. Deck stepping requires more reinfocing, more engineering then setting a mast on the keel, but, neither configuration of boat necessarily is built well, or both can be. Depends on the designer and the yard.
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Old 28-01-2009, 12:18   #25
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No,sedans and convertables have nothing to do with it.I dont understand the argument that keel stepped boats have cheap cabintops.Deck stepped masts are significantly faster/easier to step,less potential for things to go wrong,and less warranty problems.
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Old 28-01-2009, 12:47   #26
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No,sedans and convertables have nothing to do with it.I dont understand the argument that keel stepped boats have cheap cabintops.Deck stepped masts are significantly faster/easier to step,less potential for things to go wrong,and less warranty problems.

The breadth of what you don't understand speaks volumes.
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Old 28-01-2009, 14:32   #27
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Deck stepping requires more reinforcing, more engineering then setting a mast on the keel, but, neither configuration of boat necessarily is built well, or both can be. Depends on the designer and the yard.
Last I checked they both require engineering. The yards pretty much do as indicated in the designs or you can end up with other problems. Bob Perry explains about all there is. You can do a good job either way but you don't usually convert one type to the other by sawing off a hunk of mast or welding on the extra piece later on. The masts are not the same.
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Old 28-01-2009, 15:20   #28
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No, emphatically no.

A deck stepped mast cannot be a lighter section. It must be a bigger section with increased moments of intertia over a keel stepped mast. Designed correctly each method can be very satisfactory and each has it's own benefits. I leave it up to the client then design/spec the extrusion accordingly.
Shoot! You mean I got it backwards??

I'm gonna have to check your book again. Nuts. I could have sworn it was the other way around. I'm losing it Bob.
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Old 04-02-2009, 18:32   #29
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Brion Toss who is a rigger here in Washington State (who has written a book) claims a keel stepped mast is stronger than a deck stepped one. It has to do with the support the mast partners provide which is absent in a deck stepped mast. At a yacht club meeting he gave a demo to illustrate this. He passed out pieces of spaghetti and had us hold the spaghetti at the top, bottom and spreader location. We then wiggeled or bent the spaghetti. Then we added support where the deck partners would be and the difference was appreciable.
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Old 04-02-2009, 19:32   #30
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He passed out pieces of spaghetti and had us hold the spaghetti at the top, bottom and spreader location. We then wiggeled or bent the spaghetti. Then we added support where the deck partners would be and the difference was appreciable.
Well you don't get a choice. The mast is decked stepped or it is keel stepped.

I may not be Brion Toss (a pretty good rigger by my estimate) but I sure wouldn't be making any masts out of spaghetti. The real difference is for pasta masts I'm using a deck stepped rigatoni mast and why you would use spaghetti seems a bit odd. The stuff breaks pretty easy. Rigatoni is stronger.

The real truth is you don't use the same material for the two different masts.
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