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Old 03-04-2021, 00:25   #1
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Encapsulated = invulnerable ??

For a chilling look at what can go wrong with an encapsulated keel, have a look at this story in electronic Latitude:

https://www.latitude38.com/lectronic...gy-pizza-lunch

I'm not sure what marque the boat is, but the message is clear: this particular near sinking would not have happened with a bolt on keel!

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Old 03-04-2021, 01:21   #2
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Re: Encapsulated = invulnerable ??

It’s astounding the encapsulated keel isn’t fully encapsulated.

To prevent this issue, the should have put in a layer of glass at the top of the keel (bottom of the bilge) to actually encapsulate it.

Having your hull interior go 4’9” down underwater, even with a bunch of lead in it is asking for trouble. I’ve had gulfstars. My last one was the 50 sailmaster. I can’t recall any place there was access to the ballast at all in that one. I think it was properly encapsulated. But I think one of the older ones did have open ballast.
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Old 03-04-2021, 03:36   #3
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Re: Encapsulated = invulnerable ??

Chotu's right--it's not encapsulated if it's open at the top. But that sad excuse for a keel is also a design flaw--the chain would not have been able so to treat a full keel.
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Old 03-04-2021, 03:45   #4
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Re: Encapsulated = invulnerable ??

Quote:
Originally Posted by Jim Cate View Post
For a chilling look at what can go wrong with an encapsulated keel, have a look at this story in electronic Latitude:

https://www.latitude38.com/lectronic...gy-pizza-lunch

I'm not sure what marque the boat is, but the message is clear: this particular near sinking would not have happened with a bolt on keel!

Jim

Jim

"The encapsulated keel of our Gulfstar 37 Wanderlust"

You are not sure what the marque is? (Am I the one that has got his wires crossed?)





On a bolt on/fin keeled yacht the cable would have undoubtedly dragged the rudder/skeg off (and sunk), destroyed the prop shaft and cutlass bearing (and sunk) or dragged the keel off (and sunk)


Would this keel be any better? (I assume you can read Russian?)



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Old 03-04-2021, 03:59   #5
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Re: Encapsulated = invulnerable ??

That couldn't happen with a Bristol 27's encapsulated keel.

It's thicker, stronger, and totally solid plus at the leading edge is where the 2575 lb chuck of lead is located.

https://sailboatdata.com/sailboat/bristol-27
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Old 03-04-2021, 04:19   #6
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Re: Encapsulated = invulnerable ??

Thommo225

I laid lead "ingots" in my keel then poured resin around them.

I still have trim ballast laying in the keel. Once I get the yacht floating on the waterline I may pour bitumen over the ingots then heavily seal the ballast with a f/g lay-up
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Old 03-04-2021, 05:25   #7
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Re: Encapsulated = invulnerable ??

Well now, not actually being encapsulated kind of ends this as an example of an Actuality “fully encapsulated keel” being any sort of issue, does it not...

As we all know nothing is invulnerable, (a bit of hyperbole in the title) although actually fully encapsulated keels are less vulnerable than bolt on keels to the gamut of damage that can occur to a sailboats keel. Go ahead ask me how I know...
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Old 03-04-2021, 05:30   #8
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pirate Re: Encapsulated = invulnerable ??

Quote:
Originally Posted by Pegu Club View Post
Well now, not actually being encapsulated kind of ends this as an example of an Actuality “fully encapsulated keel” being any sort of issue, does it not...

As we all know nothing is invulnerable, (a bit of hyperbole in the title) although actually fully encapsulated keels are less vulnerable than bolt on keels to the gamut of damage that can occur to a sailboats keel. Go ahead ask me how I know...
I'm bored so...
How do You know..
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Old 03-04-2021, 05:44   #9
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Re: Encapsulated = invulnerable ??

I'd be a bit more concerned about a bolt-on keel falling off. Has anyone heard of a full length keel with encapsulated ballast falling off?

Keels Are Falling Off

Yes quite an alarming title but the subject has become serious to the point of World Sailing, the world governing body for the sport of sailing, to become seriously concerned and being on the verge of taking preventive actions.

https://www.sailingscuttlebutt.com/2...s-falling-off/


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Old 03-04-2021, 06:42   #10
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Re: Encapsulated = invulnerable ??

I'd say both the keel falling off stories and this watery story point to one big thing: regardless of bolt on or encapsulated keel, you have to design and build it properly. If you don't, there's potential for things to go very, very wrong.

In this particular situation, with a well designed and built bolt on keel, I'd expect to see a notch worn into the front of the keel, but nothing more. It wouldn't be anywhere near the force required to break the keel off (which wouldn't happen without tearing the hull apart of physically snapping the keel, provided the attachment is well designed and of adequate strength).

And with a properly designed encapsulated keel (that was properly sealed off from the rest of the boat), I'd expect the same basic failure: a notch worn into the keel, but no water in the boat and no immediate impact on the boat's ability to function.
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Old 03-04-2021, 07:38   #11
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Talking Re: Encapsulated = invulnerable ??

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Originally Posted by boatman61 View Post
I'm bored so...
How do You know..
Sooo, in a moment of monumental newbie stupidity, we ran into the Reedy Island dike at five plus knots, this is an under water dike, several miles long in Delaware bay, it is meant to help keep the traffic lanes from silting in, it has been there for something around ninety plus years. This happened in our first month of our first trip to the Bahamas... three years ago... to but it bluntly we came to a complete halt, instantly, this little incident put a bit of a dent in the leading edge of our “fully encapsulated keel” ,luckily for us the damage was far less than I imagined it would be, any way we had the damage repaired, and were on our way three days later. I’m thinking that if we had a bolt on keel we wouldn’t have been able to continue on with our journey so promptly as it were...

Not one of our proudest moments, but we learned from our error shall we say...

As an aside, the tech at the marina told us that around seven boats hit that dike annually, and a large Nordhausen trawler sank hitting it the previous year...

Fair winds,
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Old 03-04-2021, 08:34   #12
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Re: Encapsulated = invulnerable ??

When I first got my boat, it was located at a marina where you could only get in an hour or so either side of high tide.

A couple times I was too late or too early and would have to "bounce" on the keel across the low spots. The waves would lift the boat and she'd bounce off the bottom. Repeat until you get across.

Sometimes the boat was heeled over a bit because the sail was up so it wasn't a direct perpendicular bounce off the bottom.

No damage except some paint and maybe a layer of fiberglass but since the fiberglass is 3/4" or more on the bottom that was okay.
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Old 03-04-2021, 10:07   #13
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Re: Encapsulated = invulnerable ??

Encapsulated keels, at least in long keels that I know of, are not fully encapsulated. The ballast is encapsulated forward in the hollow keel. The aft part of my encapsulated keel is an empty and open void as I am sure it is with most if not all encapsulated keels. The article Jim cites shows there is an Achilles heel in there for those of us with old school boats. In my case the water tank is in there and that has a sufficient cap on it (I think) so that if a chain ground through that section of keel I think I'm ok, and the ballast forward is well sealed so that I'm not concerned about. But the last 7 or 8 inches of keel before the rudder is vulnerable to this kind of damage. Granted, how often do we end up with someone else's anchor chain or mooring chain under our boats sawing into the keel? Not often, but it is easily conceivable... a crowded anchorage, maybe a little stormy, someone drags etc, etc. Now if I hit something head-on with my encapsulated lead I am pretty confident I'll not be sinking, though there is another thread on this subject that pointed out even that is not guaranteed in some boats.

But a couple of things about that boat in the article; I am a little surprised they didn't hear the damage happening, and that they'd let the boat grind against a mooring ball. Also, not having seen the innerds of an encapsulated fin (sort of) keel, I had wrongly assumed that the ballast would have filled the entire bottom of the keel and then would have been fully encapsulated. Maybe some are, I don't know.

BTW I suspect many full keel boats share the same vulnerability. Behind the ballast and water tank in the drawings of many boats there seems to be the same void that, unless it is filled with something and capped, is open at the top.

All you all with encapsulated keels, crawl in there with a flashlight and an endoscope and report back what you find!
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Old 03-04-2021, 10:16   #14
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pirate Re: Encapsulated = invulnerable ??

Quote:
Originally Posted by Pegu Club View Post
Sooo, in a moment of monumental newbie stupidity, we ran into the Reedy Island dike at five plus knots, this is an under water dike, several miles long in Delaware bay, it is meant to help keep the traffic lanes from silting in, it has been there for something around ninety plus years. This happened in our first month of our first trip to the Bahamas... three years ago... to but it bluntly we came to a complete halt, instantly, this little incident put a bit of a dent in the leading edge of our “fully encapsulated keel” ,luckily for us the damage was far less than I imagined it would be, any way we had the damage repaired, and were on our way three days later. I’m thinking that if we had a bolt on keel we wouldn’t have been able to continue on with our journey so promptly as it were...

Not one of our proudest moments, but we learned from our error shall we say...

As an aside, the tech at the marina told us that around seven boats hit that dike annually, and a large Nordhausen trawler sank hitting it the previous year...

Fair winds,
Good story.. Thanks..
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Old 03-04-2021, 10:30   #15
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Re: Encapsulated = invulnerable ??

Quote:
Originally Posted by coopec43 View Post
I'd be a bit more concerned about a bolt-on keel falling off. Has anyone heard of a full length keel with encapsulated ballast falling off?

Keels Are Falling Off

Yes quite an alarming title but the subject has become serious to the point of World Sailing, the world governing body for the sport of sailing, to become seriously concerned and being on the verge of taking preventive actions.

https://www.sailingscuttlebutt.com/2...s-falling-off/
Anything can fail, but an encapsulated keel is FAR less likely to. Boats are always a balance of risks. There are 6 or 7 major risks in build and design. It's a balance of how many you are willing to live with for maintenance and risk. What's your ratio? 2 of 7? or 6 of 7?

The good point of a molded keel (fully encapsulated or not) is all the stress from the keel is distributed over a large area of the hull, along with that often it's distributed via a large blending radius to the hull. Add to that that it is a fiberglass monocoque layup bonded to the structure. The bolt on keel may have a sharp corner of stress at the hull and is held only by bolts really.
But there are bolt on ballast designs that have the advantages of a keel stub with better stress distribution to the hull.

Years ago, early 2000's I think, there was a brand new production design, was it Ericson? that the bolt on keel fell off of in the Gulf of Mexico.
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