My experience in the US has been that inland is often much more expensive than coastal, but it does very much depend on location and mood of the authorities. Boats in shallow water so salvage easier, but then I don't know how many people in the area of the boat to do salvage. Diesel fuel leakage could be greatly exaggerated in the news stories. Depending on cause of leakage, could have been stopped quickly.
The perils of Stabilizers
- Thread starter Flatswing
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My experience in the US has been that inland is often much more expensive than coastal, but it does very much depend on location and mood of the authorities. Boats in shallow water so salvage easier, but then I don't know how many people in the area of the boat to do salvage. Diesel fuel leakage could be greatly exaggerated in the news stories. Depending on cause of leakage, could have been stopped quickly.
AusCan
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Active stabilizer fins will always add some degree of hull damage risk. Some designs are a higher risk than others, same as a rudder. Regardless of how they are designed, there will always be potential for the fin to damage the hull. It may break off at a weak point in most cases, but there will always be a small possibility of hull damage. Foe example - if the boat is moving sideways and the force is on the end of the fin, hull damage can occur.
Still - I think the benefits of active fin stabilization outweigh the risks. Just give yourself an extra couple of feet in depth.
Still - I think the benefits of active fin stabilization outweigh the risks. Just give yourself an extra couple of feet in depth.
Wxx3
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In for what's it worth department:
The FRG guy who repaired and redid my hull last year, thought that with the rock I struck (about 2 ft below water line, like the Titanic) in the Baltic, had my hull been non-cored, I may have had a two foot hole, instead of a 4 foot hairline crack (with no water ingress) and the boat would have sunk.
until then, I too, assumed non-cored was better. Then I discovered that
Cored hulls are more resilient, non-cored hulls are strong, but have less tensile strength.
And also discovered that James Krogen went to non-cored hulls solely for marketing reasons.
In any case, being an after-market install, we have no idea what went wrong.
But it's truly sad to see a KK like this.
Sailor of Fortune
Guru
The environmental part of the salvage will be a dog and pony show to elevate a cleanup that looks a lot worse than it is. A reasonably small diesel spill (several hundred gallons) looks like a horriffic spill . The reality is that it doesn't get cleaned up no matter how much is billed to insurers.
The salvage of the boat is much easier, patch (temporary), pump and tow to a travel lift.
The salvage of the boat is much easier, patch (temporary), pump and tow to a travel lift.
Nomad Willy
Guru
I'd heard of "fish" running in rough water that were run too shallow jump out of the water and come flying through the boat cabin. Could kill or badly injure crew but I never thought of fin stabilizers as something that would or could sink a boat.
Delfin
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. Steel hulls excepted, I should think. Per ABT installation instructions, mine sit on top of 1" of steel, with gussets tied into the steel ribs. Not sure how you would reinforce a cored fiberglass hull.
Brings up a question of how far to the nearest lift that can handle it and how many locks to go through to get there.
RT Firefly
Enigma
Greetings,
Mr. BB. Just looked up the distances. Depending on whether or not the KK was above or below lock 42 there could be only one set of locks and about 50 miles or so to a facility that MAY be able to haul her. There are some bigger (for the area) marinas on Lake Simcoe but I have no idea of the capacities of their lifts...
Mr. BB. Just looked up the distances. Depending on whether or not the KK was above or below lock 42 there could be only one set of locks and about 50 miles or so to a facility that MAY be able to haul her. There are some bigger (for the area) marinas on Lake Simcoe but I have no idea of the capacities of their lifts...
mbevins
Guru
That's the big problem for the area. Service providers for larger boats are few and far between. When we did a trip through the Trent I dinged a prop while waiting for a lock, the gov't removed a buoy that was marking a large rock. Cost cutting, gotta love it.
We ended up bringing in a diver to change the prop as there was no lift reasonably close that was big enough to haul us.
We ended up bringing in a diver to change the prop as there was no lift reasonably close that was big enough to haul us.
FF
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I have thought long and hard about boat stability and think a different system might work.
A centerboard trunk widened a good deal , say to 6 or 8 inches could have a lifting board with a control tab on the trailing edge.
The board would be set to pivot to create the required roll control with the tab directing.
A grounding would be no more of a hassle than in any centerboard vessel, probably less as the wide trunk would shed sand, mud and small stones easily.
The trim tab could be partially balanced to require a very minor energy input , so big Hyd lines , pumps and cooling would not be required .
Should work with even a tidal stream to keep the boat on an even keel.
When not of use the stability board would simply be lifted , so no constant toss of speed or high fuel burn , and of course no fear in a grounding, or meeting with a sea land box underway.
A centerboard trunk widened a good deal , say to 6 or 8 inches could have a lifting board with a control tab on the trailing edge.
The board would be set to pivot to create the required roll control with the tab directing.
A grounding would be no more of a hassle than in any centerboard vessel, probably less as the wide trunk would shed sand, mud and small stones easily.
The trim tab could be partially balanced to require a very minor energy input , so big Hyd lines , pumps and cooling would not be required .
Should work with even a tidal stream to keep the boat on an even keel.
When not of use the stability board would simply be lifted , so no constant toss of speed or high fuel burn , and of course no fear in a grounding, or meeting with a sea land box underway.
Bay Pelican
Moderator Emeritus
Our Wesmar installation on a Krogen 42 hull reinforces the hull with a two foot diameter six inch thick block of hard wood machined to fit the inside of the hull. Everything is mounted on that block.
twistedtree
Guru
That's the same way the Naiads are installed, though the wood block dimensions may be different. You basically epoxy/glass the block in place, then the stabilizer mounts to that. What's critical is the fit, bonding, and ultimate strength of that block attachment to the hull. If that separates, you have a problem. Also a factor of course is the strength of the hull around the block.
Personally, that mounting method is what made me pick ABT when I put stabilizers in my old Grand Banks. I just couldn't get comfortable the installation approach, especially when you compare it to ABT.
ABT's approach is to use a large (24" diameter or larger depending on the actuator size) cast steel flange, kind of like a man-hole cover, on the inside of the hull. It is then paired with a similar diameter stainless plate on the outside, and thru-bolted with the hull sandwiched in between. There is simply no way for it to come off or come loose short of ripping a chunk of the hull off that's the size of a man-hole cover. And the hull thickness is usually built up in the surrounding area as well. Structural filler is used between the plates to take up all the gaps in the sandwich to provide an even, solid contact between all parts. It's very, very robust.
Good thinking Fred! I follow your stabilizer thought...
Planning to send you a PM regarding stabilizer my dad invented during late 1960's. He and I many times sea trialed throughout early 1970's.
Used it for years on a 38' SD hull, raised deck, sport fisher hull. Worked exceptionally well. Dad just couldn't get it into large scale marketing format.
sunchaser
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The iffy reasons for striking a rock and eventual sinking of a 30 year old (or so) cored hull boat of unknown integrity is hardly an indictment of stabilizers. One thing for sure, the skipper and or owner will be testing all of his insurers and personal liability. Does anyone know if this is a US or C flagged vessel?
The preferred way to install stabilizers on an FRP vessel is during and as part of the initial layup. This allows the stringers, hull and backing blocks to have a better chance to be a chemically homogenous and more robust bond. Adherence to curing times is an important aspect of through hull integrity so I've heard and seen.
I've been on several Al vessels where the stabilizer areas were bulk headed off. The oldest being built that way around 1980 when active stabilizers were first being installed in cruising boats.
The preferred way to install stabilizers on an FRP vessel is during and as part of the initial layup. This allows the stringers, hull and backing blocks to have a better chance to be a chemically homogenous and more robust bond. Adherence to curing times is an important aspect of through hull integrity so I've heard and seen.
I've been on several Al vessels where the stabilizer areas were bulk headed off. The oldest being built that way around 1980 when active stabilizers were first being installed in cruising boats.
Seems a no-brainer... i.e., stabilizer protrusion must be engineered to break off before the hull location gives way.... in regard to hitting anything. Then a sink-hole can't/won't happen:
Brooksie
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We had a stabilizer sinking on an offshore ledge nearby some years ago, went down very quickly. The "breakaway shaft" didn't break but bent back and allowed the upper aft corner of the fin to be driven up through the hull. After seeing that I wondered why that corner of the fin could not be rounded and have a protective stainless plate on the hull.
eyschulman
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Pushes my thoughts more toward the gyro solution. If I were building now I would be seriously thinking gyro.
mbevins
Guru
The gyros are very cool but how many of us really have the room to put one?
They can be very difficult to retrofit although easy to install if a builder considers them up front.
I keep looking at this thread title and thinking it should really read "The Perils of running across rocks." It happens that we may have a case of a stabilizer being hit in a way to compromise the hull and lead to sinking but I'm not sure we fully know that yet. Everything below the waterline and some things above create risks from props and shafts, to hull fittings to transducers, to engine room vents to water hoses to trim tabs to swim platforms to rain and bilge pump failure and I'm not convinced at all that a properly installed stabilizer significantly increases the risk. I agree it is an item of risk just like everything else. I don't see this as a reason not to install them. I do see it as a reason to be sure of the quality of installation especially with any after market installation.
TimButterfield
Veteran Member
The SeaKeeper 3 is for boats from 30-39'. Of course, being designed for isn't the same has having room for, though some in the range will. They must have thought enough did to make that sized model. They also claim "Over 25% of all Seakeeper units shipped are for refit installations!" With all of that said, I have no experience with it myself. But, Laura Domelo of Riveted blog said of a new Nordic Tug 40 trial, "We were out in some pretty rough water in Rosario Strait and this Seakeeper thing is seriously impressive. Sitting still in 4ft beam waves…steady as can be."
It can be refit. It's just be sure it's someone with a lot of Seakeeper experience and best to make sure they get with the builder regarding the best location. The Seakeeper 3 is 550 lbs and is 26.8" L x 27.0" W x 22.5" H.
They show an installation being done on a Contender center console on the web site.
Woodland Hills
Guru
You will have to run your genset whenever you want stabilization. Apparently they spin down pretty quickly when not powered up.
psneeld
Guru
Someone in the past did the math and thougt it possible for some boats to power it from an inveter, batteries and adequate alternators.
Not sure of the load other than a few years back it was reduced from the earlier models.
Not sure of the load other than a few years back it was reduced from the earlier models.
Just a note here: IMO - myself being a lover of KISS. I believe that in boats 39' and below... the captain should be the "stabilizer" that does not go into too rough seas. And IF a Captain were to occasionally get stuck into having deal with rough seas then bite the bullet and work ones way out of it.
If smaller mechanical stabilizers [designed for smaller boats - i.e. under 40'] have limits in the stabilizer ability for seas over 3.5 to 4,5 feet or so... then I cannot see much sense in having a stabilizer aboard. Unless, of course, the Captain were planning to cruise in steep beam seas day after day after day... then yes, even smallish boats could probably make good use of a stabilizer.
Being a KISS lover I just don't see reason to add more and more boat equipment that is seldom if ever needing to be used.
Ski in NC
Technical Guru
I like the idea of the seakeeper as it can work in an anchorage. Often in an anchorage I am running the gennie anyway for HVAC and cooking. If it could be run on a big alt and inverter under way, better yet.
Big fins sticking out of the side of the boat spooks me.
Big fins sticking out of the side of the boat spooks me.
