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Post by Deleted on Sept 20, 2015 9:31:26 GMT
'Heads Up' to Jeanneau Lift Keel owners: SO379 L/K; drying harbour; assured by the harbourmaster that the visitors pontoon had a firm level seabed. Sure enough, we took the ground nice & level - no problem. Problem arose when we took the ground a second time. At night, the sound of water under pressure entering the boat - MERDE! Found the keel box inspection cover (port side of table) had ruptured (photo). There was a layer of mud over the firm seabed. This mud had filled the keelbox; on the second grounding the pressure of the compacted mud/water had ruptured the plastic cover. Subsequently, the keel plate 'freeing tool' failed to lower the plate. In the Travelhoist, it took an hour with a high pressure hose + use of the freeing tool to free the keel plate. Final snag - the sharp edge of the keel plate 'freeing tool' badly ground into the GRP plate. (WIP there).
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Post by MalcolmP on Sept 21, 2015 16:11:47 GMT
Hi Gerry
Sorry to learn about this. I always liked the idea of lift plates, on a previous boat I used legs to dry out a shoal draft boat, but with the current 39i shoal draft I avoid drying out entirely - to date...
Glad it sounds you have it sorted and not too much damage, could have been much worse
Malcolm
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Post by seattle519 on Sept 21, 2015 21:26:19 GMT
So you might as well be talking Martian. Please explain:
Keel box. Location of plastic cover. Keel plate. Lift plates. Keel plate "freeing tool". GRP plate.
Would the boat have sunk if you were not on board?
I'm certain the half dozen sailboats I've been around a lot didn't have any of this but I would like to understand.
Dean
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Post by Deleted on Sept 22, 2015 7:58:02 GMT
Dean,
The post was a warning to Jeanneau Lift Keel (specifically the 379 Lift Keel) owners, of potential problems taking the ground on mud. Hopefully those owners will understand the terms used.
If you have a fixed keel then none of the post applies to you; sorry for the confusion. Gerry
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Post by rene460 on Sept 22, 2015 10:55:29 GMT
Hi Dean,
As Gerry says, if you have a fixed keel you have none of these items.
It might help you understand if you think of the lift keel versions of our boats as being a bit like big centreboard dinghies in which the centreboard is pushed down through a centreboard trunk or casing (or keel box). The board provides the side ways force to resist leeway when beating can be lifted by hand in a dingy or winch on a larger boat. They are ballasted so they normally lower easily but are not all so heavy that they cannot jam in the up position, so a device is provided to facilitate pushing it down. A fixed keel provides the sideways resistance by its area as well as righting moment due to its weight. The lift keel boat has its ballast either inside low in the hull, or in a shallow keel like the SO30i. The plastic cover is an inspection port that is normally above the waterline in the side of the centreboard trunk. Whether the boat would have sunk depends on how firmly the boat was stuck in the mud, the inspection port is a few inches above the waterline when the boat is afloat, but I am glad that Gerry was onboard.
I hope that clarifies things enough for you to follow this and other threads involving lift keel versions.
rene460
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Post by seattle519 on Sept 22, 2015 16:06:12 GMT
A big boat centerboard and all its accoutrements. It now all makes perfect sense.
Thanks for the explanation!
Dean
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Post by ejk on Apr 11, 2020 18:10:14 GMT
Hello, I found this topic due to the same problem I experienced with my new build SO 389, first season, Germany. We regulary use a Harbour that always dry out completely, but the ground is not hard sand but muddy. We experienced always water coming trough the inspection cover, it is quite a lot, the automatic pump is working every 30 min during the low tide period. We opened up the inspection cover later to check for failure, but it always looked fine. My dealer send me a new inspection - just in case something is wrong with the original one. My question is : Is there any information about the pressure that an inspection cover can bear? Any ideas how high the pressure is inside the keelbox when grounding in muddy ground? Are there any more stable inspection cover? Thanks Enno
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Post by rene460 on Apr 12, 2020 10:29:33 GMT
Hi Enno,
Welcome to the forum. You will find it a friendly place to talk with like minded people about your boating interests.
I had forgotten about this thread, which is from 2015. It certainly describes a situation that I had not anticipated before then, but it seems to me that the mud plugged the bottom of the keel box while the boat lay dried out. Then on refloating, the mud appears to have softened enough for the plug to be pushed in a little further at the next low tide, but not softened it enough to allow the water trapped above the mud plug or the plug itself to drain out.
The level inside the box will be the same as outside so long as the box remains open at the bottom. However in the situation described above, the pressure on the bottom of the plug is determined by the mass of the boat and the area of the bottom of the keel plus the rudders on which it sits. I have not tried to do the calculation, as it involves making an estimate of the area supporting the boat on the mud, as well as the mass of the boat, but I assume certainly very much higher than the pressure of water which applies when the bottom of the keel box is open, so the water and even the mud would rise much higher than the normal level, which on my boat is only a few cm below the bottom of the hatch.
The top of the box is vented by the tube which carries the lift rope, so the pressure is still atmospheric at the surface inside the box. But it is quite likely that the mud ( clearly higher density than water) will be forced up to a higher level than the normal water level, and will lift the water trapped above it.
For a further clue as to how high the water could have lifted, you could check for signs of water running out at the top of the lift rope tube. On my boat this would be the top of the cabin. You could also try pulling the rope into the cabin while the boat is on the hard stand and with the hatch removed, and look for tell tale signs on the rope. However, if the inspection cover breaks, it will leak the water into the cabin, and may leak mud into the boat if the process continues. (It is under the salon table on the side of the area of the box that houses the lifting tackle, for those not familiar with lift keel boats.)
You asked what pressure that inspection cover could hold before breaking. I don’t know the answer, and in any case, it would depend on the age and condition of the plastic. We all observe the degradation of plastic with age, particularly if in sunlight, which it is not in this case. However, leaking is another issue entirely.
To my experience of those hatches, they are most commonly applied, and probably designed, as an inspection opening for the floatation tanks in dinghies. The inside of those tanks is intended to be dry, and normally is pretty close to dry. If the dingy capsizes, the water is on the outside of the hatch, unlike our inspection hatch situation as described above. The hatch is held in place by a coarse thread in the plastic which is unlikely to play any part in sealing against water flow. Instead, the hatch cover is sealed by that rubber o-ring. The o-ring seals by distorting under the pressure being sealed so it seals against the surrounding surfaces. The ring, without pressure, has to be loose enough for you to screw in the hatch. It’s a little complex to picture or describe, but I would expect that o-ring to seal well against water pressure on the outside, but not so well against water from the inside. But it is highly dependent on the clearances or interferences when the hatch is screwed in place. When you inspect the ring with the hatch removed, it will have relaxed to its normal dimensions and will not be damaged unless it has been cut out nicked at a previous time.
In “normal” use the hatch is quite adequate as it only has to deal with splashing or surging in the keel box as the boat moves up and down in waves. Only a monetary pressure, not sustained. I suspect mud drying sufficiently to plug the keel case as described above is a combination of mud properties and drying height that no one ever anticipated. All the pictures show boats drying out on clean level sand, with the kids at play. With softer mud, it would not go higher than the water level outside, and would flow/fall out with the normal boat motion when the boat refloats.
You asked whether there are other hatches available. We have a similar looking but made of metal hatch over the rudder post for the emergency tiller. It would certainly be stronger, it would it seal any better? It depends on the clearances around the o-ring when the hatch is tightened. Not much help I know.
I don’t know if this is of any help. To me, problem is clearly due to the mud solidifying into a semi solid state while dried out. But when faced with these conditions, it is really difficult to see what to do. Your revival of this thread may prompt others to think more about it while we are all under lockdown.
I hope that this all translates well for you, but don’t hesitate to come back with questions if you need any clarification.
rene460
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Post by ejk on Apr 12, 2020 12:34:44 GMT
Chere René, Merci bien pour l‘information, c‘ etait tres bien traduit. A bientot, enno
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Post by yak on Apr 17, 2020 5:17:34 GMT
Hello, We had the same problem with our Sun Odyssey 35 lifting keel last year. We are sailing on the German North Sea coast and in the 1st harbour with soft mud a lot of water pressed itself over the crank mechanism into the ship. But we could solve the problem successfully and today we have no more problems. Apparently there are different ways of catching up the lifting keel by Jeanneau, but I think the principle of why water gets into the ship and how to solve it should be the same. Unfortunately I have little time right now but will try to write our solution in the next few days. Maybe it will also help in your case Greetings Yakomo
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Post by yak on Apr 27, 2020 12:17:45 GMT
Hello, I found this topic due to the same problem I experienced with my new build SO 389, first season, Germany. We regulary use a Harbour that always dry out completely, but the ground is not hard sand but muddy. We experienced always water coming trough the inspection cover, it is quite a lot, the automatic pump is working every 30 min during the low tide period. We opened up the inspection cover later to check for failure, but it always looked fine. My dealer send me a new inspection - just in case something is wrong with the original one. My question is : Is there any information about the pressure that an inspection cover can bear? Any ideas how high the pressure is inside the keelbox when grounding in muddy ground? Are there any more stable inspection cover? Thanks Enno Hello Enno, maybe our solution will help you. Our SO35 has a crank mechanism to move the lift keel up and down. As far as I know the same mechanism is used in the SO389. Above the inspection hatch there is an overflow with a hose which is supposed to drain off water when it dries up. Unfortunately Jeanneau directs the overflow to an outboard valve which is located in the bottom of the ship directly next to the centreboard box. If you fall dry on sand everything seems to be okay. But if you fall dry in soft mud a lot of mud is pressed into the centreboard box and at the same time the valve is blocked by the mud. The water is pressed upwards to the crank mechanism. The inspection hatch cannot hold this pressure, but even if it could, the water would escape through the bearing for the crank . Jim Dew has already described the solution in: Hints and Tips - Hull, Deck & Steering - Sun Odyssey 35 Swing/Lift Keel - Sun Odyssey 35 lift keel review and tips. He installed a new valve. I didn't want to install a new valve, so I looked for another solution. My first try was to use the hose of the bilge pump via a 2-way valve. Unfortunately this didn't work, because the hose of the bilge pump comes from the bilge goes up behind the bank until above the waterline, runs from there to the aft and goes outboard via a gooseneck. The hose runs higher than the highest point of the crankcase/inspection hatch. The static pressure becomes too high and a lot of water continued to enter the boat. On the SO35 is in the wet room one valve for the wash basin and one valve for the shower just above the waterline. I thought about using the shower valve to drain the centerboard. For this the shower water is led via a 2-way valve to the wash basin valve. One difficulty was to find a way for the hose below the waterline to the old shower valve. Fortunately the frames have holes for the bilge water and after a little bit of poking I could use them. It was pretty difficult to come to the wet room but in the end it worked. Today we have a dry bilge. For us this is it important because we lie in a harbour with soft mud which is dry 2 times a day. Kind Regards Yak
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Post by 131dom on Apr 27, 2020 13:09:41 GMT
Hi, I was doing some research recently on buying a sun 2000 with lift keel. They mentioned exactly the same problem as youve had. Unfortunatly their inspection cover busted open and mud and water sprayed all over the boat. There obviously is a problem in the design as i have not heard of this pressure build up in other boats lifting keels? I hope you can find a suitable solution.
Dom
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Post by MalcolmP on Apr 27, 2020 13:11:32 GMT
Excellent write-up and very logical modification to avoid this issue. Thank you for sharing, may I add it to Hints and Tips? as that will help others in the future, it seems a far from infrequent occurrence for those drying out in mud.
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Post by yak on Apr 27, 2020 14:34:10 GMT
Excellent write-up and very logical modification to avoid this issue. Thank you for sharing, may I add it to Hints and Tips? as that will help others in the future, it seems a far from infrequent occurrence for those drying out in mud. I'm glad you like it, of course you can add it to Hints and Tips
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Post by MalcolmP on Apr 29, 2020 10:08:43 GMT
Excellent write-up and very logical modification to avoid this issue. Thank you for sharing, may I add it to Hints and Tips? as that will help others in the future, it seems a far from infrequent occurrence for those drying out in mud. I'm glad you like it, of course you can add it to Hints and Tips Thanks, now published at: www.jeanneau-owners.com/hintsandtips/liftkeelleak.html
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rhino
New Member
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Post by rhino on Mar 27, 2021 18:55:12 GMT
Hello, I found this topic due to the same problem I experienced with my new build SO 389, first season, Germany. We regulary use a Harbour that always dry out completely, but the ground is not hard sand but muddy. We experienced always water coming trough the inspection cover, it is quite a lot, the automatic pump is working every 30 min during the low tide period. We opened up the inspection cover later to check for failure, but it always looked fine. My dealer send me a new inspection - just in case something is wrong with the original one. My question is : Is there any information about the pressure that an inspection cover can bear? Any ideas how high the pressure is inside the keelbox when grounding in muddy ground? Are there any more stable inspection cover? Thanks Enno Hello Enno, maybe our solution will help you. Our SO35 has a crank mechanism to move the lift keel up and down. As far as I know the same mechanism is used in the SO389. Above the inspection hatch there is an overflow with a hose which is supposed to drain off water when it dries up. Unfortunately Jeanneau directs the overflow to an outboard valve which is located in the bottom of the ship directly next to the centreboard box. If you fall dry on sand everything seems to be okay. But if you fall dry in soft mud a lot of mud is pressed into the centreboard box and at the same time the valve is blocked by the mud. The water is pressed upwards to the crank mechanism. The inspection hatch cannot hold this pressure, but even if it could, the water would escape through the bearing for the crank . Jim Dew has already described the solution in: Hints and Tips - Hull, Deck & Steering - Sun Odyssey 35 Swing/Lift Keel - Sun Odyssey 35 lift keel review and tips. He installed a new valve. I didn't want to install a new valve, so I looked for another solution. My first try was to use the hose of the bilge pump via a 2-way valve. Unfortunately this didn't work, because the hose of the bilge pump comes from the bilge goes up behind the bank until above the waterline, runs from there to the aft and goes outboard via a gooseneck. The hose runs higher than the highest point of the crankcase/inspection hatch. The static pressure becomes too high and a lot of water continued to enter the boat. On the SO35 is in the wet room one valve for the wash basin and one valve for the shower just above the waterline. I thought about using the shower valve to drain the centerboard. For this the shower water is led via a 2-way valve to the wash basin valve. One difficulty was to find a way for the hose below the waterline to the old shower valve. Fortunately the frames have holes for the bilge water and after a little bit of poking I could use them. It was pretty difficult to come to the wet room but in the end it worked. Today we have a dry bilge. For us this is it important because we lie in a harbour with soft mud which is dry 2 times a day. Kind Regards Yak
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rhino
New Member
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Post by rhino on Mar 27, 2021 19:29:38 GMT
Hi All - Im looking at this thread as I'm considering buying a lift keel SO35-38, mostly because drying out is a tremendous cost advantage long term [as well as shallow creek crawling]. I note the new JSO lift keels on offer can't dry out and does not give much more than a shoal keel ! So imho its a pointless design.
My first thought re the problems cited here is what a mess ! Is this the best J can come up with ?
I previously had an old Southerly which had to be refurbished so I am no stranger to issues, but this looks very unsatisfactory.
If water is getting into the boat via the top drain pipe [because of mud blockage] or bursting, why not discharge this hose direct into the bilge as an open end and let the bilge pump do its stuff ? Better still connect it to a powerful water main hose and blast it back occasionally to clear the crud !
Surely there is a better way of raising the JSO keel ? J have great designs but there is so much that could be better. I note a small 12v rope winch can be bought [£120+/-] that will lift the required weight and would take about 8 secs. Plus a trip could be added to prevent overload etc and even be wired to the helm. Mon petit chien - surely not ?
If Elon Musk can get a Starship shaped like a water tank to fly 6 miles high, then surely Jeanneau should be able to electrify their keels as an option and lift it 250mm. Even a simple line/cable in a rigid pipe led back to a cockpit winch should be possible ? PS I'm really looking forward to them offering twin keels and twin rudders as it solves: draft, tilt and drying out, cradle hire, cleaning etc etc....... no rudder damage and no lifting keels ! Do you think 2021 might be the year they adopt my suggestion for happy cruisers ? Twin electric props driven would also help parking !
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