Keel replacement

[Deleted]

Hi,

I have been thinking to replace my shallow keel by a deep one. Is there anybody who wants to share some experiences with me. Then, if it is possible I have to get this replacement keel somewhere. Any ideas if Jeanneau can supply it for a SO36 from '91. Or is there a second hand market for older boats available?

[rfreeland]

Hi, I have a 49DS and I'm also thinking of changing the keel to the 49 performance keel (and performance mast). Did you find a good source to obtain your replacement keel?

[Deleted]

No, there was no response whatsoever.

[MartyB]

I dought this place will work for rfreeland, maybe marien depending upon where you are. On the east coast of the US is Mars Keel. They can modify or build you a new keel, and do somenew keel building for some of the local manufactures. Last I heard they had been doing some of the Bene first series keels. Shipping etc would kill someone to Europe.

I would think, if you could find out where the keels in France were made for Jeanneau, you might be able to ship the old keel there, they melt it down and recast the iron in the mold for the deep keel. On the other hand, adding lead as Malcolm mentioned in another thread, would actually get you some more leverage for righting moment, or Mars will take the iron bulb, and make it a lead one. Again, it will not be as light, but righting moment will be stronger, and you will have in the end a stiffer boat.

Marty

[renegade27]

I inquired with Jeanneau US about getting a "standard" keel and rudder shipped over here for my SO35. It was $7K - I think $4k for the parts and $3k for shipping. I haven't done this.

Also spoke with Mars Keel. They were cautioning me to have a designer check the suitability of the keel and generally made it sound as though they weren't excited about making a keel for me or selling me a keel close to the weight/ depth needed.

[davideso37]

Response for rfreeland,
The Jeanneau part site is a great place to look for parts and it has both keel for the DS49 shown although the detail says 48. Not cheap at 17,000 euro but it is the real thing.
I wish we had a manual for the yachts as detailed as the parts list on the web site. It is a mine of information.
www.jeanneauparts.com/index.php?cp_sid=156508172c0f&cp_tpl=main
Regards
David

[davideso37]

Post Script.
Forgot to mention the page loads real slow but be patient, make a cup of tea or check on the price of your shares and come back to it. Well worth the wait.
David

[lcochrane]

I have an SO 34.2 with shallow draft bulb keel and have had it lengthened from 4' 3" to 5' 4" by adding a hardwood stub between the existing keel and hull and replacing keel bolts. All glassed over and works very well.
Much cheaper than replacing the keel and works well to stiffen the boat up. Adding only 1 foot does not alter the dynamics much (if at all) and no need to modify rigging

[davideso37]

Does the SO34.2 have a moulded sump that extends into the cast iron keel and if so how did you work around that? I have thought about the same idea of extending my keel by around 300 mm but I would want the keel bolts and additional hull stiffening in way of the keel bolts designed by a qualified Naval Architect.
Regards
David

[MartyB]

I had not thought about adding some wood or equal in the middle........might work well actually, or take a new piece of iron......hmmmmm.......

Not sure an NA would be who should redesign this, or a really good engineer with appropriate credentials might be better actually, as some NA's/building architects do refer to engineers for some of the verifying of some things, that is beyond their schooling etc.

Marty

[lcochrane]

It does have a moulded sump which we recessed into the timber

[davideso37]

Thank for the response. I presume your yacht is now stiffer than the standard 34.2. Must be awesome in a breeze.
Regards
David

[MalcolmP]

May 22, 2012 23:29:00 GMT lcochrane said:

I have an SO 34.2 with shallow draft bulb keel and have had it lengthened from 4' 3" to 5' 4" by adding a hardwood stub between the existing keel and hull and replacing keel bolts. All glassed over and works very well.
Much cheaper than replacing the keel and works well to stiffen the boat up. Adding only 1 foot does not alter the dynamics much (if at all) and no need to modify rigging

Did you also increase the depth of the rudder? I have had shallow draft Beneteau's and Jeanneau's and typically the factory removes around 6" of the standard drafts rudder tip to ensure that the rudder is not deeper than the keel, but in my opinion this does loose some critical grip at higher angles of heel

M

[lcochrane]

No- the rudder is the same length. I haven't found any problems with handling yet but admittedly I have not yet been out in any strong breezes.
I guess I could modify it if necessary

[davideso37]

Just finished reviewing this report from a keel loss in 2008.
www.tamus.edu/assets/files/communications/cynthiawoods/Appendix-E-Dobroth-Design-Science-Report.pdf
The article reinforces the need to have a Naval Architect do the design calculations for any keel modification. Also category 1 & 2 races require the that any significant modifications be certified by either the EC Recreational Directive for Category A of the ABS guide for Building and Classifying Offshore Yachts. A deeper keel is certainly a significant modification.
David

[MartyB]

David,

I'm not getting that report to show up.

I still wonder if a person changing out from a std shoal, to the same std deeper draft keel would need all the engineering. Some boat manufactures use this option as a selling point, ie that one can change as needed from a shoal to a deep and back. That would tell me the boat hull should handle the stress assuming one is more than the other, of the higher stress keel. I could see that being the shoal keel, as they many time actually weigh more by many lbs vs the deeper one. Then again, the deeper one has a lower center of gravity.......potentially more stress due that that issue to

Marty

[davideso37]

Marty,
Loads OK for me and on different computers. It is a big file.
Regards
David

[MartyB]

Yeah, it was a BIG file, needed a minute or two! forgotten about that keel loss fiasco! Never had seen the actual report either. So should be some good reading later. Up for a bit, then off to a BC fund raiser race. Need to mover the boat 2hrs south, etc.

Marty

[tedp]

I agree to Marty's suggestion that changing from a standard to a deep draught keel for the same production hull shouldn't matter as the hull should be able to handle the deep keel.

I have also read the report on the Cynthia Woods disaster, and it rung a bell as one of the members on the Dutch language Jeanneau forum reported some flexing in the keel attachment on his 1991 Jeanneau Sun Way 25. This was thought to be due to the thickness of the hull around the keel attachment. Photos of the keel bolts and backing plates can be seen HERE.

I advised him to have the bottom strengthened around the keel, for safety's sake.

[davideso37]

Tedp,
Deeper keels need more structural strength in the hull for both the broach loads and the grounding loads. For the sake of peace of mind any change should be certified by the designer or another qualified person to the same or an equivalent design code. If the designer says OK that standard production hull is designed for that standard keel option then the cost should be not much more than a phone call. Anything else will get expensive.
Regards
David

[tedp]

Yes, I agree to that. But in the case of the Sun Way 25, as far as I know, it concerns a standard keel, not a modification. I think the attachment may have weakened through repeated grounding or other accidents. The owner said the 4ft keel could be moved sideways about 2 inches at the bottom, without any sign of leaks, which may indicate severe weakness of the hull.

But I am unable to reach the owner any more. I hope he replies to my latest post on the Dutch forum.