Ok how screwed am I?

[er9]

I realized this evening that my bulkhead just in front of my mast has lifted 1/4" on both sides from my cabin sole and is taking the cabinetry with it slowly. i noticed it a long time ago after i bought the boat but wasn't experienced enough to realize what could be tyhe problem. It was like this when i bought the boat and appears to have been like this for some time. It doesn't appear to have gotten any worse or suddenly changed but now i know its a serious problem.

After doing research i was inclined to believe it could have been that the support bar/compression bar (i have keel stepped mast) that runs from my keel to interior coach roof was loose allowing the deck to pull upward when sailing taking my bulkhead with it.

well when i got home tonight i took a closer look and realized it was very loose. after giving it a few good yanks i was able to completely rip it and its connection right out of my corroded aluminum mast base. so i guess i was right.

i obviously need to completely re-build my mast step now. i knew i had to but didnt think it was this severe and could wait a while. now my question is...if i pull the boat out of the water, set it on its keel, re-step the mast, replace the compression rod (i know its not a compression rod, forget name) will the bulkhead re-settle and all is good or do i need to also re-build bulkhead?

tabbing on both sides of the bulkhead where it attaches to the hull look good and do not show any signs of movement. the only separation seems to be at the bulkhead where it meets the floor mainly towards the center of the boat closest to the mast.

obviously no more sailing until this project is finished but is the boat safe and sound just sitting in a slip until i can arrange haul out in a couple months or so?

i assume it will only get worse if i actually stress the boat sailing it?

any advice, insight, nerve calming will be appreciated.

[gamayun]

Ah, dang, ER. I hate to hear this. It sounds like a big job, but just know that worse things have been done to a boat and tabbed back together again like new (is that calming -- I do hope so!). I 'm sure you'll get really great advice here, but my recommendation is to find a specialist in your area with good references who has done similar structural repairs and can put eyeballs directly on the boat, even if it's just to advise you if you're planning to fix it yourself. Pay an expert for how to do this right.

If you're worried about it doing more damage in the interim, I suggest taking the boom and sail off now to reduce that weight, especially if you get a big storm and it pumps the boom. My only direct experience with stuff like this are bulkhead reinforcements that have been done to Cal20s to make them a little more sturdy for offshore sailing. You might find some useful ideas if you were to do a little Googling on "SF Bay area Cal20 upgrades." Good luck!!!

[Don C L]

OK, I don't know the Mariner 36, but I am guessing the upper shroud chainplates go through the deck and bolt on the main bulkhead that is tabbed from the deck down to the keel, but the lowers are mounted on smaller bulkheads tabbed in to the hull, yes?
First, I think you are fine to move the boat around the harbor and keep her in the slip. Even if the shrouds are loose, the mast won't fall down.
Now, remembering I am no engineer, I'd keep in mind that the keel stepped mast with shrouds bolted to the bulkheads are trying to separate the bulkheads from the hull, attempting to lift them off the hull with a force around the same as the displacement of the boat in a high stress situation, if I understood my research on the topic some time back. It would be nice to see some photos. There will be some down time, literally and figuratively for your mast, but you can probably do as I did, if you have room at your slip and lay the mast down on the boat while you work on her, or actually it's probably too long so you may have to store it at a yard while you rebuild the mast step. Now I am flying blind here but I think you will need, once the mast is off, to draw the cabin top and bulkhead back down to repair it, I kinda doubt it will settle back down. Diagrams and photos will help a lot, and there is a lot of GREAT help available here from REAL engineers, so FEAR NOT, everything can be fixed!

[JPA Cate]

If you tell us approximately where you are, someone may be able to recommend a surveyor. You do have a serious situation there, which your intuition accurately informed you of. You will want help assessing it, and possibly want direction repairing it; it is appropriate to pay for both.

Sorry to bear bad tidings, but, imho, best to face up to misfortune.

Ann

[Don C L]

Ok, just a thought, on looking at sailboatdata, this must be the Canning model, right? And that is a fairly flat bottom boat, and since you are saying the bottom of the bulkhead has the tabbing separated, but the rest is fine, it sounds like maybe the compression force of the mast may have been pushing the hull down at the keel away from the bulkhead there, i.e. the hull there flexed enough there to allow it but while it was flexing out there it was trying to compress on the hull sides which would account for the tabbing on the sides being fine. If so, once out of the water I would guess yes the bulkhead would join the hull again as the keel is pushed up by the boat's weight. Btw, has there been any leakage near the forward edge of the keel by chance? Any cracks in the hull there visible?

[DumnMad]

It may not have occurred during sailing.
If it hasn't moved for a long time maybe it was caused by the PO tightening the shrouds excessively and once the bulkhead moved the shroud tension was eased and stresses are back in reasonable equilibrium. Do things move or are they firm ?

[edgaroviz]

I know these are different boats but my mariner 39 has a mahogany mast stem connected to 2 bilge bulk heads. why not use a wooden mast step or a wooden fiberglass reinforced mast step?

might lower your overall costs of building/getting a proper mast step. i've just been fiddling with mine as it was painted and all I did to renew it was remove the paint and add a layer of epoxy instead of paint.

[El Pinguino]

Originally Posted by er9

...

i obviously need to completely re-build my mast step now. i knew i had to but didnt think it was this severe and could wait a while. now my question is...if i pull the boat out of the water, set it on its keel, re-step the mast, replace the compression rod (i know its not a compression rod, forget name) will the bulkhead re-settle and all is good or do i need to also re-build bulkhead?

....

any advice, insight, nerve calming will be appreciated.

This sounds not unlike my issue when the baby stay started lifting the central part of my frd saloon bulkhead... a design fault in Westerly Sealords and also possibly Oceanlords.... which was tabbed to the deckhead but not to the cabin sole....

Anyway.... once the problem itself was sorted cranking down on the new 'compression thingamabob' brought the bulkhead back down to where it belonged.

Second photo... thwartships 'bulkhead' at the base behind that lower fitting was where the centre bit of the 'bulkhead' together with that fore and aft dunny door bulkhead had lifted about 10cm before being hauled down again.... sorry but I can't find a 'before' photo.

PS photos of what you are dealing with would be good..

PPS... good luck!

[er9]

Originally Posted by gamayun

Ah, dang, ER. I hate to hear this. Good luck!!!

much thanks...boom will have to come off anyways to pull mast so probably a good idea to remove it now...i was thinking same and its something i can do myself in the slip.

[er9]

Originally Posted by Don C L

OK, I don't know the Mariner 36, but I am guessing the upper shroud chainplates go through the deck and bolt on the main bulkhead that is tabbed from the deck down to the keel, but the lowers are mounted on smaller bulkheads tabbed in to the hull, yes?
First, I think you are fine to move the boat around the harbor and keep her in the slip. Even if the shrouds are loose, the mast won't fall down.
Now, remembering I am no engineer, I'd keep in mind that the keel stepped mast with shrouds bolted to the bulkheads are trying to separate the bulkheads from the hull, attempting to lift them off the hull with a force around the same as the displacement of the boat in a high stress situation, if I understood my research on the topic some time back. It would be nice to see some photos. There will be some down time, literally and figuratively for your mast, but you can probably do as I did, if you have room at your slip and lay the mast down on the boat while you work on her, or actually it's probably too long so you may have to store it at a yard while you rebuild the mast step. Now I am flying blind here but I think you will need, once the mast is off, to draw the cabin top and bulkhead back down to repair it, I kinda doubt it will settle back down. Diagrams and photos will help a lot, and there is a lot of GREAT help available here from REAL engineers, so FEAR NOT, everything can be fixed!

Thanks Don...its a Peter Canning Mariner.

correct the chainplates go through the deck. The main upper shrouds attach to the bulkhead that is lifting, the two lowers actually are attached to two massive stringers that are glassed to the inside of the hull.

I was reading another forum that when the deck and hull deform from compression rod becoming out of adjustment or when it needs to be replaced the boat should be hauled and set on the keel, shrouds loosened, compression rod tightened and then standing rigging tuned. sitting it on its keel supposedly sets the hull back in alignment by letting it settle to its natural shape but thats something i'm not sure about and like you say might need to be drawn together. may not know the answer to this one until its out of the water unfortunately. i have a slip at a haulout yard so taking her out of the water is easy.

it appears to be that this bulkhead that has moved just rests on top of the flooring and to the best of my knowledge is not attached to it in any way i can tell except where it ties into the cabinetry. i will try and snap some pics of tabbing in the morning but the tabbing starts just above the level of the floor and continues up to the deck level.

in pics you can see seperation of edges of bulkhead port and stbd. its lifted maybe 3/16" to 1/4".

will take pics of tabbing but my gut guess from observing it is the tabbing is holding the bulkhead in place and maybe the center of the hull is being distorted downward?

the pics are port and stbd side of the bulkhead wall just left and right of the mast at the center of the boat hallway that leads to the v-berth.

[er9]

Originally Posted by JPA Cate

If you tell us approximately where you are, someone may be able to recommend a surveyor. You do have a serious situation there, which your intuition accurately informed you of. You will want help assessing it, and possibly want direction repairing it; it is appropriate to pay for both.

Sorry to bear bad tidings, but, imho, best to face up to misfortune.

Ann

los angeles.

much thanks. yeah im out of my league with this one. i definately need help assessing this properly.

[JPA Cate]

Hi, again, er9,

I could be wrong in your instance, but we had a structural failure in our first "Insatiable", and it had to be fixed in the water, because that shape is the one the boat naturally assumes in the water, with the keel pulling down.

There are many forces involved, and it is too complicated for simple me, and I hope you get it sorted.

Good on ya for facing up to it. It takes some gumption.

Ann

[er9]

Originally Posted by Don C L

Ok, just a thought, on looking at sailboatdata, this must be the Canning model, right? And that is a fairly flat bottom boat, and since you are saying the bottom of the bulkhead has the tabbing separated, but the rest is fine, it sounds like maybe the compression force of the mast may have been pushing the hull down at the keel away from the bulkhead there, i.e. the hull there flexed enough there to allow it but while it was flexing out there it was trying to compress on the hull sides which would account for the tabbing on the sides being fine. If so, once out of the water I would guess yes the bulkhead would join the hull again as the keel is pushed up by the boat's weight. Btw, has there been any leakage near the forward edge of the keel by chance? Any cracks in the hull there visible?

interesting...i do have a catalina smile but zero leakage.

as far as i can tell i cant see any tabbing below the floor level but a lot of it is not visible so its possible there are areas where its seperated? i would need to do some demolition to be able to see it all. even then not sure i could get 100% visibility of all bulkhead edges without completely tearing boat appart. depressing thought...

its so hard to tell. i cant tell if the bulkhead is lifting or the floor is being pushed down in that area.

keep in mind that my tension rod that attaches from my mast step to the coach roof is completely un-attached now and was so corroded i think for a very long time that it did not stop the coach roof around the mast from pumping when sailing.

[er9]

Originally Posted by DumnMad

It may not have occurred during sailing.
If it hasn't moved for a long time maybe it was caused by the PO tightening the shrouds excessively and once the bulkhead moved the shroud tension was eased and stresses are back in reasonable equilibrium. Do things move or are they firm ?

the floor seems to have sagged maybe an 1/8" under the port settee thats up against this particular bulkhead and the hallway flooring squeaks more than it did two years ago. i'd have to say yes things have moved a little in the two years ive had her but nothing drastically that ive noticed yet. shroud tension seems reasonably consistent. dont notice that they have gotten much looser.

[er9]

Originally Posted by edgaroviz

I know these are different boats but my mariner 39 has a mahogany mast stem connected to 2 bilge bulk heads. why not use a wooden mast step or a wooden fiberglass reinforced mast step?

might lower your overall costs of building/getting a proper mast step. i've just been fiddling with mine as it was painted and all I did to renew it was remove the paint and add a layer of epoxy instead of paint.

thanks for the suggestion but i dont mind spending the $$$ to have a new aluminum step machined. i'm guessing the bottom few inches of the mast will have to be removed anyways so a custom step will be in order. thats the least of my worries...guess my sinking gut feeling is mostly from the unknows at this point as far as structural integrity of bulkhead.