Keel bolts

[panthablue]

Last winter I went to the London Boat Show. I was looking over one of the boats there and got into discussion with the sales guy, and somehow I was allowed to look under the floorboards in main cabin.

When I looked, I was rather surprised to discover that the keel was held on with traditional keel bolts.

Could someone tell me is this normal these days?

I sail a steel boat, and the keel is nicely welded on thank you, and I haven't sailed anything else for about 20 years. I've never given it much thaught, but recently I got into discussion with some sailing friends and the subject came up.

I'm rather surprised that the world hasn't moved forward from this basic weak design, particularly as keels seem to be getting longer, with heavier weights hanging on the end.

Could anyone comment on this?

no it's common and the only way on all but metal boats, allthough I think some crappy boats once moulded a keel with hull, so all you massive run builders still use studs cast in, Bit of a misnomer (keel bolt) when in actual fact they are really studs, and often only cad plated steel, we have had forums here on this, so you should maybe search, keel bolts
what stuns me, is , why on earth you should NOT be allowed to pul any boat to bits to poke into any corner, its the builders obligation to show all

[Guest625101138]

The Custom 30 fibreglass yacht built in Perth in the 70s had a deep keel that was moulded during the initial layup. My understanding is that molten lead was poured into the keel after it had cured.

At least one boat I know of had keel delamination problems in the hot zone after about 10 years. I do not know if this was a common problem. I have no idea if there was any effort to keep the fibreglass cool during the cooling phase.

Most of the fibreglass keel boats I know of have bolt-on keels. I have heard or read of leadshot being used by just pouring into resin inside a moulded keel.

Rick W.

[panthablue]

This all sounds a bit depressing. Modern sailing boats have loads of technology stuffed into them, from hull shape, to sails, to electronics. It seems unbelievable that such a basic item has not been developed.

Anyway, just to prove I'm a closet nurd/designer, I couldn't resist having a go at improving this. See attached

[raw]

Looks like you have solved a simple problem with a complex solution.........

From what I can see:
a) your solution does the same thing
b) is more complicated
c)will be more expensive
d)is less adjustable to curve in the hull or imperfections
e)relies on grub screws to absorb the entire load over a very small area of metal. They will eventually create some indentation, and therefore slack in the system. Do not underestimate the loads involved. Loads on keel boats will be several times the magnitude of the keel weight itself due to moment/coupling effects.


The simplest solution is often the best.....

[panthablue]

Don't hold back RAW, just say what you think.

[raw]

I thought I did

Pantha, I thought same, I think though your talents are wasted doodling with these things, now I could find you a job guiding me thru dwg maze, cept you would not get paid, but you would benefit from my wit, kindness, even tempered approach, ferget plastic boats, join us men)

[charmc]

Pantha,

Your keel attachment is different and original, but did not appear (unless there is more to it than I could see in the sketch) to offer any significant advantage over well set keel bolts/studs. I think the stresses would be concentrated in the attachment area in the same way. The deep rods would have far more strength than conventional keel studs, but I'm not aware of keel studs failing deep inside the keel.

I admire your thinking, but I don't think your solution is a big advance (yet). It's good to think about those things, but, in this case, it's somewhat like through bolting chainplates and cleats with backing plates. Simple, low tech solution ... but it works.

Your asking "why no changes" is great thinking, though.

Don't take lazeyjack up on his offer. Besides no pay, you'll be forced to listen to countless sea stories and endless lectures on the superiority of Russian ... everything. (He's right about the wit and kindness, though. He's a good guy ... for a boring old Ozzie)

Originally Posted by charmc;

Pantha,

Your keel attachment is different and original, but did not appear (unless there is more to it than I could see in the sketch) to offer any significant advantage over well set keel bolts/studs. I think the stresses would be concentrated in the attachment area in the same way. The deep rods would have far more strength than conventional keel studs, but I'm not aware of keel studs failing deep inside the keel.

I admire your thinking, but I don't think your solution is a big advance (yet). It's good to think about those things, but, in this case, it's somewhat like through bolting chainplates and cleats with backing plates. Simple, low tech solution ... but it works.

Your asking "why no changes" is great thinking, though.
Get it Right Charles, I am not an Aussie, , bye the way, did you see we planted our flag down there, in the deep> oh and MIG still holds record for fastest and best fighter jet, , )

Don't take lazeyjack up on his offer. Besides no pay, you'll be forced to listen to countless sea stories and endless lectures on the superiority of Russian ... everything. (He's right about the wit and kindness, though. He's a good guy ... for a boring old Ozzie)

\\
Get it Right Charles, I am not an Aussie, , bye the way, did you see we planted our flag down there, in the deep> oh and MIG still holds record for fastest and best fighter jet, , )

[charmc]

What's this "we" stuff, Stu?

Originally Posted by charmc;

What's this "we" stuff, Stu?

I jumped ship, chucked away my Eu and NZ, passports and took up with old Pute,
Actually my heart bleeds for my Ru friends, the towns, like Moscow St Pete Vladimir and the tourist places are ok, but the rest is in ruins, they work so hard, I try to really understand by mixing, , I could not mix in the South , Louisiana, New Mex, Alabama, nuff said, On dangerous ground here
Jus joking abt passports
big smile BXB, stocks went up 11% today, I have some,
now what was the good oil on the keel fixing?