chainplate hump

[ronassis]

Good, I'm glad the doom mongers not familiar with the design have been foiled!
I'm a bit puzzled by one thing. You said there was a hump; how could this be caused by the U bolts being overtightened in assembly? That would give you a dip in the deck surely?
I didn't see any hump or dip or gel coat cracks on my SO32.
One thing to be aware of, it is not overall the stiffest of hulls. Following the procedures in the Selden book and using a Loos gauge, I ended up with the rigging at just about the maximum permissible tension but in brisk upwind sailing the leeward side would still go slack.
Do you know the owners forum, http://www.jeanneau-owners.com/ , lots of info on their including some interesting SO32 mods such as mainsheet traveller, adjustable backstay etc.
Nice cruising boat. Have fun.

Hi Plevier....................I think what he meant was that the tightness of the Ubolts had kept them pulling down allowing the deck perhaps to rise slightly in between them as they were squeezed somehow by the forces at work. I'm not sure if there is a plate under the plastic covers on deck that are over the ubolts don't really want to disturb anything else.
Maybe a stainless steel plate on topdeck would have stopped the squeezing.
I seem to get only very slightly less tensioned leeward shrouds going upwind and have had the rig checked each year by the riggers. How loose do yours get?
I am indeed on the jeanneau forum but in this instance the YBW forum has been more interesting. Also made various changes to the mainsheet arrangements so I can alter and dump the main from the tiller whilst steering, much safer and controllable than the original coachroof arrangement. But this is another thread.
All the best Ron

 

[Plevier]

I think the U bolts do have a plate above deck.
On the wind my lowers would go very slack and the capstays would be almost tension free in a good breeze. Accentuated by my pulling backstay on I guess.
It was a lift keel one, don't know if that could affect hull stiffness, can't see why it should.
I sold it to Christchurch, not many 32 footers can get in there!

 

[Concerto]

Slack lee shrouds should not occur, so it is an indication there is a rig problem. It is either not tensioned enough or when under load the mast is not being fully supported (if deck stepped) and is dropping/pushing downward or the deck at the shrouds is lifting or moving toward the mast. It may be just flexing in the hull form, but personally I would investigate further. Slack rigging can cause metal fatigue and ultimately rig failure. Go back to the riggers and ask for their opinion.

 

[30boat]

Slack lee shrouds should not occur, so it is an indication there is a rig problem. It is either not tensioned enough or when under load the mast is not being fully supported (if deck stepped) and is dropping/pushing downward or the deck at the shrouds is lifting or moving toward the mast. It may be just flexing in the hull form, but personally I would investigate further. Slack rigging can cause metal fatigue and ultimately rig failure. Go back to the riggers and ask for their opinion.

A masthead rig will always show some slack on the leward shrouds when the boat is healed beyond 15ºor so which doesn't mean it hasn't been tightened to specs.When stationary the rig should be taught.It's the fractional aftswept rigs that should remain tight under those conditions because they need higer tensions to stay in place.

 

[dulcibella]

Some strange things are found on some older boats. My previous boat was a Halmatic 30, well regarded as an ocean-going 9m long keeler. This also had a deck hump around the U-bolt attachment for the inner shroud. I ignored it (hoping that it would go away), only to notice during a windward Biscay crossing that on each roll a rectangular flap of deck was lifting a fraction of a mm. I rigged a heavy line from the shroud base through the windward genoa sheet car to a spare winch and cranked it up to provide extra support. After getting back to Portsmouth via the Azores I removed the flap to see what was going on. The shroud was entirely supported by a postcard-sized plate of aluminium laid up in the deck This plate had corroded and the expanding mass of corrosion produced the deck hump. Needless to say, I replaced this and its opposite number with proper chain plates attaching to a bulkhead.

 

[Leighb]

Some strange things are found on some older boats. My previous boat was a Halmatic 30, well regarded as an ocean-going 9m long keeler. This also had a deck hump around the U-bolt attachment for the inner shroud. I ignored it (hoping that it would go away), only to notice during a windward Biscay crossing that on each roll a rectangular flap of deck was lifting a fraction of a mm. I rigged a heavy line from the shroud base through the windward genoa sheet car to a spare winch and cranked it up to provide extra support. After getting back to Portsmouth via the Azores I removed the flap to see what was going on. The shroud was entirely supported by a postcard-sized plate of aluminium laid up in the deck This plate had corroded and the expanding mass of corrosion produced the deck hump. Needless to say, I replaced this and its opposite number with proper chain plates attaching to a bulkhead.

I also own a Halmatic 30, and noticed a modest hump appearing around the port cap shroud chain plate. Investigation should that the load was taken entirely by the deck moulding with only a relatively small stainless plate below the deck. It did not progress like yours though.

I had the yard fabricate right angle brackets with webs to take the load from the chainplates into the hull topsides. I feel much happier having done this. I felt that in my case the bulkhead was not sufficiently strong on the port side as it is only a partial bulkhead compared to the starboard one.

I believe this a known weakness of this design?