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S&S Swan General - Swan 40 Bulkheads
20 January 2021 - 07:05
#1
Join Date: 18 November 2008
Posts: 4

Swan 40 Bulkheads

I posted on this matter about twelve months ago, and thanks for the responses.  The problem is that the bulkhead on my Swan 40 #26 (1972) creaks alarmingly when the vessel rolls.  I have now removed the linings around the bulkhead, and can find no evidence of any movement or problem with the bulkhead/hull bonding.  The yard I use here (very good) have also examined the bulkhead,and are as bemused as am I.  As the noise seems to be linked to rolling, I am wondering if the issue could be mast or shrouds related.  I tried to attach a short video of the bulkhead which records the sound, but the format will not permit me to do so, so include some photos of the bulkhead in lieu.  I have also felt the problem insofar as the bulkhead seems to judder when it occurs.

 

Byzance is on the hard at the yard now, so any advice would be greatly appreciated.

Bulkhead Exposed

21 January 2021 - 07:31
#2
Join Date: 03 March 2007
Posts: 240

Hi,

Are you sure the noise is in the forward section and not coming from the elbows where the chain plates are attached? That would be my first guess? I had creaking in my 40 and after supporting the chainplates all was well. Do you have a bulge in the deck at the chain plates and is the hull deformed there?

Fair winds 

Mike

Stormsvale

S&S Swan 40

21 January 2021 - 13:36
#3
Join Date: 14 May 2017
Posts: 66

Hi,

 

Here you find some discussion, photo's and solutions around the chaninplate issue.

https://www.classicswan.org/forum/post_thread.php?pagina=2&thread=120

Good luck!

Jolling Lodema

Swan 40 #22, Becca

25 January 2021 - 10:26
#4
Join Date: 18 November 2008
Posts: 4

Thanks Mike

 

I did have thaty problem many years ago when I first bought Byzance.  I had the chainplates extened and strengthened and have not had a problem since.  The yard have re-examined the repair, and all seems fine there.

25 January 2021 - 13:36
#5
Join Date: 03 March 2007
Posts: 240

Ok Detective work.

 

1) You have two bulkheads in play.

2) You have eliminated the chainplate issue.

3) is the sound located near the bulkhead aft or forward of the head or in the head.. 

4) is it located on the head wall or closet wall

5) is it at floor level

6) does it occur on both tacks

7) only in heavy seas or strong winds

8) loads that could cause creaking

         a) baby stay (mast pumping due to waves)

         b) jib tracks or cars ( again waves and flexing )

         c) Mast: mast chocks ( squeaking due to rubbing) 

 

9) have you modified any of these areas recently??

 

Answering these should give some clues

 

You have probably already thought of these and I am posing stupid questions, if so my apologies!!!

 

Fair winds

 

Mike

 

 

27 January 2021 - 05:41
#6
Join Date: 18 November 2008
Posts: 4

Thanks Mike

The creak is actually in the bulkhead between the galley and main saloon.  Apologies for not making this clear.  It can be heard at anchor - in fact I first noticed it when sitting on a mooring - when the vessel rolls, and have heard it subsequently when Byzance has been sitting in her pen.  As I am normally behind the wheel when we are out, I haven't heard it under way but it would seem unlikely that it would disapppear under these conditions.  It seems to occur when the vessel rolls to starboard (same side as the galley) and I have not noticed it on the port side.  All this makes me think it has something to do with the mast, but so far neither I nor the yard have been able to develop this thought.  We will be going out in the next few days to check the situation when under sail.

 

Cheers

 

David

27 January 2021 - 08:44
#7
Join Date: 03 March 2007
Posts: 240

H'mmmm

our boats do flex a little bit but...

I have a hard time linking this to the mast. Also if it is doing this while not sailing I ask the question what is under tension at that point that could be working... also that it is only one side makes me suspicious! 

A thought or question.  When you are not sailing do you roll the job sheets around the forestay and then tighten them up on the winches potentially putting an upward force on the jib car which is potentially sitting about there.  Then the  car or the track may be the culprit.  
Question do you use Dyneema sheets?  These do not stretch and there have been issues with some boats as this lack of Stretch removes a bit of shock adsorption and has caused the jib track to lift a bit or break/ loosen bolts..

Anyway, if that is the problem it is easy to check... fixing not so much if it is on the galley side of the bulkhead. 

Good luck

 

 Mike

03 February 2021 - 23:48
#8
Join Date: 31 July 2007
Posts: 86

Mine creaks too and  have investigated: it seems that it is the same bulkhead by the galley. One dark night I was underway from Rose Harbour on Queen Charlotte Island to Port Hardy, a broad reach with the wind on my port side all night long like maybe 20 knots of wind. I could never fogure out where the creaking came from. I was on autopilot and had plenty of time to investgate. Left about 08:00 and got into Beaver Harbour South of Port Hardy the next day. Wanted to anchor in Port Alexander but it was full of fishing vessels. If you find out where it creaks I would be much obliged. 

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