[Rhodes22-list] Compression Repair and Addition of CompressionPost

[Michael D. Weisner]

David,

I keep looking at your photos for an explanation and I believe that the 
cause of the failure may be documented in the photo labeled "shimpost.jpg" 
from your website (see attached photo.)  The more I think about it, the more 
I am inclined to think that it is a failure of the deck structure.  Your 
boat has two hatches, one either side of the mast, with a small ribbon of 
deck between them to support the mast.  It appears to be no wider than about 
a foot and the mast is offset about a foot towards the stern from the 
support column.  This transfers all of the mast load (static and dynamic) to 
this small portion of deck material.  I wonder if the load exceeded the 
capability of the deck materials, without a plate to spread the load.  Your 
solution to add another column achieves a bridge effect, bolstering the 
weakened ability of the deck to carry a substantial load.

The questions are: Was the boat manufactured this way?  Were the hatches 
factory installed?  Was the mast always IMF?  Did water intrusion into the 
deck, possibly from a leak near the hatches, compromise the deck load 
bearing ability?  Was the mast overloaded due to collision with a fixed 
object or overtensioning of the stays?  Is the hardware attached to the mast 
(furling genny or IMF) affixed improperly or damaged creating a repetitive 
motion (excessive movement and noise while at anchor) able to drive the mast 
(hammer) into the cabin top?

Mike
s/v Shanghaid'd Summer ('81)
       Nissequogue River, NY

From: "David Culp" Friday, February 06, 2009 12:55 AM
> Mike:
> Yes, we made a through examination of everything we could and everything
> else appears normal  The bulkhead which normally supports the cabin roof 
> has
> not moved-what happened is that the cabin roof was bending downward behind
> the bulkhead and the roof liner was being crushed in by the rear edge of 
> the
> bulkhead.  Once we flexed the cabin top up back into its proper position, 
> it
> was this crushed indention that had to be filled with the shims, otherwise
> the weight of the mast would only be borne by the cabin-top structure and
> the new post.  I think we fixed it, but I would like to know what caused
> this in the first place.
>
> David
>
>
>
> From: "Michael D. Weisner" <mweisner at ebsmed.com>
> Subject: Re: [Rhodes22-list] Compression Repair and Addition of
>       Compression     Post
> To: "The Rhodes 22 Email List" <rhodes22-list at rhodes22.org>
> Message-ID: <013367FE3C614147A443FDDE0AD33C7A at D9X7C761>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>       reply-type=original
>
> David,
>
> Nice job!  This appears to be a good solution to the problem that has
> plagued you since you bought the boat.  I understand your statement "the
> hand tight shrouds match correspondingly in tension and length from the
> chain-plates for the first time since I've owned the boat. (The port 
> shrouds
> were always a slight bit shorter)"  These observations are usually a good
> clue to something being "not quite right" structurally.
>
> Did the yard check the structure below the floor?  On these older boats, 
> it
> has been common for the stringers to compress under load due to water 
> damage
> in the forward area of the cabin bilge, permitting the cabin sole to sag,
> particularly if the boat was stored on the trailer with the bow lower than
> the stern permitting rainwater accumulation in this area.
>
> Mike
> s/v Shanghaid'd Summer ('81)
>      Nissequogue River, NY
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