Double Bottoms

[Dave2859 (Guest)]

<div style="color: #000000; font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10px; background-image: initial; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: #ffffff; background-position: initial initial; margin: 8px;">Hi there, 
Was just wondering if anyone could give me a quote for fitting a double bottom to my old admirals cup 12, N2859, design greyhound, ideally the double bottom would be wooden since i cant afford carbon!

Dave

[emzcrusader]

We may be interested in this too, and I know of at least 1 other talking about similar modifictaions.  Possible production line/small batch....?
Phil
N3379
 

[Dare Barry (Guest)]

Hi. This is a job I have done before and would be happy to discuss. I will be at Thorpe Bay or give me a call. 01983 529901
Dare Barry

[gerry ledger]

Hi So will I. Before you go for a double bottom I would advise you try one first. Gerry

[John Hugo]

Gerry's advice is wise.   There are pros and cons for double bottoms. They do add stiffness to the hull, and they empty the boat of water in seconds,but the downside includes less legroom for the crew, and floating much higher in the water when capsized, which results in a tendancy to blow away quicker than a man overboard can swim, and to turn turtle.   It is also more difficult to climb onto the centreboard, especially if you are old and feeble like me.    The more competent twelve sailors can minimise these problems, and they generally favour double bottoms.
There are many affordable single bottom boats which are very suitable for inland sailing, but which have a problem when righted after a capsise when the top of the centreboard case and the dished transom are at water level.   (The buoyancy bags are not low enough).    It can take a long time to empty on a narrow river without room for a good reach, and when the wind has dropped after the gust that caught you out.
I am considering modifiying an old four planker which needs redecking: fitting a double floor from transom to thwart, and a dished buoyancy tank from bow to a bulkhead between the shrouds.    This should add stifness and allow the boat to float lower when capsised and higher when righted, and leave more leg- room for the crew.   I would expect it to be sailed dry quite quickly.   I am unsure whether this would be in class, and if it would fit the redefinition of AC.                              
There is no need to use carbon.   Plywood construction as used by Dare, or foam epoxy with glass sheathing are both feasible.
 N3475 (DB)    
      
     

[FuzzyDuck]

Gerry and I were discsussing this at the weekend, and whilst there is no doubt my man-o-war is significantly faster than my Crusdaer if I had sailed with a Double floor for any length of time before I bought one I would still be in an AC boat!
They absolutely knacker your knees in the light winds and if you did not know you bad bad knees before sailing one you will soon know within a few weeks like I have done. Costing me a fortune as well, pain killers, fish oil, Glucoscomine sulphate, etc. 
Go ahead and fit a double floor and you to could be taking all these tablets you never took before!??)

[Giles (Guest)]

Funnily enough, Bob Murrell in our club (Chipstead) went the other way and modified a Foolish (3435) by cutting the double floor away forward of the thwart.
This doesn't seem to have affected the stiffness or speed of the boat, but has made life more comfortable for the crew and easier to right after a capsise, while still draining most of the water quickly, the only bit that remains is in the crew "footwell" in front of the thwart.
As far as I know this conversion is unique, but it seems to be a very practical and well thought out solution to a number  of problems.
Quite a few '80's boats seem to have large rear tanks instead of bags, which have a similar effect. Weight is, of course, an issue. A partial rear floor is, effectively, a longer and lower stern tank.