Cock Pit Drainage

Discussion in 'Metal Boat Building' started by Allan Jennings, Jan 13, 2006.

  1. Allan Jennings
    Joined: Nov 2005
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    Location: Bahrain

    Allan Jennings Junior Member

    Having nearly finished my boat ( 53 ft) I realise that if my centre cock pit is swamped there is no where for the water to go. OK for the foot well, I have two 2" dia dains but looking at the overall cock pit that dosen't seem nearly eanough. Does anyone know how to calculate how much water goes through a 2 " hole under gravity. What is the maximum time you should be flooded for? I feel an idiot as I designed the cock pit so that the seat backs kept the water out in most weather but if I get really pooped then the water is stuck and only the duck boards in the entrance will keep the central pilot house dry, which won't be for very long!!
     
    Allan Jennings, Jan 13, 2006
    #1
  2. Raggi_Thor
    Joined: Jan 2004
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    Location: Trondheim, NORWAY

    Raggi_Thor Nav.arch/Designer/Builder

    There are several rules for this, the volume of your cockpit may be more critical than the size of tha drains. See for example http://www.phrfchesbay.com/eastdscert.pdf :

    6.23 Maximum cockpit volume below lowest coaming shall not exceed 9% of LWL x Max Beam x Freeboard aft.
    Cockpit sole shall be at least 2% of LOA above LWL. (Sailboats built before
    January 1980 shall not be required to retrofit provided that their maximum cockpit volume does not exceed 12% of LWL x Max Beam x Freeboard aft.)
     
    Raggi_Thor, Jan 13, 2006
    #2
  3. FAST FRED
    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    Fill it with a hose , and time the drain.

    5 min is barely acceptable and 3 min is lots better.

    Waves come more often than that,

    Some boats can drain aft with big scuppers similar to "racing" sailboats.

    3 sq ft of scupper on either side would not be too big.

    FAST FRED
     
    FAST FRED, Jan 13, 2006
    #3

  5. Raggi_Thor
    Joined: Jan 2004
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    Location: Trondheim, NORWAY

    Raggi_Thor Nav.arch/Designer/Builder

    That's i nice practical approach Fred :)
     
    Raggi_Thor, Jan 13, 2006
    #4
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