[Code of Federal Regulations]
[Title 46, Volume 7]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 46CFR178.450]

[Page 240-241]
 
                           TITLE 46--SHIPPING
 
   CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
 
PART 178--INTACT STABILITY AND SEAWORTHINESS--Table of Contents
 
                  Subpart D--Drainage of Weather Decks
 
Sec. 178.450  Calculation of drainage area for cockpit and well deck vessels.

    (a) The drainage area required on a vessel must be computed using 
the following formula:

For protected waters required drainage = .1 x Basic Drainage

For partially protected waters required drainage = .5 x Basis Drainage

For exposed waters required drainage = Basic Drainage


where:


[[Page 241]]


Basic Drainage area in centimeters\2\ = 4389.12 x [(Recess Volume x 
    Recess Ratio) + (Weather Deck Volume x Weather Deck Ratio)]; or

Basic Drainage area in inch\2\ = (Recess Volume x Recess Ratio) + 
    (Weather Deck Volume x Weather Deck Ratio)

Recess Volume = (BR x DR) - VR

BR=average height in centimeters (feet) of the bulwark above 
the well deck or cockpit deck;
DR=total deck area of the cockpit or well deck in the after 
\2/3\ of the vessel length (LOD) measured in centimeters 2 
(feet 2).
VR=volume of any weather tight structure below the bulwark of 
the well deck or cockpit deck.

Recess Ratio = LR / LC

LR=the length of the recess in the after \2/3\ vessel length 
(LOD).
LC=\2/3\ vessel length (LOD).

Weather Deck Volume = (BD x DD) - VS

BD=average height in centimeters (feet) of the bulwark above 
the weather deck;
DD=total deck area of the weather deck adjacent to bulwarks 
but not in way of the cockpit or well deck in the after \2/3\ of the 
vessel length (LOD) measured in centimenters 2 (feet 
2).
VS=volume of any weather tight superstructure below the 
bulwark on the weather deck located within DD.

Weather Deck Ratio = LD / LC

LD=the length of the weather deck bulwark in the after \2/3\ 
of the vessel length (LOD).
LC=\2/3\ vessel length (LOD).

    (b) Vessels with bulwarks in the forward part of the vessel shall 
not form a well with the deckhouse which retains water.

[CGD 85-080, 61 FR 966, Jan. 10, 1996; 61 FR 20557, May 7, 1996]