[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: 46CFR178.330]
[Page 237-238]
TITLE 46--SHIPPING
CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED)
PART 178--INTACT STABILITY AND SEAWORTHINESS--Table of Contents
Subpart C--Intact Stability Standards
Sec. 178.330 Simplified stability proof test.
(a) A vessel must be in the condition specified in this paragraph
when a simplified stability proof test is performed.
(1) The construction of the vessel must be complete in all respects.
(2) Ballast, if necessary, must be in compliance with Sec. 178.510
and must be on board and in place.
(3) Each fuel and water tank must be approximately three-quarters
full.
(4) A weight equal to the total weight of all passengers, crew, and
other loads permitted on the vessel must be on board and distributed so
as to provide normal operating trim and to simulate the vertical center
of gravity causing the least stable condition that is likely to occur in
service. Unless otherwise specified, weight and vertical center of
gravity is assumed to be as follows:
(i) The weight of primary lifesaving equipment should be simulated
at its normal location, if not on board at the time of the test;
(ii) The weight of one person is considered to be 72.6 kilograms
(160 pounds) except the weight of one person is considered to be 63.5
kilograms (140 pounds) if the vessel operates exclusively on protected
waters and the passenger load consists of men, women, and children;
(iii) The vertical center for the simulated weight of passengers,
crew, and other loads must be at least 760 millimeters (2.5 feet) above
the deck; and
(iv) If the vessel carries passengers on diving excursions, the
total weight of diving gear must be included in the loaded condition as
follows:
(A) The total weight of individual diving gear for each passenger
carried is assumed to be 36 kilograms (80 pounds), which includes the
weight of scuba tanks, harness, regulator, weight belt, wet suit, mask,
and other personal diving equipment; and
(B) The weight of any air compressors carried.
(v) On vessels having one upper deck above the main deck available
to passengers, the weight distribution must not be less severe than the
following:
Total Test Weight (W) = ----
Passenger Capacity of Upper Deck: ----
Weight on Upper Deck = ( of Passengers on Upper Deck) x (Wt per
Passenger) x 1.33''
Weight on Main Deck = Total Test Weight-Weight on Upper Deck
(5) All non-return closures on cockpit scuppers or on weather deck
drains must be kept open during the test.
(b) A vessel must not exceed the limitations in paragraph (f) of
this section, when subjected to the greater of the following heeling
moments:
Mp = (W) (Bp)/6; or
Mw = (P) (A) (H)
where:
Mp = passenger heeling moment in kilogram-meters (foot-
pounds);
W = the total passenger weight using 72.6 kilograms (160 pounds) per
passenger, or, if the vessel operates exclusively on protected waters
and the passenger load consists of men, women, and children, 63.5
kilograms (140 pounds) per passenger may be used;
Bp = the maximum transverse distance in meters (feet) of a
deck that is accessible to passengers;
Mw = wind heeling moment in kilogram-meters (foot-pounds);
P = wind pressure of:
(1) 36.6 kilograms/square meter (7.5 pounds/square foot) for
operation on protected waters;
(2) 48.8 kilogram/square meter (10.0 pounds/square foot) for
operation on partially protected waters; or
(3) 73.3 kilograms/square meter (15.0 pounds/square foot) for
operation on exposed waters;
A = area, in square meters (square feet), of the projected lateral
surface of the vessel above the waterline (including each projected area
of the hull, superstructure and area bounded by railings and structural
canopies). For sailing vessels this is the bare poles area, or, if the
vessel has no auxiliary power, with storm sails set; and
H = height, in meters (feet), of the center of area (A) above the
waterline, measured up from the waterline.
(c) For sailing vessels the heeling moment used for this test must
be the greater of the following:
(1) Passenger heeling moment from paragraph (b) of this section.
(2) Wind heeling moment from paragraph (b) of this section.
(3) Wind heeling moment calculated from the wind heeling moment
equation in paragraph (b) of this section, where:
[[Page 238]]
Mw = wind heeling moment in kilogram-meters (foot-pounds);
P=4.9 kilograms/square meter (1.0 pounds/square foot) for both protected
and partially protected waters.
A=the windage area of the vessel in square meters (square feet) with all
sails set and trimmed flat;
H=height, in meters (feet), of the center of effort of area (A) above
the waterline, measured up from the waterline; and
(d) A vessel must not exceed the following limits of heel:
(1) On a flush deck vessel, not more than one-half of the freeboard
may be immersed.
(2) On a well deck vessel, not more than one-half of the freeboard
may be immersed, except that, on a well deck vessel that operates on
protected waters and has non-return scuppers or freeing ports, the full
freeboard may be immersed if the full freeboard is not more than one-
quarter of the distance from the waterline to the gunwale.
(3) On a cockpit vessel, the maximum allowable immersion is
calculated from the following equation:
(i) On exposed waters--
i=f(2L-1.5L')/4L
(ii) On protected or partially protected waters--
i=f(2L-L')/4L
where:
i=maximum allowable immersion in meters (feet);
f=freeboard in meters (feet);
L=length of the weather deck, in meters (feet); and
L'=length of cockpit in meters (feet).
(4) On an open boat, not more than one quarter of the freeboard may
be immersed.
(5) On a flush deck sailing vessel, the full freeboard may be
immersed.
(6) In no case may the angle of heel exceed 14 degrees.
(e) The limits of heel must be measured at:
(1) The point of minimum freeboard; or
(2) At a point three-quarters of the vessel's length from the bow if
the point of minimum freeboard is aft of this point.
(f) When demonstrating compliance with paragraph (d) of this
section, the freeboard must be measured as follows:
(1) For a flush deck or well deck vessel, the freeboard must be
measured to the top of the weatherdeck at the side of the vessel; and
(2) For a cockpit vessel or for an open boat, the freeboard must be
measured to the top of the gunwale.
(g) A ferry must also be tested in a manner acceptable to the
cognizant OCMI to determine whether the trim or heel during loading or
unloading will submerge the deck edge. A ferry passes this test if, with
the total number of passengers and the maximum vehicle weight permitted
on board, the deck edge is not submerged during loading or unloading of
the vessel.
[CGD 85-080, 61 FR 966, Jan. 10, 1996; 61 FR 20557, May 7, 1996, as
amended at 62 FR 51356, Sept. 30, 1997; 62 FR 64306, Dec. 5, 1997]