Vessel service | Required range (degrees) |
Exposed waters, oceans, or Great Lakes winter | 15 |
Partially protected waters or Great Lakes summer | 10 |
Protected waters | 5 |
where-
C = 1.00 for vessels on exposed waters, oceans, or Great Lakes winter;
C = 0.75 for vessels on partially protected waters or Great Lakes summer;
C = 0.50 for vessels on protected waters;
[DELTA] = intact displacement; and
Heeling moment = greatest of the heeling moments as calculated in paragraphs (f)(4) (i) through (iv) of this section.
Passenger Heeling Moment = 0.5 (n w b)
where-
n = number of passengers;
w = passenger weight used for calculations as determined in accordance with § 170.090(c) of this chapter; and
b = distance from the centerline of the vessel to the geometric center on one side of the centerline of the passenger deck used to leave the vessel in case of flooding.
A [GREATER THAN EQUAL TO]0.0025([THETA]-1)
where-
A = Area required in m-rad under each righting-arm curve measured from the angle of equilibrium to the smaller of either the angle at which downflooding occurs or the angle of vanishing stability.
[THETA] = actual angle of equilibrium in degrees
Vessel service | Required range (degrees) | Required maximum righting arm |
Exposed waters, oceans, or Great Lakes winter | 7 | 0.05 m |
Partially-protected waters or Great Lakes summer | 5 | 0.035 m |
Protected waters | 5 | 0.035 m |
Only one breach in the hull and only one free surface need be assumed when meeting the requirements of this paragraph.
Table 171.080(a)-Extent and Character of Damage
Vessel designator1 | Longitudinal penetration2 | Transverse penetration3 4 | Vertical penetration | Character of Damage |
Z | 10 feet (3 meters) plus ).03L or 35 feet (10.7 meters) whichever is less.5 | B/5 | from the baseline upward without limit | Assumes no damage to any main transverse watertight bulkhead. |
Y | 10 feet (3 meters) plus )0.03L or 35 feet (10.7 meters) whichever is less | B/5 | From the baseline upward without limit | Assumes damage to no more than one main transverse watertight bulkhead. |
X | 10 feet (3 meters) plus )0.03L or 35 feet (10.7 meters whichever is less | B/5 | from the baseline upward without limit | Assumes damage to no more than one main transverse watertight bulkhead. |
20 feet (6.1 meters) plus 0.04L | B/5 | From the top of the double bottom upward without limit | Assumes damage to no more than one main transverse watertight bulkhead. | |
W | 20 feet (6.1 meters) plus 0.04L | B/5 | From the baseline upward without limit | Assumes damage to at least two main transverse watertight bulkheads. |
1 W,X,Y, and Z are determined from Table 171.080(b).
2 L = LBP of the vessel in feet (meters).
3 B = the beam of the vessel in feet (meters) measured at or below the deepest subdivision load line as defined in § 171.010(b) except that, when doing calculations for a vessel that operates only on inland waters or a ferry vessel, B may be taken as the mean of the maximum beam on the bulkhead deck and the maximum beam at the deepest subdivision load line.
4 The transverse penetration is applied inboard from the side of the vessel, at right angles to the centerline, at the level of the deepest subdivision load line.
5 .1L or 6 feet (1.8 meters) whichever is greater for vessels described in § 171.070(e)(2) .
Table 171.080(b)
Vessel category | Vessel designator |
Vessels with type I subdivision and a factor of subdivision as determined from § 171.065 (a) or (b) of 0.33 or less | W. |
Vessels with type I subdivision and a factor of subdivision as determined from § 171.065 (a) or (b) greater than 0.33 and less than or equal to 0.50 | X. |
Vessels with Type II subdivision that are required to meet a two compartment standard of flooding | Y. |
All other vessels | Z. |
Table 171.080(c)-Permeability
Spaces and tanks | Permeability (percent |
Cargo, coal, stores | 60. |
Accommodations | 95. |
Machinery | 85. |
Tanks | o or 95.1 |
1 Whichever value results in the more disabling condition.
46 C.F.R. §171.080