Subpart C-Large Vessels 171.045 Specific applicability. 171.050 Intact stability requirements for a mechanically propelled or a nonself-propelled vessel. 171.055 Intact stability requirements for a monohull sailing vessel or a monohull auxiliary sailing vessel. 171.057 Intact stability requirements for a sailing catamaran. 171.060 Watertight subdivision: general. 171.065 Subdivision requirements-Type I. 171.066 Calculation of permeability for Type I subdivision. 171.067 Treatment of stepped and recessed bulkheads in Type I subdivision. 171.068 Special considerations for Type I subdivision for vessels on short international voyages. 171.070 Subdivision requirements-Type II. 171.072 Calculation of permeability for Type II subdivision. 171.073 Treatment of stepped and recessed bulkheads in Type II subdivision. 171.075 Subdivision III. requirements-Type Subpart F-Openings in the Side of a Vessel Below the Bulkhead or Weather Deck 171.115 Specific applicability. 171.116 Port lights. 171.117 Dead covers. 171.118 Automatic ventilators and side ports. 171.119 Openings below the weather deck in the side of a vessel less than 100 gross tons. Subpart G-Watertight Integrity Above the Margin Line 171.120 Specific applicability. 171.122 Watertight integrity above the margin line in a vessel of 100 gross tons or more. 171.124 Watertight integrity above the margin line in a vessel less than 100 gross tons. Subpart H-Drainage of Weather Decks 171.130 Specific applicability. 171.135 Weather deck drainage on a vessel of 100 gross tmns or more. 171.140 Drainage of a flush deck vessel. 171.145 Drainage mf a vessel with a cockpit. 171.150 Drainage of a vessel with a well deck. 171.155 Drainage of an open boat. AUTHORITY: 46 U.S.C. 2101, 2104, 3301, 3306, 3316; 46 App. U.S.C. 86, 88a; 43 U.S.C. 1333(d); 50 U.S.C. 198; 49 CFR 1.46. SOURCE: CGD 79-023, 48 FR 51017, Nov. 4, 1983, unless otherwise noted. (a) "Cockpit" means an exposed recess in the weather deck extending no more than one-half of the length of the vessel (LMD) measured over the weather deck. (b) "Deepest subdivision load line" means the waterline that corresponds to the deepest draft permitted by the applicable subdivision requirements in this part. (c) “Equivalent plane bulkhead" means a bulkhead that is (1) Used in lieu of a recessed or stepped bulkhead when doing the subdivision calculations required in this part; and (2) Located as shown in Figure 171.010(a). (d) "Ferry" means a vessel that(1) Operates in rivers or lakes, bays, and sounds service only; (2) Has provisions only for deck passengers or vehicles, or both; (3) Operates on a frequent schedule between two points over the most direct water route; and (4) Offers a public service of a type normally attributed to a bridge or tunnel. (e) "Floodable length" means the length of a shell to shell segment of the vessel that, when flooded, will sink and trim the vessel until the margin line is tangent to the waterline. (f) "Flush deck" means a continuous weather deck located at the uppermost sheer line of the hull. (g) "International voyage" has the same meaning provided for the term in § 70.05-10 of this chapter. (h) "Machinery space" means, unless otherwise prescribed by the Commandant for unusual arrangeme the space extending from the molded base line to the margin line and between the main transverse watertight bulkheads bounding the following spaces: (1) Each space containing main and auxiliary propelling machinery. (2) Each space containing propulsion boilers. (3) Each space containing permanent coal bunkers. (i) "Open boat" means a vessel not protected from entry of water by means of a complete deck, or by a combination of a partial weather deck and superstructure which is seaworthy for the waters upon which the vessel operates. (j) "Passenger space" means a space which is provided for the accommodation and use of passengers, other than a baggage, store, provision or mail 53-165 0-85-3 Margin Line for a Vessel With a Continuous Bulkhead Deck and With an Average Value of Sheer at the FP and AP of at Least 12 Inches (30.5 cm) 3 in. (7.6cm) Bulkhead Deck Margin Line (b) A vessel with a continuous bulkhead deck and insufficient sheer. If the average value of the sheer at the forward perpendicular (FP) and the after perpendicular (AP) is less than 12 inches (30.5 cm), the margin line must be a parabolic curve with the following characteristics: (1) The parabolic curve must be at least 3 inches (7.6 cm) below the upper surface of the bulkhead deck at the FP and AP. (2) The parabolic curve must be at least the distance given in Table 171.015 below the surface of the bulkhead deck amidships. (3) Intermediate values not shown in Table 171.015 must be interpolated. (4) Figure 171.015(b) illustrates a margin line drawn in this manner. |