§157.10d. Double hulls on tank vessels. — Inbound Citations

(e) This section does not apply to a tank vessel that does not meet the double hull requirements of § 157.10d of this chapter and, under 46 U.S.C. 3703a(c), may not operate in the navigable waters or Exclusive Economic Zone of the United States after January 1, 2000.

(2) If verified by an approved oil discharge monitoring and control system, has an oil content that does not exceed 15 p.m.

Combination carrier means a vessel designed to carry oil or solid cargoes in bulk.

Crude oil means any liquid hydrocarbon mixture occurring naturally in the earth, whether or not treated to render it suitable for transportation, and includes crude oil from which certain distillate fractions may have been removed, and crude oil to which certain distillate fractions may have been added.

Deadweight or DWT means the difference in metric tons between the lightweight displacement and the total displacement of a vessel measured in water of specific gravity 1.025 at the load waterline corresponding to the assigned summer freeboard.

Dedicated clean ballast tank means a cargo tank that is allocated solely for the carriage of clean ballast.

Domestic trade means trade between ports or places within the United States, its territories and possessions, either directly or via a foreign port including trade on the navigable rivers, lakes, and inland waters.

Double bottom means watertight protective spaces that do not carry any oil and which separate the bottom of tanks that hold any oil within the cargo tank length from the outer skin of the vessel.

Double hull means watertight protective spaces that do not carry any oil and which separate the sides, bottom, forward end, and aft end of tanks that hold any oil within the cargo tank length from the outer skin of the vessel as prescribed in § 157.10d.

Doubles sides means watertight protective spaces that do not carry any oil and which separate the sides of tanks that hold any oil within the cargo tank length from the outer skin of the vessel.

Existing vessel means any vessel that is not a new vessel.

Fleeting or assist towing vessel means any commercial vessel engaged in towing astern, alongside, or pushing ahead, used solely within a limited geographic area, such as a particular barge fleeting area or commercial facility, and used solely for restricted service, such as making up or breaking up larger tows.

Foreign trade means any trade that is not domestic trade.

From the nearest land means from the baseline from which the territorial sea of the United States is established in accordance with international law.

Fuel oil means any oil used as fuel for machinery in the vessel in which it is carried.

Inland vessel means a vessel that is not oceangoing and that does not operate on the Great Lakes.

Instantaneous rate of discharge of oil content means the rate of discharge of oil in liters per hour at any instant, divided by the speed of the vessel in knots at the same instant.

Integrated tug barge means a tug and a tank barge with a mechanical system that allows the connection of the propulsion unit (the tug) to the stern of the cargo carrying unit (the tank barge) so that the two vessels function as a single self-propelled vessel.

Large primary structural member includes any of the following:

(a) Sections 157.10d and 157.11(g) apply to each vessel to which this part applies.

(1) For a vessel to which § 157.10d applies, in accordance with § 157.10d(c)(4); or,

(g) Each tank vessel to which § 157.10d applies that is built under a contract awarded after September 11, 1992 must be arranged so that:

(1) Except for short lengths of completely welded (or equivalent) piping,

(i) Ballast piping and other piping to ballast tanks, such as sounding and vent piping, do not pass through cargo tanks, and

(ii) Cargo piping and other piping to cargo tanks do not pass through ballast tanks;

(2) Suction wells in cargo tanks that protrude into the double bottom are as small as practicable and extend no closer to the bottom shell plating than 0.5h, as specified in § 157.10d(c)(2) or § 157.10d(d)(2), as applicable; and

(3) On a vessel that is constructed and certificated for service exclusively on inland, Great Lakes, or limited short protected coastwise routes, any oil piping that is located within double hull spaces must be placed as far from the outer shell as is practicable and must be fitted with valves at the point of connection to the tank served, to prevent oil outflow in the event of damage to the piping. Such valves must be closed whenever the vessel is underway with any oil in tanks served by the associated piping, except as necessary during transfer operations.

The owner, builder or designer of a new vessel to which this part applies shall submit the documentation specified in this section to the Coast Guard before that vessel enters the navigable waters of the United States. The owner, builder, or designer of a vessel that must comply with § 157.10d shall submit the documentation specified in this section to the Coast Guard before that vessel enters the navigable waters of the United States or the U.S. Exclusive Economic Zone.

(3) Is not equipped with a double hull meeting § 157.10d of this part, or an equivalent to the requirements of § 157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).

(3) Is not equipped with a double hull meeting § 157.10d of this part, or an equivalent to the requirements of § 157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).

(3) Is not equipped with a double hull meeting § 157.10d of this part, or an equivalent to the requirements of § 157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).

As used in this part—

(e) On an OSV of at least 6,000 GT ITC (500 GRT if GT ITC is not assigned), tanks authorized for carriage of oil as defined by 33 CFR 157.03, including drilling fluids containing oil as defined by 33 CFR 157.03, must comply with double hull requirements stated in 33 CFR 157.10d.

Note to § 125.110(e): Additional limitations on the carriage of flammable or combustible liquid cargoes are found in § 127.650 of this part.

(f) On each vessel, the cargo tank length must not extend aft to any point closer to the stern than the distance equal to the required width of the double side, as prescribed in § 157.10d(c)(1) or § 157.10d(d)(1).

(2) Suction wells in cargo tanks that protrude into the double bottom are as small as practicable and extend no closer to the bottom shell plating than 0.5h, as specified in § 157.10d(c)(2) or § 157.10d(d)(2), as applicable; and

(1) For a vessel to which § 157.10d applies, in accordance with § 157.10d(c)(4); or,

(c) Except on a vessel to which § 157.10d(d) applies, tanks within the cargo tank length that carry any oil must be protected by double sides and a double bottom as follows:

(1) Double sides must extend for the full depth of the vessel's side or from the uppermost deck, disregarding a rounded gunwale where fitted, to the top of the double bottom. At any cross section, the molded width of the double side, measured at right angles to the side shell plating, from the side of tanks containing oil to the side shell plating, must not be less than the distance w as shown in Figure 157.10d(c) and specified as follows:

(i) w = [0.5 + (DWT/20,000)] meters; or, w = 2.0 meters (79 in.), whichever is less, but in no case less than 1.0 meter (39 in.).

(ii) w = [0.4 + (2.4)(DWT/20,000)] meters, but in no case less than 0.76 meter (30 in.).

(iii) w = 0.76 meter (30 in.), provided that the double side was fitted under a construction or conversion contract awarded prior to June 30, 1990.

(2) At any cross section, the molded depth of the double bottom, measured at right angles to the bottom shell plating, from the bottom of tanks containing oil to the bottom shell plating, must not be less than the distance h as shown in Figure 157.10d(c) and specified as follows:

(i) h = B/15; or, h = 2.0 meters (79 in.), whichever is less, but in no case less than 1.0 meter (39 in.).

(ii) h = B/15, but in no case less than 0.76 meter (30 in.).

(iii) h = B/15; or, h = 2.0 meters (79 in.), whichever is the lesser, but in no case less than 0.76 meter (30 in.), provided that the double bottom was fitted under a construction or conversion contract awarded prior to June 30, 1990.

(3) For a vessel built under a contract awarded after September 11, 1992, within the turn of the bilge or at cross sections where the turn of the bilge is not clearly defined, tanks containing oil must be located inboard of the outer shell—

(i) At levels up to 1.5h above the base line, not less than the distance h, as shown in Figure 157.10d(c) and specified in paragraph (c)(2) of this section. At levels greater than 1.5h above the base line, not less than the distance w, as shown in Figure 157.10d(c) and specified in paragraph (c)(1) of this section.

(ii) Not less than the distance h above the line of the mid-ship flat bottom, as shown in Figure 157.10d(c)(3)(ii) and specified in paragraph (c)(2) of this section. At levels greater than h above the line of the mid-ship flat bottom, not less than the distance w, as shown in Figure 157.10d(c)(3)(ii) and specified in paragraph (c)(1) of this section.

(4) For a vessel to which § 157.10(b) applies that is built under a contract awarded after September 11, 1992.

(i) The aggregate volume of the double sides, double bottom, forepeak tanks, and afterpeak tanks must not be less than the capacity of segregated ballast tanks required under § 157.10(b). Segregated ballast tanks that may be provided in addition to those required under § 157.10(b) may be located anywhere within the vessel.

(ii) Double side and double bottom tanks used to meet the requirements of § 157.10(b) must be located as uniformly as practicable along the cargo tank length. Large inboard extensions of individual double side and double bottom tanks, which result in a reduction of overall side or bottom protection, must be avoided.

(f) On each vessel, the cargo tank length must not extend aft to any point closer to the stern than the distance equal to the required width of the double side, as prescribed in § 157.10d(c)(1) or § 157.10d(d)(1).

(2) Suction wells in cargo tanks that protrude into the double bottom are as small as practicable and extend no closer to the bottom shell plating than 0.5h, as specified in § 157.10d(c)(2) or § 157.10d(d)(2), as applicable; and