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(continued)
(3) The branch vent lines shall consist of either:
(i) Pipe with no valves or other hindrances to a free flow of gas; or,
(ii) Piping fitted with a pressure vacuum relief valve, provided means are supplied for relieving all internal pressure on cargo tanks by fitting the valve with a positive means for opening its pressure valve to allow free passage of gases through the branch vent line or by the installation of a by-pass fitted with a manually operated stop valve.
(4) The vent header shall be fitted with a flame arrester or pressure vacuum relief valve. If a pressure vacuum relief valve is used in the header, means shall be provided for relieving all internal pressure on cargo tanks by fitting the valve with a positive means for opening its pressure valve to allow free passage of gases through the header or by the installation of a by-pass fitted with a manually operated stop valve. A suitable means of relieving pressure shall be fitted in the header in order to prevent excess pressure being built up in the tanks, in the event of overfilling of the latter. The vent header system shall be provided with suitable connections for flushing and draining. The vent header system shall be of sufficient capacity as to be able to carry off all displaced air and vapors during loading of the cargo tanks without opening of ullage plates, cargo hatches, etc. See §32.20–20 for liquid level gaging requirements.
(c) Grade B or C liquids. Cargo tanks in which Grade B or C liquids are to be transported shall be fitted with either individual pressure-vacuum relief valves which shall extend to a reasonable height above the weather deck or shall be fitted with a venting system consisting of branch vent lines connected to a vent header which shall extend to a reasonable height above the weather deck and be fitted with a flame arrester or a pressure-vacuum relief valve. The vent header system, if fitted, shall be provided with suitable connections for flushing and draining, and if desired, stop valves may be placed in the individual branch vent lines provided that each stop valve is bypassed by a pressure-vacuum relief valve.
(d) Grade D or E liquids. Cargo tanks in which Grade D or E liquids only are to be transported shall be fitted with gooseneck vents and flame screens.
(e) Tank vents which meet the requirements of SOLAS will be considered equivalent to the provisions of this section.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGD 73–96, 42 FR 49024, Sept. 26, 1977; CGD 95–028, 62 FR 51198, Sept. 30, 1997]
§ 32.55-25 Venting of cargo tanks of tank barges constructed on or after July 1, 1951—B/ALL.
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(a) Venting required. (1) On all tank barges, subject to the provisions of this subchapter the construction or conversion of which is started on or after July 1, 1951, each cargo tank shall be equipped with a vent. The diameter of a vent shall be not less than 2 1/2 inches.
(2) In any case where a venting system is required for a particular grade of liquid, the venting system permitted for a higher grade of liquid may be used instead.
(b) Grade A, B, or C liquids. Cargo tanks in which Grade A, B, or C liquids are to be transported shall be fitted with either individual pressure-vacuum relief valves which shall extend to a reasonable height above the weather deck or shall be fitted with a venting system consisting of branch vent lines connected to a vent header which shall extend to a reasonable height above the weather deck and be fitted with a pressure-vacuum relief valve. The vent header system, if fitted, shall be provided with suitable connections for flushing and draining, and if desired, stop valves may be placed in the individual branch vent lines: Provided, That each such stop valve is bypassed by a pressure-vacuum relief valve.
(c) Grade D or E liquids. Cargo tanks in which Grade D or E liquids only are to be transported shall be fitted with gooseneck vents and flame screens.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 70–10, 35 FR 3709, Feb. 25, 1970]
§ 32.55-30 Venting of cargo tanks of tank vessels constructed between November 10, 1936, and July 1, 1951—TB/ALL.
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(a) Venting required. On all tank vessels, the construction or alteration of which is started on or after November 10, 1936, and prior to July 1, 1951, each cargo tank shall be equipped with a vent. The details of the venting system shall meet the requirements of this section, or alternatively, the requirements of either §32.55–20 or §32.55–25, as applicable, shall be met.
(b) Grade A liquids. (1) Cargo tanks in which Grade A liquids are to be transported shall be fitted with a venting system consisting of branch vent line from each cargo tank connected to a vent header which shall extend to a reasonable height above the weather deck and be fitted with a flame arrester or pressure-vacuum relief valve. Each branch vent line may be provided with a manually operated control valve, provided it is bypassed with a pressure-vacuum relief valve or each cargo tank to which such a branch vent line is connected is fitted with an independent pressure-vacuum relief valve. The vent header system shall be provided with suitable connections for flushing and draining.
(2) In barges with independent tanks carrying Grade A liquids, separate discharge pipes may be fitted to each pressure-vacuum relief valve, or the pressure-vacuum relief valve may be elevated, so that in either case the discharge from such valve will not be less than 7 feet above the deck where practicable.
(c) Grade B or C liquids. Cargo tanks in which Grade B or C liquids are to be transported shall be fitted with individual pressure-vacuum relief valves or shall be fitted with a venting system consisting of branch vent lines connected to a vent header which shall extend to a reasonable height above the weather deck and be fitted with a flame arrester or a pressure-vacuum relief valve.
(d) Grade D or E liquids. Cargo tanks in which Grade D or E liquids only are to be transported shall be fitted with gooseneck vents and flame screens unless such tanks are vented by pressure-vacuum relief valves or a venting system of branch vent lines and a vent header.
§ 32.55-35 Venting of cargo tanks on tank vessels constructed prior to November 10, 1936—TB/ALL.
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The venting of cargo tanks of tank vessels, the construction or alteration of which was started prior to November 10, 1936, shall be made to equal the requirements of tank vessels constructed before July 1, 1951, where the changes are, in the opinion of the Officer in Charge, Marine Inspection, necessary in the interests of safety: Provided, That on such vessels carrying Grade A cargo the requirements in §32.55–30(b) shall be met.
§ 32.55-45 Venting of cofferdams and void spaces of tank vessels constructed on or after November 10, 1936—TB/ALL.
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(a) Except as provided in paragraph (b) of this section, on all tank vessels, the construction or conversion of which was started on or after November 10, 1936, cofferdams and void spaces shall be provided with gooseneck vents fitted with a flame screen or pressure-vacuum relief valves. The diameter of a vent shall be not less than 2 1/2 inches.
(b) On unmanned tank barges not fitted with fixed bilge systems in the cofferdams and void spaces, vents for cofferdams and void spaces will not be required.
§ 32.55-50 Ventilation of tankships that have a keel laying date on or after January 1, 1975—T/ALL.
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Each tankship that has a keel laying date on or after January 1, 1975, must have deckhouse and superstructure ventilation inlets and outlets and other openings to the exterior arranged to minimize the admission of flammable gas to enclosed spaces that contain a source of ignition.
[CGD 74–127, 41 FR 3844, Jan. 26, 1976]
Subpart 32.56—Structural Fire Protection for Tank Ships With a Keel Laying Date On or After January 1, 1975
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Source: CGD 74–127, 41 FR 3844, Jan. 26, 1976, unless otherwise noted.
§ 32.56-1 Application—T/ALL.
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(a)This subpart applies to all tankships that have a keel laying date on or after January 1, 1975.
(b) SOLAS-certificated vessels may be considered equivalent to the provisions of this subpart.
[CGD 74–127, 41 FR 3844, Jan. 26, 1976, as amended by CGD 95–028, 62 FR 51198, Sept. 30, 1997]
§ 32.56-5 General—T/ALL.
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(a) Except as provided in paragraphs (c) and (d) of this section, each category A machinery space must be aft of the cargo area and pumprooms.
(b) Except as provided in paragraphs (c), (d), and (e) of this section, each accommodation space, service space except isolated storage spaces, and control space and each main cargo control station must be aft of:
(1) The cargo area;
(2) All cargo pumprooms; and
(3) All cofferdams that isolate the cargo area from category A machinery spaces.
(c) Except as provided in paragraph (e) of this section, any pumproom may be recessed below accommodation, service, and control spaces and recessed into any category A machinery space if the distance between the deckhead of the recess and the underside of the accommodation, service, or control space is at least equal to the height of the recess.
(d) Accommodation, service, control and certain machinery spaces, such as spaces for bow thrusters, windlass, and emergency fire pumps, may be located forward of the cargo area and pumprooms if it is demonstrated to the Commandant that the overall degree of safety of the vessel is improved and that the degree of fire and life safety for these spaces is not less than the degree of fire and life safety for similar spaces located aft.
(e) On liquefied gas carriers:
(1) Main cargo control stations may be located in the cargo area;
(2) Accommodation, service, and control spaces may be located over cofferdams that isolate cargo tanks other than integral tanks from category A machinery spaces;
(3) Pumprooms may not be recessed into any space below deck.
§ 32.56-10 Navigation positions—T/ALL.
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(a) No navigation position may be above the cargo area unless it is approved by the Commandant as necessary for the safe operation of the vessel.
(b) Each navigation position that is above the cargo area must be separated from the deck by an unenclosed space that extends at least 2 meters (6.6 feet) from the deck to the navigation position.
(c) Openings to navigation positions above cargo areas, except air locks, must be at least 2.4 meters (7.9 feet) above the deck.
§ 32.56-15 Deck spills—T/ALL.
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A coaming or other barrier at least .3 meters (1 foot) higher than adjacent spill containment barrier must be provided to prevent cargo spills from flowing aft of the housefront.
§ 32.56-20 Insulation of exterior boundaries: Superstructures and deckhouses—T/ALL.
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The following exterior boundaries of superstructures and deckhouses that contain accommodation, service, and control spaces, except wheelhouses, must be insulated to “A-60” Class:
(a) The exterior boundaries that face the cargo area.
(b) The portion of the exterior bulkheads and decks within 3 meters (10 feet) of these boundaries.
§ 32.56-21 Openings in exterior boundaries: Accommodation, service, and control spaces—T/ALL.
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The following exterior boundaries of accommodation, service, and control spaces, except wheelhouses, must have no openings, and portlights must be of a fixed type with easily operable steel covers on the inside:
(a) The exterior boundaries that face the cargo area.
(b) The portion of the exterior boundaries within 3 meters (10 feet) or the length of the vessel divided by 25, whichever is greater, except that the distance need not exceed 5 meters (16.4 feet), of these boundaries.
§ 32.56-22 Openings in and insulation of boundaries: Other spaces—T/ALL.
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If openings are fitted into the following exterior boundaries of any space other than an accommodation, service, or control space, the interior of the space must be insulated to “A-60” Class and the space must not provide access to any accommodation, service, or control space:
(a) The exterior boundaries that face the cargo area.
(b) The portion of the exterior boundaries within 3 meters (10 feet) or the length of the vessel divided by 25, whichever is greater, except that the distance need not exceed 5 meters (16.4 feet), of these boundaries.
§ 32.56-25 Category A machinery spaces: Windows and port lights—T/ALL.
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(a) Except as provided in paragraph (b) of this section and subpart 111.105, of this chapter, boundaries of category A machinery spaces and boundaries of cargo pumprooms must not be pierced for windows or portlights.
(b) Skylights that can be closed from outside the spaces they serve may be fitted in boundaries of category A machinery spaces.
[CGD 74–127, 41 FR 3844, Jan. 26, 1976, as amended by CGD 74–125A, 47 FR 15230, Apr. 8, 1982]
§ 32.56-30 Category A machinery spaces: Bulkheads and decks—T/ALL.
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(a) Bulkheads and decks that separate category A machinery spaces from cargo pumprooms must be “A” Class construction.
(b) Bulkheads and decks that separate category A machinery spaces or cargo pumprooms, including the pumproom entrance, from accommodation, service, or control spaces must be “A-60” Class construction.
§ 32.56-35 Doors—T/ALL.
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(a) Casing doors in category A machinery spaces and all elevator doors must be self-closing and must meet the requirements of 46 CFR 72.05–25(b).
(b) If a means of holding a door open is used, it must be a magnetic holdback or equivalent device that is operated from the bridge or other suitable remote control position.
§ 32.56-40 Category A machinery spaces: Insulation—T/ALL.
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Structural insulation within category A machinery spaces must have a barrier such as metal foil, sheet metal, cementitious coating, or other vapor barrier so that the surface of that insulation is impervious to oil and oil vapors.
[CGD 74–127, 41 FR 3844, Jan. 26, 1976, as amended by CGD 74–127, 41 FR 4826, Feb. 2, 1976]
§ 32.56-45 Draft stops—T/ALL.
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(a) Where ceilings or linings are fitted in accommodation, service, or control spaces, “B” Class bulkheads, except those that form passageways, may stop at the ceiling or lining if draft stops of “B” Class construction are fitted between the ceiling or lining and the deck or shell at intervals of 14 meters (45 feet) or less.
(b) Spaces behind the linings of stairways and other trunks must have draft stops at each deck.
§ 32.56-50 Combustible veneers—T/ALL.
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(a) Except as provided in paragraph (b) of this section combustible veneers on bulkheads, linings, and ceilings within accommodation, service, or control spaces must be 2 millimeters (.079 inches) or less in thickness.
(b) Veneers on bulkheads, linings, and ceilings in concealed spaces, corridors, stairway enclosures, or control spaces must be an approved interior finish material or a reasonable number of coats of paint.
§ 32.56-55 Control spaces—T/ALL.
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Bulkheads and decks that separate control spaces from adjacent spaces must be “A” Class construction and insulated against fire. 46 CFR Table 72.05–10(e) of the Passenger Vessel Regulations may be used as a guide.
§ 32.56-60 Ventilation ducts—T/ALL.
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(a) Each duct for ventilation of Category A machinery spaces that passes through accommodation, service, or control spaces must be:
(1) Constructed of steel and insulated to “A-60” Class; or
(2) Constructed of steel, fitted with an automatic fire damper at each boundary where it enters and leaves the Category A machinery space, and insulated to “A-60” Class for a distance of 5 meters (16.4 feet) beyond each machinery space boundary.
(b) Each duct for ventilation of accommodation, service, and control spaces that passes through Category A machinery spaces must be constructed of steel and be fitted with an automatic fire damper at each Category A machinery space boundary.
Subpart 32.57—Structural Fire Protection for Tank Vessels Contracted for On or After January 1, 1963
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§ 32.57-1 Application—TB/ALL.
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(a) The provisions of this subpart shall apply to all tank vessels contracted for on or after January 1, 1963.
(b) SOLAS-certificated vessels may be considered equivalent to the provisions of this subpart.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGD 95–028, 62 FR 51198, Sept. 30, 1997]
§ 32.57-5 Definitions—TB/ALL.
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(a) Standard fire test. A “standard fire test” is one which develops in the test furnace a series of time temperature relationships as follows:
5
minutes_1,000
° F.
10
minutes_1,300
° F.
30
minutes_1,550
° F.
60
minutes_1,700
° F.
(b) “A” Class divisions. “A” Class divisions such as bulkheads and decks, means divisions that are composed of steel or an equivalent metal, suitably stiffened, and made intact with the main structure of the vessel, including the shell, structural bulkheads, or decks. They are constructed so that, if subjected to the standard fire test, they are capable of preventing the passage of flame and smoke for one hour. In addition, they are insulated with approved structural insulation, bulkhead panels, or deck coverings so that the average temperature on the unexposed side does not rise more than 139° C (250° F) above the original temperature, nor does the temperature at any one point, including any joint, rise more than 181° C (325° F) above the original temperature, within the time listed below:
Class A-60 60 minutes
Class A-30 30 minutes
Class A-15 15 minutes
Class A-0 0 minutes with no insulation
requirement
(c) “B” Class bulkheads. Bulkheads of the “B” Class shall be constructed with approved incombustible materials and made intact from deck to deck and to shell or other boundaries. They shall be so constructed that, if subjected to the standard fire test, they would be capable of preventing the passage of flame for one-half hour.
(d) “C” Class divisions. Bulkheads or decks of the “C” Class shall be constructed of approved incombustible materials, but need meet no requirements relative to the passage of flame.
(e) Steel. Where the term “steel or other equivalent metal” is used in this subpart, it is intended to require a material which, by itself or due to insulation provided, has structural and integrity qualities equivalent to steel at the end of the applicable fire exposure.
(f) Approved material. Where in this subpart approved materials are required, they refer to materials approved under the applicable subparts of subchapter Q (Specifications) of this chapter, as follows:
Deck Coverings 164.006
Structural 164.007
Insulations
Bulkhead Panels 164.008
Incombustible 164.009
Materials
Interior 164.012
Finishes
(g) Stairtower. A stairtower is a stairway which penetrates more than a single deck within the same enclosure.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 67–90, 33 FR 1015, Jan. 26, 1968; CGD 74–127, 41 FR 3845, Jan. 26, 1976; CGD 75–032, 41 FR 17910, Apr. 29, 1976]
§ 32.57-10 Construction—TB/ALL.
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(a) The hull, superstructure, structural bulkheads, decks, and deckhouses shall be constructed of steel. Alternately, the Commandant may permit the use of other suitable material in special cases, having in mind the risk of fire.
(b) Bulkheads of galleys, paint and lamp lockers, and emergency generator rooms shall be of “A” Class construction.
(c) The boundary bulkheads and decks separating the accommodations and control stations from cargo, and machinery spaces and from galleys, main pantries and storerooms other than small service lockers shall be of “A” Class Construction.
(d) The following conditions apply within accommodation, service, and control spaces:
(1) Corridor bulkheads in accommodation areas shall be of “A” or “B” Class intact from deck to deck Stateroom doors in such bulkheads may have a louver in the lower half.
(2) Stairtowers, elevator, dumbwaiter, and other trunks shall be of “A” Class construction.
(3) Bulkheads not already specified to be of “A” or “B” Class construction may be of “A”, “B”, or “C” Class Construction.
(4) The integrity of any deck in way of a stairway opening, other than a stairtower, shall be maintained by means of “A” or “B” Class divisions or bulkheads and doors at one level. The integrity of a stairtower shall be maintained by “A” Class doors at every level. The doors shall be of the self-closing type. No means shall be provided for locking such doors, except that crash doors or locking devices capable of being easily forced in an emergency may be employed provided a permanent and conspicuous notice to this effect is attatched to both sides of the door. Holdback hooks or other means of permanently holding the door open will not be permitted. However, magnetic holdbacks operated from the bridge or from other suitable remote control positions are acceptable.
(5) Interior stairs, including stringers and treads shall be of steel or other suitable material having in mind the risk of fire. This is not intended to preclude the use of other material for nosing, walking surfaces, etc., over the steel.
(6) Except for washrooms and toilet spaces, deck coverings within accommodation spaces shall be of an approved type. However, overlays for leveling or finishing purposes which do not meet the requirements for an approved deck covering may be used in thicknesses not exceeding 3/8 of an inch.
(7) Except as provided in paragraph (d)(7–a) of this section, ceilings, linings, and insulation, including pipe and duct laggings, must be made of approved incombustible material.
(7–a) Combustible insulations and vapor barriers that have a maximum extent of burning of 122 millimeters (5 inches) or less when tested in accordance with ASTM D 4986, “Standard Test Method for Horizontal Burning Characteristics of Cellular Polymeric Materials” (incorporated by reference, see §32.01–1), may be used within refrigerated compartments.
(8) Any sheathing, furring or holding pieces incidental to the securing of any bulkhead, ceiling, lining, or insulation shall be of approved incombustible materials.
(9) Bulkheads, linings and ceilings may have a combustible veneer within a room not to exceed 2 millimeters (.079 inch) in thickness. However, combustible veneers, trim, decorations, etc., shall not be used in corridors or hidden spaces. This is not intended to preclude the use of an approved interior finish or a reasonable number of coats of paint.
(e) Wood hatch covers may be used between cargo spaces or between stores spaces. Hatch covers in other locations shall be of steel or equivalent metal construction. Tonnage openings shall be closed by means of steel plates or equivalent metal construction.
(f) Nitrocellulose or other highly flammable or noxious fume-producing paints or lacquers shall not be used.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 66–33, 31 FR 15268, Dec. 6, 1966; CGFR 67–90, 33 FR 1015, Jan. 26, 1968; CGD 74–127, 41 FR 3845, Jan. 26, 1976; CGD 95–028, 62 FR 51198, Sept. 30, 1997; USCG-1998–4442, 63 FR 52190, Sept. 30, 1998; USCG-1999–5151, 64 FR 67177, Dec. 1, 1999]
Subpart 32.59—Minimum Longitudinal Strength and Plating Thickness Requirements for Unclassed Tank Vessels That Carry Certain Oil Cargoes—TB/ALL
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§ 32.59-1 Minimum section modulus and plating thickness requirements—TB/ALL.
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(a) As used in this section, Rule means the current Rules of the American Bureau of Shipping or other recognized classification society, as appropriate for the vessel's present service and regardless of the year the vessel was constructed.
(b) The requirements of this section apply to all in-service, unclassed tank vessels certificated to carry a pollution category I oil cargo listed in 46 CFR Table 30.25–1.
(c) For all vessels except those limited on their Certificate of Inspection to river routes only, the minimum midship section modulus must be—
(1) At least 90 percent of that required by Rule; or
(2) Where there is no specific Rule requirement, at least 100 percent of that which is necessary to meet the bending moment developed under a full load condition in still water, using a permissible bending stress of 12.74 kN/cm2 (1.30 t/cm2, 8.25 Ltf/in2).
(d) Within the 40-percent midship length, the average flange and web thicknesses of each longitudinal stiffener must be as follows:
(1) For deck and bottom stiffeners: at least 85 percent of Rule thickness, unless a buckling analysis demonstrates that lesser thicknesses can be safely tolerated. However, the average thickness must never be less than 80 percent of Rule thickness; and
(2) For side stiffeners: at least 75 percent of Rule thickness.
(e) Within the 40-percent midship length, the average thickness for longitudinal strength plating must be at least as follows:
(1) Weather deck: 75 percent of Rule thickness;
(2) Hatch: 70 percent of Rule thickness;
(3) Trunk: 75 percent of Rule thickness;
(4) Sheer strake: 75 percent of Rule thickness;
(5) Outer sideshell: 75 percent of Rule thickness;
(6) Inner sideshell: 75 percent of Rule thickness;
(7) Outer bottom; 75 percent of Rule thickness;
(8) Inner bottom: 70 percent of Rule thickness;
(9) Keel: 75 percent of Rule thickness;
(10) Bulkheads: 75 percent of Rule thickness.
[CGD 91–209, 58 FR 52602, Oct. 8, 1993]
Subpart 32.60—Hull Requirements for Tank Vessels Constructed On or After July 1, 1951
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Note: Requirements for double hull construction for vessels carrying oil, as defined in 33 CFR 157.03, in bulk as cargo are found in 33 CFR 157.10d.
§ 32.60-1 Scantlings, material, and workmanship—TB/ALL.
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(a) All tank vessels, the construction or conversion of which is started on or after July 1, 1951, shall conform to the requirements in this subpart in construction of hulls. The hull and deckhouses shall be of steel or iron construction except that the pilothouse and decks over quarters may be constructed of wood. Scantlings, material, and workmanship, subdivision of cargo spaces, fitting of cofferdams, and testing of tanks shall be at least equivalent to the requirements of the American Bureau of Shipping or other recognized classification society.
(b) See subpart 32.57 for structural fire protection requirements for tank vessels contracted for on or after January 1, 1963.
§ 32.60-5 Subdivision of cargo space—TB/ALL.
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The cargo space shall be divided into tight compartments as necessary to avoid excessive stresses and to provide stability.
§ 32.60-10 Segregation of cargo; Grade A, B, C, or D—TB/ALL.
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(a) General. The galleys, living quarters, navigation spaces, general cargo spaces, boiler rooms, and enclosed spaces where sources of vapor ignition are normally present, shall be segregated from cargo tanks by cofferdams or pump rooms or tanks, either empty or used to carry liquid having a flashpoint of 150° F. or above, or deck spaces enclosed or open.
(b) Cargo tank spaces. Cargo tank spaces shall extend to the main deck, with hatches and vents located on the weather deck. Liquids having a flash point of not less than 150° F. may be carried in the bulk tanks located beyond the segregating cofferdams and/or pump rooms.
(c) Enclosed spaces. (1) Cargo and vent piping passing through enclosed spaces immediately above the bulk cargo tanks shall be continuous except that flanged joints connecting pipe sections will be permitted.
(2) No openings to cargo tank shall be permitted other than stuffing boxes through which valve control rods or permanently installed gage tapes extend and openings for use of tank cleaning machines. Openings for tank cleaning machines, when not in use, shall be kept closed by means of gastight bolted plates and when in use shall be made essentially gas and watertight by covers through which hose or pipe to the tank cleaning machines extend.
(3) The overhead in way of quarters shall be gastight.
(d) Stowage spaces. The spaces described in paragraph (c) of this section may be used for stowage purposes and for general cargo provided that adequate ventilation is furnished.
(e) Openings. (1) Except as provided in paragraph (c) of this section, there shall be no manholes or other openings from cargo tanks to any other enclosed spaces. An exception may be made to allow direct access from cargo tanks to innerbottoms through gas tight bolted manholes, provided:
(i) The innerbottom tanks are voids or ballast tanks only, and
(ii) The innerbottom tanks are protected from sources of ignition similar to the cargo tanks, and any bilge or ballast pumping system serving the innerbottom tanks are treated like cargo pumping systems.
(2) Any vents, sounding tubes, and similar piping passing through such tanks shall be run in a suitable trunk; or such piping shall have a wall thickness equal to or greater than the innerbottom plating, but not less than schedule 80, and shall be welded continuously on both sides of the innerbottom plating.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 69–72, 34 FR 17481, Oct. 29, 1969]
§ 32.60-15 Segregation of cargo; Grade E—TB/ALL.
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(a) General. The galleys, living quarters, navigation spaces, general cargo spaces, boilerrooms, and enclosed spaces containing machinery, where sources of vapor ignition are normally present, shall be segregated from the cargo tanks by tight bulkheads and intervening spaces are not required.
(b) Cargo tank spaces. Cargo tank spaces can be terminated at any deck with hatches on the same deck, but the vent lines shall be extended to the weather deck. Butterworth openings and extension rods may be located on the tank top.
§ 32.60-20 Pumprooms on tank vessels carrying Grade A, B, C, D and/or E liquid cargo—TB/ALL.
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(a) Cargo pumps. In tank vessels carrying Grade A, B, C, or D liquid cargo, cargo pumps shall be isolated from source of vapor ignition by gastight bulkheads. A gastight bulkhead between the pumproom and the pump engine room may be pierced for drive shaft and pump engine control rods provided such openings are fitted with stuffing boxes or other approved gland arrangement. A steam driven pump shall not be considered a source of vapor ignition provided the steam temperature does not exceed 500° F.
(b) Ventilation for pumprooms on tank vessels the construction or conversion of which is started between July 1, 1951, and January 1, 1963. (1) Pumprooms of all tank vessels, the construction or conversion of which is started between July 1, 1951, and January 1, 1963, shall be ventilated in such a way as to remove vapors from points near the floor level or bilges. Pumprooms on tankships handling Grade A, B, or C liquid cargo, with machinery located below the freeboard deck, shall be equipped with power ventilation. Pumprooms equipped with power ventilation shall have the ventilation outlets terminate more than six feet from any opening to the interior part of the vessel which normally contains sources of vapor ignition.
(2) For all tank vessels, the construction or conversion of which is started between October 1, 1959, and January 1, 1963, the power ventilation shall not produce a source of vapor ignition in either the pumproom or the ventilation systems associated with the pumproom. The capacity of power ventilation units shall be sufficient to effect a complete change of air in not more than 3 minutes, based upon the volume of the pumproom and associated trunks up to the deck at which access from the weather is provided.
(c) Ventilation for pumprooms on tank vessels the construction or conversion of which is started on or after January 1, 1963. (1) For all tank vessels, the construction or conversion of which is started on or after January 1, 1963, the cargo pumprooms shall be fitted in accordance with paragraphs (a) and (d) of this section. Cargo pumprooms on these vessels shall be ventilated in such a way as to remove vapors from points near the floor level or bilges. Cargo pumprooms on tank vessels handling Grade A, B, or C liquid cargo, shall be equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete change of air in not more than 3 minutes based upon the volume of the pumproom and associated trunks up to the deck at which access from the weather is provided.
(2) The power ventilation units shall not produce a source of vapor ignition in either the pumproom or the ventilation systems associated with the pumproom. Inlets to exhaust ducts shall be provided and located near the floor level at points where concentrations of vapors may be expected. Ventilation from the weather deck shall be provided. Power supply ventilation may be fitted in lieu of natural ventilation, but when fitted shall be arranged to avoid turbulence in the cargo pumproom. Cargo pumprooms equipped with power ventilation shall have the ventilation outlets terminate more than 6 feet from any opening to the interior part of the vessel which normally contains sources of vapor ignition, and shall be so located as to minimize the possibility of recirculating contaminated air through the pumproom.
(3) Cargo pumprooms handling Grade D and/or E liquid cargo only shall be fitted with at least two ducts extended to the weather deck, one of which shall be extended to a point near the floor level. This does not preclude installation of power ventilation, if desired.
(4) The ventilation required in this paragraph shall be sufficient to properly ventilate the pumproom with the access openings closed.
(d) Access. The access to a cargo pumproom in a tank vessel carrying Grade A, B, C, or D liquid cargo shall be from the open deck.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 70–143, 35 FR 19905, Dec. 30, 1970]
§ 32.60-25 Living quarters—TB/ALL.
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For living quarters the partitions and sheathing shall be of an approved fire resistive construction. The specification for incombustible materials is in subchapter Q (Specifications) of this chapter.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGD 95–028, 62 FR 51198, Sept. 30, 1997]
§ 32.60-30 Tank vessels with independent tanks—TB/ALL.
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(a) Independent cargo tanks may be located in hold spaces or in other cargo tanks; however, a working space of at least 15 inches shall be maintained around each independent tank, or else provisions shall be made for moving such tanks to furnish such working space, except that less than 15 inches around such tanks may be permitted if in the judgment of the Officer in Charge, Marine Inspection, having jurisdiction, a satisfactory inspection of the cargo tanks and hull structure can be made.
(b) When an independent cargo tank is located in an enclosed space other than a cargo tank, such enclosed space shall be considered as equivalent to a pumproom and shall be safeguarded as such as required by this subpart.
(c) Cargo tanks independent of the hull structure shall be supported in saddles or on foundations of steel or other suitable material and securely attached in place to preclude the cargo from being damaged or shifting as a result of collision. The arrangement shall be such as to permit longitudinal and circumferential, or athwartship and vertical, expansion of the cargo tanks. Each tank shall be supported so as to prevent the concentration of excessive loads on the supporting portion of the shell.
§ 32.60-35 Tank vessels carrying Grade A liquid cargo—TB/ALL.
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(a) Grade A liquids having a Reid vapor pressure in excess of 25 pounds per square inch shall be transported in cargo tanks which are independent of the hull.
(b) Barges carrying Grade A liquids having a Reid vapor pressure in excess of 25 pounds per square inch shall be of a Type III barge hull as defined in §32.63–5(b)(3).
[CGFR 70–10, 35 FR 3709, Feb. 25, 1970]
§ 32.60-40 Construction and testing of cargo tanks and bulkheads—TB/ALL.
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(a) All cargo tanks vented at gage pressure of 4 pounds per square inch or less shall be constructed and tested as required by standards established by the American Bureau of Shipping or other recognized classification society. The design of cargo tanks integral with the hull and vented at a gage pressure exceeding 4 pounds per square inch but not exceeding 10 pounds per square inch gage pressure will be given special consideration by the Commandant.
(b) Cargo tanks vented at a gage pressure exceeding 10 pounds per square inch are considered to be pressure vessels and shall be of cylindrical or similar design and shall meet the requirements of subchapter F (Marine Engineering) of this chapter.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 68–82, 33 FR 18805, Dec. 18, 1968]
§ 32.60-45 Segregation of spaces containing the emergency source of electric power—TB/ALL.
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(a) The provisions of this section shall apply to all vessels contracted for on or after October 1, 1958.
(b) When a compartment containing the emergency source of electric power, or vital components thereof, adjoins a space containing either the ship's service generators or machinery necessary for the operation of the ship's service generators, all common bulkheads and/or decks shall be protected by approved “structural insulation” or other approved material. This protection shall be such as to be capable of preventing an excessive temperature rise in the space containing the emergency source of electric power, or vital components thereof, for a period of at least one hour in the event of fire in the adjoining space. Bulkheads or decks meeting Class A-60 requirements, as defined by §72.05–10 of subchapter H (Passenger Vessels) of this chapter, will be considered as meeting the requirements of this paragraph.
Subpart 32.63—Hull and Cargo Tank Requirements for Tank Barges Constructed or Converted On or After July 1, 1964, and Carrying Certain Dangerous Bulk Cargoes
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§ 32.63-1 Application—B/ALL.
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(a) The requirements of this subpart shall apply to all tank barges, the construction or conversion of which is started on or after July 1, 1964, and carrying those cargoes listed in Table 30.25–1 which are defined as:
(1) Flammable liquids having a Reid vapor pressure in excess of 25 pounds per square inch, absolute, in independent tanks (part 32).
(2) Liquefied flammable gases (part 38 of this subchapter).
[CGFR 70–10, 35 FR 3709, Feb. 25, 1970]
§ 32.63-5 Barge hull classifications—B/ALL.
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(a) Each barge subject to the provision of this subpart shall be assigned a hull type number. The Commandant will designate the barge hull types to be used for carrying cargoes in order to insure that the vessel is designed consistent with the degree and nature of the hazard of the commodity carried.
(b) For this purpose the barge hull types shall be as follows:
(1) Type I barge hull. Barge hulls classed as Type I are those designed to carry products which require the maximum preventive measures to preclude the uncontrolled release of the cargo to the waterways and/or atmosphere.
(2) Type II barge hull. Barge hulls classed as Type II are those designed to carry products which require substantial preventive measures to preclude uncontrolled release to the atmosphere, but whose uncontrolled release to the waterways does not constitute a longlasting public or operating personnel hazard, though local and temporary pollution may occur.
(3) Type III barge hull. Barge hulls classed as Type III are those designed to carry products of sufficient hazard to require a moderate degree of control.
§ 32.63-8 Alternative arrangements—B/ALL.
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(a) Alternative arrangements, differing from those specifically required by this subpart, may be considered and approved by the Commandant, if it is demonstrated to his satisfaction that a degree of safety is obtained which is consistent with the intent of this subpart.
§ 32.63-10 Rakes and coamings—B/ALL.
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(a) Each barge hull shall be constructed with a suitable blow form (length, shape, and height of headlog) to protect against diving at the maximum speed at which the barge is designed to be towed. In any integrated tow, only the lead barge need comply with this requirement. In any case, the operator of the towing vessel shall be guided by appropriate speed limitations.
(b) All open hopper type barge hulls shall be provided with coamings around the hopper space and, additionally, a 36-inch minimum height plowshare breakwater on the forward rake. Coamings shall have a minimum height of 36 inches forward graduated to a minimum height of 24 inches at midlength and 18 inches thereafter.
§ 32.63-20 Hull structure—B/ALL.
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(a) General. In addition to complying with the requirements of §32.60–1, as applicable, barge hulls of Types I and II shall comply with the provisions of this section.
(b) Types I and II barge hull. Under an assumed grounding condition such that the forward rake bulkhead rests upon a pinnacle at the water surface, the maximum hull bending stress shall not exceed the following limits:
(1) Independent tanks may be installed in such a manner that they do not contribute to the strength and stiffness of the barge. In such case, the hull stress shall not exceed either 50 percent of the minimum ultimate tensile strength of the material or 70 percent of the yield strength when specified, whichever is greater.
(2) The Commandant may consider a reduction in hull stress when independent tanks are installed in such a manner as to contribute to the strength and stiffness of the barge and this is accounted for in determining the effective section modulus of the barge. In such case, the hull stress shall not exceed the percentage stress values prescribed in paragraph (b)(1) of this section multiplied by the quantity (1.5-SWT/UTS), where SWT is the stress calculated without including the effect of the tanks, and UTS is the minimum ultimate tensile strength of the material. The value SWT, however, shall in no case be more than 75 percent of UTS.
§ 32.63-25 Cargo tanks and supports—B/ALL.
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(a) General. Saddles and hold-down securing straps for independent cargo tanks shall be designed to prevent tank failure due to loads induced in the saddles or straps by barge deflection.
(b) Collision protection. (1) All independent cargo tanks installed on Type I and Type II barge hulls shall be protected with suitable collision chocks or collision straps to withstand a longitudinal collision load of one and one-half times the weight of the tank and cargo. All other independent cargo tanks shall be provided with suitable collision chocks or collision straps to withstand a longitudinal collision load equal to the weight of the tank and cargo.
(2) All cargo tanks shall be so located as to reduce the likelihood of their being damaged in the event of collision. This protection shall be obtained by locating the cargo tanks not less than 4 feet from the side shell and box-end for Type I hulls and 3 feet for Type II barge hulls, and not less than 25 feet from the headlog at the bow for both types.
(c) Cargo tank design—(1) Types I and II barge hulls. (i) In addition to requirements provided for in applicable regulations for a specific commodity, cargoes subject to the provisions of this subpart shall be transported in cargo tanks meeting the requirements of this paragraph. Pressure vessel-type cargo tanks shall have sufficient additional strength so as to limit the maximum combined tank stress, including saddle horn and bending stresses, to 1.5 times the maximum allowable hoop stress in still water, and to the yield strength of the tank material or 70 percent of the minimum ultimate tensile strength of the tank material, if less, in the grounded condition as required by §32.63–20(b).
(ii) Gravity type cargo tanks shall have sufficient additional strength to limit the maximum combined tank stress, including saddle horn and bending stresses, to the yield strength of the tank material or 70 percent of the minimum ultimate tensile strength of the tank material, if less, in the grounded condition as required by §32.63–20(b).
(2) Type III barge hulls. In addition to the requirements of this paragraph, pressure vessel-type cargo tanks shall have sufficient additional strength so as to limit the maximum combined stress, including saddle horn and bending stresses, to 1.5 times the maximum allowable hoop stress.
Subpart 32.65—Hull Requirements for Tank Vessels Constructed On or After November 10, 1936, and Prior to July 1, 1951
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§ 32.65-1 Application—TB/ALL.
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The requirements in this subpart apply to all tank vessels, the construction or conversion of which was started on or after November 10, 1936, and prior to July 1, 1951.
§ 32.65-5 Scantlings, material, and workmanship—TB/ALL.
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The hull and deck houses shall be of steel or iron construction except that the pilothouse and decks over quarters may be constructed of wood. Scantlings, material, and workmanship, subdivision of cargo spaces, fitting of cofferdams, and testing of tanks shall be at least equivalent to the requirements of the American Bureau of Shipping or other recognized classification society.
§ 32.65-10 Subdivision of cargo space—TB/ALL.
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The cargo space shall be divided into tight compartments as necessary to avoid excessive stresses and to provide stability.
§ 32.65-15 Cofferdams—TB/ALL.
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Tank vessels equipped to carry Grade A, B, C, or D liquids shall have their galleys, living quarters, general cargo spaces, boiler rooms, and enclosed spaces containing propelling machinery or other machinery where sources of vapor ignition are normally present, segregated from their cargo tanks by cofferdams or equivalent pumprooms, tanks, or air spaces.
§ 32.65-20 Pumprooms—TB/ALL.
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(a) Tank vessels handling Grade A, B, C, or D liquids shall have their cargo pumps isolated from all sources of vapor ignition by gastight bulkheads. Totally enclosed motors of the “explosion proof” type, motors ventilated on both the intake and exhaust by ducts to atmosphere, and engines driven by steam shall not be considered to be sources of vapor ignition. The gastight bulkhead between the pumproom and the pump-engine compartment may be pierced by fixed lights, drive shaft and pump-engine control rods, provided that the shafts and rods are fitted with stuffing boxes where they pass through the gastight bulkheads. The access to a cargo pumproom handling such liquids shall be from the open deck. (See §32.60–20.0.)
§ 32.65-25 Living quarters—TB/ALL.
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Partitions and sheathing shall be of approved fire-resistive construction.
§ 32.65-30 Tank vessels with independent tanks—TB/ALL.
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Independent cargo tanks may be located in hold spaces or in other cargo tanks but in all cases a working space of at least 15 inches shall be provided around such independent tanks, or else provisions shall be made for moving them to secure such space. When independent cargo tanks are located in an enclosed space other than a cargo tank, such enclosed space shall be considered as equivalent to a pumproom, and shall be safeguarded as such, as required in the regulations in this subchapter.
§ 32.65-35 Tank vessels carrying Grade A liquids—TB/ALL.
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Cargo tanks for Grade A liquids having a Reid vapor pressure in excess of 25 pounds shall be independent of the hull.
§ 32.65-40 Construction and testing of cargo tanks and bulkheads—TB/ALL.
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(a) All cargo tanks to be vented at gage pressures of 4 pounds per square inch or less shall be constructed and tested as required by the requirements of the American Bureau of Shipping or other recognized classification society.
(b) All cargo tanks to be vented at gage pressures above 4 pounds per square inch shall be considered as pressure vessels and shall meet the requirements for such vessels as to construction and testing, as set forth in subchapter F (Marine Engineering) of this chapter.
(c) Gastight bulkheads shall be subjected to a thorough hose test.
[CGFR 65–50, 30 FR 16671, Dec. 30, 1965, as amended by CGFR 68–82, 33 FR 18805, Dec. 18, 1968]
Subpart 32.70—Hull Requirements for Steel Hull Tank Vessels Constructed Prior to November 10, 1936
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§ 32.70-1 Application—TB/ALL.
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All steel hull tank vessels, the construction or conversion of which was started prior to November 10, 1936, shall conform to the requirements in this subpart.
§ 32.70-5 Hull requirements; general—TB/ALL.
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The scantlings, material, and workmanship, the subdivision of cargo spaces, the arrangement of cofferdams, the testing of tanks and cofferdams, shall be at least equivalent to the requirements of a recognized classification society for the particular service specified in the application for the certificate of inspection and permit for the transportation of liquid flammable cargoes in bulk as of the date when the tank vessel was built or as of the date when the vessel was converted into a tank vessel. In the absence of such classification requirements, the Officer in Charge, Marine Inspection, shall satisfy himself that the vessel's structure as specified in this section is safe for the service to be specified in its certificate of inspection.
[CGFR 66–33, 31 FR 15268, Dec. 6, 1966]
§ 32.70-10 Cofferdams—TB/ALL.
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Tank vessels carrying Grade A, B, or C liquids shall be required to conform to the construction requirements in regard to vertical cofferdams in §32.65–15, except that a dry cargo compartment shall be considered to be equivalent to a cofferdam, and except as provided for in §32.70–20. (continued)