Title 46—Shipping--Volume 1
PART 172—SPECIAL RULES PERTAINING TO BULK CARGOES
§ 172.005   Applicability.
This part applies to each vessel that carries one of the following cargoes in bulk:
(a) Grain.
(b) A cargo listed in Table 30.25-1 of this chapter.
(c) A cargo regulated under 33 CFR part 157.
(d) A cargo listed in Table 151.01-10(b) of this chapter.
(e) A cargo listed in Table I of part 153 of this chapter.
(f) A cargo listed in Table 4 of part 154 of this chapter.
(g) Any dry bulk cargo carried in a new Great Lakes vessel.
§ 172.010   Applicability.
This subpart applies to each vessel that loads grain in bulk, except vessels engaged solely on voyages on rivers, lakes, bays, and sounds or on voyages between Great Lake ports and St. Lawrence River ports as far east as a straight line drawn from Cape de Rosiers to West Point, Anticosti Island and as far east of a line drawn along the 63rd meridian from Anticosti Island to the north shore of the St. Lawrence River.
§ 172.015   Document of authorization.
(a) Except as specified in § 172.030, each vessel that loads grain in bulk must have a Document of Authorization issued in accordance with one of the following:
(1) Section 3 of the International Code for the Safe Carriage of Grain in Bulk if the Document of Authorization is issued on or after January 1, 1994. As used in the Code, the term “Administration” means “U.S. Coast Guard”.
(2) Regulation 10 part (a) of the Annex to IMO Assembly resolution A.264(VIII) if the Document of Authorization was issued before January 1, 1994.
(b) The Commandant recognizes the National Cargo Bureau, Inc., 17 Battery Place, Suite 1232, New York, New York 10004-1110, for the purpose of issuing Documents of Authorization in accordance with paragraph (a)(1) of this section.
§ 172.020   Incorporation by reference.
(a) Certain material is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, the Coast Guard must publish a notice of change in the Federal Register and the material must be available to the public. All approved material is available for inspection at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. It is also available for inspection at Coast Guard Headquarters. Contact Commandant (CG-ENG-2), Attn: Naval Architecture Division, U.S. Coast Guard Stop 7509, 2703 Martin Luther King Jr. Avenue SE., Washington, DC 20593-7509. The material is also available from the source listed in paragraph (b) of this section.
(b) International Maritime Organization (IMO), Publications Section, 4 Albert Embankment, London SE1 7SR, United Kingdom, + 44 (0)20 7735 7611, http://www.imo.org/.
(1) Amendment to Chapter VI of the International Convention for the Safety of Life at Sea, 1960, Resolution A.264(VIII), incorporation by reference (IBR) approved for § 172.015.
(2) Publication No. 240-E, International Code for the Safe Carriage of Grain in Bulk, IBR approved for § 172.015.
(3) Resolution MEPC.117(52), Amendments to the Annex of the Protocol of 1978 Relating to the International Convention for the Prevention of Pollution from Ships, 1973 (IMO Res. MEPC.117(52)), Adopted on 15 October 2004, IBR approved for § 172.070.
§ 172.030   Exemptions for certain vessels.
(a) Vessels are exempt from 172.015 on voyages between:
(1) United States ports along the East Coast as far south as Cape Henry, VA;
(2) Wilmington, NC and Miami, FL;
(3) United States ports in the Gulf of America;
(4) Puget Sound ports and Canadian west coast ports or Columbia River ports, or both;
(5) San Francisco, Los Angeles, and San Diego, CA.
(b) Vessels exempt by paragraph (a) of this section must comply with the following conditions:
(1) The master is satisfied that the vessel's longitudinal strength is not impaired.
(2) The master ascertains the weather to be encountered on the voyage.
(3) Potential heeling moments are reduced to a minimum by carrying as few slack holds as possible.
(4) Each slack surface must be leveled.
(5) The transverse metacentric height (GM), in meters, of the vessel throughout the voyage, after correction for liquid free surface, has been shown by stability calculations to be in excess of the required GM (GMR), in meters.
(i) The GMR is the sum of the increments of GM (GMI) multiplied by the correction factor, f and r.
(ii) The GMI for each compartment which has a slack surface of grain, i.e. , is not trimmed full, is calculated by the following formula:
(c) Vessels which do not have the Document of Authorization required by § 172.015 may carry grain in bulk up to one third of their deadweight tonnage provided the stability complies with the requirements of Section 9 of the International Code for the Safe Carriage of Grain in Bulk.
§ 172.040   Certificate of loading.
(a) Before it sails, each vessel that loads grain in bulk, except vessels engaged solely on voyages on the Great Lakes, rivers, or lakes, bays, and sounds, must have a certificate of loading issued by an organization recognized by the Commandant for that purpose. The certificate of loading may be accepted as prima facie evidence of compliance with the regulations in this subpart.
(b) The Commandant recognizes the National Cargo Bureau, Inc., 180 Maiden Lane, Suite 903, New York, NY 10038, for the purpose of issuing certificates of loading.
§ 172.047   Specific applicability.
This section applies to each tank barge that carries, in independent tanks described in § 151.15-1(b) of this chapter, a cargo listed in Table 30.25-1 of this chapter that is a—
(a) Liquefied flammable gas; or
(b) Flammable liquid that has a Reid vapor pressure in excess of 25 pounds per square inch (172.4 KPa).
§ 172.048   Definitions.
As used in this subpart—
MARPOL 73/38 means the International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating to that Convention.
§ 172.050   Damage stability.
(a) Each tank barge is assigned a hull type number by the Commandant in accordance with § 32.63-5 of this chapter. The requirements in this section are specified according to the hull type number assigned.
(b) Except as provided in paragraph (c) of this section, each Type I and II barge hull must have a watertight weather deck.
(c) If a Type I or II barge hull has an open hopper, the fully loaded barge must be shown by design calculations to have at least 2 inches (50mm) of positive GM when the hopper space is flooded to the height of the weather deck.
(d) When demonstrating compliance with paragraph (c) of this section, credit may be given for the buoyancy of the immersed portion of cargo tanks if the tank securing devices are shown by design calculations to be strong enough to hold the tanks in place when they are subjected to the buoyant forces resulting from the water in the hopper.
(e) Each tank barge must be shown by design calculations to have at least 2 inches (50 mm) of positive GM in each condition of loading and operation after assuming the damage specified in paragraph (f) of this section is applied in the following locations:
(1) Type I barge hull not in an integrated tow. If a Type I hull is required and the barge is not a box barge designed for use in an integrated tow, design calculations must show that the barge hull can survive damage at any location including on the intersection of a transverse and longitudinal watertight bulkhead.
(2) Type I barge hull in an integrated tow. If a Type I hull is required and the barge is a box barge designed for operation in an integrated tow, design calculations must show that the barge can survive damage—
(i) To any location on the bottom of the tank barge except on a transverse watertight bulkhead; and
(ii) To any location on the side of the tank barge including on a transverse watertight bulkhead.
(3) Type II hull. If a Type II hull is required, design calculations must show that the barge can survive damage to any location except to a transverse watertight bulkhead.
(f) For the purpose of paragraph (e) of this section—
(1) Design calculations must include both side and bottom damage, applied separately; and
(2) Damage must consist of the most disabling penetration up to and including penetrations having the following dimensions:
(i) Side damage must be assumed to be as follows:
(A) Longitudinal extent—6 feet (183 centimeters).
(B) Transverse extent—30 inches (76 centimeters).
(C) Vertical extent—from the baseline upward without limit.
(ii) Bottom damage must be assumed to be 15 inches (38.1 centimeters) from the baseline upward.
§ 172.060   Specific applicability.
This subpart applies to each U.S. tank vessel that is required to comply with 33 CFR 157.21.
§ 172.065   Damage stability.
(a) Definitions. As used in this section, Length or L means load line length (LLL).
(b) Calculations. Each tank vessel must be shown by design calculations to meet the survival conditions in paragraph (g) of this section in each condition of loading and operation except as specified in paragraph (c) of this section, assuming the damage specified in paragraph (d) of this section.
(c) Conditions of loading and operation. The design calculations required by paragraph (b) of this section need not be done for ballast conditions if the vessel is not carrying oil, other than oily residues, in cargo tanks.
(d) Character of damage. (1) If a tank vessel is longer than 738 feet (225 meters) in length, design calculations must show that it can survive damage at any location.
(2) If a tank vessel is longer than 492 feet (150 meters) in length, but not longer than 738 feet (225 meters), design calculations must show that it can survive damage at any location except the transverse bulkheads bounding an aft machinery space. The machinery space is calculated as a single floodable compartment.
(3) If a tank vessel is 492 feet (150 meters) or less in length, design calculations must show that it can survive damage—
(i) At any location between adjacent main transverse watertight bulkheads except to an aft machinery space;
(ii) To a main transverse watertight bulkhead spaced closer than the longitudinal extent of collision penetration specified in Table 172.065(a) from another main transverse watertight bulkhead; and
(iii) To a main transverse watertight bulkhead or a transverse watertight bulkhead bounding a side tank or double bottom tank if there is a step or a recess in the transverse bulkhead that is longer than 10 feet (3.05 meters) and that is located within the extent of penetration of assumed damage. The step formed by the after peak bulkhead and after peak tank top is not a step for the purpose of this regulation.
(e) Extent of damage. For the purpose of paragraph (b) of this section—
(1) Design calculations must include both side and bottom damage, applied separately; and
(2) Damage must consist of the penetrations having the dimensions given in Table 172.065(a) except that, if the most disabling penetrations would be less than the penetrations described in this paragraph, the smaller penetration must be assumed.
(f) Permeability of spaces. When doing the calculations required in paragraph (b) of this section—
(1) The permeability of a floodable space, other than a machinery space, must be as listed in Table 172.065(b);
(2) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 85%, unless the use of an assumed permeability of less than 85% is justified in detail; and
(3) If a cargo tank would be penetrated under the assumed damage, the cargo tank must be assumed to lose all cargo and refill with salt water, or fresh water if the vessel operates solely on the Great Lakes, up to the level of the tank vessel's final equilibrium waterline.
(g) Survival conditions. A vessel is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
(1) Final waterline. The final waterline, in the final condition of sinkage, heel, and trim, must be below the lower edge of an opening through which progressive flooding may take place, such as an air pipe, or an opening that is closed by means of a weathertight door or hatch cover. This opening does not include an opening closed by a—
(i) Watertight manhole cover;
(ii) Flush scuttle;
(iii) Small watertight cargo tank hatch cover that maintains the high integrity of the deck;
(iv) Class 1 door in a watertight bulkhead within the superstructure;
(v) Remotely operated sliding watertight door; or
(vi) Side scuttle of the non-opening type.
(2) Heel angle. The maximum angle of heel must not exceed 25 degrees, except that this angle may be increased to 30 degrees if no deck edge immersion occurs.
(3) Range of stability. Through an angle of 20 degrees beyond its position of equilibrium after flooding, a tank vessel must meet the following conditions:
(i) The righting arm curve must be positive.
(ii) The maximum righting arm must be at least 3.94 inches (10 cm).
(iii) Each submerged opening must be weathertight.
(4) Progressive flooding. Pipes, ducts or tunnels within the assumed extent of damage must be either—
(i) Equipped with arrangements such as stop check valves to prevent progressive flooding to other spaces with which they connect; or
(ii) Assumed in the design calculations required in paragraph (b) of this section to permit progressive flooding to the spaces with which they connect.
(h) Buoyancy of superstructure. For the purpose of paragraph (b) of this section, the buoyancy of any superstructure directly above the side damage is to be disregarded. The unflooded parts of superstructures beyond the extent of damage may be taken into consideration if they are separated from the damaged space by watertight bulkheads and no progressive flooding of these intact spaces takes place.
Table 172.065( a )—Extent of Damage
1 Damage applied inboard from the vessel's side at right angles to the centerline at the level of the summer load line assigned under Subchapter E of this chapter.
Table 172.065( b )—Permeability
1 Whichever results in the more disabling condition.
2 If tanks are partially filled, the permeability must be determined from the actual density and amount of liquid carried.
§ 172.070   Intact stability.
All tank vessels of 5,000 deadweight tons (DWT) and above, contracted after December 3, 2001, must comply with the intact stability requirements of IMO Res. MEPC.117(52) (incorporated by reference, see § 172.020).
§ 172.080   Specific applicability.
This subpart applies to each tank barge that carries a cargo listed in Table 151.05 of this chapter.
§ 172.085   Hull type.
If a cargo listed in Table 151.05 of part 151 of this chapter is to be carried, the tank barge must be at least the hull type specified in Table 151.05 of this chapter for that cargo.
§ 172.087   Cargo loading assumptions.
(a) The calculations required in this subpart must be done for cargo weights and densities up to and including the maximum that is to be endorsed on the Certificate of Inspection in accordance with § 151.04-1(c) of this chapter.
(b) For each condition of loading and operation, each cargo tank must be assumed to have its maximum free surface.
§ 172.090   Intact transverse stability.
(a) Except as provided in paragraph (b) of this section, each tank barge must be shown by design calculations to have a righting arm curve with the following characteristics:
(1) If the tank barge is in river service, the area under the righting arm curve must be at least 5 foot-degrees (1.52 meter-degrees) up to the smallest of the following angles:
(i) The angle of maximum righting arm.
(ii) The downflooding angle.
(2) If the tank barge is in lakes, bays and sounds or Great Lakes summer service, the area under the righting arm curve must be at least 10 foot-degrees (3.05 meter-degrees) up to the smallest of the following angles:
(i) The angle of maximum righting arm.
(ii) The downflooding angle.
(3) If the tank barge is in ocean or Great Lakes winter service, the area under the righting arm curve must be at least 15 foot-degrees (4.57 meter-degrees) up to the smallest of the following angles:
(i) The angle of maximum righting arm.
(ii) The downflooding angle.
(b) If the vertical center of gravity of the cargo is below the weather deck at the side of the tank barge amidships, it must be shown by design calculations that the barge has at least the following metacentric height (GM) in feet (meters) in each condition of loading and operation:
(c) The effective freeboard is given by—
(d) For the purpose of this section, downflooding angle means the static angle from the intersection of the vessel's centerline and waterline in calm water to the first opening that does not close watertight automatically.
§ 172.095   Intact longitudinal stability.
Each tank barge must be shown by design calculations to have a longitudinal metacentric height (GM) in feet (meters) in each condition of loading and operation, at least equal to the following:
§ 172.100   Watertight integrity.
(a) Except as provided in paragraph (b) of this section, each Type I or II hopper barge hull must have a weathertight weather deck.
(b) If a Type I or II barge hull has an open hopper, the fully loaded barge must be shown by design calculations to have at least 2 inches (50 mm) of positive GM when the hopper space is flooded to the height of the weather deck.
(c) When doing the calculations required by this section, credit may be given for the buoyancy of the immersed portion of cargo tanks if the tank securing devices are shown by design calculations to be strong enough to hold the tanks in place when they are subjected to the buoyant forces resulting from the water in the hopper.
§ 172.103   Damage stability.
Each tank barge must be shown by design calculations to meet the survival conditions in § 172.110 assuming the damage specified in § 172.104 to the hull type specified in Table 151.05 of part 151 of this chapter.
§ 172.104   Character of damage.
(a) Type I barge hull not in an integrated tow. If a Type I hull is required and the barge is not a box barge designed for use in an integrated tow, design calculations must show that the barge can survive damage at any location including the intersection of a transverse and a longitudinal bulkhead.
(b) Type I barge hull in an integrated tow. If a Type I barge hull is required and the barge is a box barge designed for operation in an integrated tow, design calculations must show that the barge can survive damage—
(1) At any location on the bottom of the tank barge except on a transverse watertight bulkhead; and
(2) At any location on the side of the tank barge including on a transverse watertight bulkhead.
(c) Type II barge hull. If a Type II hull is required, design calculations must show that a barge can survive damage at any location except on a transverse watertight bulkhead.
§ 172.105   Extent of damage.
For the purpose of § 172.103, design calculations must include both side and bottom damage, applied separately. Damage must consist of the most disabling penetration up to and including penetrations having the following dimensions:
(a) Side damage must be assumed to be as follows:
(1) Longitudinal extent—6 feet (183 centimeters).
(2) Transverse extent—30 inches (76 centimeters).
(3) Vertical extent—from the baseline upward without limit.
(b) Bottom damage must be assumed to be 15 inches (38 centimeters) from the baseline upward.
§ 172.110   Survival conditions.
(a) Paragraphs (c) and (d) of this section apply to a hopper barge and paragraphs (e) through (i) apply to all other tank barges.
(b) A barge is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
(c) A hopper barge must not heel or trim beyond the angle at which—
(1) The deck edge is first submerged; or
(2) If the barge has a coaming that is at least 36 inches (91.5 centimeters) in height, the intersection of the deck and the coaming is first submerged, except as provided in paragraph (d) of this section.
(d) A hopper barge must not heel beyond the angle at which the deck edge is first submerged by more than “fa” as defined in § 172.090(c).
(e) Except as provided in paragraphs (h) and (i) of this section, each tank barge must not heel beyond the angle at which—
(1) The deck edge is first submerged; or
(2) If the barge has one or more watertight trunks, the deck edge is first submerged by more than “fa” as defined in § 172.090(c).
(f) Except as provided in paragraphs (h) and (i) of this section, a tank barge must not trim beyond the angle at which—
(1) The deck edge is first submerged; or
(2) If the barge has one or more watertight trunks, the intersection of the deck and the trunk is first submerged.
(g) If a tank barge experiences simultaneous heel and trim, the trim requirements in paragraph (f) of this section apply only at the centerline.
(h) Except as provided in paragraph (i) of this section, in no case may any part of the actual cargo tank top be underwater in the final condition of equilibrium.
(i) If a barge has a “step-down” in hull depth on either or both ends and all cargo tank openings are located on the higher deck level, the deck edge and tank top in the stepped-down area may be submerged.
§ 172.125   Specific applicability.
This subpart applies to each tankship that carries a cargo listed in Table I of part 153 of this chapter, except that it does not apply to a tankship whose cargo tanks are clean and gas free.
§ 172.127   Definitions.
Length or L means load line length (LLL).
§ 172.130   Calculations.
(a) Except as provided in § 153.7 of this chapter, each tankship must be shown by design calculations to meet the survival conditions in § 172.150 in each condition of loading and operation assuming the damage specified in § 172.133 for the hull type prescribed in part 153 of this chapter.
(b) If a cargo listed in Table I of part 153 of this chapter is to be carried, the vessel must be at least the hull type specified in part 153 of this chapter for that cargo.
§ 172.133   Character of damage.
(a) If a type I hull is required, design calculations must show that the vessel can survive damage at any location.
(b) Except as provided in § 153.7 of this chapter, if a type II hull is required, design calculations must show that a vessel—
(1) Longer than 492 feet (150 meters) in length can survive damage at any location; and
(2) Except as specified in paragraph (d) of this section, 492 feet (150 meters) or less in length can survive damage at any location.
(c) If a Type III hull is required, design calculations must show that a vessel—
(1) Except as specified in paragraph (d) of this section, 410 feet (125 meters) in length or longer can survive damage at any location; and
(2) Less than 410 feet (125 meters) in length can survive damage at any location except to an aft machinery space.
(d) A vessel described in paragraph (b)(2) or (c)(1) of this section need not be designed to survive damage to a main transverse watertight bulkhead bounding an aft machinery space. Except as provided in § 153.7 of this chapter, the machinery space must be calculated as a single floodable compartment.
§ 172.135   Extent of damage.
For the purpose of § 172.133—
(a) Design calculations must include both side and bottom damage, applied separately; and
(b) Damage must consist of the penetrations having the dimensions given in Table 172.135 except that, if the most disabling penetrations would be less than the penetrations given in Table 172.135, the smaller penetration must be assumed.
Table 172.135—Extent of Damage
1 Damage applied inboard from the vessel's side at right angles to the centerline at the level of the summer load line assigned under Subchapter E of this chapter.
2 B is measured amidships.
§ 172.140   Permeability of spaces.
(a) When doing the calculations required in § 172.130, the permeability of a floodable space other than a machinery space must be as listed in Table 172.060(b).
(b) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 0.85, unless the use of an assumed permeability of less than 0.85 is justified in detail.
(c) If a cargo tank would be penetrated under the assumed damage, the cargo tank must be assumed to lose all cargo and refill with salt water up to the level of the tankship's final equilibrium waterline.
§ 172.150   Survival conditions.
A tankship is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
(a) Final waterline. The final waterline, in the final condition of sinkage, heel, and trim, must be below the lower edge of openings such as air pipes and openings closed by weathertight doors or hatch covers. The following types of openings may be submerged when the tankship is at the final waterline:
(1) Openings covered by watertight manhole covers or watertight flush scuttles.
(2) Small watertight cargo tank hatch covers.
(3) A Class 1 door in a watertight bulkhead within the superstructure.
(4) Remotely operated sliding watertight doors.
(5) Side scuttles of the non-opening type.
(b) Heel angle. (1) Except as described in paragraph (b)(2) of this section, the maximum angle of heel must not exceed 15 degrees (17 degrees if no part of the freeboard deck is immersed).
(2) The Commanding Officer, Marine Safety Center will consider on a case by case basis each vessel 492 feet (150 meters) or less in length having a final heel angle greater than 17 degrees but less than 25 degrees.
(c) Range of stability. Through an angle of 20 degrees beyond its position of equilibrium after flooding, a tankship must meet the following conditions:
(1) The righting arm curve must be positive.
(2) The maximum righting arm must be at least 3.95 inches (10 cm).
(3) Each submerged opening must be weathertight.
(d) Progressive flooding. Pipes, ducts or tunnels within the assumed extent of damage must be either—
(1) Equipped with arrangements such as stop check valves to prevent progressive flooding to other spaces with which they connect; or
(2) Assumed in the design calculations required by § 172.130 to flood the spaces with which they connect.
(e) Buoyancy of superstructure. The buoyancy of any superstructure directly above the side damage is to be disregarded. The unflooded parts of superstructures beyond the extent of damage may be taken into consideration if they are separated from the damaged space by watertight bulkheads and no progressive flooding of these intact spaces takes place.
(f) Metacentric height. After flooding, the tankship's metacentric height must be at least 2 inches (50mm) when the ship is in the upright position.
(g) Equalization arrangements. Flooding equalization arrangements requiring mechanical operation such as valves or cross-flooding lines may not be assumed to reduce the angle of heel. Spaces joined by ducts of large cross sectional area are treated as common spaces.
(h) Intermediate stages of flooding. If an intermediate stage of flooding is more critical than the final stage, the tankship must be shown by design calculations to meet the requirements in this section in the intermediate stage.
§ 172.155   Specific applicability.
This subpart applies to each tankship that has on board a bulk liquefied gas listed in Table 4 of part 154 of this chapter as cargo, cargo residue, or vapor.
§ 172.160   Definitions.
As used in this subpart—
(a) Length or L means the load line length (LLL).
(b) MARVS means the Maximum Allowable Relief Valve Setting of a cargo tank.
§ 172.165   Intact stability calculations.
(a) Design calculations must show that 2 inches (50mm) of positive metacentric height can be maintained by each tankship when it is being loaded and unloaded.
(b) For the purpose of demonstrating compliance with the requirements of paragraph (a) of this section, the effects of the addition of water ballast may be considered.
§ 172.170   Damage stability calculations.
(a) Each tankship must be shown by design calculations to meet the survival conditions in § 172.195 in each condition of loading and operation assuming the damage specified in § 172.175 for the hull type specified in Table 4 of part 154 of this chapter.
(b) If a cargo listed in Table 4 of part 154 of this chapter is to be carried, the vessel must be at least the ship type specified in Table 4 of part 154 of this chapter for the cargo.
§ 172.175   Character of damage.
(a) If a type IG hull is required, design calculations must show that the vessel can survive damage at any location.
(b) If a type IIG hull is required, design calculations must show that a vessel—
(1) Longer than 492 feet (150 meters) in length can survive damage at any location; and
(2) 492 feet (150 meters) or less in length can survive damage at any location except the transverse bulkheads bounding an aft machinery space. The machinery space is calculated as a single floodable compartment.
(c) If a vessel has independent tanks type C with a MARVS of 100 psi (689 kPa) gauge or greater, is 492 feet (150 meters) or less in length, and Table 4 of part 154 of this chapter allows a type IIPG hull, design calculations must show that the vessel can survive damage at any location, except as prescribed in paragraph (e) of this section.
(d) If a type IIIG hull is required, except as specified in paragraph (e) of this section, design calculations must show that a vessel—
(1) 410 feet (125 meters) in length or longer can survive damage at any location; and
(2) Less than 410 feet (125 meters) in length can survive damage at any location, except in the main machinery space.
(e) The calculations in paragraphs (c) and (d) of this section need not assume damage to a transverse bulkhead unless it is spaced closer than the longitudinal extent of collision penetration specified in Table 172.180 from another transverse bulkhead.
(f) If a main transverse watertight bulkhead or transverse watertight bulkhead bounding a side tank or double bottom tank has a step or a recess that is longer than 10 feet (3.05 meters) located within the extent of penetration of assumed damage, the vessel must be shown by design calculations to survive damage to this bulkhead. The step formed by the after peak bulkhead and after peak tank top is not a step for the purpose of this regulation.
§ 172.180   Extent of damage.
For the purpose of § 172.170—
(a) Design calculations must include both side and bottom damage, applied separately; and
(b) Damage must consist of the penetrations having the dimensions given in Table 172.180 except that, if the most disabling penetrations would be less than the penetrations given in Table 172.180, the smaller penetration must be assumed.
Table 172.180—Extent of Damage
1 Damage applied inboard from the vessel's side at right angles to the centerline at the level of the summer load line assigned under Subchapter E of this chapter.
2 B is measured amidships.
§ 172.185   Permeability of spaces.
(a) When doing the calculations required in § 172.170, the permeability of a floodable space other than a machinery space must be as listed in Table 172.060(b).
(b) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 85%, unless the use of an assumed permeability of less than 85% is justified in detail.
(c) If a cargo tank would be penetrated under the assumed damage, the cargo tank must be assumed to lose all cargo and refill with salt water up to the level of the tankship's final equilibrium waterline.
§ 172.195   Survival conditions.
A vessel is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
(a) Final waterline. The final waterline, in the final condition of sinkage, heel, and trim, must be below the lower edge of an opening through which progressive flooding may take place, such as an air pipe, or an opening that is closed by means of a weathertight door or hatch cover. This opening does not include an opening closed by a—
(1) Watertight manhole cover;
(2) Flush scuttle;
(3) Small watertight cargo tank hatch cover that maintains the high integrity of the deck;
(4) A Class 1 door in a watertight bulkhead within the superstructure;
(5) Remotely operated sliding watertight door; or
(6) A side scuttle of the non-opening type.
(b) Heel angle. The maximum angle of heel must not exceed 30 degrees.
(c) Range of stability. Through an angle of 20 degrees beyond its position of equilibrium after flooding, a tankship must meet the following conditions:
(1) The righting arm curve must be positive.
(2) The maximum righting arm must be at least 3.94 inches (10 cm).
(3) Each submerged opening must be weathertight.
(d) Progressive flooding. If pipes, ducts, or tunnels are within the assumed extent of damage, arrangements must be made to prevent progressive flooding to a space that is not assumed to be flooded in the damaged stability calculations.
(e) Buoyancy of superstructure. The buoyancy of any superstructure directly above the side damage is to be disregarded. The unflooded parts of superstructures beyond the extent of damage may be taken into consideration if they are separated from the damaged space by watertight bulkheads and no progressive flooding of these intact spaces takes place.
(f) Metacentric height. After flooding, the tank ship's metacentric height must be at least 2 inches (50 mm) when the vessel is in the upright position.
(g) Equalization arrangements. Equalization arrangements requiring mechanical aids such as valves or cross-flooding lines may not be considered for reducing the angle of heel. Spaces joined by ducts of large cross-sectional area are treated as common spaces.
(h) Intermediate stages of flooding. If an intermediate stage of flooding is more critical than the final stage, the tank vessel must be shown by design calculations to meet the requirements in this section in the intermediate stage.
§ 172.205   Local damage.
(a) Each tankship must be shown by design calculations to meet the survival conditions in paragraph (b) of this section in each condition of loading and operation assuming that local damage extending 30 inches (76 cm) normal to the hull shell is applied at any location in the cargo length:
(b) The vessel is presumed to survive assumed local damage if it does not heel beyond the smaller of the following angles in the final stage of flooding:
(1) 30 degrees.
(2) The angle at which restoration of propulsion and steering, and use of the ballast system is precluded.
§ 172.215   Specific applicability.
This subpart applies to each new Great Lakes vessel of 1600 gross tons or more carrying dry cargo in bulk.
§ 172.220   Definitions.
(a) As used in this subpart Length (L), Breadth (B), and Molded Depth (D) are as defined in § 45.3 of this chapter.
(b) As used in this part new Great Lakes Vessel means a vessel operating solely within the limits of the Great Lakes as defined in this subchapter that:
(1) Was contracted for on or after November 17, 1986, or delivered on or after November 17, 1988.
(2) Has undergone a major conversion under a contract made on or after November 17, 1986, or completed a major conversion on or after November 17, 1987.
§ 172.225   Calculations.
(a) Each vessel must be shown by design calculations to meet the survival conditions in § 172.245 in each condition of loading and operation, assuming the damage specified in § 172.230.
(b) When doing the calculations required by paragraph (a) of this section, the virtual increase in the vertical center of gravity due to a liquid in a space must be determined by calculating either—
(1) The free surface effect of the liquid with the vessel assumed heeled five degrees from the vertical; or
(2) The shift of the center of gravity of the liquid by the moment of transference method.
(c) In calculating the free surface effect of consumable liquids, it must be assumed that, for each type of liquid, at least one transverse pair of wing tanks or a single centerline tank has a free surface. The tank or combination of tanks selected must be those having the greatest free surface effect.
(d) When doing the calculations required by paragraph (a) of this section, the buoyancy of any superstructure directly above the side damage must not be considered. The unflooded parts of superstructures beyond the extent of damage may be considered if they are separated from the damaged space by watertight bulkheads and no progressive flooding of these intact spaces takes place.
§ 172.230   Character of damage.
(a) Design calculations must show that each vessel can survive damage—
(1) To any location between adjacent main transverse watertight bulkheads;
(2) To any location between a main transverse bulkhead and a partial transverse bulkhead in way of a side wing tank;
(3) To a main or wing tank transverse watertight bulkhead spaced closer than the longitudinal extent of collision penetration specified in Table 172.235 to another main transverse watertight bulkhead; and
(4) To a main transverse watertight bulkhead or a transverse watertight bulkhead bounding a side tank or double bottom tank if there is a step or a recess in the transverse bulkhead that is longer than 10 feet (3.05 meters) and that is located within the extent of penetration of assumed damage. The step formed by the after peak bulkhead and after peak tank top is not a step for the purpose of this paragraph.
§ 172.235   Extent of damage.
For the purpose of the calculations required in § 172.225—
(a) Design calculations must include both side and bottom damage, applied separately; and
(b) Damage must consist of the penetrations having the dimensions given in Table 172.235 except that, if the most disabling penetrations would be less than the penetrations described in this paragraph, the smaller penetration must be assumed.
Table 172.235—Extent of Damage
1 Damage applied inboard from the vessel's side at right angles to the centerline at the level of the summer load line assigned under Subchapter E of this chapter.
§ 172.240   Permeability of spaces.
When doing the calculations required in § 172.225,
(a) The permeability of a floodable space, other than a machinery or cargo space, must be assumed as listed in Table 172.240;
(b) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 85% unless the use of an assumed permeability of less than 85% is justified in detail; and
(c) Calculations in which a cargo space that is completely filled is considered flooded must be based on an assumed cargo space permeability of 60% unless the use of an assumed permeability of less than 60% is justified in detail. If the cargo space is not completely filled, a cargo space permeability of 95% must be assumed unless the use of an assumed permeability of less than 95% is justified in detail.
Table 172.240—Permeability
1 Whichever results in the more disabling condition.
2 If tanks are partially filled, the permeability must be determined from the actual density and amount of liquid carried.
§ 172.245   Survival conditions.
A vessel is presumed to survive assumed damage if it meets the following conditions in the final stage of flooding:
(a) Final waterline. The final waterline, in the final condition of sinkage, heel, and trim must be below the lower edge of an opening through which progressive flooding may take place, such as an air pipe, or an opening that is closed by means of a weathertight door or hatch cover. This opening does not include an opening closed by a:
(1) Watertight manhole cover;
(2) Flush scuttle;
(3) Small watertight cargo tank hatch cover that maintains the high integrity of the deck;
(4) Class 1 door in a watertight bulkhead;
(5) Remotely operated sliding watertight door;
(6) Side scuttle of the nonopening type;
(7) Retractable inflatable seal; or
(8) Guillotine door.
(b) Heel angle. The maximum angle of heel must not exceed 15 degrees, except that this angle may be increased to 17 degrees if no deck edge immersion occurs.
(c) Range of stability. Through an angle of 20 degrees beyond its position of equilibrium after flooding, a vessel must meet the following conditions:
(1) The righting arm curve must be positive.
(2) The maximum righting arm must be at least 4 inches (10 cm).
(3) Each submerged opening must be weathertight
(d) Metacentric height. After flooding, the metacentric height must be at least 2 inches (50 mm) when the vessel is in the equilibrium position.
(e) Progressive flooding. In the design calculations required by § 172.225, progressive flooding between spaces connected by pipes, ducts or tunnels must be assumed unless:
(1) Pipes within the assumed extent of damage are equipped with arrangements such as stop check valves to prevent progressive flooding to other spaces with which they connect; and,
(2) Progressive flooding through ducts or tunnels is protected against by:
(i) Retractable inflatable seals to cargo hopper gates; or
(ii) Guillotine doors in bulkheads in way of the conveyor belt.