Loading (50 kb)...'
(continued)
(c) For a tankship of less than 20,000 deadweight tons (dwt) carrying crude oil, a tankship of less than 30,000 dwt carrying product, or a tank barge, implement an enhanced survey program that—
(1) Includes oversight of the program by the Coast Guard, the vessel's flag administration, an authorized classification society as described in §157.04 of this part, or a licensed professional engineer;
(2) Has the frequency of survey which is no less than the inspections required by 46 CFR subpart 31.10;
(3) Has survey scope and recordkeeping requirements that are comparable to the requirements of paragraph (a)(1) of this section; and
(4) Includes keeping a copy of the most recent survey on board the vessel or, upon request by the Coast Guard, making the surveys available within 24 hours for examination.
[CGD 91–045, 61 FR 39789, July 30, 1996]
§ 157.435 Vital systems surveys.
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(a) A tank vessel owner or operator shall ensure that surveys of the following systems are conducted:
(1) Cargo systems. The survey must include the examination and testing of the items listed in chapters 6, 7, and 10 of the International Safety Guide for Oil Tankers and Terminals, if applicable, prior to cargo transfer operations.
(2) Mooring systems. The survey must include a visual examination of the emergency towline, the anchor releasing mechanism, and mooring lines prior to entering the port or place of destination, if weather permits, or prior to getting underway.
(b) Surveys must be conducted by company management personnel, company designated individuals, or vessel officers knowledgeable about the equipment operating parameters and having the authority, capability, and responsibility to initiate corrective action when the equipment is not functioning properly.
(c) The results of the survey required in paragraph (a) of this section, including the material condition of each system, must be recorded in the tank vessel's deck log or other onboard documentation.
[CGD 91–045, 61 FR 39789, July 30, 1996; 61 FR 41685, Aug. 9, 1996]
§ 157.440 Autopilot alarm or indicator.
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(a) A tankship owner or operator shall ensure that each installed autopilot unit without automatic manual override has an audible and visual alarm, which is distinct from other required bridge alarms, that will activate if the helm is manually moved while the autopilot is engaged.
(b) A tank barge owner or operator shall ensure that each autopilot unit without automatic manual override installed on the primary towing vessel has a means to clearly indicate the autopilot status and warns personnel of the requirement to disengage the autopilot if positive rudder control is needed.
[CGD 91–045, 61 FR 39790, July 30, 1996]
§ 157.445 Maneuvering performance capability.
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(a) A tankship owner or operator shall ensure that maneuvering tests in accordance with IMO Resolution A.751(18), sections 1.2, 2.3–2.4, 3–4.2, and 5 (with Explanatory Notes in MSC/Circ.644) have been conducted by July 29, 1997. Completion of maneuvering performance tests must be shown by—
(1) For a foreign flag tankship, a letter from the flag administration or an authorized classification society, as described in §157.04 of this part, stating the requirements in paragraph (a) of this section have been met; or
(2) For a U.S. flag tankship, results from the vessel owner confirming the completion of the tests or a letter from an authorized classification society, as described in §157.04 of this part, stating the requirements in paragraph (a) of this section have been met.
(b) If a tankship undergoes a major conversion or alteration affecting the control systems, control surfaces, propulsion system, or other areas which may be expected to alter maneuvering performance, the tankship owner or operator shall ensure that new maneuvering tests are conducted as required by paragraph (a) of this section.
(c) If a tankship is one of a class of vessels with identical propulsion, steering, hydrodynamic, and other relevant design characteristics, maneuvering performance test results for any tankship in the class may be used to satisfy the requirements of paragraph (a) of this section.
(d) The tankship owner or operator shall ensure that the performance test results, recorded in the format of Appendix 6 of the Explanatory Notes in MSC/Circ.644, are prominently displayed in the wheelhouse.
(e) Prior to entering the port or place of destination and prior to getting underway, the tankship master shall discuss the results of the performance tests with the pilot while reviewing the anticipated transit and the possible impact of the tankship's maneuvering capability on the transit.
[CGD 91–045, 61 FR 39790, July 30, 1996; 61 FR 41685, Aug. 9, 1996]
§ 157.450 Maneuvering and vessel status information.
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A tankship owner, master, or operator shall comply with IMO Resolution A.601(15), Annex sections 1.1, 2.3, 3.1, and 3.2, with appendices.
[CGD 91–045, 61 FR 39790, July 30, 1996]
§ 157.455 Minimum under-keel clearance.
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(a) The owner or operator of a tankship, that is not fitted with a double bottom that covers the entire cargo tank length, shall provide the tankship master with written under-keel clearance guidance that includes—
(1) Factors to consider when calculating the ship's deepest navigational draft;
(2) Factors to consider when calculating the anticipated controlling depth;
(3) Consideration of weather or environmental conditions; and
(4) Conditions which mandate when the tankship owner or operator shall be contacted prior to port entry or getting underway; if no such conditions exist, the guidance must contain a statement to that effect.
(b) Prior to entering the port or place of destination and prior to getting underway, the master of a tankship that is not fitted with the double bottom that covers the entire cargo tank length shall plan the ship's passage using guidance issued under paragraph (a) of this section and estimate the anticipated under-keel clearance. The tankship master and the pilot shall discuss the ship's planned transit including the anticipated under-keel clearance. An entry must be made in the tankship's official log or in other onboard documentation reflecting discussion of the ship's anticipated passage.
(c) The owner or operator of a tank barge, that is not fitted with a double bottom that covers the entire cargo tank length, shall not permit the barge to be towed unless the primary towing vessel master or operator has been provided with written under-keel clearance guidance that includes—
(1) Factors to consider when calculating the tank barge's deepest navigational draft;
(2) Factors to consider when calculating the anticipated controlling depth;
(3) Consideration of weather or environmental conditions; and
(4) Conditions which mandate when the tank barge owner or operator shall be contacted prior to port entry or getting underway; if no such conditions exist, the guidance must contain a statement to that effect.
[CGD 91–045, 62 FR 49608, Sept. 23, 1997]
§ 157.460 Additional operational requirements for tank barges.
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(a) Emergency steering capability. The owner or operator of each tank barge shall not permit the barge to be towed unless, by November 27, 1997, the primary towing vessel has—
(1) A steering gear system with a main power unit, an alternative power unit, and two remote steering gear control systems, except that separate steering wheels or steering levers are not required. The steering gear control systems must be arranged so that if the system in operation fails, the other system can be brought into immediate operation from a position on the navigating bridge; or
(2) Twin screw propulsion with separate control systems for each propeller.
(b) Fendering system. An owner or operator of a tank barge shall not permit the barge to be towed unless the primary towing vessel and any fleeting or assist towing vessels have a fendering system that is of substantial size and composition to prevent metal to metal contact between the towing vessel and the barge during maneuvering operations.
[CGD 91–045, 61 FR 39790, July 30, 1996; 61 FR 41685, Aug. 9, 1996]
Subpart H—Interim Measures for Certain Tank Vessels Without Double Hulls Carrying Animal Fat or Vegetable Oil
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Source; CGD 91–045, 61 FR 39791, July 30, 1996, unless otherwise noted.
§ 157.500 Purpose and applicability.
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(a) The purpose of this subpart is to establish mandatory safety and operational requirements to reduce environmental damage resulting from the discharge of animal fat or vegetable oil.
(b) This subpart applies to each tank vessel specified in §157.01 of this part that—
(1) Is 5,000 gross tons or more;
(2) Carries animal fat or vegetable oil in bulk as cargo or cargo residue; and
(3) Is not equipped with a double hull meeting §157.10d of this part, or an equivalent to the requirements of §157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).
§ 157.510 Operational measures.
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An owner or operator of a tank vessel that carries animal fat or vegetable oil in bulk as cargo or cargo residue shall comply with the requirements in all sections of subpart G of this part.
Subpart I—Interim Measures for Certain Tank Vessels Without Double Hulls Carrying Other Non-Petroleum Oil
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Source; CGD 91–045, 61 FR 39791, July 30, 1996, unless otherwise noted.
§ 157.600 Purpose and applicability.
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(a) The purpose of this subpart is to establish mandatory safety and operational requirements to reduce environmental damage resulting from the discharge of other non-petroleum oil.
(b) This subpart applies to each tank vessel specified in §157.01 of this part that—
(1) Is 5,000 gross tons or more;
(2) Carries other non-petroleum oil in bulk as cargo or cargo residue; and
(3) Is not equipped with a double hull meeting §157.10d of this part, or an equivalent to the requirements of §157.10d, but required to be equipped with a double hull at a date set forth in 46 U.S.C. 3703a (b)(3) and (c)(3).
§ 157.610 Operational measures.
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An owner or operator of a tank vessel that carries other non-petroleum oil in bulk as cargo or cargo residue shall comply with the requirements in all sections of subpart G of this part.
Appendix A to Part 157—Damage Assumptions, Hypothetical Outflows, and Cargo Tank Size and Arrangements
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1. Source. The procedures for the damage assumption calculations contained in this Appendix conform to Regulations 22, 23, and 24 of Annex I of the International Convention for the Prevention of the Pollution from Ships, 1973, done at London, November 2, 1973.
2. Assumptions. For the purpose of calculating hypothetical outflow from tank vessels, three dimensions of the extent of damage of a parallelepiped on the side and bottom of the vessel are assumed.
(a) For side damage, the conditions are as follows:
------------------------------------------------------------------------
Damage Conditions
------------------------------------------------------------------------
(1) Longitudinal extent lc................ \1/3\ L2/3 or 14.5 m,
whichever is less.
(2) Transverse extent (tc) (inboard from B
the vessel's side at right angles to the _or 11.5 m, whichever is 5
centerline at the level corresponding to less.
the assigned summer freeboard).
(3) Vertical extent (vc).................. From the base line upwards
without limit.
------------------------------------------------------------------------
(b) For bottom damage, two conditions to be applied individually to the stated portions of the vessel, as follows:
------------------------------------------------------------------------
Conditions
------------------------------------------
Damage For 0.3L from the
forward perpendicular Any other part
of ship of ship
------------------------------------------------------------------------
(1) Longitudinal extent (ls). L/10................... L/10 or 5
meters,
whichever is
less.
(2) Transverse extent (ts)... B/6 or 10 meters, 5 meters.
whichever is less but
not less than 5 meters.
(3) Vertical extent from the B/15 or 6 meters, B/15 or 6
base line (vs). whichever is less. meters,
whichever is
less.
------------------------------------------------------------------------
3. Hypothetical Outflow of Oil. (a) The hypothetical outflow of oil in the case of side damage (Oc) and bottom damage (Os) is calculated by the following formula with respect to compartments breached by damage to all conceivable locations along the length of the vessel to the extent as defined in section 2 of this Appendix.
(1) For side damages: Formula
Oc=SWi+SKiCi
(2) For bottom damage: Formula II
Os= 1/3(SZiWi+SZiCi)
Where:
Wi=Volume of a wing tank assumed to be breached by the damage as specified in section 2 of this Appendix; Wi for a segregated ballast tank may be taken equal to zero;
Ci=Volume of a center tank assumed to be breached by the damage as specified in section 2 of this Appendix; Ci for a segregated ballast tank may be taken equal to zero;
when bi is equal to or greater than tc, Ki is equal to zero;
when hi is equal to or greater than vs, Zi is equal to zero;
bi=Minimum width of wing tank under consideration measured inboard from the vessel's side at right angles to the centerline at the level corresponding to the assigned summer freeboard; and
hi=Minimum depth of the double bottom under consideration; where no double bottom is fitted, hi is equal to zero.
(b) If a void space or segregated ballast tank of a length less than lc is located between wing oil tanks, Oc in formula I of this section may be calculated on the basis of volume Wi being the actual volume of one such tank (where they are of equal capacity) or the smaller of the two tanks (if they differ in capacity), adjacent to such space, multiplied by Si as defined below and taking for all other wing tanks involved in such a collision the value of the actual full volume.
Where li=length of void space or segregated ballast tank under consideration.
(c) Credit is only given in respect to double bottom tanks which are either empty or carrying clean water when cargo is carried in the tanks above.
(1) If the double bottom does not extend for the full length and width of the tank involved, the double bottom is considered nonexistent and the volume of the tanks above the area of the bottom damage must be included in formula II of this section even if the tank is not considered breached because of the installation of such a partial double bottom.
(2) Suction wells may be neglected in the determination of the value hi if such wells are not excessive in area and extend below the tank for a minimum distance and in no case more than half the height of the double bottom. If the depth of such a well exceeds half the height of the double bottom, hi is taken equal to the double bottom height minus the well height.
(d) In the case where bottom damage simultaneously involves four center tanks, the value of Os may be calculated according to formula III as follows:
Os= 1/4(SZiWi+SZiCi)
(e) Credit for reduced oil outflow from bottom damage may be applied to formula III for an installed emergency high suction cargo transfer system that:
(1) transfers within two hours oil equal to one half of the volume of the largest tank involved;
(2) has sufficient ballast or cargo tankage available to receive the transferred oil; and
(3) has the high suction piping installed at a height not less than the vertical extent of bottom damage (vs).
4. Allowable volumes of cargo tanks.
(a) The allowable volume of a wing cargo tank (VOLw) is equal to seventy-five percent of OA. In a segregated ballast tank vessel VOLw may equal OA for a wing cargo oil tank located between two segregated ballast tanks each of length greater than lc and width greater than tc.
(b) The allowable volume of a center cargo tank (VOLc) is 50,000 cubic meters.
5. Allowable length of cargo tanks.
The length of each cargo tank (1 a) must not exceed 10 meters or the distance calculated from (a), (b), or (c), as appropriate, whichever is greater:
(a) Where no longitudinal bulkhead is provided inside the cargo tanks: 1 a=[0.5(bi/B)+0.1] L, but not to exceed 0.2L.
(b) Where a centerline longitudinal bulkhead is provided inside the cargo tanks: 1 a=[0.25(bi/B)+0.15] L, but not to exceed 0.2L.
(c) Where two or more longitudinal bulkheads are provided inside the cargo tanks:
(1) For wing cargo tanks: 1 a = 0.2L.
(2) For center cargo tanks:
(i) If (bi/B) is equal to or greater than 0.2, 1 a = 0.2L.
(ii) If (bi/B) is less than 0.2:
(A) Where no centerline longitudinal bulkhead is provided, 1 a = [0.5(bi/B) + 0.1] L.
(B) Where a centerline longitudinal bulkhead is provided, 1 a = [0.25(bi/B) + 0.15] L.
(d) “bi” is the minimum distance from the ship's side to the outer longitudinal bulkhead of the tank in question, measured inboard at right angles to the centerline at the level corresponding to the assigned summer freeboard.
[CGD 74–32, 40 FR 48283, Oct. 14, 1975, as amended by CGD 74–32, 40 FR 49328, Oct. 22, 1975; CGD 90–051, 57 FR 36245, Aug. 12, 1992]
Appendix B to Part 157—Subdivision and Stability Assumptions
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1. Source. The procedures for the loading assumption calculations contained in this Appendix conform to Regulation 25 of Annex I of the International Convention for the Prevention of the Pollution from Ships, 1973, done at London, November 2, 1973.
2. Loading Assumptions. For the purpose of calculating subdivision and damage stability for a tank vessel, the operating drafts must reflect actual partial or full load conditions consistent with trim and strength of the vessel. Ballast conditions need not be considered if the tank vessel is not carrying oil in cargo tanks excluding oily residues. Loading condition must reflect the specific gravities of the cargo.
3. Damage Assumptions.
(a) Damage is applied to all conceivable locations along the length of the vessel as follows:
(1) For a vessel of more than 225 meters in length, anywhere in the vessel's length.
(2) For a vessel of more than 150 meters, but not exceeding 225 meters in length, anywhere in the vessel's length except where the after or forward bulkhead bounding a machinery space located aft is involved in the damage assumption. The machinery space is calculated as a single floodable compartment.
(3) For a vessel 150 meters or less in length, anywhere in the vessel's length between adjacent transverse bulkheads except the machinery space.
(b) The extent and the character of the assumed side or bottom damage, as defined in section 2 of Appendix A of this part, must be applied except longitudinal bottom damage within 0.3L from the forward perpendicular must be assumed to be the same as that for side damage. If any damage of lesser extent results in a more severe condition, such damage must be assumed.
(c) If damage involves transverse bulkheads as specified in paragraphs (a)(1) and (2) of this section, transverse watertight bulkheads must be spaced at least at a distance equal to the longitudinal extent of the assumed damage specified in paragraph (b) of this section in order to be considered effective. Where transverse bulkheads are spaced at a lesser distance, one or more of these bulkheads within such extent of damage must be assumed as nonexistent for the purpose of determining flooded compartments.
(d) If the damages between adjacent transverse watertight bulkheads is within the definition contained in paragraph (a)(3) of this section, no main transverse bulkhead or a transverse bulkhead bounding side tanks or double bottom tanks is to be assumed damaged, unless:
(1) the spacing of the adjacent bulkheads is less than the longitudinal extent of assumed damage defined in paragraph (b) of this section; or
(2) there is a step or a recess in a transverse bulkhead of more than 3.05 meters in length, located within the extent of penetrations of assumed damage. The step formed by the after peak bulkhead and after peak tank top is not regarded as a step for these calculations.
(e) If pipes, ducts, or tunnels are situated within the assumed extent of damage, there must be arrangements so that progressive flooding may not thereby extend to compartments other than those assumed to be floodable for each case of damage.
(f) For oil tankers of 20,000 DWT and above, the damage assumptions must be supplemented by the following assumed bottom raking damage:
(1) Longitudinal extent:
(i) For ships of 75,000 DWT and above, 0.6L measured from the forward perpendicular.
(ii) For ships of less than 75,000 DWT, 0.4L measured from the forward perpendicular.
(2) Transverse extent: B/3 anywhere in the bottom.
(3) Vertical extent: Breach of the outer hull.
4. Characteristic and Condition Assumption for Calculations.
(a) Account must be taken of any empty or partially filled tanks, the specific gravity of cargoes carried, and any outflow of liquids from damaged compartments.
(b) The permeabilities are assumed as follows:
------------------------------------------------------------------------
Intended space use Permeability
------------------------------------------------------------------------
Stores.................................................... 0.60
Accommodation............................................. 0.95
Machinery................................................. 0.85
Voids..................................................... 0.95
Consumable liquids........................................ \1\ 0 or
0.95
Other liquids............................................. \2\ 10 or
0.95
------------------------------------------------------------------------
\1\ Whichever results in the more severe requirements.
\2\ The permeability of partially filled compartments must be consistent
with actual density and the amount of liquid carried.
(c) 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. Class I doors are allowed in watertight bulkheads in the superstructure.
(d) The free surface effect is to be calculated:
(1) at an angle of heel of 5 degrees for each individual compartment; or
(2) by assessing the shift of liquids by moment of transference calculations.
(e) In calculating the effect of free surfaces of consumable liquids, it is to be assumed that, for each type of liquid, at least one transverse pair or a single centerline tank has a free surface and the tank or combination of tanks to be taken into account is to be those where the effect of free surface is the greatest.
[CGD 74–32, 40 FR 48283, Oct. 14, 1975, as amended by USCG–2000–7641, 66 FR 55573, Nov. 2, 2001]
Appendix C to Part 157—Procedure for Determining Distribution of Segregated Ballast Tanks To Provide Protection Against Oil Outflow in the Event of Grounding, Ramming, or Collision
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1. Source. The procedure for determining the distribution of segregated ballast tanks contained in this appendix conforms to Regulation 13E of the MARPOL Protocol.
2. Procedure. Protective location of segregated ballast tanks, voids, and other spaces that do not carry cargo which are within the cargo tank length is determined from the following:
S PAc+S PAs=J[Lt(B+2D)]
Where:
PAc=the side shell area in square meters based on projected molded dimensions for each segregated ballast tank, void, or other space that does not carry cargo and which complies with paragraph 2(b) of this appendix;
PAs=the bottom shell area in square meters based on projected molded dimensions for each segregated ballast tank, void, or other space that does not carry cargo and which complies with paragraph 2(b) of this appendix;
Lt=the length in meters between the forward and after extremities of the cargo tanks;
B=the maximum breadth of the ship in meters measured amidship to the molded line of the frame; and
D=the molded depth in meters measured vertically from the top of the keel plate to the top of the freeboard deck beam at the side amidships. In tank vessels having rounded gunwales, the molded depth is measured from the top of the keel plate to the point of intersection of the molded lines of the deck and side shell plating, the lines being extended as though the gunwale were of angular design.
(a) Method of determining a value for J.
(1) For tank vessels for 20,000 DWT, J=0.45.
(2) For tank vessels of 200,000 DWT or more:
(i) J=0.30; or
(ii) J=the greater of 0.20, or
where:
a=0.25 for tank vessels of 200,000 DWT.
a=0.40 for tank vessels of 300,000 DWT.
a=0.50 for tank vessels of 420,000 DWT.
For values of DWT between 200,000 and 300,000 DWT, 300,000 and 420,000 DWT, and greater than 420,000 DWT, the value of “a” is determined by linear interpolation.
Oc = as calculated in Appendix A of this part.
Os = as calculated in Appendix A of this part.
OA = the allowable oil outflow meeting §157.19(b)(1) of this part.
(3) For values of DWT between 20,000 and 200,000 DWT, the value of “J” is determined by linear interpolation between 0.45 and 0.30 respectively.
(b) PAc and PAs: Criteria for determining the segregated ballast tanks, voids, and other spaces that do not carry cargo.
The following criteria are to be met for a segregated ballast tank, void, or space that does not carry cargo, to be used in determining PAc and PAs:
(1) The minimum width of each wing tank or space, either of which extends for the full depth of the vessel's side or from the main deck to the top of the double bottoms is 2 meters or more. The width is measured inboard from the vessel's side shell plating at right angles to the vessel's center line. If a wing tank or space has a width anywhere within it that is less than 2 meters, that wing tank or space is not used when calculating PAc.
(2) The minimum vertical depth of each double bottom tank or space is B/15 or 2 meters, whichever is smaller. If a double bottom tank or space has a depth less than B/15 or 2 meters, whichever is smaller, anywhere within it, the double bottom or space is not to be used when calculating PAs.
(3) The minimum width of a wing tank or space is not measured in the way of—
(i) the turn of the bilge area; or
(ii) a rounded gunwale area.
(4) The minimum depth of a double bottom tank or space is not measured in the way of the turn of the bilge area.
[CGD 77–058b, 45 FR 43716, June 30, 1980]
Appendix D to Part 157—Example of a Procedure for Dedicated Clean Ballast Tanks Operations
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1. Source. The example procedure for dedicated clean ballast tanks operation contained in this appendix conforms to the Annex of Resolution 14 of the MARPOL Protocol.
2. Example Procedure. Dedicated clean ballast tanks operational procedure:
(a) Before arrival at the loading port:
(1) Transfer all remaining oily mixtures to a cargo tank.
(2) Ensure that the pumping and piping designated for clean ballast operation have been properly cleaned to accommodate simultaneous discharge of clean ballast while loading.
(3) Ensure that all valves to the slop tank and the cargo tanks are closed.
(4) Perform visual inspection of all dedicated clean ballast tanks and their contents, if any, for signs of contamination.
(5) Discharge a sufficient amount of clean ballast water to ensure that remaining ballast water and cargo to be loaded will not exceed the permissible deadweight or draft. Leave a sufficient amount of water for flushing the piping, and as a minimum, a quantity equal to 10 times the volume of the affected piping.
(6) Ensure that all valves to the dedicated clean ballast tanks are closed.
(7) If no further ballast discharge is anticipated, drain the clean ballast piping.
(b) In the loading port:
(1) Perform normal loading operations of cargo tanks.
(2) Ensure sufficient slop tank capacity is available for subsequent reception of cargo pump and piping flushings.
(3) When applicable, discharge remaining clean ballast before entire piping system is used for loading. Leave the required minimum quantity of flushing water in ballast tanks.
(4) Ensure that all valves to the dedicated clean ballast tanks are closed.
(5) Ensure that all valves to the cargo tank are closed upon completion of loading.
(c) After departure from the loading port:
(1) Flush appropriate pumping and piping with sufficient water from dedicated clean ballast tanks into a slop tank.
(2) Ensure that valves to the slop tank are closed before pumping the remaining clean water overboard and monitoring oil content of the water.
(3) Ensure that all valves in the dedicated clean ballast tanks are closed.
(d) Before arrival at the unloading port:
(1) Ensure that all valves to the slop tank and cargo tanks are closed.
(2) Recheck that the pumping and piping designated for clean ballast operation have been properly cleaned.
(3) Ballast through clean cargo pumps and piping, considering the port's draft requirements.
(4) Ensure that all valves in the dedicated clean ballast tanks are closed.
(e) In the unloading port:
(1) Allocate pumping and piping intended for clean ballast operation.
(2) Perform normal unloading operations.
(3) As soon as draft conditions permit, complete ballasting to departure conditions.
(4) Ensure that all valves to the dedicated clean ballast tanks are closed.
(5) Complete unloading.
(f) After departure from the unloading port:
(1) Flush pumps and piping servicing the dedicated clean ballast tanks into the slop tank.
(2) Top up dedicated clean ballast tanks.
(3) Process the slop tank content in accordance with load on top (LOT) procedures.
[CGD 77–058b, 45 FR 43717, June 30, 1980, as amended by USCG–2000–7641, 66 FR 55573, Nov. 2, 2001]
Appendix E to Part 157—Specifications for the Design, Installation and Operation of a Part Flow System for Control of Overboard Discharges
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Source. Appendix 2 to Annex 5 of IMO's Marine Environment Protection Committee document MEPC/Circ. 97. Paragraphs 1 and 2 are printed for information. Paragraphs 3, 4, and 5 are incorporated into §§157.11 and 157.37.
Note: Information in square brackets on Figure 1 has been added by the Coast Guard for clarity.
1 Purpose
The purpose of these Specifications is to provide specific design criteria and installation and operational requirements for the part flow system referred to in Regulation 18(6)(e) of Annex I of the International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978 relating thereto.
2 Application
2.1 Existing oil tankers may, in accordance with Regulation 18(6)(e) of Annex I of MARPOL 73/78, discharge dirty ballast water and oil contaminated water from cargo tank areas below the waterline, provided part of the flow is led through permanent piping to a readily accessible location on the upper deck or above where it may be visually observed during the discharge operation and provided that the arrangements comply with the requirements established by the Administration and which shall at least contain all the provisions of these Specifications.
2.2 The part flow concept is based on the principle that the observation of a representative part flow of the overboard effluent is equivalent to observing the entire effluent stream. These specifications provide the details of the design installation, and operation of a part flow system.
3 General Provisions
3.1 The part flow system shall be so fitted that it can effectively provide a representative sample of the overboard effluent for visual display under all normal operating conditions.
3.2 The part flow system is in many respects similar to the sampling system for an oil discharge monitoring and control system but shall have pumping and piping arrangements separate from such a system, or combined equivalent arrangements acceptable to the Administration.
3.3 The display of the part flow shall be arranged in a sheltered and readily accessible location on the upper deck or above, approved by the Administration (e.g. the entrance to the pump room). Regard should be given to effective communication between the location of the part flow display and the discharge control position.
3.4 Samples shall be taken from relevant sections of the overboard discharge piping and be passed to the display arrangement through a permanent piping system.
3.5 The part flow system shall include the following components:
.1 Sampling probes;
.2 Sample water piping system;
.3 Sample feed pump(s);
.4 Display arrangement;
.5 Sample discharge arrangement; and, subject to the diameter of the sample piping:
.6 Flushing arrangement.
.3.6 The part flow system shall comply with the applicable safety requirements.
4 System Arrangement
4.1 Sampling points.
4.1.1 Sampling point locations:
.1 Sampling points shall be so located that relevant samples can be obtained of the effluent being discharged through outlets below the waterline which are being used for operational discharges.
.2 Sampling points shall as far as practicable be located in pipe sections where a turbulent flow is normally encountered.
.3 Sampling points shall as far as practicable be arranged in accessible locations in vertical sections of the discharge piping.
4.1.2 Sampling probes:
.1 Sampling probes shall be arranged to protrude into the pipe a distance of about one fourth of the pipe diameter.
.2 Sampling probes shall be arranged for easy withdrawal for cleaning.
.3 The part flow system shall have a stop valve fitted adjacent to each probe, except that were the probe is mounted in a cargo line, two stop valves shall be fitted in series, in the sample line.
.4 Sampling probes should be of corrosion resistant and oil resistant material, of adequate strength, properly jointed and supported.
.5 Sampling probes shall have a shape that is not prone to becoming clogged by particle contaminants and should not generate high hydrodynamic pressures at the sampling probe tip. Figure 1 is an example of one suitable shape of a sampling probe.
.6 Sampling probes shall have the same nominal bore as the sample piping.
4.2 Sample piping:
.1 The sample piping shall be arranged as straight as possible between the sampling points and the display arrangement. Sharp bends and pockets where settled oil or sediment may accumulate should be avoided.
.2 The sample piping shall be so arranged that sample water is conveyed to the display arrangement within 20 seconds. The flow velocity in the piping should not be less than 2 metres per second.
.3 The diameter of the piping shall not be less than 40 millimetres if no fixed flushing arrangement is provided and shall not be less than 25 millimetres if a pressurized flushing arrangement as detailed in paragraph 4.4 is installed.
.4 The sample piping should be of corrosion-resistant and oil-resistant material, of adequate strength, properly jointed and supported.
.5 Where several sampling points are installed the piping shall be connected to a valve chest at the suction side of the sample feed pump.
4.3 Sample feed pump:
.1 The sample feed pump capacity shall be suitable to allow the flow rate of the sample water to comply with 4.2.2.
4.4 Flushing arrangement:
.1 If the diameter of sample piping is less than 40 millimetres, a fixed connexion from a pressurized sea or fresh water piping system shall be installed to enable flushing of the sample piping system.
4.5 Display arrangement:
.1 The display arrangement shall consist of a display chamber provided with a sight glass. The chamber should be of a size that will allow a free fall stream of the sample water to be clearly visible over a length of at least 200 millimetres. The Administration may approve equivalent arrangements.
.2 The display arrangement shall incorporate valves and piping in order to allow a part of the sample water to bypass the display chamber to obtain a laminar flow for display in the chamber.
.3 The display arrangement shall be designed to be easily opened and cleaned.
.4 The internal of the display chamber shall be white except for the background wall which shall be so coloured in order to facilitate the observation of any change in the quality of the sample water.
.5 The lower part of the display chamber shall be shaped as a funnel for collection of the sample water.
.6 A test cock for taking a grab sample shall be provided in order that a sample of the water can be examined independent of that in the chamber.
.7 The display arrangement shall be adequately lighted to facilitate visual observation of the sample water.
4.6 Sample discharge arrangement:
.1 The sample water leaving the display chamber shall be routed to the sea or to a slop tank through piping of adequate diameter.
5 Operation
5.1 When a discharge of dirty ballast water or other oil contaminated water from the cargo tank area is taking place through an outlet below the waterline, the part flow system shall provide sample water from the relevant discharge outlet at all times.
5.2 The sample water should be observed particularly during those phases of the discharge operation when the greatest possibility of oil contamination occurs. The discharge shall be stopped whenever any traces of oil are visible in the flow and when the oil content meter reading indicates oil content exceeds permissible limits.
5.3 On those systems that are fitted with flushing arrangements, the sample piping should be flushed after contamination has been observed and additionally it is recommended that the sample piping be flushed after each period of usage.
5.4 The ship's cargo and ballast handling manuals and, where applicable, those manuals required for crude oil washing systems or dedicated clean ballast tanks operation shall clearly describe the use of the part flow system in conjunction with the ballast discharge and the slop tank decanting procedures.
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[CGD 75–124a, 48 FR 45721, Oct. 6, 1983]
Appendix F to Part 157—Guidelines and Specifications for Oil Discharge Monitoring and Control Systems for Tankers
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Source. IMO Resolution A.496(XII). Paragraphs 1, 2, 3, and 7 are printed for information. Paragraphs 4, 5, and 6 are incorporated into §157.12.
Mandatory Language. Wherever the word “should” is used in this appendix, substitute the word “shall”. Compliance with these provisions is mandatory.
Note. Numbered footnotes have been added by the Coast Guard for clarity. Footnotes in the original text have been inserted parenthetically in the text and are identified by an asterisk.
1 Purpose
1.1 The purpose of these Guidelines and Specifications is:
.1 To provide a uniform interpretation of the requirements of Regulation 15(3)(a) of Annex I to the MARPOL 73/78 Convention(1), and
.2 To assist Administrations in determining appropriate design, construction and operational parameters for oil discharge monitoring and control systems when such systems are fitted in ships flying the flag of their State.
2 Background
2.1 The requirements of Annex I to the MARPOL 73/78 Convention relating to oil content monitoring of oil tanker ballast and tank washing water are contained in Regulation 15(3)(a), which stipulates that oil tankers of 150 tons gross tonnage and above shall be equipped with an approved oil discharge monitoring and control system and that the system shall record continuously:
.1 The discharge of oil in litres per nautical mile and total quantity of oil discharge; or
.2 In lieu of the total quantity of oil discharged, the oil content of the effluent and rate of discharge.
In both cases the record shall be “identifiable as to time and date” and shall be kept for at least three years.
2.2 Regulation 15 also stipulates that the system shall come into operation when there is any discharge of effluent into the sea and shall be such as will ensure that any discharge of oily mixture is automatically stopped when the instantaneous rate of discharge of oil exceeds that permitted by Regulation 9(1)(a). In existing oil tankers the stopping of the discharge may be performed manually and the rate of discharge may be estimated from the pump characteristics.
2.3 A test and performance specification for the basic oil content meter, indicating oil content in ppm, has been adopted by Resolution A.393(X).
2.4 Resolution A.445(XI) recognizes the need for early installation of oil discharge monitoring and control systems in order that operational experience can be gained. That resolution further invites the Marine Environment Protection Committee (MEPC) to develop guidelines for the progressive installation of oil discharge monitoring and control systems for new and existing oil tankers.
3 Application
3.1 An oil discharge monitoring and control system, approved by the Administration, shall be fitted in every oil tanker of 150 tons gross tonnage and above, and shall be fitted in:
.1 New (*as defined in Regulation 1(6))(2) tankers, on the date of entry into force of the Convention;
.2 Existing tankers, within three years of the date of entry into force of the Convention.
3.2 Existing tankers operating with a tank cleaning procedure using crude oil washing in accordance with Regulation 13(8) or with dedicated clean ballast tanks in accordance with Regulation 13(9) must fit an oil content meter not later than the first scheduled shipyard visit after entry into force of the Convention.
3.3 An incentive scheme to encourage the early installation of oil discharge monitoring and control systems (Resolution A.445(XI)) has been developed which allows different requirements depending on the date of installation of the system and the size and building date of the oil tanker. The terms used in the description of the various requirements are defined in section 4 below.
4 Definitions
4.1 “Oil discharge monitoring and control system”
4.1.1 Oil discharge monitoring and control system is a general term covering any one of the units referred to in paragraphs 4.2, 4.3, and 4.4.
4.2 “Control unit”
4.2.1 A control unit is a system which receives automatic signals of:
.1 Oil content;
.2 Flow rate of discharge;
.3 Ship's speed;
.4 Date and time (G.M.T.); and
.5 Discharge valve position (open or closed).
4.2.2 The unit shall make automatic recordings of:
.1 Instantaneous rate of discharge of oil;
.2 Total quantity of oil discharged;
.3 Date and time (G.M.T.);
.4 Discharge valve position (open or closed);
.5 Alarm condition;
.6 Failure (i.e., no flow, fault etc.); and
.7 Override action (i.e., manual override, flushing, calibration etc.).
4.2.3 The unit shall be fitted with a starting interlock and discharge valve control capability. The unit shall meet the specifications contained in the relevant paragraphs of section 6.
4.3 “Computing unit”.
4.3.1 A computing unit is a system which receives automatic signals of:
.1 Oil content;
.2 Date and time (G.M.T.);
.3 Discharge valve activation;
.4 Flow rate of discharge; and
.5 Ship's speed in knots.
The flow rate and ship's speed may be manually inserted into the unit.
4.3.2 The unit shall make automatic recordings of:
.1 Instantaneous rate of discharge of oil;
.2 Total quantity of oil discharged;
.3 Date and time (G.M.T.);
.4 Discharge valve position (open or closed);
.5 Alarm condition;
.6 Failure (i.e., no flow, fault etc.);
.7 Override action;
.8 Manual input (i.e., speed, flow); and
.9 Oil content if the flow rate has been manually inserted.
4.3.3 Unless explicitly stated in the Implementation Requirements (see section 5 below) the unit need not be fitted with a starting interlock or discharge valve control capability.
4.3.4 The unit shall meet the specifications contained in the relevant paragraphs of section 6.
4.4 “Calculating unit”.
4.4.1 A calculating unit is a system which received automatic signals of:
.1 Oil content;
.2 Flow rate of discharge; and
.3 Ship's speed.
The flow rate and ship's speed may be manually inserted into the unit.
4.4.2 The unit shall make an automatic recording of:
.1 Oil content, unless the oil content meter is provided with a recorder.
4.4.3 The unit shall display:
.1 Instantaneous rate of discharge of oil;
.2 Total quantity of oil discharged, unless permitted to be calculated manually.
4.4.4 The time and date, instantaneous rate of discharge of oil and, the total quantity of oil discharged may be recorded manually.
4.4.5 The unit need not be fitted with a starting interlock nor discharge valve control capability.
4.4.6 The unit shall meet the specifications contained in the relevant paragraphs of section 6.
4.5 “Starting interlock” is an automatic device which prevents the initiation of the opening of the discharge valve before the monitoring and control system is fully operational when use of this system is required by the Convention.
4.6 The “discharge valve control” is an automatic device which initiates the sequence to stop the overboard discharge.
5 Implementation Requirements
5.1 To assist in the implementation of Resolution A.445(XI), an implementation scheme has been developed by the MEPC which provides slightly different requirements for oil discharge monitoring and control systems depending on size and building date of the oil tanker. The scheme also allows for different requirements, depending on the installation date of the system.
5.2 Under the implementation scheme contained in paragraph 5.4 oil tankers of 150 tons gross tonnage and above have been arranged into five categories. Each category of oil tanker shall be fitted with an oil discharge monitoring and control system as set out below. The definitions given in section 4 should be consulted for a description of the different systems.
5.3 The implementation scheme set out in paragraph 5.4 gives details, with reference to paragraph 4, of the minimum equipment required to comply with this scheme. Where it is expedient to fit equipment of a higher category than required no objection shall be raised to this arrangement.
5.4 Implementation scheme:
5.4.1 Category I—
.1 An oil tanker of this category is of 4,000 tons deadweight and above and is a “new ship” as defined in Regulation 1(6) of Annex I of MARPOL 73/78 and the oil discharge monitoring and control system is installed on or after 1 June 1982.
.2 This category of ship shall be fitted with a control unit as defined under paragraph 4.2.
5.4.2 Category II—
.1 An oil tanker of this category is of 4,000 tons deadweight and above and is a “new ship” as defined in Regulation 1(6) of Annex I of MARPOL 73/78 and the oil discharge monitoring and control system is installed before 1 June 1982.
.2 This category of ship shall be fitted with a computing unit as defined under paragraph 4.3.
.3 The system shall also be fitted with a starting interlock and a discharge valve control.
5.4.3 Category III—
.1 An oil tanker of this category is of 150 tons gross tonnage and above, but less than 4,000 tons deadweight and is a “new ship” as defined in Regulation 1(6) of Annex I of MARPOL 73/78.
.2 This category of ship shall be fitted with a computing unit as defined under paragraph 4.3.
.3 No automatic devices are required to activate overboard discharge valve closure, neither is a starting interlock required.
5.4.4 Category IV(a)—
.1 An oil tanker of this category is of 20,000 tons deadweight and above and is an “existing ship” as defined in Regulation 1(7) of Annex I of MARPOL 73/78 and the oil discharge monitoring and control system is installed between one year and three years after the date of entry into force of MARPOL 73/78.
.2 This category of ship shall be fitted with a computing unit as defined under paragraph 4.3.
.3 The system shall also be fitted with a starting interlock, but need not be fitted with a discharge valve control.
.4 For oil tankers within this category up to and including 100,000 tons deadweight, where the overboard discharge has local manual control or where control is provided by means of extension rods, Administrations may grant waivers or exemptions from the requirement to fit a starting interlock system (3).
5.4.5 Category IV(b)—
.1 An oil tanker of this category is of 20,000 tons deadweight and above and is an “existing ship” as defined in Regulation 1(7) of Annex I of MARPOL 73/78 and the oil discharge monitoring and control system is installed not later than one year after the date of entry into force of MARPOL 73/78. (continued)