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資料
資料1 Annex I 改正案（BLG8/18/Add.1）から抜粋、Reg.21 Accidental oil outflow performance
資料2 詳細計算手法の解説
資料3 簡易計算方法の例（VLCCを用いた計算例、ステップbyステップの解説）
資料4 係数C3の解説
資料1 Annex I 改正案（BLG8/18/Add.1）から抜粋 “Reg.21 Accidental oil outflow performance”
ANNEX 5
DRAFT REVISED MARPOL ANNEX I
（省略）
Regulation 21
Accidental oil outflow performance
1 This regulation shall apply to oil tankers delivered on or after [date of entry into force of revised Annex I plus 36 months] as defined in regulation 1.28.8.
2 For the purpose of this regulation, the following definitions shall apply:
.1 "Load line draught (dS)" is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to the summer freeboard to be assigned to the ship. Calculations pertaining to this regulation should be based on draught dS, notwithstanding assigned draughts that may exceed dS, such as the tropical loadline.
.2 "Waterline (dB)" is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to 30% of the depth DS.
.3 "Breadth (BS)" is the greatest moulded breadth of the ship, in metres, at or below the deepest load line dS.
.4 "Breadth (BB)" is the greatest moulded breadth of the ship, in metres, at or below the waterline dB.
.5 the tanker operates with hydrostatically balanced loading, taking into account the guidelines developed by the Organization*.
3 The Administration may allow continued operation of a Category 1 oil tanker beyond the anniversary of the date of delivery of the ship in 2005, and of a Category 2 oil tanker beyond the anniversary of the date of delivery of the ship in 2010, subject to compliance with the Condition Assessment Scheme adopted by the Marine Environment Protection Committee by resolution MEPC.94(46), as may be amended, provided that such amendments shall be adopted, brought into force and take effect in accordance with the provisions of article 16 of the present Convention relating to amendment procedures applicable to an appendix to an Annex.
4 .1 The Administration of a State which allows the application of paragraph 5 of this regulation, or allows, suspends, withdraws or declines the application of paragraph 7 of this regulation, to a ship entitled to fly its flag shall forthwith communicate to the Organization for circulation to the Parties to the present Convention particulars thereof, for their information and appropriate action, if any.
.2 A Party to the present Convention shall be entitled to deny entry of an oil tanker operating in accordance with the provisions of paragraph 5 of this regulation into the ports or offshore terminals under its jurisdiction. In such cases, that Party shall communicate to the Organization for circulation to the Parties to the present Convention particulars thereof for their information.
Regulation 21
Accidental oil outflow performance
1 This regulation shall apply to oil tankers delivered on or after [date of entry into force of revised Annex I plus 36 months] as defined in regulation 1.28.8.
2 For the purpose of this regulation, the following definitions shall apply:
.1 "Load line draught (dS)" is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to the summer freeboard to be assigned to the ship. Calculations pertaining to this regulation should be based on draught dS, notwithstanding assigned draughts that may exceed dS, such as the tropical loadline.
.2 "Waterline (dB)" is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to 30% of the depth DS.
.3 "Breadth (BS)" is the greatest moulded breadth of the ship, in metres, at or below the deepest load line dS.
.4 "Breadth (BB)" is the greatest moulded breadth of the ship, in metres, at or below the waterline dB.
.5 "Depth (DS)" is the moulded depth, in metres, measured at mid-length to the upper deck at side.
.6 "Length (L)" and "deadweight (DW)" are as defined in regulations 1.19 and 1.23 respectively.
3 To provide adequate protection against oil pollution in the event of collision or stranding the following shall be complied with:
.1 for oil tankers of 5,000 tonnes deadweight (DWT) and above, the mean oil outflow parameter shall be as follows:
OM≤0.015 for C≤200,000 m3
OM≤0.012 + (0.003/200,000) (400,000-C) for 200,000 m3<C<400,000 m3
OM≤0.012 for C≥400,000 m3
for combination carriers between 5,000 tonnes deadweight (DWT) and 200,000 m3 capacity, the mean oil outflow parameter may be applied, provided calculations are submitted to the satisfaction of the Administration, demonstrating that after accounting for its increased structural strength, the combination carrier has at least equivalent oil out flow performance to a standard double hull tanker of the same size having a OM < = 0.015.
OM≤0.021 for C≤100,000m3
OM≤0.015 + (0.006/100,000) (200,000-C) for 100,000 m3<C≤200,000m3
where:
OM = mean oil outflow parameter.
C = total volume of cargo oil, in m3, at 98% tank filling
.2 for oil tankers of less than 5,000 tonnes deadweight (DWT):
The length of each cargo tank shall not exceed 10 m or one of the following values. whichever is the greater:
.1 where no longitudinal bulkhead is provided inside the cargo tanks:
.2 where a centreline longitudinal bulkhead is provided inside the cargo tanks:
.3 where two or more longitudinal bulkheads are provided inside the cargo tanks:
.1 for wing cargo tanks: 0.2L
.2 for centre cargo tanks:
- where no centreline longitudinal bulkhead is provided:
- where a centreline longitudinal bulkhead is provided:
.4 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 centreline at the level corresponding to the assigned summer freeboard.
4 The following general assumptions shall apply when calculating the mean oil outflow parameter:
.1 The cargo block length extends between the forward and aft extremities of all tanks arranged for the carriage of cargo oil, including slop tanks.
.2 Where this regulation refers to cargo tanks, it shall be understood to include all cargo tanks, slop tanks and fuel tanks located within the cargo block length.
.3 The ship shall be assumed loaded to the load line draught dS without trim or heel.
.4 All cargo oil tanks shall be assumed loaded to 98% of their volumetric capacity. The nominal density of the cargo oil (ρn) shall be calculated as follows:
ρn = 1000 (DWT)/C (kg/m3)
.5 For the purposes of these outflow calculations, the permeability of each space within the cargo block, including cargo tanks, ballast tanks and other non-oil spaces shall be taken as 0.99, unless proven otherwise.
.6 Suction wells may be neglected in the determination of tank location provided that such wells are as small as practicable and the distance between the well bottom and bottom shell plating is not less than O.5h, where h is the height as defined in regulation 19.3.2.
5 The following assumptions shall be used when combining the oil outflow parameters:
.1 The mean oil outflow shall be calculated independently for side damage and for bottom damage and then combined into the non-dimensional oil outflow parameter OM, as follows:
OM = (0.4 OMS + 0.6 OMB)/C
where:
OMS = mean outflow for side damage, in m3; and
OMB = mean outflow for bottom damage, in m3.
.2 For bottom damage, independent calculations for mean outflow shall be done for 0 m and minus 2.5 m tide conditions, and then combined as follows:
OMB = 0.7 OMB(0) + 0.3 OMB(2.5)
where:
OMB(0) = mean outflow for 0 m tide condition; and
OMB(2.5) = mean outflow for minus 2.5 m tide condition, in m3.
6 The mean outflow for side damage OMS shall be calculated as follows:
where:
i = represents each cargo tank under consideration;
n = total number of cargo tanks;
PS(i) = the probability of penetrating cargo tank i from side damage, calculated in accordance with paragraph 8.1 of this regulation;
OS(i) = the outflow, in m3, from side damage to cargo tank i, which is assumed equal to the total volume in cargo tank i at 98% filling, unless it is proven through the application of the Guidelines referred to in regulation 19.5 that any significant cargo volume will be retained; and
C3 = 0.77 for ships having two longitudinal bulkheads inside the cargo tanks, provided these bulkheads are continuous over the cargo block and PS(i) is developed in accordance with this regulation.. C3 equals 1.0 for all other ships or when PS(i) is developed in accordance with paragraph 10 of this regulation.
7 The mean outflow for bottom damage shall be calculated for each tidal condition as follows:
.1
where:
i = represents each cargo tank under consideration;
n = the total number of cargo tanks;
PB(i) = the probability of penetrating cargo tank i from bottom damage, calculated in accordance with, paragraph 9.1 of this regulation;
OB(i) = the outflow from cargo tank i, in m3 , calculated in accordance with paragraph 7.3 of this regulation; and
CDB(i) = factor to account for oil capture as defined in paragraph 7.4 of this regulation
.2
where:
i,n, PB(i) and CDB(i) = as defined in subparagraph .1 above;
OB(i)= the outflow from cargo tank i, in m3, after tidal change
.3 The oil outflow OB(i) for each cargo oil tank shall be calculated based on pressure balance principles, in accordance with the following assumptions:
.1 The ship shall be assumed stranded with zero trim and heel, with the stranded draught prior to tidal change equal to the load line draught ds.
.2 The cargo level after damage shall be calculated as follows:
where:
hc = the height of the cargo oil above Z1, in metres;
tc = the tidal change, in m. Reductions in tide shall be expressed as negative values;
Z1 = the height of the lowest point in the cargo tank above baseline, in m;
ρs = density of seawater, to be taken as 1,025 kg/m3
P = if an inert gas system is fitted, the normal overpressure, in kPa, to be taken as not less than 5 kPa; if an inert gas system is not fitted, the overpressure may be taken as 0.
g = the acceleration of gravity, to be taken as 9.81 m/s2; and
ρn = nominal density of cargo oil, calculated in accordance with paragraph 4.4 of this regulation.
.3 For cargo tanks bounded by the bottom shell, unless proven otherwise, oil outflow OB(i) shall be taken not less than 1% of the total volume of cargo oil loaded in cargo tank i, to account for initial exchange losses and dynamic effects due to current and waves.
.4 In the case of bottom damage, a portion from the outflow from a cargo tank may be captured by non-oil compartments. This effect is approximated by application of the factor CDB(i) for each tank, which shall be taken as follows:
CDB(i) = 0.6 for cargo tanks bounded from below by non-oil compartments;
CDB(i) = 1.0 for cargo tanks bounded by the bottom shell.
*
Refer to the Guidelines for Approval of Alternative Structural or Operational Arrangements adopted by
resolution MEPC.64(36). |
