Annex I

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.1.

shall be of adequate capacity, having regard to the type of machinery and length of voyage, to receive the oil residues (sludge) which cannot be dealt with otherwise in accordance with the requirements of this Annex;

.2.

shall be provided with a designated pump that is capable of taking suction from the oil residue (sludge) tank(s) for disposal of oil residue (sludge) by means as described in regulation 12.2;

.3.

shall have no discharge connections to the bilge system, oily bilge water holding tank(s), tank top or oily water separators, except that:

.1.

the tank(s) may be fitted with drains, with manually operated self-closing valves and arrangements for subsequent visual monitoring of the settled water, that lead to an oily bilge water holding tank or bilge well, or an alternative arrangement, provided such arrangement does not connect directly to the bilge discharge piping system; and

.2.

the sludge tank discharge piping and bilge-water piping may be connected to a common piping leading to the standard discharge connection referred to in regulation 13; the connection of both systems to the possible common piping leading to the standard discharge connection referred to in regulation 13 shall not allow for the transfer of sludge to the bilge system;

.4.

Piping to and from oil residue (sludge) tanks shall have no direct connection overboard, other than the standard discharge connection referred to in regulation 13.

.5.

In ships delivered after 31 December 1979, as defined in regulation 1.28.2, tanks for oil residues shall be designed and constructed so as to facilitate their cleaning and the discharge of residues to reception facilities. Ships delivered on or before 31 December 1979, as defined in regulation 1.28.1, shall comply with this requirement as far as is reasonable and practicable.

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.1.

‘Oil fuel’ means any oil used as fuel oil in connection with the propulsion and auxiliary machinery of the ship in which such oil is carried.

.2.

‘Load line draught (d_s)’ is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to the summer freeboard draught to be assigned to the ship.

.3.

‘Light ship draught’ is the moulded draught amidships corresponding to the lightweight.

.4.

‘Partial load line draught (d_p)’ is the light ship draught plus 60% of the difference between the light ship draught and the load line draught (d_s). The partial load line draught (d_p) shall be measured in metres.

.5.

‘Waterline d_B’ is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to 30% of the depth D_s.

.6.

‘Breadth B_S’ is the greatest moulded breadth of the ship, in metres, at or below the deepest load line line draught d_S.

.7.

‘Breadth B_B’ is the greatest moulded breadth of the ship, in metres, at or below the waterline d_B.

.8.

‘Depth D_s’ is the moulded depth, in metres, measured at mid-length to the upper deck at side. For the purpose of the application, ‘upper deck’ means the highest deck to which the watertight transverse bulkheads except aft peak bulkheads extend.

.9.

‘Length L’ means 96% of the total length on a waterline at 85% of the least moulded depth measured from the top of the keel, or the length from the foreside of the stem to the axis of the rudder stock on that waterline, if that be greater. In ships designed with a rake of keel the waterline on which this length is measured shall be parallel to the designed waterline. The length L shall be measured in metres.

.10.

‘Breadth B’ means the maximum breadth of the ship, in metres, measured amidships to the moulded line of the frame in a ship with a metal shell and to the outer surface of the hull in a ship with a shell of any other material.

.11.

‘Oil fuel tank’ means a tank in which oil fuel is carried, but excludes those tanks which would not contain oil fuel in normal operation, such as overflow tanks.

.12.

‘Small oil fuel tank’ is an oil fuel tank with a maximum individual capacity not greater than 30 m³.

.13.

‘C’ is the ship's total volume of oil fuel, including that of the small oil fuel tanks, in m³, at 98% tank filling.

.14.

‘Oil fuel capacity’ means the volume of a tank in m³, at 98% filling.

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.1.

The level of protection against oil fuel pollution in the event of collision or grounding shall be assessed on the basis of the mean oil outflow parameter as follows:

OM < 0.0157−1.14E-6.C	for 600 m3 ≤ C < 5,000 m3
OM < 0.010	for C ≥ 5,000 m3

Where:

O_M = mean oil outflow parameter;

C = total oil fuel volume.

.2.

The following general assumption shall apply when calculating the mean oil outflow parameter:

.1.

the ship shall be assumed loaded to the partial load line draught (d_p) without trim or heel;

.2.

all oil fuel tanks shall be assumed loaded to 98% of their volumetric capacity;

.3.

the nominal density of the oil fuel (ρ_n) shall generally be taken as 1,000 kg/m³. If the density of the oil fuel is specifically restricted to a lesser value, the lesser value may be applied; and

.4.

for the purpose of these outflow calculations, the permeability of each oil fuel tank shall be taken as 0.99, unless proven otherwise.

.3.

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 a non-dimensional oil outflow parameter O_M, as follows:

O_M = (0.4 O_MS + 0.6 O_MB) / C

Where:

O_MS = mean outflow for side damage, in m³

O_MB = mean outflow for bottom damage, in m³

C = total oil fuel volume.

.2.

For bottom damage, independent calculations for mean outflow shall be done for 0 m and 2.5 m tide conditions, and then combined as follows:

O_MB = 0.7 O_MB(0) + 0.3 O_MB(2.5)

where:

O_MB(0) = mean outflow for 0 m tide condition, and

O_MB(25) = mean outflow for minus 2.5 m tide condition, in m³.

.4.

The mean outflow for side damage O_MS shall be calculated as follows:

where:

i = represents each oil fuel tank under consideration;

n = total number of oil fuel tanks;

P_s(i) = the probability of penetrating oil fuel tank i from side damage, calculated in accordance with paragraph 11.6 of this regulation;

O_s(i) = the outflow, in m³, from side damage to oil fuel tank i, which is assumed equal to the total volume in oil fuel tank i at 98% filling.

.5.

The mean outflow for bottom damage shall be calculated for each tidal condition as follows:

.1

where:

i = represents each oil fuel tank under consideration;

n = total number of oil fuel tanks;

P_B(i) = the probability of penetrating oil fuel tank i from bottom damage, calculated in accordance with paragraph 11.7 of this regulation;

O_B(i) = the outflow from oil fuel tank, in m³, calculated in accordance with paragraph 11.5.3 of this regulation; and

C_DB(i) = factor to account for oil capture as defined in paragraph 11.5.4.

.2

where:

i, n P_B(i) and C_DB(i) = as defined in subparagraph .1 above

O_B(i) = the outflow oil fuel tank i, in m³, after tidal change.

.3.

The oil outflow O_B(i) for each oil fuel 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 partial load line draught d_p.

.2.

The oil fuel level after damage shall be calculated as follows:

h_F = {(d_p + t_C − Z_l)(p_S)}/p_n

where:

h_F = the height of the oil fuel surface above Z_l, in m;

t_c = the tidal change, in m. Reductions in tide shall be expressed as negative values;

Z_l = the height of the lowest point in the oil fuel tank above the baseline, in m;

p_s = density of seawater, to be taken as 1,025 kg/m³; and,

p_n = nominal density of the oil fuel, as defined in 11.2.3.

.3.

The oil outflow O_B(i) for any tank bounding the bottom shell plating shall be taken not less than the following formula, but no more than the tank capacity:

O_B(i) = H_w A

where:

H_w = 1.0 m , when Y_B = 0

H_w = B_B/50 but not greater than 0.4 m, when Y_B is greater than B_B/5 or 11.5 m, whichever is less

H_w is to be measured upwards from the midship flat bottom line. In the turn of the bilge area and at locations without a clearly defined turn of the bilge, H_w is to be measured from a line parallel to the midship flat bottom, as shown for distance ‘h’ in Figure 1.

For Y_B values outboard B_B/5 or 11.5 m, whichever is less, H_w is to be linearly interpolated.

Y_B = the minimum value of Y_B over the length of the oil fuel tank, where at any given location, Y_B is the transverse distance between the side shell at waterline d_B and the tank at or below waterline d_B.

A = the maximum horizontal projected area of the oil fuel tank up to the level of H_w from the bottom of the tank.

Figure 3. Dimensions for calculation of the minimum oil outflow for the purpose of subparagraph 11.5.3.3

.4.

In the case of bottom damage, a portion from the outflow from an oil fuel tank may be captured by non-oil compartments. This effect is approximated by application of the factor C_DB(i) for each tank, which shall be taken as follows:

C_DB(i) = 0.6 for oil fuel tanks bounded from below by non-oil compartments;

C_DB(i) = 1 otherwise.

.6.

The probability P_S of breaching a compartment from side damage shall be calculated as follows:

.1.

P_S = P_SL · P_SV · P_ST

where:

P_SL = (1 − P_Sf − P_Sa) = probability the damage will extend into the longitudinal zone bounded by X_a and X_f;

P_SV = (1 − P_Sa − P_Sl) = probability the damage will extend into the vertical zone bounded by Z_l and Z_u;

P_ST = (1 − P_Sy) = probability the damage will extend transversely beyond the boundary defined by y;

.2.

P_Sa, P_Sf, P_Su and P_Sl shall be determined by linear interpolation from the table of probabilities for side damage provided in 11.6.3, and P_Sy shall be calculated from the formulas provided in 11.6.3, where:

P_Sa = the probability the damage will lie entirely aft of location X_a/L;

P_Sf = the probability the damage will lie entirely forward of location X_f/L;

P_Sl = probability the damage will lie entirely below the tank;

P_Su = probability the damage will lie entirely above the tank; and

P_Sy = probability the damage will lie entirely outboard the tank.

Compartment boundaries X_a, X_f, Z_l, Z_u and y shall be developed as follows:

X_a = the longitudinal distance from aft terminal of L to the aft most point on the compartment being considered, in m;

X_f = the longitudinal distance from aft terminal of L to the foremost point on the compartment being considered, in m;

Z_l = the vertical distance from the moulded baseline to the lowest point on the compartment being considered, in m. Where Z_l is greater than D_S, Z_l shall be taken as D_S;

Z_u = the vertical distance from the moulded baseline to the highest point on the compartment being considered, in m. Where Z_u is greater than D_S, Z_u shall be taken as D_S; and,

y = the minimum horizontal distance measured at right angles to the centreline between the compartment under consideration and the side shell, in m1).

In way of the turn of the bilge, y need not to be considered below a distance h above baseline, where h is lesser of B/10, 3 m or the top of the tank.

.3.

Table of Probabilities for side damage

Xa/L	PSa	Xf/L	PSf	Zl/DS	PSl	Zu/DS	PSu
0,00	0,000	0,00	0,967	0,00	0,000	0,00	0,968
0,05	0,023	0,05	0,917	0,05	0,000	0,05	0,952
0,10	0,068	0,10	0,867	0,10	0,001	0,10	0,931
0,15	0,117	0,15	0,817	0,15	0,003	0,15	0,905
0,20	0,167	0,20	0,767	0,20	0,007	0,20	0,873
0,25	0,217	0,25	0,717	0,25	0,013	0,25	0,836
0,30	0,267	0,30	0,667	0,30	0,021	0,30	0,789
0,35	0,317	0,35	0,617	0,35	0,034	0,35	0,733
0,40	0,367	0,40	0,567	0,40	0,055	0,40	0,670
0,45	0,417	0,45	0,517	0,45	0,085	0,45	0,599
0,50	0,467	0,50	0,467	0,50	0,123	0,50	0,525
0,55	0,517	0,55	0,417	0,55	0,172	0,55	0,452
0,60	0,567	0,60	0,367	0,60	0,226	0,60	0,383
0,65	0,617	0,65	0,317	0,65	0,285	0,65	0,317
0,70	0,667	0,70	0,267	0,70	0,347	0,70	0,255
0,75	0,717	0,75	0,217	0,75	0,413	0,75	0,197
0,80	0,767	0,80	0,167	0,80	0,482	0,80	0,143
0,85	0,817	0,85	0,117	0,85	0,553	0,85	0,092
0,90	0,867	0,90	0,068	0,90	0,626	0,90	0,046
0,95	0,917	0,95	0,023	0,95	0,700	0,95	0,013
1,00	0,967	1,00	0,000	1,00	0,775	1,00	0,000

P_Sy shall be calculated as follows:

PSy = (24.96 − 199.6 y/BS)(y/BS)	for y/BS ≤ 0.05
PSy = 0.749 + {5 − 44.4 (y/BS − 0.05)} {(y/BS) − 0.05}	for 0.05 ≤ y/BS ≤ 0.1
PSy = 0.888 + 0.56 (y/BS − 0.1)	for y/BS ≥ 0.1
PSy is not to be taken greater than 1.

.7.

The probability P_B of breaching a compartment from bottom damage shall be calculated as follows:

.1.

P_B = P_BL · P_BT · P_BV

where:

P_BL = (1 − P_Bf − P_Ba) = probability the damage will extend into the longitudinal zone bounded by X_a and X_f;

P_BT = (1 − P_Bp − P_Bs) = probability the damage will extend into transverse zone bounded by Y_p and Y_s; and

P_BV = (1 − P_Bz) = probability the damage will extend vertically above the boundary defined by z;

.2.

P_Ba, P_Bf, P_Bp and P_Bs shall be determined by linear interpolation from the table of probabilities for bottom damage provided in 11.7.3, and P_Bz shall be calculated from the formulas provided in 11.7.3, where:

P_Ba = the probability the damage will lie entirely aft of location X_a/L;

P_Bf = the probability the damage will lie entirely forward of location X_f/L;

P_Bp = probability the damage will lie entirely to port of the tank;

P_Bs = probability the damage will lie entirely to starboard the tank; and

P_Bz = probability the damage will lie entirely below the tank.

Compartment boundaries X_a, X_f, Y_p, Y_s and z shall be developed as follows:

X_a and X_f as defined in 11.6.2;

Y_p = the transverse distance from the port-most point on the compartment located at or below the waterline d_B, to a vertical plane located B_B/2 to starboard of the ship's centreline;

Y_s = the transverse distance from the starboard-most point on the compartment located at or below the waterline d_B, to a vertical plane located B_B/2 to starboard of the ship's centreline; and

z = the minimum value of z over the length of the compartment, where, at any given longitudinal location, z is the vertical distance from the lower point of the bottom shell at that longitudinal location to the lower point of the compartment at that longitudinal location.

.3.

Table of probabilities for bottom damage

Xa/L	PBa	Xp/L	PBf	Yp/BB	PBp	Ys/BB	PBs
0,00	0,000	0,00	0,969	0,00	0,844	0,00	0,000
0,05	0,002	0,05	0,953	0,05	0,794	0,05	0,009
0,10	0,008	0,10	0,936	0,10	0,744	0,10	0,032
0,15	0,017	0,15	0,916	0,15	0,694	0,15	0,063
0,20	0,029	0,20	0,894	0,20	0,644	0,20	0,097
0,25	0,042	0,25	0,870	0,25	0,594	0,25	0,133
0,30	0,058	0,30	0,842	0,30	0,544	0,30	0,171
0,35	0,076	0,35	0,810	0,35	0,494	0,35	0,211
0,40	0,096	0,40	0,775	0,40	0,444	0,40	0,253
0,45	0,119	0,45	0,734	0,45	0,394	0,45	0,297
0,50	0,143	0,50	0,687	0,50	0,344	0,50	0,344
0,55	0,171	0,55	0,630	0,55	0,297	0,55	0,394
0,60	0,203	0,60	0,563	0,60	0,253	0,60	0,444
0,65	0,242	0,65	0,489	0,65	0,211	0,65	0,494
0,70	0,289	0,70	0,413	0,70	0,171	0,70	0,544
0,80	0,409	0,80	0,252	0,80	0,097	0,80	0,644
0,85	0,482	0,85	0,170	0,85	0,063	0,85	0,694
0,90	0,565	0,90	0,089	0,90	0,032	0,90	0,744
0,95	0,658	0,95	0,026	0,95	0,009	0,95	0,794
1,00	0,761	1,00	0,000	1,00	0,000	1,00	0,844

P_Bz shall be calculated as follows:

PBz = (14.5 − 67 z/Ds) (z/Ds)	for z/Ds ≤ 0.1
PBz = 0.78 + 1.1 {(z/Ds − 0.1)}	for z/Ds > 0.1
PBz is not to be taken greater than 1.

.8.

For the purpose of maintenance and inspection, any oil fuel tanks that do not border the outer shell plating shall be located no closer to the bottom shell plating than the minimum value of h in paragraph 6 and no closer to the side shell plating than the applicable minimum value of w in paragraph 7 or 8.

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.1.

any ship engaged exclusively on voyages within special areas or Arctic waters, or

.2.

any ship certified under the International Code of Safety for High-Speed Craft (or otherwise within the scope of this Code with regard to size and design) engaged on a scheduled service with a turn-around time not exceeding 24 hours and covering also non-passenger/cargo-carrying relocation voyages for these ships,

.3.

with regard to the provision of subparagraphs .1 and .2 above, the following conditions shall be complied with:

.1.

the ship is fitted with a holding tank having a volume adequate, to the satisfaction of the Administration, for the total retention on board of the oily bilge water;

.2.

all oily bilge water is retained on board for subsequent discharge to reception facilities;

.3.

the Administration has determined that adequate reception facilities are available to receive such oily bilge water in a sufficient number of ports or terminals the ship calls at;

.4.

the International Oil Pollution Prevention Certificate, when required, is endorsed to the effect that the ship is exclusively engaged on the voyages within special areas or Arctic waters or has been accepted as a high-speed craft for the purpose of this regulation and the service is identified; and

.5.

the quantity, time, and port of the discharge are recorded in the Oil Record Book Part I.

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.1.

the ship is proceeding en route;

.2.

the oily mixture is processed through an oil filtering equipment meeting the requirements of regulation 14 of this Annex;

.3.

the oil content of the effluent without dilution does not exceed 15 parts per million;

.4.

the oily mixture does not originate from cargo pump room bilges on oil tankers; and

.5.

the oily mixture, in case of oil tankers, is not mixed with oil cargo residues.

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.1.

the ship is proceeding en route;

.2.

the oily mixture is processed through an oil filtering equipment meeting the requirements of regulation 14.7 of this Annex;

.3.

the oil content of the effluent without dilution does not exceed 15 parts per million;

.4.

the oily mixture does not originate from cargo pump room bilges on oil tankers; and

.5.

the oily mixture, in case of oil tankers, is not mixed with oil cargo residues.

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.1.

the ship is proceeding en route;

.2.

the ship has in operation equipment of a design approved by the Administration that ensures that the oil content of the effluent without dilution does not exceed 15 parts per million;

.3.

the oily mixture does not originate from cargo pump room bilges on oil tankers; and

.4.

the oily mixture, in case of oil tankers, is not mixed with oil cargo residues.

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.1.

ballasting or cleaning of oil fuel tanks;

.2.

discharge of dirty ballast or cleaning water from oil fuel tanks;

.3.

collection and disposal of oil residues (oil residue (sludge));

.4.

discharge overboard or disposal otherwise of bilge water which has accumulated in machinery spaces; and

.5.

bunkering of fuel or bulk lubricating oil.

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.1.

the moulded draught amidships (d_m) in metres (without taking into account any ship's deformation) shall not be less than:

d_m = 2.0 + 0.02L

.2.

the draughts at the forward and after perpendiculars shall correspond to those determined by the draught amidships (dm) as specified in paragraph 2.1 of this regulation, in association with the trim by the stern of not greater than 0.015L; and

.3.

in any case the draught at the after perpendicular shall not be less than that which is necessary to obtain full immersion of the propeller(s).

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.1.

on those rare voyages when weather conditions are so severe that, in the opinion of the master, it is necessary to carry additional ballast water in cargo tanks for the safety of the ship; and

.2.

in exceptional cases where the particular character of the operation of an oil tanker renders it necessary to carry ballast water in excess of the quantity required under paragraph 2 of this regulation, provided that such operation of the oil tanker falls under the category of exceptional cases as established by the Organization.

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.1.

The product carrier shall have adequate tank capacity, dedicated solely to the carriage of clean ballast as defined in regulation 1.17 of this Annex, to meet the requirements of paragraphs 2 and 3 of this regulation.

.2.

The arrangements and operational procedures for dedicated clean ballast tanks shall comply with the requirements established by the Administration. Such requirements shall contain at least all the provisions of the revised Specifications for Oil Tankers with Dedicated Clean Ballast Tanks adopted by the Organization by resolution A.495(XII).

.3.

The product carrier shall be equipped with an oil content meter, approved by the Administration on the basis of specifications recommended by the Organization, to enable supervision of the oil content in ballast water being discharged.

.4.

Every product carrier operating with dedicated clean ballast tanks shall be provided with a Dedicated Clean Ballast Tank Operation Manual detailing the system and specifying operational procedures. Such a Manual shall be to the satisfaction of the Administration and shall contain all the information set out in the Specifications referred to in subparagraph 8.2 of this regulation. If an alteration affecting the dedicated clean ballast tank system is made, the Operation Manual shall be revised accordingly.

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.1.

Where an oil tanker delivered on or before 1 June 1982, as defined in regulation 1.28.3, is so constructed or operates in such a manner that it complies at all times with the draught and trim requirements set out in paragraph 2 of this regulation without recourse to the use of ballast water, it shall be deemed to comply with the segregated ballast tank requirements referred to in paragraph 6 of this regulation, provided that all of the following conditions are complied with:

.1.

operational procedures and ballast arrangements are approved by the Administration;

.2.

agreement is reached between the Administration and the Governments of the port States Parties to the present convention concerned when the draught and trim requirements are achieved through an operational procedure; and

.3.

the International Oil Pollution Prevention Certificate is endorsed to the effect that the oil tanker is operating with special ballast arrangements.

.2.

In no case shall ballast water be carried in oil tanks except on those rare voyages when weather conditions are so severe that, in the opinion of the master, it is necessary to carry additional ballast water in cargo tanks for the safety of the ship. Such additional ballast water shall be processed and discharged in compliance with regulation 34 of this Annex and in accordance with the requirements of regulations 29, 31 and 32 of this Annex, and entry shall be made in the Oil Record Book referred to in regulation 36 of this Annex.

.3.

An Administration which has endorsed a Certificate in accordance with subparagraph 10.1.3 of this regulation shall communicate to the Organization the particulars thereof for circulation to the Parties to the present Convention.

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.1.

the minimum width of each wing tank or space either of which extends for the full depth of the ship's side or from the deck to the top of the double bottom shall be not less than 2 metres. The width shall be measured inboard from the ship's side at right angles to the centreline. Where a lesser width is provided the wing tank or space shall not be taken into account when calculating the protecting area PAc; and

.2.

the minimum vertical depth of each double bottom tank or space shall be B/15 or 2 metres, whichever is the lesser. Where a lesser depth is provided the bottom tank or space shall not be taken into account when calculating the protecting area PAs.

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.1.

in lieu of paragraphs 12 to 15 of regulation 18, as applicable, comply with the requirements of paragraph 3 of this regulation unless it is subject to the provisions of paragraphs 4 and 5 of this regulation; and

.2.

comply, if applicable, with the requirements of regulation 28.7.

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.1.

Wing tanks or spaces

Wing tanks or spaces shall extend either for the full depth of the ship's side or from the top of the double bottom to the uppermost deck, disregarding a rounded gunwale where fitted. They shall be arranged such that the cargo tanks are located inboard of the moulded line of the side shell plating nowhere less than the distance w which, as shown in figure 1 is measured at any cross-section at right angles to the side shell, as specified below:

w = 0.5 + (DW/20,000) (m), or

w = 2.0 m, whichever is the lesser.

The minimum value of w = 1.0 m.

.2.

Double bottom tanks or spaces

At any cross-section the depth of each double bottom tank or space shall be such that the distance h between the bottom of the cargo tanks and the moulded line of the bottom shell plating measured at right angles to the bottom shell plating as shown in figure 1 is not less than specified below:

h = B/15 (m) or

h = 2.0 m, whichever is the lesser.

The minimum value of h = 1.0 m.

.3.

Turn of the bilge area or at locations without a clearly defined turn of the bilge

When the distances h and w are different, the distance w shall have preference at levels exceeding 1.5h above the baseline as shown in figure 1.

.4.

The aggregate capacity of ballast tanks

On crude oil tankers of 20,000 tonnes deadweight and above and product carriers of 30,000 tonnes deadweight and above, the aggregate capacity of wing tanks, double bottom tanks, fore-peak tanks and after peak tanks shall not be less than the capacity of segregated ballast tanks necessary to meet the requirements of regulation 18 of this Annex. Wing tanks or spaces and double bottom tanks used to meet the requirements of regulation 18 shall be located as uniformly as practicable along the cargo tank length. Additional segregated ballast capacity provided for reducing longitudinal hull girder bending stress, trim, etc., may be located anywhere within the ship.

.5.

Suction wells in cargo tanks

Suction wells in cargo tanks may protrude into the double bottom below the boundary line defined by the distance h provided that such wells are as small as practicable and the distance between the well bottom and bottom shell plating is not less than 0.5h.

.6.

Ballast and cargo piping

Ballast piping and other piping such as sounding and vent piping to ballast tanks shall not pass through cargo tanks. Cargo piping and similar piping to cargo tanks shall not pass through ballast tanks. Exemptions to this requirement may be granted for short lengths of piping, provided that they are completely welded or equivalent.

4

.1.

Double bottom tanks or spaces as required by paragraph 3.2 of this regulation may be dispensed with, provided that the design of the tanker is such that the cargo and vapour pressure exerted on the bottom shell plating forming a single boundary between the cargo and the sea does not exceed the external hydrostatic water pressure, as expressed by the following formula:

ƒ × hc × ρc × g + p ≤ dn × ρs × g

where:

h_c = height of cargo in contract with the bottom shell plating in metres

ρ_c = maximum cargo density in kg/m³

d_n = minimum operating draught under any expected loading condition in metres

ρ_s = density of seawater in kg/m³

p = maximum set pressure above atmospheric pressure (gauge pressure) of pressure/vacuum valve provided for the cargo tank in Pa

ƒ = safety factor = 1.1

g = standard acceleration of gravitv (9.81 m/s²)

.2.

Any horizontal partition necessary to fulfil the above requirements shall be located at a height not less than B/6 or 6 m, whichever is the lesser, but not more than 0.6D, above the baseline where D is the moulded depth amidships.

.3.

The location of wing tanks or spaces shall be as defined in paragraph 3.1 of this regulation except that, below a level 1.5 h above the baseline where h is as defined in paragraph 3.2 of this regulation, the cargo tank boundary line may be vertical down to the bottom plating, as shown in figure 2.

5

6

.1.

at least be fitted with double bottom tanks or spaces having such a depth that the distance h specified in paragraph 3.2 of this regulation, complies with the following:

h = B/15 (m)

with a minimum value of h = 0.76 m;

in the turn of the bilge area and at locations without a clearly defined turn of the bilge, the cargo tank boundary line shall run parallel to the line of the midship flat bottom as shown in figure 3; and

.2.

be provided with cargo tanks so arranged that the capacity of each cargo tank does not exceed 700 m³ unless wing tanks or spaces are arranged in accordance with paragraph 3.1 of this regulation, complying with the following:

w = 0.4 + (2.4DW/20000) (m) with a minimum value of w = 0.76 m.

7

8

1

.1.

apply to oil tankers of 5,000 tonnes deadweight and above, which are delivered before 6 July 1996, as defined in regulation 1.28.5 of this Annex; and

.2.

not apply to oil tankers complying with regulation 19 and regulation 28 in respect of paragraph 28.7, which are delivered before 6 July 1996, as defined in regulation 1.28.5 of this Annex; and

.3.

not apply to oil tankers covered by subparagraph 1 above which comply with regulation 19.3.1 and 19.3.2 or 19.4 or 19.5 of this Annex, except that the requirement for minimum distances between the cargo tank boundaries and the ship side and bottom plating need not be met in all respects. In that event, the side protection distances shall not be less than those specified in the International Bulk Chemical Code for type 2 cargo tank location and the bottom protection distances at centreline shall comply with regulation 18.15.2 of this Annex.

2

.1.

‘Heavy diesel oil’ means diesel oil other than those distillates of which more than 50 per cent by volume distils at a temperature not exceeding 340°C when tested by the method acceptable to the Organization.

.2.

‘Fuel oil’ means heavy distillates or residues from crude oil or blends of such materials intended for use as a fuel for the production of heat or power of a quality equivalent to the specification acceptable to the Organization.

3

.1.

‘Category 1 oil tanker’ means an oil tanker of 20,000 tonnes deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tonnes deadweight and above carrying oil other than the above, which does not comply with the requirements for oil tankers delivered after 1 June 1982, as defined in regulation 1.28.4 of this Annex;

.2.

‘Category 2 oil tanker’ means an oil tanker of 20,000 tonnes deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tonnes deadweight and above carrying oil other than the above, which complies with the requirements for oil tankers delivered after 1 June 1982, as defined in regulation 1.28.4 of this Annex; and

.3.

‘Category 3 oil tanker’ means an oil tanker of 5,000 tonnes deadweight and above but less than that specified in subparagraph 1 or 2 of this paragraph.

4

5

.1.

the ship was in service on 1 July 2001;

.2.

the Administration is satisfied by verification of the official records that the ship complied with the conditions specified above;

.3.

the conditions of the ship specified above remain unchanged; and

.4.

such continued operation does not go beyond the date on which the ship reaches 25 years after the date of its delivery.

6

7

1

.1.

apply to oil tankers of 600 tonnes deadweight and above carrying heavy grade oil as cargo regardless of the date of delivery; and

.2.

not apply to oil tankers covered by subparagraph 1 above which comply with regulations 19.3.1 and 19.3.2 or 19.4 or 19.5 of this Annex, except that the requirement for minimum distances between the cargo tank boundaries and the ship side and bottom plating need not be met in all respects. In that event, the side protection distances shall not be less than those specified in the International Bulk Chemical Code for type 2 cargo tank location and the bottom protection distances at centreline shall comply with regulation 18.15.2 of this Annex.

2

.1.

crude oils having a density at 15°C higher than 900 kg/m³;

.2.

oils, other than crude oils, having either a density at 15°C higher than 900 kg/m³ or a kinematic viscosity at 50°C higher than 180 mm²/s; or

.3.

bitumen, tar and their emulsions.

3

4

.1.

if 5,000 tonnes deadweight and above, comply with the requirements of regulation 19 of this Annex not later than 5 April 2005; or

.2.

if 600 tonnes deadweight and above but less than 5,000 tonnes deadweight, be fitted with both double bottom tanks or spaces complying with the provisions of regulation 19.6.1 of this Annex, and wing tanks or spaces arranged in accordance with regulation 19.3.1 and complying with the requirement for distance w as referred to in regulation 19.6.2, not later than the anniversary of the date of delivery of the ship in the year 2008.

5

.1.

the ship was in service on 4 December 2003;

.2.

the Administration is satisfied by verification of the official records that the ship complied with the conditions specified above;

.3.

the conditions of the ship specified above remain unchanged;

and

.4.

such continued operation does not go beyond the date on which the ship reaches 25 years after the date of its delivery.

1

2

3

4

5

1

2

.1.

‘Load line draught (d_s)’ 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 d_s, notwithstanding assigned draughts that may exceed d_s, such as the tropical loadline.

.2.

‘Waterline (d_B)’ is the vertical distance, in metres, from the moulded baseline at mid-length to the waterline corresponding to 30% of the depth D_s.

.3.

‘Breadth (B_s)’ is the greatest moulded breadth of the ship, in metres, at or below the deepest load line d_s.

.4.

‘Breadth (B_B)’ is the greatest moulded breadth of the ship, in metres, at or below the waterline d_B.

.5.

‘Depth (D_s)’ 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

.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 O_M < = 0.015.

OM ≤ 0.021	for C ≤ 100,000 m3
OM ≤ 0.015 + (0.006/100,000) (200,000−C)	for 100,000 m3 < C ≤ 200,000 m3

where:

O_M = 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:

(0.5 (b_i/B) + 0.1)L but not to exceed 0.2L

.2.

where a centreline longitudinal bulkhead is provided inside the cargo tanks:

(0.25 (b_i/B) + 0.15)L

.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:

.1.

if (b_i/B) ≥ 0,2L : 0,2L

.2.

if (b_i/B) is < 0,2:

—

where no centreline longitudinal bulkhead is provided:

(0,5 (b_i/B) + 0,1) L

—

where a centreline longitudinal bulkhead is provided:

(0,25 (b_i/B) + 0,15) L

.4.

b_i 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

.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 0.5h, where h is the height as defined in regulation 19.3.2.

5

.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 O_M, as follows:

O_M = (0.4 O_MS + 0.6 O_MB ) / C

where:

O_MS = mean outflow for side damage, in m³; and

O_MB = 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:

O_MB => 0.7 O_MB(0) + 0.3 O_MB(2.5)

where:

O_MB(0) = mean outflow for 0 m tide condition; and

O_MB(2.5) = mean outflow for minus 2.5 m tide condition, in m³.

6

7

.1

where:

i = represents each cargo tank under consideration;

n = the total number of cargo tanks;

P_B(i) = the probability of penetrating cargo tank i from bottom damage, calculated in accordance with, paragraph 9.1 of this regulation;

O_B(i) = the outflow from cargo tank i, in m³, calculated in accordance with paragraph 7.3 of this regulation; and

C_DB(i) = factor to account for oil capture as defined in paragraph 7.4 of this regulation

.2

where:

i,n, P_B(i) and C_DB(i) = as defined in subparagraph .1 above;

O_B(i) = the outflow from cargo tank i, in m³, after tidal change

.3.

The oil outflow O_B(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 d_s.

.2.

The cargo level after damage shall be calculated as follows:

h_c = {(d_s + t_c − Z₁) (ρ_s) − (1000 p) / g }/ρ_n

where:

h_c = the height of the cargo oil above Z₁; in metres;

t_c = the tidal change, in m. Reductions in tide shall be expressed as negative values;

Z_l = the height of the lowest point in the cargo tank above baseline, in m;

ρ_s = 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

ρ_n = 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 O_B(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 C_DB(i) for each tank, which shall be taken as follows:

C_DB(i) = 0.6 for cargo tanks bounded from below by non-oil compartments;

C_DB(i) = 1.0 for cargo tanks bounded by the bottom shell.

8

.1.

P_S = P_SL P_SV P_ST

where:

P_SL = 1 − P_Sf − P_Sa = probability the damage will extend into the longitudinal zone bounded by X_a and X_f;

P_SV = 1 − P_SU − P_Sl = probability the damage will extend into the vertical zone bounded by Z₁ and Z_U; and

P_ST = 1 − P_Sy = probability the damage will extend transversely beyond the boundary defined by y.

.2.

P_Sa, P_Sf, P_Sl, P_Su and P_Sy shall be determined by linear interpolation from the table of probabilities for side damage provided in paragraph 8.3 of this regulation, where:

P_Sa = the probability the damage will lie entirely aft of location X_a/L;

P_Sf = the probability the damage will lie entirely forward of location X_f/L;

P_Sl = the probability the damage will lie entirely below the tank;

P_Su = the probability the damage will lie entirely above the tank; and

P_Sy = the probability the damage will lie entirely outboard of the tank.

Compartment boundaries X_a, X_f, Z_l, Z_u and y shall be developed as follows:

X_a = the longitudinal distance from the aft terminal of L to the aftmost point on the compartment being considered, in metres;

X_f = the longitudinal distance from the aft terminal of L to the foremost point on the compartment being considered, in metres;

X_a = the longitudinal distance from the aft terminal of L to the aftmost point on the compartment being considered, in metres;

Z_l = the vertical distance from the moulded baseline to the lowest point on the compartment being considered, in metres;

Z_u = the vertical distance from the moulded baseline to the highest point on the compartment being considered, in metres. Z_u is not to be taken greater than D_s; and

y = the minimum horizontal distance measured at right angles to the centreline between the compartment under consideration and the side shell in metres;

.3.

Table of orobabilities for side damage

Xa/L	PSa	Xf/L	PSf	Zl/DS	PSl	Zu/SS	PSu
0.00	0.000	0.00	0.967	0.00	0.000	0.00	0.968
0.05	0.023	0.05	0.917	0.05	0.000	0.05	0.952
0.10	0.068	0.10	0.867	0.10	0.001	0.10	0.931
0.15	0.117	0.15	0.817	0.15	0.003	0.15	0.905
0.20	0.167	0.20	0.767	0.20	0.007	0.20	0.873
0.25	0.217	0.25	0.717	0.25	0.013	0.25	0.836
0.30	0.267	0.30	0.667	0.30	0.021	0.30	0.789
0.35	0.317	0.35	0.617	0.35	0.034	0.35	0.733
0.40	0.367	0.40	0.567	0.40	0.055	0.40	0.670
0.45	0.417	0.45	0.517	0.45	0.085	0.45	0.599
0.50	0.467	0.50	0.467	0.50	0.123	0.50	0.525
0.55	0.517	0.55	0.417	0.55	0.172	0.55	0.452
0.60	0.567	0.60	0.367	0.60	0.226	0.60	0.383
0.65	0.617	0.65	0.317	0.65	0.285	0.65	0.317
0.70	0.667	0.70	0.267	0.70	0.347	0.70	0.255
0.75	0.717	0.75	0.217	0.75	0.413	0.75	0.197
0.80	0.767	0.80	0.167	0.80	0.482	0.80	0.143
0.85	0.817	0.85	0.117	0.85	0.553	0.85	0.092
0.90	0.867	0.90	0.068	0.90	0.626	0.90	0.046
0.95	0.917	0.95	0.023	0.95	0.700	0.95	0.013
1.00	0.967	1.00	0.000	1.00	0.775	1.00	0.000

P_Sy shall be calculated as follows:

P_Sy = (24.96 − 199.6 y/B_S) (y/B_S) for y/B_S ≤ 0.05

P_Sy = 0.749 + {5 −44.4 (y/B_S − 0.05)} (y/B_S − 0.05) for 0.05 < y/B_s < 0.1

P_Sy = 0.888 + 0.56 (y/B_S − 0.1) for y/B_S ≤ 0.1

P_Sy shall not be taken greater than 1.

9

.1.

P_B = P_BL P_BTP_BV

where:

P_BL = 1 − P_Bf − P_Ba = probability the damage will extend into the longitudinal zone bounded by X_a and X_f;

P_BT = 1 − P_Bp − P_Bs = probability the damage will extend into the transverse zone bounded by Y_p and Y_s; and

P_BV = 1 − P_Bz = probability the damage will extend vertically above the boundary defined by z.

.2.

P_Ba, P_Bf, P_Bp,P_Bs, and P_Bz shall be determined by linear interpolation from the table of probabilities for bottom damage provided in paragraph 9.3 of this regulation, where:

P_Ba = the probability the damage will lie entirely aft of location X_a/L;

P_Bf = the probability the damage will lie entirely forward of location X_f/L;

P_Bp = the probability the damage will lie entirely to port of the tank;

P_Bs = the probability the damage will lie entirely to starboard of the tank; and

P_Bz = the probability the damage will lie entirely below the tank.

Compartment boundaries X_a, X_f, Y_p, Y_s, and z shall be developed as follows:

X_a and X_f are as defined in paragraph 8.2 of this regulation;

Y_p = the transverse distance from the port-most point on the compartment located at or below the waterline d_B, to a vertical plane located B_B/2 to starboard of the ship's centreline, in metres;

Y_s = the transverse distance from the starboard-most point on the compartment located at or below the waterline d_B, to a vertical plane located B_B/2 to starboard of the ship's centreline, in metres; and

z = the minimum value of z over the length of the compartment, where, at any given longitudinal location, z is the vertical distance from the lowerpoint of the bottom shell at that longitudinal location to the lower point of the compartment at that longitudinal location, in metres.

.3.

Table of probabilities for bottom damage

Xa/L	PBa	Xf/L	PBf	Yp/BB	PBp	Ys/BB	PBs
0.00	0.000	0.00	0.969	0.00	0.844	0.00	0.000
0.05	0.002	0.05	0.953	0.05	0.794	0.05	0.009
0.10	0.008	0.10	0.936	0.10	0.744	0.10	0.032
0.15	0.017	0.15	0.916	0.15	0.694	0.15	0.063
0.20	0.029	0.20	0.894	0.20	0.644	0.20	0.097
0.25	0.042	0.25	0.870	0.25	0.594	0.25	0.133
0.30	0.058	0.30	0.842	0.30	0.544	0.30	0.171
0.35	0.076	0.35	0.810	0.35	0.494	0.35	0.211
0.40	0.096	0.40	0.775	0.40	0.444	0.40	0.253
0.45	0.119	0.45	0.734	0.45	0.394	0.45	0.297
0.50	0.143	0.50	0.687	0.50	0.344	0.50	0.344
0.55	0.171	0.55	0.630	0.55	0.297	0.55	0.394
0.60	0.203	0.60	0.563	0.60	0.253	0.60	0.444
0.65	0.242	0.65	0.489	0.65	0.211	0.65	0.494
0.70	0.289	0.70	0.413	0.70	0.171	0.70	0.544
0.75	0.344	0.75	0.333	0.75	0.133	0.75	0.594
0.80	0.409	0.80	0.252	0.80	0.097	0.80	0.644
0.85	0.482	0.85	0.170	0.85	0.063	0.85	0.694
0.90	0.565	0.90	0.089	0.90	0.032	0.90	0.744
0.95	0.658	0.95	0.026	0.95	0.009	0.95	0.794
1.00	0.761	1.00	0.000	1.00	0.000	1.00	0.844

P_Bz shall be calculated as follows:

P_Bz = (14.5 − 67 z/D_s) (z/D_s) for z/D_s≤ 0.1,

P_Bz = 0.78 + 1.1 (z/D_s − 0.1) for z/D_s > 0.1.

P_Bz shall not be taken greater than 1.

10

.1.

The probabilities referred to in 8 and 9 above may be calculated with more precision through application of hypothetical subcompartments.

.2.

The probabilities referred to in 8 and 9 above may be calculated through direct application of the probability density functions contained in the Guidelines referred to in regulation 19.5.

.3.

The oil outflow performance may be evaluated in accordance with the method described in the Guidelines referred to in regulation 19.5.

11

.1.

Lines of piping that run through cargo tanks in a position less than 0.30B_s from the ship's side or less than 0.30D_s from the ship's bottom shall be fitted with valves or similar closing devices at the point at which they open into any cargo tank. These valves shall be kept closed at sea at any time when the tanks contain cargo oil, except that they may be opened only for cargo transfer needed for essential cargo operations.

.2.

Credit for reducing oil outflow through the use of an emergency rapid cargo transfer system or other system arranged to mitigate oil outflow in the event of an accident may be taken into account only after the effectiveness and safety aspects of the system are approved by the Organization. Submittal for approval shall be made in accordance with the provisions of the Guidelines referred to in regulation 19.5.

1

.1.

Side damage:

1.

Longitudinal extent (l_c):

1/3 L ^2/3 or 14.5 metres, whichever is less.

2.

Transverse extent (t_c) (inboard from the ship's side at right angles to the centreline at the level corresponding to the assigned summer freeboard):

B/5 or 11.5 metres, whichever is less.

3.

Vertical extent (v_c):

From the base line upwards without limit.

.2.

Bottom damage:

		For 0.3L from the forward perpendicular of the ship	Any other part of the ship
1.	Longitudinal extent (ls):	L/10	L/10 or 5 metres, whichever is less
2.	Transverse extent (ts):	B/6 or 10 metres, whichever is less but not less than 5 metres	5 metres
3.	Vertical extent from the base line (vs):	B/15 or 6 metres, whichever is less

2

1

.1.

For side damages:

O_c = ΣW_i + Σ K_iC_i (I)

.2.

For bottom damages:

O_s = 1/3 (Σ Z_iW_i + Σ Z_iC_i) (II)

where: W_i = volume of a wing tank in cubic metres assumed to be breached by the damage as specified in regulation 24 of this Annex; W_i for a segregated ballast tank may be taken equal to zero.

C_i = volume of a centre tank in cubic metres assumed to be breached by the damage as specified in regulation 24 of this Annex; C_i for a segregated ballast tank may be taken equal to zero.

K_i = 1− b_i/t_c when b_i is equal to or greater than t_c, K_i shall be taken equal to zero.

Z_i = 1− h_i/v_s, when h_i is equal to or greater than v_s, Z_i shall be taken equal to zero.

b_i = width of wing tank in metres under consideration measured inboard from the ship's side at right angles to the centreline at the level corresponding to the assigned summer freeboard.

h_i = minimum depth of the double bottom in metres under consideration; where no double bottom is fitted h_i shall be taken equal to zero.

2

1

1.

every oil tanker of 150 gross tonnage and above delivered after 31 December 1979, as defined in regulation 1.28.2, and

2.

every oil tanker of 150 gross tonnage and above delivered on or before 31 December 1979, as defined in regulation 1.28.1, which falls into either of the following categories:

.1.

a tanker, the delivery of which is after 1 January 1977, or

.2.

a tanker to which both the following conditions apply:

.1.

delivery is not later than 1 January 1977; and

.2.

the building contract is placed after 1 January 1974, or in cases where no building contract has previously been placed, the keel is laid or the tanker is at a similar stage of construction after 30 June 1974,

2

3

4

.1.

where no longitudinal bulkhead is provided inside the cargo tanks:

(0.5 (b_i/B) + 0.1) L but not to exceed 0.2L

.2.

where a centreline longitudinal bulkhead is provided inside the cargo tanks:

(0.25 (b_i/B) + 0.15) L

.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:

.1.

if b_i/B is equal to or greater than one fifth: 0.2L

.2.

if b_i/B is less than one fifth:

—

where no centreline longitudinal bulkhead is provided:

(0.5 (b_i/B) + 0.1) L

—

where a centreline longitudinal bulkhead is provided:

(0.25 (b_i/B) + 0.15) L

.4.

b_i 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.

5

6

7

1

.1.

In port, the initial metacentric height GMo, corrected for the free surface measured at 0° heel, shall be not less than 0.15 m;

.2.

At sea, the following criteria shall be applicable:

.1.

the area under the righting lever curve (GZ curve) shall be not less than 0.055 m.rad up to θ = 30° angle of heel and not less than 0.09 m.rad up to θ = 40° or other angle of flooding θ_f if this angle is less than 40°. Additionally, the area under the righting lever curve (GZ curve) between the angles of heel of 30° and 40° or between 30° and θf, if this angle is less than 40°, shall be not less than 0.03 m.rad;

.2.

the righting lever GZ shall be at least 0.20 m at an angle of heel equal to or greater than 30°;

.3.

the maximum righting arm shall occur at an angle of heel preferably exceeding 30° but not less than 25°; and

.4.

the initial metacentric height GMo, corrected for free surface measured at 0° heel, shall be not less than 0.15 m.

2

3

.1.

are approved by the Administration;

.2.

indicate those cargo and ballast tanks which may, under any specific condition of liquid transfer and possible range of cargo densities, be slack and still allow the stability criteria to be met. The slack tanks may vary during the liquid transfer operations and be of any combination provided they satisfy the criteria;

.3.

will be readily understandable to the officer-in-charge of liquid transfer operations;

.4.

provide for planned sequences of cargo/ballast transfer operations;

.5.

allow comparisons of attained and required stability using stability performance criteria in graphical or tabular form;

.6.

require no extensive mathematical calculations by the officer-in-charge;

.7.

provide for corrective actions to be taken by the officer-in-charge in case of departure from recommended values and in case of emergency situations; and

.8.

are prominently displayed in the approved trim and stability booklet and at the cargo/ballast transfer control station and in any computer software by which stability calculations are performed.

1

.1.

in tankers of more than 225 metres in length, anywhere in the ship's length;

.2.

in tankers of more than 150 metres, but not exceeding 225 metres in length, anywhere in the ship's length except involving either after or forward bulkhead bounding the machinery space located aft. The machinery space shall be treated as a single floodable compartment; and

.3.

in tankers not exceeding 150 metres in length, anywhere in the ship's length between adjacent transverse bulkheads with the exception of the machinery space. For tankers of 100 metres or less in length where all requirements of paragraph 3 of this regulation cannot be fulfilled without materially impairing the operational qualities of the ship, Administrations may allow relaxations from these requirements.

2

.1.

Side damage:

1.

Longitudinal extent: (1/3) (L²₃) or 14.5 metres,

whichever is less

2.

Transverse extent (inboard from the ship's side at right angles to the centreline at the level of the summer load line): B/5 or 11.5 metres,

whichever is less

3.

Vertical extent: From the moulded line of the bottom shell plating at centreline, upwards without limit

.2.

Bottom damage:

	For 0.3L from the forward perpendicular of the ship	Any other part of the ship
1. Longitudinal extent:	(1/3) (L23) or 14.5 metres, whichever is less	(1/3) (L23) or 5 metres, whichever is less
2. Transverse extent:	B/6 or 10 metres, whichever is less	B/6 or 5 metres, whichever is less
3. Vertical extent:	B/15 or 6 metres whichever is less, measured from the moulded line of the bottom shell plating at centreline	B/15 or 6 metres, which ever is less, measured from the moulded line of the bottom shell plating at centreline

.3.

If any damage of a lesser extent than the maximum extent of damage specified in subparagraphs 2.1 and 2.2 of this paragraph would result in a more severe condition, such damage shall be considered.

.4.

Where the damage involving transverse bulkheads is envisaged as specified in subparagraphs 1.1 and 1.2 of this regulation, transverse watertight bulkheads shall be spaced at least at a distance equal to the longitudinal extent of assumed damage specified in subparagraph 2.1 of this paragraph in order to be considered effective. Where transverse bulkhead are spaced at a lesser distance, one or more of these bulkheads within such extent of damage shall be assumed as non-existent for the purpose of determining flooded compartments.

.5.

Where the damage between adjacent transverse watertight bulkheads is envisaged as specified in subparagraph 1.3 of this regulation, no main transverse bulkhead or a transverse bulkhead bounding side tanks or double bottom tanks shall be assumed damaged, unless:

.1.

the spacing of the adjacent bulkheads is less than the longitudinal extent of assumed damage specified in subparagraph 2.1 of this paragraph; or

.2.

there is a step or recess in a transverse bulkhead of more than 3.05 metres in length, located within the extent of penetration of assumed damage. The step formed by the after peak bulkhead and after peak top shall not be regarded as a step for the purpose of this regulation.

.6.

If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements shall be made so that progressive flooding cannot thereby extend to compartments other than those assumed to be floodable for each case of damage.

3

.1.

The final waterline, taking into account sinkage, heel and trim, shall be below the lower edge of any opening through which progressive flooding may take place. Such openings shall include air pipes and those which are closed by means of weathertight doors or hatch covers and may exclude those openings closed by means of watertight manhole covers and flush scuttles, small watertight cargo tank hatch covers which maintain the high integrity of the deck, remotely operated sliding watertight doors, hinged watertight access doors with open/closed indication locally and at the navigation bridge, of the quick-acting or single-action type that are normally closed at sea, hinged watertight doors that are permanently closed at sea, and sidescuttles of the non-opening type.

.2.

In the final stage of flooding, the angle of heel due to unsymmetrical flooding shall not exceed 25°, provided that this angle may be increased up to 30° if no deck edge immersion occurs.

.3.

The stability in the final stage of flooding shall be investigated and may be regarded as sufficient if the righting lever curve has at least a range of 20° beyond the position of equilibrium in association with a maximum residual righting lever of at least 0.1 metre within the 20° range; the area under the curve within this range shall not be less than 0.0175 metre radians. Unprotected openings shall not be immersed within this range unless the space concerned is assumed to be flooded. Within this range, the immersion of any of the openings listed in subparagraph 3.1 of this paragraph and other openings capable of being closed watertight may be permitted.

.4.

The Administration shall be satisfied that the stability is sufficient during intermediate stages of flooding.

.5.

Equalization arrangements requiring mechanical aids such as valves or cross-levelling pipes, if fitted, shall not be considered for the purpose of reducing an angle of heel or attaining the minimum range of residual stability to meet the requirements of subparagraphs 3.1, 3.2 and 3.3 of this paragraph and sufficient residual stability shall be maintained during all stages where equalization is used. Spaces which are linked by ducts of a large cross-sectional area may be considered to be common.

4

.1.

Account shall be taken of any empty or partially filled tank, the relative density of cargoes carried, as well as any outflow of liquids from damaged compartments.

.2.

The permeabilities assumed for spaces flooded as a result of damage shall be as follows:

Spaces	Permeabilities
Appropriated to stores	0.60
Occupied by accommodation	0.95
Occupied by machinery	0.85
Voids	0.95
Intended for consumable liquids	0 to 0.95
Intended for other liquids	0 to 0.95

.3.

The buoyancy of any superstructure directly above the side damage shall be disregarded. The unflooded parts of superstructures beyond the extent of damage, however, may be taken into consideration provided that they are separated from the damaged space by watertight bulkheads and the requirements of subparagraph .1 of this regulation in respect of these intact spaces are complied with. Hinged watertight doors may be acceptable in watertight bulkheads in the superstructure.

.4.

The free surface effect shall be calculated at an angle of heel of 5° for each individual compartment. The Administration may require or allow the free surface corrections to be calculated at an angle of heel greater than 5° for partially filled tanks.

.5.

In calculating the effect of free surfaces of consumable liquids it shall be assumed that, for each type of liquid at least one transverse pair or a single centreline tank has a free surface and the tank or combination of tanks to be taken into account shall be those where the effect of free surface is the greatest.

5

.1.

information relative to loading and distribution of cargo necessary to ensure compliance with the provisions of this regulation; and

.2.

data on the ability of the ship to comply with damage stability criteria as determined by this regulation, including the effect of relaxations that may have been allowed under subparagraph 1.3 of this regulation.

6

.1.

oil tankers constructed before 1 January 2016 shall comply with this regulation at the first scheduled renewal survey of the ship on or after 1 January 2016 but not later than 1 January 2021;

.2.

notwithstanding the requirements of subparagraph .1 a stability instrument fitted on an oil tanker constructed before 1 January 2016 need not be replaced provided it is capable of verifying compliance with intact and damage stability, to the satisfaction of the Administration; and

.3.

for the purposes of control under regulation 11, the Administration shall issue a document of approval for the stability instrument.

7

.1.

longitudinal extent:

.1.

ships of 75,000 tonnes deadweight and above:

0.6L measured from the forward perpendicular;

.2.

ships of less than 75,000 tonnes deadweight:

0.4L measured from the forward perpendicular;

.2.

transverse extent: B/3 anywhere in the bottom;

.3.

vertical extent: breach of the outer hull.

1

2.1

2.2

2.3

.1.

2 per cent for such oil tankers where the tank washing arrangement are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system;

.2.

2 per cent where segregated ballast tanks or dedicated clean ballast tanks are provided in accordance with regulation 18 of this Annex, or where a cargo tank cleaning system using crude oil washing is fitted in accordance with regulation 3 of this Annex. This capacity may be further reduced to 1.5 per cent for such oil tankers where the tank washing arrangements are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system; and

.3.

1 per cent for combination carriers where oil cargo is only carried in tanks with smooth walls. This capacity may be further reduced to 0.8 per cent where the tank washing arrangements are such that once the slop tank or tanks are charged with washing water, this water is sufficient for tank washing and, where applicable, for providing the driving fluid for eductors, without the introduction of additional water into the system.

2.4

3

1

2

3

4

.1.

it shall be equipped with oil piping so designed and installed that oil retention in the lines is minimized; and

.2.

means shall be provided to drain all cargo pumps and all oil lines at the completion of cargo discharge, where necessary by connection to a stripping device. The line and pump draining shall be capable of being discharged both ashore and to a cargo tank or a slop tank. For discharge ashore a special small diameter line shall be provided and shall be connected outboard of the ship's manifold valves.

5

6

.1.

Segregated ballast and clean ballast may be discharged below the waterline:

.1.

in ports or at offshore terminals, or

.2.

at sea by gravity, or

.3.

at sea by pumps if the ballast water exchange is performed under the provisions of regulation D-1.1 of the International Convention for the Control and Management of Ships’ Ballast Water and Sediments,

provided that the surface of the ballast water has been examined either visually or by other means immediately before the discharge to ensure that no contamination with oil has taken place.

.2.

Oil tankers delivered on or before 31 December 1979, as defined in regulation 1.28.1, which, without modification, are not capable of discharging segregated ballast above the waterline may discharge segregated ballast below the waterline at sea, provided that the surface of the ballast water has been examined immediately before the discharge to ensure that no contamination with oil has taken place.

.3.

Oil tankers delivered on or before 1 June 1982, as defined in regulation 1.28.3 operating with dedicated clean ballast tanks, which without modification are not capable of discharging ballast water from dedicated clean ballast tanks above the waterline, may discharge this ballast below the waterline provided that the discharge of the ballast water is supervised in accordance with regulation 18.8.3 of this Annex.

.4.

On every oil tanker at sea, dirty ballast water or oil contaminated water from tanks in the cargo area, other than slop tanks, may be discharged by gravity below the waterline, provided that sufficient time has elapsed in order to allow oil/water separation to have taken place and the ballast water has been examined immediately before the discharge with an oil/water interface detector referred to in regulation 32 of this Annex, in order to ensure that the height of the interface is such that the discharge does not involve any increased risk of harm to the marine environment.

.5.

On oil tankers delivered on or before 31 December 1979, as defined in regulation 1.28.1, at sea dirty ballast water or oil contaminated water from cargo tank areas may be discharged below the waterline, subsequent to or in lieu of the discharge by the method referred to in subparagraph 6.4 of this paragraph, provided that:

.1.

a part of the flow of such water 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

.2.

such part flow arrangements comply with the requirements established by the Administration, which shall contain at least all the provisions of the Specifications for the Design, Installation and Operation of a Part Flow System for Control of Overboard Discharges adopted by the Organization.

7

1

2

3

4

1

2

3

1

.1.

the tanker is not within a special area;

.2.

the tanker is more than 50 nautical miles from the nearest land;

.3.

the tanker is proceeding en route;

.4.

the instantaneous rate of discharge of oil content does not exceed 30 litres per nautical mile;

.5.

the total quantity of oil discharged into the sea does not exceed for tankers delivered on or before 31 December 1979, as defined in regulation 1.28.1, 1/15,000 of the total quantity of the particular cargo of which the residue formed a part, and for tankers delivered after 31 December 1979, as defined in regulation 1.28.2, 1/30,000 of the total quantity of the particular cargo of which the residue formed a part; and

.6.

the tanker has in operation an oil discharge monitoring and control system and a slop tank arrangement as required by regulations 29 and 31 of this Annex.

2

3

4

5

6

7

8

9

1

2

3

1

2

.1.

loading of oil cargo;

.2.

internal transfer of oil cargo during voyage;

.3.

unloading of oil cargo;

.4.

ballasting of cargo tanks and dedicated clean ballast tanks;

.5.

cleaning of cargo tanks including crude oil washing;

.6.

discharge of ballast except from segregated ballast tanks;

.7.

discharge of water from slop tanks;

.8.

closing of all applicable valves or similar devices after slop tank discharge operations;

.9.

closing of valves necessary for isolation of dedicated clean ballast tanks from cargo and stripping lines after slop tank discharge operations; and

.10.

disposal of residues.

3

4

5

6

7

8

9

1

2

.1.

all ports and terminals in which crude oil is loaded into oil tankers where such tankers have immediately prior to arrival completed a ballast voyage of not more than 72 hours or not more than 1,200 nautical miles;

.2.

all ports and terminals in which oil other than crude oil in bulk is loaded at an average quantity of more than 1,000 tonnes per day;

.3.

all ports having ship repair yards or tank cleaning facilities;

.4.

all ports and terminals which handle ships provided with the oil residue (sludge) tank(s) required by regulation 12 of this Annex;

.5.

all ports in respect of oily bilge waters and other residues that cannot be discharged in accordance with regulations 15 and 34 of this Annex and paragraph 1.1.1 of part II-A of the Polar Code; and

.6.

all loading ports for bulk cargoes in respect of oil residues from combination carriers which cannot be discharged in accordance with regulation 34 of this Annex.

3

.1.

Crude oil loading terminals shall have sufficient reception facilities to receive oil and oily mixtures which cannot be discharged in accordance with the provisions of regulation 34.1 of this Annex from all oil tankers on voyages as described in paragraph 2.1 of this regulation.

.2.

Loading ports and terminals referred to in paragraph 2.2 of this regulation shall have sufficient reception facilities to receive oil and oily mixtures which cannot be discharged in accordance with the provisions of regulation 34.1 of this Annex from oil tankers which load oil other than crude oil in bulk.

.3.

All ports having ship repair yards or tank cleaning facilities shall have sufficient reception facilities to receive all residues and oily mixtures which remain on board for disposal from ships prior to entering such yards or facilities.

.4.

All facilities provided in ports and terminals under paragraph 2.4 of this regulation shall be sufficient to receive all residues retained according to regulation 12 of this Annex from all ships that may reasonably be expected to call at such ports and terminals.

.5.

All facilities provided in ports and terminals under this regulation shall be sufficient to receive oily bilge waters and other residues which cannot be discharged in accordance with regulation 15 of this Annex and paragraph 1.1.1 of part II-A of the Polar Code.

.6.

The facilities provided in loading ports for bulk cargoes shall take into account the special problems of combination carriers as appropriate.

3bis

.1.

how the Regional Reception Facilities Plan takes into account the Guidelines;

.2.

particulars of the identified Regional Ships Waste Reception Centres; and

.3.

particulars of those ports with only limited facilities.

4

.1.

small island developing States; and

.2.

States the coastline of which borders on Arctic waters, provided that regional arrangements shall cover only ports within Arctic waters of those States.

.1.

how the Regional Reception Facilities Plan takes into account the guidelines developed by the Organization;

.2.

particulars of the identified Regional Ships Waste Reception Centres taking into account the guidelines developed by the Organization; and

.3.

particulars of those ports with only limited facilities.

4bis

.1.

how the Regional Reception Facilities Plan takes into account the Guidelines;

.2.

particulars of the identified Regional Ships Waste Reception Centres; and

.3.

particulars of those ports with only limited facilities.