FINAL CLAUSES
Regulation 24 Damage assumptions
1 Fo r the purpose of calculating hypothetical oil outflow from oil tankers in accordance with regulations 25 and 26, three dimensions of the extent of damage of a parallelepipe d on the side and botto m of the ship are assumed as follows. I n the case of bottom damages two conditions are set forth to be applied individuall y to the stated portions of the oil tanker.
.1 Sid e damage:
.1.1 Longitudina l extent (lc): or 14.5 m , whichever is less .1.2 Transvers e exten t ( tc ) o r 11. 5 m , whicheve r i s les s
(inboard from the ship's side at right angles to the centreline at the level correspondin g to the assigned summer freeboard):
.1.3 Vertica l exten t (vc): Fro m the baseline upwards without limi t
* Referenc e is made to the Explanatory Notes on matters related to the accidental oil outflow performance, adopted by the Organiza- tion by resolution MEPC.122(52), as amended.
.2 Botto m damage :
.2.1 Longitudina l exten t (/s):
.2.2 Transvers e exten t (ts):
whichever i s less , bu t not les s than 5 m
.2.3 Vertica l exten t from th e baselin e (vs): or 6 m , whicheve r i s les s
1 Th e hypothetica l outflo w o f oi l i n th e cas e o f sid e damag e (Oc) an d botto m damag e (Os) shal l b e calculated b y th e followin g formula e wit h respec t t o compartment s breache d b y damag e t o al l conceivabl e locations alon g the lengt h o f the ship to the extent as define d i n regulatio n 2 4 o f this Annex.
.1 Fo r side damages:
(I) .2 Fo r botto m damages :
where:
Wi= volum e o f a win g tank , i n cubi c metres , assume d t o b e breache d b y th e damag e a s specified i n regulatio n 2 4 o f this Annex ; W , fo r a segregate d ballas t tan k ma y b e take n equal t o zero .
Ci = volum e o f a centr e tank , i n cubi c metres , assume d t o b e breache d b y th e damag e a s specified i n regulatio n 2 4 o f this Annex ; C fo r a segregate d ballas t tan k ma y b e take n equal t o zero .
when bi i s equal t o or greater than tc, Ki, shall b e taken equa l t o zero.
when hi i s equa l t o or greater than vs, Zi, shall b e taken equa l t o zero.
bi; = widt h o f win g tan k unde r consideration , i n metres , measure d inboar d fro m th e ship' s side a t righ t angle s t o th e centrelin e a t the leve l correspondin g to th e assigne d summe r freeboard.
hi = minimu m dept h o f the double botto m unde r consideration, i n metres ; wher e n o double bottom i s fitted, hj shall b e taken equa l t o zero .
2 Whereve r the symbol s give n i n thi s regulatio n appea r i n thi s chapter , the y hav e th e meanin g a s define d in thi s regulation .
Regulation 2 5
Hypothetical outflow of oil SEE INTERPRETATION 49 SEE INTERPRETATION 48
Regulation 2 5
Whenever symbols give n i n thi s paragrap h appea r i n thi s chapter , the y hav e th e meanin g a s define d i n thi s Insulation.
If a void space or segregated ballast tank of a length less than
lcas defined in regulation 24 of this Annex s located between wing oil tanks , O
ci n formula (I ) ma y be calculated on the basis of volume
Wi,being the actual volum e o f one suc h tan k (wher e the y ar e o f equal capacity ) o r the smalle r o f the tw o tank s (i f they differ in capacity) adjacent to such space, multiplied by S
i; as defined below and taking for all other wing tanks involved in such collision the value of the actual full volume.
where li = length , i n metres , o f void spac e o r segregate d ballas t tank unde r consideration .
1.1 Credi t shal l onl y b e give n i n respec t o f double botto m tank s whic h ar e eithe r empt y o r carryin g clea n water when cargo is carried in the tanks above.
3-2 Wher e the double bottom doe s no t extend for the full lengt h an d width o f the tank involved , th e double bottom i s considere d non-existen t and th e volume of the tanks abov e the area o f the botto m damag e shall b e included i n formula (II ) even i f the tank i s no t considered breache d becaus e of the installatio n o f such a partia l double bottom .
3.3 Suctio n well s ma y b e neglecte d i n th e determinatio n o f the valu e hi provide d suc h well s ar e no t exces - sive i n are a an d exten d belo w th e tan k fo r a minimu m distanc e an d i n n o cas e mor e tha n hal f the heigh t o f the double bottom . I f the dept h o f such a wel l exceed s hal f the heigh t of the doubl e bottom , hi shal l b e taken equal t o the doubl e botto m heigh t minu s th e wel l height .
Piping servin g suc h well s i f installe d withi n th e doubl e botto m shal l b e fitte d wit h valve s o r othe r closin g arrangements locate d a t th e poin t o f connectio n t o th e tan k serve d t o preven t oi l outflo w i n th e even t o f damage t o th e piping . Suc h pipin g shal l b e installe d a s hig h fro m th e botto m shel l a s possible . Thes e valve s shall b e kep t closed a t sea at any time when th e tank contains oil cargo , excep t that they ma y b e opened onl y for carg o transfe r neede d fo r th e purpos e o f trimming o f the ship .
5 A n Administratio n ma y credi t a s reducin g oi l outflo w i n cas e o f botto m damage , a n installe d carg o transfer syste m havin g a n emergenc y hig h suctio n i n eac h carg o oi l tank , capabl e o f transferrin g fro m a breached tan k or tanks t o segregate d ballas t tanks o r to availabl e carg o tankag e i f i t ca n b e assure d tha t such tanks wil l hav e sufficien t ullage . Credi t fo r suc h a syste m woul d b e governe d b y abilit y t o transfe r i n tw o hours o f operatio n oi l equa l t o on e hal f o f th e larges t o f th e breache d tank s involve d an d b y availabilit y o f equivalent receivin g capacit y i n ballas t o r carg o tanks . Th e credi t shal l b e confine d t o permittin g calculatio n of Os accordin g t o formul a (III) . Th e pipe s fo r suc h suction s shal l b e installe d a t leas t a t a heigh t no t les s than th e vertica l exten t o f the botto m damag e vs. Th e Administratio n shal l suppl y th e Organizatio n wit h th e information concernin g the arrangements accepte d b y it , fo r circulatio n t o othe r Partie s t o th e Convention . 6 Thi s regulatio n doe s no t appl y t o oi l tanker s delivere d o n o r afte r 1 Januar y 2010 , a s define d i n regulation 1.28.8 .
SEE INTERPRETATION 51
4 I n th e cas e wher e botto m damag e simultaneousl y involve s fou r centr e tanks , th e valu e o f Os ma y b e calculated accordin g to th e formula:
SEE INTERPRETATION 50
Regulation 26
Limitations of size and arrangement of cargo tanks 1 Excep t as provide d i n paragrap h 7 below :
.1 ever y oi l tanke r o f 15 0 gros s tonnage an d abov e delivere d afte r 3 1 Decembe r 1979 , a s define d i n regulation 1.28.2 , an d
.2 ever y oi l tanke r o f 15 0 gros s tonnag e an d abov e delivere d o n o r befor e 3 1 Decembe r 1979 , a s defined i n regulatio n 1.28.1 , whic h fall s int o either of the following categories:
.2.1 a tanker, th e delivery of which i s after 1 Januar y 1977 , o r .2.2 a tanker to which bot h th e following condition s apply :
.2.2.1 deliver y i s no t later than 1 Januar y 1977 ; an d
.2.2.2 th e buildin g contrac t i s place d afte r 1 Januar y 1974 , o r i n case s wher e n o buildin g contract ha s previousl y bee n placed , th e kee l i s lai d o r the tanker i s a t a simila r stage of construction afte r 3 0 June 197 4
shall compl y wit h th e provision s o f this regulation .
2 Carg o tanks o f oil tanker s shal l b e of such siz e and arrangement s that the hypothetica l outflo w Oc o r Os
calculated i n accordanc e with the provision s of regulation 2 5 o f this Annex anywhere i n th e lengt h o f the ship does no t exceed 30,00 0 m3 o r whicheve r i s the greater , bu t subjec t to a maximu m o f 40,000 m3. 3 Th e volum e o f an y on e win g carg o oi l tan k o f a n oi l tanke r shal l no t excee d 75 % o f th e limit s o f th e hypothetical oi l outflo w referre d t o i n paragrap h 2 o f this regulation . Th e volum e o f any on e centr e carg o oi l tank shall no t exceed 50,000 m3. However , i n segregated ballast oil tanker s as defined i n regulatio n 1 8 of this Annex, th e permitte d volum e o f a win g carg o oi l tan k situate d betwee n tw o segregate d ballas t tanks , eac h exceeding lc i n length , ma y b e increase d t o th e maximu m limi t o f hypothetica l oi l outflo w provide d tha t the width o f the win g tank s exceed s tc.
4 Th e lengt h o f eac h carg o tan k shal l no t excee d 1 0 m o r on e o f th e followin g values , whicheve r i s th e greater:
.1 wher e n o longitudina l bulkhea d i s provide d insid e the cargo tanks:
but no t to excee d 0.2/ .
.2 wher e a centreline longitudina l bulkhea d i s provide d insid e the cargo tanks:
.3 wher e two o r mor e longitudina l bulkhead s ar e provide d insid e the carg o tanks:
.3.1 fo r wing cargo tanks: 0.2/ . .3.2 fo r centr e carg o tanks:
.3.2.1 i f i s equal t o or greater than on e fifth: 0.2/ . .3.2.2 i f i s les s than on e fifth:
.3.2.2.1 wher e n o centreline longitudina l bulkhea d i s provided :
.3.2.2.2 wher e a centreline longitudina l bulkhea d i s provided :
Regulation 2 7
bi, is the minimu m distanc e from th e ship's side to the outer longitudina l bulkhea d o f the tank i n questio n measured inboar d a t righ t angle s t o th e centrelin e a t th e leve l correspondin g t o th e assigne d summe r freeboard.
In orde r no t t o excee d th e volum e limit s establishe d b y paragraph s 2 , 3 an d 4 o f thi s regulatio n an d irrespective o f the accepte d typ e o f carg o transfe r syste m installed , whe n suc h syste m interconnect s tw o o r more carg o tanks, valve s o r other similar closing device s shal l b e provide d fo r separatin g the tanks fro m eac h other. Thes e valves o r devices shal l b e closed whe n th e tanker i s a t sea.
6 Line s o f piping whic h ru n throug h carg o tank s i n a positio n les s tha n tc fro m th e ship' s sid e o r les s tha n vc fro m th e ship's botto m shal l b e fitte d wit h valve s o r similar closin g device s a t the poin t at which the y ope n into an y carg o tank . Thes e valve s shal l b e kep t close d a t se a a t an y tim e whe n th e tank s contai n carg o oil , except that they ma y b e opene d onl y fo r carg o transfe r neede d fo r the purpos e o f trimming o f the ship .
This regulatio n doe s no t appl y t o oi l tanker s delivere d o n o r afte r 1 Januar y 2010 , a s define d i n regulation 1.28.8 .
Regulation 2 7 intact stability
Every oil tanke r of 5,000 tonnes deadweight and above delivered on or after 1 Februar y 2002, a s defined in regulatio n 1.28.7 , shal l compl y wit h th e intac t stabilit y criteri a specifie d i n paragraph s 1. 1 an d 1. 2 o f this regulation, a s appropriate , fo r an y operatin g draugh t unde r the wors t possibl e condition s o f cargo an d ballas t loading, consisten t with goo d operationa l practice , includin g intermediat e stage s o f liqui d transfer operations.
Under all condition s th e ballas t tanks shal l b e assume d slack .
.1 I n port , th e initia l metacentri c heigh t CM0, correcte d for the free surface measure d at 0° heel, shal l be no t les s tha n 0.1 5 m ;
.2 A t sea, th e following criteria shal l b e applicable:
.2.1 th e are a unde r th e rightin g leve r curv e (G Z curve ) shal l b e no t les s tha n 0.05 5 m-ra d u p t o
= 30 ° angl e o f hee l an d no t les s tha n 0.0 9 m-ra d u p t o 0 = 40 ° o r othe r angl e o f flooding if this angle is les s than 40°. Additionally, the area under the righting lever curve (GZ curve) between the angles of heel o f 30° and 40° or between 30 ° and OS, if this angle is les s than 40°, shall b e no t les s than 0.0 3 m-rad ;
.2.2 th e rightin g leve r G Z shal l b e a t leas t 0.20 m a t an angl e o f hee l equa l t o o r greater than 30° ; .2.3 th e maximu m rightin g ar m shal l occu r a t a n angl e o f hee l preferabl y exceedin g 30 ° bu t no t
less than 25° ; an d
.2.4 th e initia l metacentri c heigh t GM0, corrected for free surface measure d at 0° heel, shal l b e not less than 0.1 5 m .
The requirement s o f paragraph 1 o f this regulatio n shal l b e me t through desig n measures . Fo r combina- Sofi carrier s simpl e supplementar y operationa l procedure s ma y b e allowed .
Simple supplementary operational procedure s for liqui d transfe r operations referre d t o i n paragrap h 2 o f this regulatio n shal l mea n writte n procedure s mad e availabl e to th e maste r which:
.1 ar e approved b y the Administration;
0s s the angle o f hee l a t which opening s i n th e hul l superstructure s o r deckhouse s whic h canno t b e close d weathertigh t immerse , In applying this criterion, smal l openings through which progressive flooding cannot take place need no t be considered as open.
SEE INTERPRETATION 52
.2 indicat e thos e carg o an d ballas t tank s whic h may , unde r an y specifi c conditio n o f liqui d transfe r and possibl e rang e o f carg o densities , b e slac k an d stil l allo w th e stabilit y criteri a t o b e met . Th e slack tanks ma y var y durin g the liqui d transfe r operations an d b e of any combinatio n provide d they satisfy th e criteria ;
.3 wil l b e readil y understandabl e to the officer-in-charg e o f liqui d transfe r operations;
.4 provid e fo r planne d sequence s o f cargo/ballast transfer operations ;
.5 allo w comparison s o f attained an d require d stabilit y usin g stabilit y performanc e criteri a i n graphi - cal o r tabular form;
.6 requir e n o extensiv e mathematica l calculation s b y th e officer-in-charge ;
.7 provid e for corrective actions to b e taken b y the officer-in-charge i n cas e of departure from recom - mended value s an d i n cas e o f emergency situations ; an d
.8 ar e prominently displayed i n the approved trim and stability booklet and at the cargo/ballast transfer control statio n an d i n an y compute r softwar e b y whic h stabilit y calculation s ar e performed .
Regulation 28
Subdivision and damage stability
1 Ever y oil tanke r delivered afte r 31 Decembe r 1979 , a s defined i n regulatio n 1.28.2 , o f 150 gross tonnage and above , shal l compl y with th e subdivisio n an d damag e stability criteri a a s specifie d i n paragrap h 3 o f this regulation, afte r th e assume d sid e o r botto m damag e a s specifie d i n paragrap h 2 o f this regulation , fo r an y operating draught reflectin g actua l partia l o r full loa d condition s consisten t with tri m an d strengt h o f the shi p as well a s relativ e densities o f the cargo. Suc h damag e shall b e applie d t o all conceivabl e location s alon g the length o f the ship a s follows:
.1 i n tankers of more than 225 m i n length , anywher e i n the ship's length ;
.2 i n tanker s o f mor e tha n 15 0 m , bu t no t exceeding 225 m i n length , anywher e i n th e ship' s lengt h except involvin g eithe r afte r o r forwar d bulkhea d boundin g th e machiner y spac e locate d aft . The machinery space shall b e treated a s a singl e floodable compartment; an d
.3 i n tanker s no t exceedin g 15 0 m i n length , anywher e i n th e ship' s lengt h betwee n adjacen t trans- verse bulkhead s wit h th e exceptio n o f the machiner y space . Fo r tankers o f 10 0 m o r les s i n lengt h where al l requirement s o f paragrap h 3 o f thi s regulatio n canno t b e fulfille d withou t materiall y impairing th e operationa l qualitie s o f th e ship , Administration s ma y allo w relaxation s fro m thes e requirements.
Ballast condition s wher e the tanker i s no t carrying oi l i n carg o tanks , excludin g any oi l residues , shal l no t be considered.
SEE INTERPRETATION 53
2 Th e following provision s regardin g the exten t and th e characte r o f the assume d damag e shal l apply : .1 Sid e damage:
.1.1 Longitudina l extent: or 14. 5 m , whicheve r i s les s .1.2 Transvers e exten t 11. 5 m , whicheve r i s les s
(inboard fro m th e ship's sid e at righ t angles to the centrelin e a t the leve l o f the summe r loa d line) :
.1.3 Vertica l extent : Fro m th e moulde d lin e o f the botto m shel l plating a t centreline, upward s withou t limi t
Regulation 2 8
.2 Botto m damage :
.2.1 Longitudina l exten t
.2.2 Transvers e extent :
.2.3 Vertica l extent :
.3 I f any damage of a lesse r extent than the maximum extent of damage specified i n subparagraph s 2.1 and 2.2 of this paragraph would result in a more severe condition, such damage shall be considered.
.4 Wher e the damag e involvin g transverse bulkhead s i s envisage d a s specifie d i n subparagraph s 1. 1 and 1. 2 o f thi s regulation , transvers e watertigh t bulkhead s shal l b e space d a t leas t a t a distanc e equal t o the longitudina l exten t of assumed damage specified i n subparagrap h 2.1 o f this paragrap h in orde r t o b e considere d effective . Wher e transvers e bulkhead s ar e space d a t a lesse r distance , one or mor e of these bulkhead s within suc h exten t of damage shall b e assume d a s non-existen t for the purpos e o f determining floode d compartments .
.5 Wher e th e damag e betwee n adjacen t transverse watertigh t bulkhead s i s envisage d a s specifie d i n subparagraph 1. 3 o f this regulation , n o mai n transvers e bulkhea d o r a transvers e bulkhea d bound - ing side tanks or double botto m tank s shal l b e assumed damaged , unless :
.5.1 th e spacing of the adjacent bulkhead s i s les s tha n th e longitudina l exten t of assumed damag e specified i n subparagrap h 2. 1 o f this paragraph ; o r
.5.2 ther e i s a step or recess i n a transverse bulkhead of more than 3.0 5 m i n length , locate d within the exten t o f penetratio n o f assume d damage . Th e ste p forme d b y th e afte r pea k bulkhea d and afte r pea k top shal l no t b e regarde d a s a ste p fo r the purpos e o f this regulation .
.6 I f pipes , duct s o r tunnel s ar e situate d withi n th e assume d exten t o f damage , arrangement s shal l be mad e s o tha t progressiv e floodin g canno t thereb y exten d t o compartment s othe r tha n thos e assumed to b e floodabl e for eac h cas e o f damage.
3 Oi l tanker s shal l b e regarde d a s complyin g wit h th e damag e stabilit y criteri a i f th e followin g require - ments ar e met :
.1 Th e final waterline, taking into account sinkage, hee l an d trim, shal l b e below the lower edge of any opening through whic h progressiv e floodin g ma y take place . Suc h opening s shal l includ e air-pipe s and thos e whic h ar e close d b y mean s o f weathertigh t door s o r hatc h cover s an d ma y exclud e those opening s close d b y mean s o f watertight manhol e cover s an d flus h scuttles , smal l watertigh t cargo tank hatc h cover s which maintai n th e hig h integrit y of the deck, remotel y operated watertigh t sliding doors , an d sidescuttle s o f the non-openin g type.
For 0.3L from the forward perpendicular of the ship
or 14. 5 m , whichever i s les s
or 1 0 m , whichever i s les s
or 6 m , whichever i s less , measured fro m th e moulded lin e o f the bottom shel l platin g at centrelin e
Any other part of the ship
or 5 m , whichever i s les s
or 5 m , whichever i s les s
or 6 m , whichever i s less , measured fro m th e moulded lin e o f the bottom shel l platin g at centrelin e
SEE INTERPRETATION 54
.2 I n the final stag e of flooding, th e angle of heel du e to unsymmetrical floodin g shall no t exceed 25°, provided tha t this angl e ma y b e increase d u p to 30 ° i f no dec k edge immersio n occurs .
.3 Th e stabilit y i n th e final stag e o f flooding shall b e investigate d an d ma y b e regarde d a s sufficien t i f the rightin g leve r curve ha s a t leas t a rang e of 20° beyon d th e positio n o f equilibrium i n associatio n with a maximu m residua l rightin g leve r o f a t leas t 0. 1 m withi n th e 20° range ; th e are a unde r th e curve withi n thi s rang e shal l no t b e les s tha n 0.017 5 m.rad . Unprotecte d opening s shal l no t b e immersed withi n thi s rang e unles s th e spac e concerne d i s assume d t o b e flooded . Withi n thi s range, th e immersio n o f any of the openings liste d i n subparagrap h 3. 1 o f this paragrap h an d othe r openings capabl e o f bein g close d weathertigh t ma y b e permitted .
.4 Th e Administratio n shal l b e satisfie d tha t th e stabilit y i s sufficien t durin g intermediat e stage s o f flooding.
.5 Equalizatio n arrangements requiring mechanical aids such as valves or cross-levelling pipes, i f fitted, shall no t be considered for the purpose of reducing an angle of heel o r attaining the minimum rang e of residua l stabilit y t o mee t th e requirement s o f subparagraph s 3.1 , 3. 2 an d 3. 3 o f this paragrap h and sufficien t residua l stabilit y shal l b e maintaine d durin g al l stage s wher e equalizatio n i s used . Spaces which ar e linke d b y ducts of a larg e cross-sectional are a ma y be considered to be common.
4 Th e requirement s o f paragrap h 1 o f this regulatio n shal l b e confirme d b y calculation s whic h tak e int o consideration th e desig n characteristic s o f th e ship , th e arrangements , configuratio n an d content s o f th e damaged compartments ; an d th e distribution , relativ e densitie s an d th e fre e surfac e effec t o f liquids . Th e calculations shal l b e based o n th e following:
.1 Accoun t shall b e taken o f any empt y or partiall y filled tank , th e relativ e densit y of cargoes carried, as wel l a s an y outflo w of liquid s fro m damage d compartments .
.2 Th e permeabilities assume d fo r spaces flooded a s a resul t of damage shall b e as follows:
Spaces Permeabilities
Appropriated to store s 0.6 0
Occupied b y accommodation 0.9 5
Occupied b y machiner y 0.8 5
Voids 0.9 5
Intended for consumable liquid s 0 t o 0.95 *
Intended for other liquid s 0 t o 0.95 *
.3 Th e buoyanc y o f an y superstructur e directl y abov e th e sid e damag e shal l b e disregarded . Th e unflooded part s o f superstructure s beyon d th e exten t o f damage , however , ma y b e take n int o consideration provide d tha t the y ar e separate d fro m th e damage d spac e b y watertigh t bulkhead s and th e requirement s o f subparagrap h .3. 1 o f thi s regulatio n i n respec t o f thes e intac t space s are complie d with . Hinge d watertigh t door s ma y b e acceptabl e i n watertigh t bulkhead s i n th e superstructure.
.4 Th e free surface effect shall b e calculated at an angl e of heel o f 5° for each individua l compartment . The Administratio n ma y requir e o r allo w th e fre e surfac e correction s t o b e calculate d a t a n angl e of hee l greate r than 5 ° for partiall y fille d tanks .
.5 I n calculatin g th e effec t o f fre e surface s o f consumabl e liquid s i t shal l b e assume d that , fo r eac h type of liquid, a t leas t one transverse pai r or a single centreline tank ha s a free surfac e and th e tank or combinatio n o f tanks t o b e taken int o accoun t shall b e thos e wher e th e effec t of free surfac e i s the greatest .
* The permeability of partially filled compartments shall be consistent with the amount of liquid carried in the compartment. Whenever damage penetrate s a tank containing liquids , i t shall b e assumed that the contents ar e completely los t from tha t compartment and replaced by salt water up to the leve l of the final plan e of equilibrium.
Regulation 2 9
The maste r o f every oi l tanke r t o whic h thi s regulatio n applie s an d th e perso n i n charg e o f a non-self - propelled oi l tanke r to whic h thi s regulatio n applie s shal l b e supplie d i n a n approve d for m with :
.1 informatio n relativ e t o loadin g an d distributio n o f cargo necessar y t o ensur e complianc e wit h th e provisions o f this regulation ; an d
.2 dat a on th e ability of the ship to comply with damag e stability criteria a s determined b y this regula - tion, includin g the effect of relaxations that may hav e been allowe d unde r subparagraph 1. 3 o f this regulation.
6 Fo r oi l tanker s o f 20,00 0 tonne s deadweigh t an d abov e delivere d o n o r afte r 6 Jul y 1996 , a s define d in regulatio n 1.28.6 , th e damag e assumption s prescribe d i n paragrap h 2. 2 o f this regulatio n shal l b e supple - mented b y the following assume d botto m rakin g damage:
.1 longitudina l extent :
.1.1 ship s o f 75,00 0 tonne s deadweigh t an d above : 0.6/. measure d fro m th e forward perpendicular ; .1.2 ship s o f less tha n 75,00 0 tonnes deadweight:
0.4/. measure d fro m th e forward perpendicular ; .2 transvers e extent: anywher e i n th e bottom ;
.3 vertica l extent : breac h o f the oute r hull .
Regulation 2 9 Slop tanks
1 Subjec t to the provisions of paragraph 4 of regulation 3 o f this Annex, oi l tankers of 150 gross tonnage and above shall b e provided with slo p tank arrangements i n accordance with the requirements of paragraphs 2.1 t o 2.3 o f this regulation . I n oi l tanker s delivered on o r before 31 Decembe r 1979 , a s defined i n regulatio n 1.28.1 , any cargo tank ma y b e designated a s a slo p tank.
2.1 Adequat e mean s shal l b e provide d fo r cleaning the carg o tanks an d transferrin g the dirt y ballas t residu e and tan k washings fro m th e carg o tank s int o a slo p tan k approve d b y the Administration.
2.2 I n this system arrangements shall b e provided to transfer the oily waste int o a slop tank or combination of slop tanks i n suc h a way that any effluent discharged int o the sea will b e such as to comply with th e provisions of regulation 3 4 o f this Annex .
2.3 Th e arrangements o f the slop tank or combination o f slop tanks shal l hav e a capacit y necessar y to retai n the slop generated b y tank washings, oi l residue s an d dirt y ballas t residues . Th e total capacit y of the slop tank or tanks shal l no t be les s tha n 3 % o f the oil-carryin g capacit y o f the ship , excep t that the Administration ma y accept:
.1 2 % fo r suc h oi l tanker s wher e th e tan k washin g arrangement s ar e suc h tha t onc e th e slo p tan k or tank s ar e charge d wit h washin g water , thi s wate r i s sufficien t fo r tan k washin g and , wher e applicable, fo r providin g the drivin g fluid fo r eductors, withou t the introductio n o f additional wate r into the system ;
.2 2 % wher e segregate d ballas t tank s o r dedicate d clea n ballas t tank s ar e provide d i n accordanc e with regulatio n 1 8 o f this Annex , o r where a carg o tank cleanin g system usin g crud e oil washin g i s fitted i n accordanc e with regulatio n 3 3 o f this Annex. Thi s capacity may be further reduced to 1.5 % for such oi l tanker s where the tank washing arrangements are such tha t once the slop tank or tanks are charge d wit h washin g water , thi s wate r i s sufficien t fo r tan k washin g and , wher e applicable , for providin g th e drivin g flui d fo r eductors , withou t th e introductio n o f additiona l wate r int o th e system; an d