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RULESFOR THE CLASSIFICATION OF
SHIPS
Part 5 - SUBDIVISION
2013
CROATIAN REGISTER OF SHIPPING
Hrvatska (Croatia) 21000 Split Marasovieva 67 P.O.B. 187Tel.:
(...) 385 (0)21 40 81 11Fax.: (...) 385 (0)21 35 81 59E-mail:
[email protected]
web site: www.crs.hr
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By decision of the General Committee to the Croatian Register of
Shipping,
RULES FOR THE CLASSIFICATION OF SHIPSPART 5 - SUBDIVISION
have been adopted on 28th December 2012 and shall enter into
force on 1st January 2013
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RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
REVIEW OF AMENDMENTS IN RELATION TO 2011EDITION
RULES FOR THE CLASSIFICATION OF SHIPSPart 5 SUBDIVISION
All major changes throughout the text are shaded.
Items not being indicated as corrected have not been changed in
relation to 2011 edition.
The grammatical and print errors have also been corrected
throughout the text of subject Rules, but are not indicated asa
correction.
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RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
The subject Rules include the requirements of the following
international Organizations:
International Maritime Organization (IMO)
Conventions: International Convention for the Safety of Life at
Sea 1974 (SOLAS 1974) and all sub-sequent amendments up to and
including the 2011 amendments (MSC. 320(89))
Protocol of 1988 relating to the International Convention for
the Safety of Life at Sea1974, as amended (SOLAS PROT 1988)
International Convention for the Prevention of Pollution from
Ships 1973, as modifiedby the Protocol of 1978 thereto (MARPOL
73/78) and all subsequent amendments up toand including amendments
2011 (MEPC.201(62))
Codes: International Code of Safety for High-Speed Craft (HSC
Code), MSC. 36(63), MSC.97(73)
Code of Safety for Dynamically Supported Craft, A.373(X)
Resolutions: Guidelines for the design and construction of
offshore supply vessels, 2006, MSC.235(82)
Code of Safety for Special Purpose Ships, 2008, MSC. 266(84)
Regulation equivalent to Regulation 27 of the International
Convention on Load Lines,1966, A.320(IX), as amended by res.
A.514(13) and modified according toMSC.143(77)
International Association of Classification Societies (IACS)
Unified Interpretations (UI): LL 63(Rev.2, 2008); LL 65(Rev.2,
2008); LL 69(Rev.1, 2008); LL 75(Rev.1, 2009);SC 161(Rev.1,
2008)
Recommendations (Rec.): No.110 (Rev.1, 2010)
EU Directives: Directive 2003/25/EC of the European Parliament
and of the Council of 14 April 2003as amended by Commission
Directive 2005/12/EC of 18 February 2005.
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RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
Contents:Page
1 GENERAL
.............................................................................................................................................................11.1
APPLICATION
..........................................................................................................................................................................
11.2 DEFINITIONS AND
EXPLANATIONS...................................................................................................................................
11.3 SCOPE OF SUPERVISION
.......................................................................................................................................................
21.4 GENERAL TECHNICAL
REQUIREMENTS...........................................................................................................................
21.5 ADDITIONAL CLASS NOTATION FOR SHIPS COMPLYING SUBDIVISION
REQUIREMENTS .................................. 31.6 DOCUMENTATION
.................................................................................................................................................................
3
2 SUBDIVISION AND DAMAGE STABILITY OF PASSENGER SHIPS AND CARGO
SHIPS .................42.1 APPLICATION
..........................................................................................................................................................................
42.2 DEFINITIONS
...........................................................................................................................................................................
42.3 DOCUMENTATION
.................................................................................................................................................................
42.4 REQUIRED SUBDIVISION INDEX R
.................................................................................................................................
52.5 ATTAINED SUBDIVISION INDEX A
.................................................................................................................................
52.6 CALCULATION OF THE FACTOR
Pi.....................................................................................................................................
62.7 CALCULATION OF THE FACTOR si
.....................................................................................................................................
72.8
PERMEABILITY.......................................................................................................................................................................
92.9 SPECIAL REQUIREMENTS CONCERNING PASSENGER SHIP STABILITY
...................................................................
92.10 SYSTEM CAPABILITIES AFTER A FLOODING CASUALTY ON PASSENGER
SHIPS ................................................ 102.11
DOUBLE BOTTOMS IN PASSENGER SHIPS AND CARGO SHIPS OTHER THAN
TANKERS .................................... 102.12 PASSENGER SHIPS
CARRYING GOODS VECHILES AND ACCOMPANYING PERSONNEL
..................................... 102.13 INTERNAL WATERTIGHT
INTEGRITY OF PASSENGER SHIPS ABOVE THE BULKHEAD DECK
.......................... 112.14 INTEGRITY OF THE HULL AND
SUPERSTRUCTURE, DAMAGE PREVENTION AND CONTROL ON RO-RO
PASSENGER
SHIPS................................................................................................................................................................
112.15 ASSIGNING, MARKING AND RECORDING OF SUBDIVISION LOAD LINES
FOR PASSENGER SHIPS .................. 112.16 DAMAGE CONTROL
INFORMATION
................................................................................................................................
122.17 PERIODICAL OPERATION AND INSPECTION OF WATERTIGHT DOORS,
ETC., IN PASSENGER SHIPS............... 122.18 PREVENTION AND
CONTROL OF WATER INGRESS, ETC.
...........................................................................................
122.19 SPECIAL REQUIREMENTS FOR RO-RO PASSENGER SHIPS
.........................................................................................
132.20 PREVENTION AND CONTROL OF WATER INGRESS, ETC., IN CARGO
SHIPS ..........................................................
142.21 TIMBER DECK CARGO IN THE CONTEX OF DAMAGE STABILITY
REQUIREMENTS ............................................ 14
3 SPECIFIC STABILITY REQUIREMENTS FOR RO-RO PASSENGER SHIPS
.......................................153.1
GENERAL................................................................................................................................................................................
153.2 SPECIFIC STABILITY REQUIREMENTS
............................................................................................................................
163.3 MODEL TEST
METHOD........................................................................................................................................................
17
4 SPECIAL REQUIREMENTS FOR TYPE B SHIPS WITH REDUCED FREEBOARD
............................204.1 APPLICATION
........................................................................................................................................................................
204.2 INITIAL CONDITION OF
LOADING....................................................................................................................................
204.3 DAMAGE ASSUMPTIONS
....................................................................................................................................................
204.4 CONDITION OF
EQUILIBRIUM...........................................................................................................................................
224.5 SHIPS WITH ASSIGNED REDUCED FREEBOARD INTENDED TO CARRY DECK
CARGO ....................................... 22
5 DAMAGE STABILITY REQUIREMENTS APPLICABLE TO BULK CARRIERS
.................................23
6 SPECIAL PURPOSE
SHIPS..............................................................................................................................246.1
APPLICATION
........................................................................................................................................................................
246.2 DEFINITIONS
.........................................................................................................................................................................
246.3 SUBDIVISION AND DAMAGE
STABILITY........................................................................................................................
24
7 OFFSHORE SUPPLY VESSELS
......................................................................................................................257.1
APPLICATION
........................................................................................................................................................................
257.2 DEFINITIONS
.........................................................................................................................................................................
257.3 SUBDIVISION AND DAMAGE STABILITY, GENERAL
...................................................................................................
257.4 DAMAGE ASSUMPTIONS
....................................................................................................................................................
257.5 DAMAGE STABILITY CRITERIA
........................................................................................................................................
267.6 ASSUMPTIONS FOR CALCULATING DAMAGE STABILITY
.........................................................................................
267.7
SUBDIVISION.........................................................................................................................................................................
26
8 HIGH SPEED
CRAFTS......................................................................................................................................278.1
DYNAMICALLY SUPPORTED CRAFTS
(DSC)..................................................................................................................
27
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RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
8.2 HIGH SPEED CRAFTS, ACCORDING TO HSC 1994
..........................................................................................................278.3
HIGH SPEED CRAFTS, ACCORDING TO HSC 2000
..........................................................................................................27
9 TANKERS
............................................................................................................................................................289.1
SUBDIVISION AND STABILITY
..........................................................................................................................................289.2
DAMAGE
ASSUMPTIONS.....................................................................................................................................................289.3
DAMAGE STABILITY
CRITERIA.........................................................................................................................................299.4
ASSUMPTION FOR CALCULATING DAMAGE
STABILITY............................................................................................299.5
STABILITY INFORMATION
.................................................................................................................................................299.6
ACCIDENTAL OIL OUTFLOW PERFORMANCE
...............................................................................................................309.7
DAMAGE STABILITY VERIFICATION OF PARTICULAR LOADING CASE ON NEW
TANKERS .............................34
APPENDIX 1
...................................................................................................................................................................37
1
APPLICATION.........................................................................................................................................................................372
MODEL
TESTING...................................................................................................................................................................45
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RULES FOR THE CLASSIFICATION OF SHIPS 1PART 5
2013
1 GENERAL
1.1 APPLICATION
1.1.1 The requirements of this part of Rules apply toships of
following types:
.1 Passenger ships engaged on internationalvoyage;
.2 cargo ships over 80 m in length;
.3 oil tankers;
.4 chemical tankers;
.5 special purpose ships;
.6 supply vessels;
.7 high speed crafts;
.8 ro-ro passenger ships on which is applica-ble Directive
2003/25/EC as amended.
1.1.2 Passenger ships engaged on national servicenavigation on
which the Directive 98/18/EC, as amended, isapplied, are to be in
compliance with requirements for subdivi-sion stated in the
Directive.
1.1.3 For the purpose of this Part of the Rules a cargoship,
whenever built, which is converted to a passenger shipshall be
treated as a passenger ship constructed on the date onwhich such a
conversion commences.
1.1.4 The expression alterations and modifications ofa major
character means, in the context of cargo ship subdivi-sion and
stability, any modification to the construction whichaffects the
level of subdivision of that ship. Where a cargo shipis subject to
such modification, it shall be demonstrated that theA/R ratio
calculated for the ship after such modifications is notless than
the A/R ratio calculated for the ship before the modi-fication.
However, in those cases where the ships A/R ratiobefore
modification is equal to or greater than unity, it is onlynecessary
that the ship after modification has an A value whichis not less
than R, calculated for the modified ship.
1.1.5 All ships which undergo repairs,
alternations,modifications and outfitting related thereto shall
continue tocomply with at least the requirements previously
applicable tothese ships. Such ships, if constructed before the
date on whichany relevant regulations of this Part of the Rules
enter intoforce, shall, as a rule, comply with the requirements for
shipsconstructed on or after that date to at least the same extent
asthey did before undergoing such repairs, alterations,
modifica-tions or outfitting. Repairs, alterations and
modifications of amajor character and outfitting related thereto
shall meet the re-quirements for ships constructed on or after the
date on whichany relevant regulations of this Part of the Rules
enter intoforce, in so far as the Register deems reasonable and
practica-ble.
1.1.6 The Register may, if it considers that the shel-tered
nature and conditions of the voyage are such as to renderthe
application of any specific requirements of this Part of theRules
unreasonable or unnecessary, exempt from those re-quirements
individual ships or classes of ships engaged in na-tional service
navigation.
1.1.7 It is recommended to undertake all measureswhich permit
the assignment and service conditions of the shipto attain the best
subdivision characteristics for the ships whichare not subjected to
the requirements of the present Rules.
Besides, if the shipowner requests to assign asubdivision mark
in a sign of the ships class, it should satisfythe requirements of
this Part of the Rules.
The Register considers and decides in each par-ticular case
about the appliance of this Part of the Rules con-cerning the ships
of novel design.
1.2 DEFINITIONS ANDEXPLANATIONS
Definitions and explanations relating to the gen-eral
terminology of the Rules, are given in the Rules for
theclassification of ships, Part 1 - General Requirements, Ch. 1
-General Information.
For the purpose of the present Part of the Rulesthe following
definitions have been applied:
1.2.1 Length (L) is the length as defined in the In-ternational
Convention on Load Lines in force.
1.2.2 Freeboard deck is the deck as defined in theInternational
Convention on Load Lines in force.
1.2.3 Forward perpendicular is the forward per-pendicular as
defined in the International Convention on LoadLines in force.
1.2.4 Amidship is at the middle of the length (L).
1.2.5 Keel line is a line parallel to the slope of thekeel
passing amidships through:
.1 the top of the keel at centerline or line ofintersection of
the inside of shell platingwith the keel if a bar keel extends
belowthat line, on a ship with a metal shell; or
.2 in wood and composite ships, the distanceis measured from the
lower edge of the keelrabbet. When the form at the lower part ofthe
midship section is of a hollow charac-ter, or where thick garboards
are fitted, thedistance is measured from the point wherethe line of
the flat of the bottom continuedinward intersects the centerline
amidships.
1.2.6 Bulkhead deck is the uppermost deck up towhich the
transverse watertight bulkheads are carried.
1.2.7 The margin line is a line draw at least 76 mmbelow the
upper surface of the bulkhead deck at side.
1.2.8 Permeability of a space is the proportion ofthe immersed
volume of that space which can be occupied bywater. The volume of a
space which extends above the marginline shall be measured only to
the only to the height of thatline.
1.2.9 Machinery spaces - are spaces between the wa-tertight
boundaries of a space containing the main and auxil-iary propulsion
machinery, including boilers, generators andelectric motors
primarily intended for propulsion. In the case ofunusual
arrangements, the Register may define the limits of themachinery
spaces.
1.2.10 Passenger spaces - are those spaces which areprovided for
the accommodation and use of passengers, ex-cluding baggage, store,
provision and mail rooms.
1.2.11 Volumes and areas - in all cases volumes andareas shall
be calculated to moulded lines.
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2 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
1.2.12 Weathertight - means that in any sea conditionswater will
not penetrate into the ship.
1.2.13 Watertight - means having scantlings and ar-rangements
capable of preventing the passage of water in anydirection under
the head of water likely to occur in intact anddamaged conditions.
In the damaged condition, the head ofwater is to be considered in
the worst situation at equilibrium,including intermediate stages of
flooding.
1.2.14 Design pressure - means the hydrostatic pressurefor which
each structure or appliance assumed watertight in theintact and
damage stability calculations is designed to with-stand.
1.2.15 Deadweight - is the difference in tonnes betweenthe
displacement of a ship in water of a specific gravity of1.025 at
the draught corresponding to the assigned summerfreeboard and the
lightweight of the ship.
1.2.16 Lightweight is the displacement of a ship intonnes
without cargo, fuel, lubricating oil, ballast water, freshwater and
feedwater in tanks, consumable stores, and passen-gers and crew and
their effects.
1.2.17 Oil tanker is the oil tanker defined in regula-tion 1 of
Annex 1 of the Protocol of 1978 relating to the Inter-national
Convention for the Prevention of Pollution fromShips, 1973.
1.2.18 Ro-ro passenger ship means a passenger shipwith ro-ro
cargo spaces or special category spaces as follows:
.1 Ro-ro cargo spaces - are spaces normallysubdivided in any way
and extending toeither a substantial length or the entirelength of
the ship in which goods (packedor in bulk, in or on rail or road
cars, vehi-cles (including road or rail tankers),
trailers,containers, pallets, demountable tanks or inor on similar
stowage units or other recep-tacles) can be loaded and unloaded
nor-mally in a horizontal direction.
.2 Open ro-ro cargo spaces either open atboth ends, or open at
one end and providedwith adequate natural ventilation effectiveover
their entire length through permanentopenings in the side plating
or deckhead tothe satisfaction of the Register.
.3 Closed ro-ro cargo spaces are ro-rocargo spaces which are
neither open ro-rocargo spaces nor weather decks.
.4 Weather deck is a deck which is com-pletely exposed to the
weather from aboveand from at least two sides.
.5 Special category spaces are those en-closed spaces above or
below the bulkheaddeck intended for the carriage of motor ve-hicles
with fuel in their tanks for their ownpropulsion, into and from
which such vehi-cles can be driven and to which passengershave
access.
1.2.19 Internal watertight integrity is the capabilityof
internal structures and their closing appliances to
preventprogressive flooding to volumes assumed as a buoyant or
in-tact.
The internal watertight integrity includes positionand type of
closing appliances, alarms, indicators, remote con-trols and
signboards fitted to such appliances.
Further, watertight closing of pipes, ducts andtunnels in the
damage penetration zone is regarded as a part ofthe internal
watertight integrity.
1.2.20 Progressive flooding is ingress of waterthrough internal
openings to compartments assumed to be in-tact.
1.2.21 Downflooding angle related to intact stability is the
minimum heel angle where an external opening withoutweathertight
closing appliances is submerged.
1.2.22 Downflooding angle related to damage stabil-ity is the
minimum heel angle where and external openingwithout watertight
closing appliance is submerged.
1.2.23 Damage zone is the zone of the ship where thestipulated
damage can be assumed. The stipulated damage isdefined in the
applicable damage stability requirements.
1.2.24 Residual stability is the positive range of therighting
level curve after damage with external heeling leverstaken into
account.
1.2.25 Combination carrier means a ship designed tocarry either
oil or solid cargoes in bulk.
1.3 SCOPE OF SUPERVISION
1.3.1 The provisions relating to the procedure of su-pervision
during construction, surveys and classification ofships, as well as
the requirements for the technical documenta-tion to be submitted
for consideration of Register, are con-tained in the Rules for the
classification of ships, Part 1 - Gen-eral requirements
1.3.2 For every ship meeting the requirements of thepresent Part
of the Rules, Register shall carry out the follow-ing:
.1 checking the compliance of the structuralmeasures taken to
ensure subdivision in ac-cordance with requirements specified in
theRules for the classification of ships, Part 2- Hull, Sections 7
and 10, Part 3-HullEquipment, Section 7 and Part 8-Pipingrelative
items;
.2 checking and approval of the calculationfor subdivision and
damaged stability;
.3 checking of the correct assignment andmarking of additional
load lines at ship'ssides corresponding to the
subdivisionloadline.
1.4 GENERAL TECHNICALREQUIREMENTS
1.4.1 Any approved subdivision loadline shall not beplaced above
the waterline corresponding to the minimumfreeboard in salt water,
which may be assigned to a ship in ac-cordance with the
requirements of the International Conven-tion on Load Lines 1966
and Protocol of 1988, as amended.
The position of the subdivision loadline deter-mined for the
given ship shall be recorded in ships documentsby the Register.
Subdivision load lines shall be marked at theship's sides.
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RULES FOR THE CLASSIFICATION OF SHIPS 3PART 5
2013
1.4.2 In all cases the volumes and areas shall be calcu-lated to
moulded lines. The volumes and free surfaces of thewater penetrated
into compartments of reinforced concrete,plastic, wood and
composite ships, shall be calculated to theinner shell areas.
1.4.3 When determining the initial metacentric heightof a
damaged ship, the correction for the effect of free surfacesof
liquid cargoes, ship's stores and ballast water shall be takeninto
account in the same manner as in the case of calculatingthe intact
stability of a ship, in accordance with the require-ments of the
Rules for the classification of ships, Part 4-Stability, 1.4.7.
When plotting the statical stability curves for adamaged ship,
enclosed superstructures, trunks, deck housesand deck cargo, angles
of flooding through openings in ship'ssides, deck and hull and
superstructure bulkheads, consideredto be open, as well as the
correction for the effect of free sur-faces of liquid cargoes,
shall be calculated in the same manneras for the elaboration of
curves for an intact ship, in accordancewith the requirements of
the Rules for the classification ofships, Part 4 Stability, item
1.4.2.
The superstructures, trunks and deck houses,which have sustained
damage, may be taken into account onlywith regard to the
permeability factor, specified in 2.8.1 orneed not be taken into
consideration at all. The openings insidesuch structures leading to
the spaces which will not be flooded,are considered to be open at
appropriate angles of heel only incases when regular watertight
means for closing thereof are notfitted.
1.4.4 When calculating damage stability and trim, ac-count shall
be taken on the changes of draught, heeling angleand trim due to
replacing liquid cargo by sea water in damagedtanks.
1.4.5 The ships to which the present Part of the Rulesis
applicable shall be provided with the approved Informationon damage
stability, draught, side inclination and trim in caseof compartment
flooding. This information shall enable themaster in different
conditions of ship's operation, to take intoaccount the
requirements concerning subdivision and to esti-mate the state of
the ship in the case of flooding of its com-partments and to take
measures for maintaining the damagedship afloat.
The Information shall contain the following data:.1 data on the
ship, its longitudinal section,
deck and double bottom plans as well astypical cross-section
with indication of allwatertight bulkheads and enclosures
withopenings therein, method and means fortheir closing as well as
diagram arrange-ments of systems necessary for the survivalof
damaged ship;
.2 instructions necessary for maintenance ofstability of an
intact ship sufficient to with-stand the most dangerous extent of
damagein accordance with the present Part of theRules; instructions
on loading and bal-lasting the ship, including the recommen-dations
on distributing the cargo in holdswith regard to subdivision,
meeting at thesame time the requirements for trim, stabil-ity and
strength of a ship.In order to maintain sufficient damage
sta-bility, the Information shall include themaximum permissible
height of the ship'scentre of gravity above keel (KG) or alter-
natively the minimum permissible meta-centric height (MG) for a
range of draughtsand displacements, requested according toRules for
the classification of ships Part 4 Stability, 1.5.1;
.3 survey of the results of the symmetrical andunsymmetrical
flooding calculations withthe data on initial and damage
draught,keel, trim and metacentric height both be-fore and after
taken measures for equaliza-tion of a ship or improvement of its
stabil-ity. Parameters of the statical stabilitycurves provided
under the worst floodingconditions shall also be shown. For
theships to which Section 2 of the present Partof the Rules is
applicable, it is sufficient topresent the documentation stated in
2.3.1;
.4 procedures recommended for the measuresfor equalization of a
ship or improvementof its stability and the period of time
re-quired for that procedures, as well as otherdata on structural
measures to ensure ship'ssubdivision, instructions for use of
thecross-flooding arrangements and otheremergency appliances;
.5 possible consequences of flooding due toparticular features
of ships and the advis-able and prohibited actions of the crew
inthe course of service of ship and in case ofdamage involving
flooding.
1.4.6 The information on damaged stability shall becompiled on
the basis of the data contained in the StabilityBook stated in the
Rules, Part 4 - Stability, 1.5.1.
1.4.7 Information on damage stability of a ship is al-lowed to
be included in the Intact stability book as a separatechapter.
1.4.8 If the computer installed on the ship is used toestimate
uprighting ships procedure after damage or calculatedamage
stability, the computer as well as programme usedshall be approved
by the Register.
The use of the computer shall not substitute theinformation on
damage stability.
1.5 ADDITIONAL CLASS NOTATIONFOR SHIPS COMPLYING SUBDIVISION
REQUIREMENTS1.5.1 As additional class notation the letters SD
shallbe marked according to the Rules for the classification
ofships, Part 1 - General requirements, item 1. General - if
dam-age stability calculations for any computed cases satisfy
re-quirements of this Part of the Rules.
1.6 DOCUMENTATION1.6.1 Documentation for approval:
- Preliminary Damage Stability Calculations- Final Damage
Stability Calculations - Damage Control Plan
1.6.2 Documentation for information:- Internal Watertight
Integrity Plan
Not required in case of approved limit curves, or if
approvedlightweight data are not less favourable than estimated
lightweight data.
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4 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
2 SUBDIVISION AND DAMAGESTABILITY OF PASSENGERSHIPS AND CARGO
SHIPS
2.1 APPLICATION
2.1.1 The damage stability requirements stated in thisSection
shall apply to cargo ships of 80 m in length (L) andupwards and to
all passenger ships regardless of length butshall exclude those
cargo ships which are shown to complywith subdivision and damage
stability regulations in other in-struments developed by the
International Maritime Organiza-tion (IMO).
2.1.2 Any reference hereinafter to regulation refers tothe set
of regulations contained in this Section.
2.1.3 The Register may, for a particular ship or groupof ships,
accept alternative methodologies if it is satisfied thatat least
the same degree of safety as represented by theseregulations is
achieved. In the case when the Register allowssuch alternative
arrangements, previously it shall communicateto the International
Maritime Organization (IMO) particularsthereof.
2.1.4 Unless expressly provided otherwise, this Sectionshall
apply to ships the keels of which are laid or which are at asimilar
stage of construction on or after 1 January 2009.
2.1.5 Ships shall be as efficiently subdivided as is pos-sible
having regard to the nature of the service for which theyare
intended. The degree of subdivision shall vary with thesubdivision
length (LS) of the ship and with the service, in suchmanner that
the highest degree of subdivision corresponds withthe ships of
greatest subdivision length (LS), primarily engagedin the carriage
of passengers.
2.1.6 Where it is proposed to fit decks, inner skins
orlongitudinal bulkheads of sufficient tightness to seriously
re-strict the flow of water, the Register shall be satisfied
thatproper consideration is given to beneficial or adverse effects
ofsuch structures in the calculations.
Ships shown to comply with the following regulation may be
ex-
cluded from the applications of this Section:.1 Annex I to
MARPOL 73/78, except OBO ships with type B
freeboards are not excluded;.2 International Bulk Chemical
Code;.3 International Gas Carrier Code;.4 Guidelines for the design
and construction of offshore supply
vessels, 2006 (resolution MSC.235(82));.5 Code of Safety for
Special Purpose Ships, 2008 (resolution
MSC.266(84));.6 Damage stability requirements of regulation 27
of the 1966
Load Lines Convention as applied in compliance with resolu-tions
A.320(IX) and A.514(13), provided that in the case ofcargo ships to
which regulation 27(9) applies, main transversewatertight
bulkheads, to be considered effective, are spacedaccording to
paragraph (12)(f) of resolution A.320(IX), exceptships intended for
the carriage of deck cargo; and
.7 Damage stability requirements of regulation 27 of the
1988Load Lines Protocol, except ships intended for the carriage
ofdeck cargo.
2.2 DEFINITIONS
For the purpose of this Section, unless expresslyprovided
otherwise:
2.2.1 Subdivision length (Ls) of the ship - is thegreatest
projected moulded length of that part of the ship at orbelow deck
or decks limiting the vertical extent of floodingwith the ship at
the deepest subdivision draught.
2.2.2 Mid-length is the mid-point of the subdivisionlength of
the ship.
2.2.3 Aft terminal - is the aft limit of the
subdivisionlength.
2.2.4 Forward terminal - is the forward limit of thesubdivision
length.
2.2.5 Breadth (B) - is the greatest moulded breadth ofthe ship
at or below the deepest subdivision draught.
2.2.6 Draught (d) - is the vertical distance from thekeel line
at mid-length to the waterline in question.
2.2.7 Deepest subdivision draught (ds) is the water-line which
corresponds to the summer load line draught of theship.
2.2.8 Light service draught (dl) is the servicedraught
corresponding to the lightest anticipated loading andassociated
tankage, including, however, such ballast as may benecessary for
stability and/or immersion. Passenger shipsshould include the full
complement of passengers and crew onboard.
2.2.9 Partial subdivision draught (dp) is the lightservice
draught plus 60% of the difference between the lightservice draught
and the deepest subdivision draught.
2.2.10 Trim is the difference between the draughtforward and the
draught aft, where the draughts are measuredat the forward and aft
terminals respectively, disregarding anyrake of keel.
2.2.11 Permeability ( ) of a space - is the proportionof the
immersed volume of that space which can be occupiedby water.
2.2.12 For the purpose of this chapter, the term a simi-lar
stage of construction means the stage at which:
.1 construction identifiable with a specificship begins; and
.2 assembly of that ship has commenced com-prising at least 50
tonnes or one per cent ofthe estimated mass of all structural
mate-rial, whichever is less.
2.3 DOCUMENTATION
2.3.1 The following documentation is to be submittedfor
approval:
- calculation of subdivisions indices R andA;
- damage stability calculations for theflooding cases included
in the calculationof A;
- stability information as required in regula-tion 1.5.1 Rules
for the classification ofships, Part 4 - Stability;
- damage control plan.
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RULES FOR THE CLASSIFICATION OF SHIPS 5PART 5
2013
2.3.2 The following documentation is to be submittedfor
information only:
- internal watertight integrity plan.
2.4 REQUIRED SUBDIVISION INDEXR
2.4.1 The subdivision of a ship is considered sufficientif the
attained subdivision index A, determined in accordancewith Head
2.5, is not less than the required subdivision index Rcalculated in
accordance with this Head and if, in addition, thepartial indices
As, Ap and Al are not less than 0.9R for passen-ger ships and 0.5R
for cargo ships.
2.4.2 For all ships to which the damage stability re-quirements
of this Section apply, the degree of subdivision tobe provided
shall be determined by the required subdivisionindex R, as
follows:
.1 In the case of cargo ships greater than 100 m inlength
(Ls):
1521281+
=sL
R
and.2 In the case of cargo ships not less than 80 m in
length (Ls) and not greater than 100 m in length(Ls):
+=o
osR
RLR1100
1/11
where Ro is the value R as calculated in ac-cordance with the
formula in sub-item .1
.3 In the case of passenger ships:
152255.250001
++=
NLR
swhere:N = N1+2N2N1 number of persons for whom lifeboats are
provided,N2 number of persons (including officers and
crew) the ship is permitted to carry in ex-cess of N1.
.4 Where the conditions of service are such that com-pliance
with sub-item .3 of this item on the basis ofN = N1+2N2 is
impracticable and where the Regis-ter considers that a suitably
reduced degree of haz-ard exists, a lesser value of N may be taken
but inno case less than N1+N2.
2.5 ATTAINED SUBDIVISION INDEXA
2.5.1 The attained subdivision index A is obtained bythe
summation of the partial indices As, Ap and Al, (weightedas shown)
calculated for the draughts ds, dp and dl, defined inHead 2.2, in
accordance with the following formula:
A = 0.4As + 0.4Ap + 0.2Al
Each partial index is a summation of contribu-tions from all
damage cases taken in consideration, using thefollowing
formula:
See MSC/Circ. 651, Explanatory notes for part B-1 SOLAS,
Chapter II-1.
A = pi si
where:i - represents each compartment or group of
compartments under consideration,pi - accounts for the
probability that only the
compartment or group of compartments un-der consideration may be
flooded, disregard-ing any horizontal subdivision, as defined
inHead 2.6,
si - accounts for the probability of survival afterflooding the
compartment or group of com-partments under consideration, and
includesthe effect of any horizontal subdivision, asdefined in Head
2.7.
2.5.2 In the calculation of A, the level trim shall beused for
the deepest subdivision draught and the partial subdi-vision
draught. The actual service trim shall be used for thelight service
draught. If in any service condition, the trimvariation in
comparison with the calculated trim is greater than0.5% of Ls, one
or more additional calculations of A are to besubmitted for the
same draughts but different trims so that, forall service
conditions, the difference in trim in comparison withthe reference
trim used for one calculation will be less than0.5% of Ls.
2.5.3 When determining the positive righting lever(GZ) of the
residual stability curve, the displacement usedshould be that of
the intact condition. That is, the constant dis-placement method of
calculation should be used.
2.5.4 The summation indicated by the above formulashall be taken
over the ships subdivision length Ls for all casesof flooding in
which a single compartment or two or more ad-jacent compartments
are involved. In the case of unsymmetri-cal arrangements, the
calculated A value should be the meanvalue obtained from
calculations involving both sides. Alter-natively, it should be
taken as that corresponding to the sidewhich evidently gives the
least favourable result.
2.5.5 Wherever wing compartments are fitted, contri-bution to
the summation indicated by the formula shall betaken for all cases
of flooding in which wing compartments areinvolved. Additionally,
cases of simultaneous flooding of awing compartment or group of
compartments and the adjacentinboard compartment or group of
compartments, but excludingdamage of transverse extent greater than
one half of the shipbreadth B, may be added. For the purpose of
this regulation,transverse extent is measured inboard from ships
side, at rightangle to the centreline at the level of the deepest
subdivisiondraught.
2.5.6 In the flooding calculations carried out accordingto this
Section of the Rules, only one breach of the hull andonly one free
surface need to be assumed. The assumed verticalextent of damage is
to extend from the baseline upwards to anywatertight horizontal
subdivision above the waterline or higher.However, if a lesser
extent of damage will give a more severeresult, such extent is to
be assumed.
2.5.7 If pipes, ducts or tunnels are situated within theassumed
extent of damage, arrangements are to be made to en-sure that
progressive flooding cannot thereby extend to com-partments other
than those assumed flooded. However, theRegister may permit minor
progressive flooding if it is demon-strated that its effects can be
easily controlled and the safety ofthe ship is not impaired.
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6 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
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2.6 CALCULATION OF THE FACTORPi
2.6.1 The factor pi for a compartment or group of com-partments
shall be calculated in accordance with items 2.6.2and 2.6.3, using
the following notations:
j = the aftmost damage zone number in-volved in the damage
starting with no.1 atthe stern;
n = the number of adjacent damage zones in-volved in the
damage;
k = is the number of a particular longitudinalbulkhead as
barrier for transverse pene-tration in a damage zone counted
fromshell towards the centreline. The shell hask = 0;
x1 = the distance from the aft terminal of Ls tothe aft end of
the zone in question;
x2 = the distance from the aft terminal of Ls tothe forward end
of the zone in question;
b = the mean transverse distance in metresmeasured at right
angles to the centrelineat the deepest subdivision loadline
be-tween the shell and an assumed verticalextended between the
longitudinal limitsused in calculating the factor pi andwhich is a
tangent to, or common with,all or part of the outermost portion of
thelongitudinal bulkhead under considera-tion. This vertical plane
shall be so ori-entated that the mean transverse distanceto the
shell is a maximum, but not morethan twice the least distance
between theplane and the shell. If the upper part of alongitudinal
bulkhead is below the deep-est subdivision loadline the vertical
planeused for determination of b is assumed toextend upwards to the
deepest subdivi-sion waterline. In any case, b is not to betaken
greater than B/2.
If the damage involves a single zone only:
pi = p(x1j, x2j) [r(x1j, x2j,bk)- r(x1j, x2j,bk-1)]
If the damage involves two adjacent zones:
pi = p(x1j, x2j+1) [r(x1j, x2j+1,bk)- r(x1j, x2j+1,bk-1)]-
p(x1j, x2j) [r(x1j, x2j,bk)- r(x1j, x2j,bk-1)]- p(x1j+1, x2j+1)
[r(x1j+1, x2j+1,bk)- r(x1j+1, x2j+1,bk-1)]
If the damage involves three or more adjacent zones:
pi = p(x1j, x2j+n-1) [r(x1j, x2j+n-1,bk)- r(x1j, x2j+n-1,bk-1)]-
p(x1j, x2j+n-2) [r(x1j, x2j+n-2,bk)- r(x1j, x2j+n-2,bk-1)]-
p(x1j+1, x2j+n-1) [r(x1j+1, x2j+n-1,bk)- r(x1j+1,
x2j+n-1,bk-1)]
+p(x1j+1, x2j+n-2) [r(x1j+1, x2j+n-2,bk)- r(x1j+1,
x2j+n-2,bk-1)]
and where r(x1, x2, b0) = 0
2.6.2 The factor pi (x1, x2) is to be calculated accord-ing to
the following formulae:
Overall normalized max damage length: Jmax = 10/33Knuckle point
in the distribution:Jkn = 5/33Cumulative probability at Jkn : pk =
11/12Maximum absolute damage length: lmax = 60 mLength where
normalized distribution ends: L* = 260 mProbability density at J =
0:
=
kn
k
kn
k
JJp
Jpb
max0
12
When Ls < L* :
=s
m LlJJ maxmax ,min
( )
0
2200 4
12111
2 b
JbJbpJJmmk
mk
+++=
012 bb =
When Ls > L* :
= *
maxmax
* ,minL
lJJm
( )
0
2*20
*0*
* 412111
2 b
JbJbpJJmmk
mk
+++=
s
mm L
LJJ**
=
s
kk L
LJJ**
=
=
km
k
k
k
JJp
Jpb 1212
( ) 211 214
k
k
kkm
k
Jp
JJJpb
=
( )22112
km
k
JJpb
=
mJbb 2122 =
The non-dimensional damage length:( )
sL1x2xJ =
The normalized length of a compartment orgroup of
compartments:
Jn - is to be taken as the lesser of J and Jm
2.6.2.1 Where neither limits of the compartment or groupof
compartments under consideration coincides with the aft orforward
terminals:
J < Jk :
p(x1, x2) = p1 = 61 J2(b11J+3b12)
J > Jk :
p(x1, x2) = p2 = - 31 b11Jk3+ 2
1 (b11J-b12)Jk2+b12JJk
-31 b21(Jn3-Jk3)+ 2
1 (b21J-b22)(Jn2-Jk2)
+b22J(Jn-Jk)
2.6.2.2 Where the aft limit of the compartment or groupof
compartments under consideration coincides with the aftterminal or
the forward limit of the compartment or group ofcompartments under
consideration coincides with the forwardterminal:
J < Jk :
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p(x1, x2) = 21 (p1+J)
J > Jk :
p(x1, x2) = 21 (p2+J)
2.6.2.3 Where the compartment or groups of compart-ments
considered extends over the entire subdivision length(Ls):
p(x1, x2) = 1
2.6.3 The factor r(x1, x2, b) shall be determined by
thefollowing formulae:
r(x1, x2, b) = 1-(1-C)
)(1
x2x1,pG
where:C = 12Jb(-45Jb+4) , where
Jb = Bb15
2.6.3.1 Where the compartment or groups of compart-ments
considered extends over the entire subdivision length(Ls):
G = G1 = 21 b11Jb2+b12Jb
2.6.3.2 Where neither limits of the compartment or groupof
compartments under consideration coincides with the aft orforward
terminals:
G = G2 = - 31 b11J03+ 2
1 (b11J-b12)J02+b12JJ0 where
J0 = min(J, Jb)
2.6.3.3 Where the aft limit of the compartment or groupof
compartments under consideration coincides with the aftterminal or
the forward limit of the compartment or group ofcompartments under
consideration coincides with the forwardterminal:
G = 21 (G2+G1J)
2.7 CALCULATION OF THE FACTORsI
2.7.1 The factor si shall be determined for each case ofassumed
flooding, involving a compartment or group of com-partments, in
accordance with the following notations and theprovisions in this
Head:
e - is the equilibrium heel angle in anystage of flooding, in
degrees;
v - is the angle, in any stage of flooding,where the righting
lever becomes nega-tive, or the angle at which an openingincapable
of being closed weathertightbecomes submerged;
GZmax - is the maximum positive righting lever,in metres, up to
the angle v;
Range - is the range of positive righting levers,in degrees,
measured from the angle e.The positive range is to be taken up
tothe angle v;
Flooding stage - is any discrete step during theflooding
process, including the stagebefore equalization (if any) until
finalequilibrium has been reached.
2.7.1.1 The factor si, for any damage case at any initialloading
condition, at draught di, , shall be obtained from theformula:
si = minimum { sintermediate,i or sfinal,i smom,i }where:
sintermediate,i - is the probability to survive all
intermedi-ate flooding stages until the final equilib-rium stage,
and is calculated in accor-dance with 2.7.2;
sfinal,i - is the probability to survive in the finalequilibrium
stage of flooding. It is calcu-lated in accordance with 2.7.3;
smom,i - is the probability to survive heeling mo-ments, and is
calculated in accordancewith 2.7.4.
2.7.2 The factor sintermediate,i is applicable only to
pas-senger ships (for cargo ships sintermediate,i should be taken
asunity) and shall be taken as the least of the s-factors
obtainedfrom all flooding stages including the stage before
equaliza-tion, if any, and is to be calculated as follows:
sintermediate,i = 41
max705.0
RangeGZ
where GZmax is not to be taken as more than 0.05 m and Rangeas
not more than 7. sintermediate,i = 0, if the intermediate heel
an-gle exceeds 15. Where cross-flooding fittings are required,
thetime for equalization shall not exceed 10 min.
2.7.3 The factor sfinal,i shall be obtained from the
for-mula:
sfinal,i = K 41
max1612.0
RangeGZ
where:GZmax - is not to be taken as more than 0.12 m;Range - is
not to be taken as more than 16;K = 1 if e < minK = 0 if e >
max
K =minmax
max
e otherwise,
where:min is 7 for passenger ships and 25 for cargo ships;andmax
is 15 for passenger ships and 30 for cargo ships.
2.7.4 The factor smom,i is applicable only to passengerships
(for cargo ships smom,i shall be taken as unity) and shall
becalculated at the final equilibrium from the formula:
smom,i = ( )
heelMGZ 04.0max
where: - is the intact displacement at the subdivision
draught;Mheel - is the maximum assumed heeling moment as
calculated in accordance with 2.7.5; andsmom,i < 1
2.7.5 The heeling moment Mheel is to be calculated
asfollows:
Mheel = maximum{Mpassenger or Mwind or Msurvivalcraft }
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8 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
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2.7.5.1 Mpassenger is the maximum assumed heeling mo-ment
resulting from movement of passengers, and is to be ob-tained as
follows:
Mpassenger = (0.075Np) (0.45B) [tm]where:
Np - is the maximum number of passengerspermitted to be on board
in the service con-dition corresponding to the deepest subdivi-sion
draught under consideration; and
B - is the beam of the ship.Alternatively, the heeling moment
may be cal-
culated assuming the passengers are distributed with 4
personsper square metre on available deck areas towards one side
ofthe ship on the decks where muster stations are located and
insuch a way that they produce the most adverse heeling mo-ment. In
doing so, a weight of 75 kg per passenger is to be as-sumed.
2.7.5.2 Mwind is the maximum assumed wind force actingin a
damage situation:
Mwind = (PAZ) / 9.806 [tm]where:
P = 120 N/m2 ;A = projected lateral area above waterline;Z =
distance from centre of lateral projected
area above waterline to T/2; andT = ships draught, di.
2.7.5.3 Msurvivalcraft is the maximum assumed heelingmoment due
to the launching of all fully loaded davit-launchedsurvival craft
on one side of the ship. It shall be calculated us-ing the
following assumptions:
.1 all lifeboats and rescue boats fitted on theside to which the
ship has heeled afterhaving sustained damage shall be assumedto be
swung out fully loaded and ready forlowering;
.2 for lifeboats which are arranged to belaunched fully loaded
from the stowed po-sition, the maximum heeling moment dur-ing
launching shall be taken;
.3 a fully loaded davit-launched liferaft at-tached to each
davit on the side to whichthe ship has heeled after having
sustaineddamage shall be assumed to be swung outready for
lowering;
.4 persons not in the life-saving applianceswhich are swung out
shall not provide ei-ther additional heeling or righting
moment;and;
.5 life-saving appliances on the side of theship opposite to the
side to which the shiphas heeled shall be assumed to be in astowed
position.
2.7.6 Unsymmetrical flooding is to be kept to a mini-mum
consistent with the efficient arrangements. Where it isnecessary to
correct large angles of heel, the means adoptedshall, where
practicable, be self-acting, but in any case wherecontrols to
equalization devices are provided they shall be op-erable from
above the bulkhead deck. These fittings togetherwith their controls
shall be acceptable to the Register. Suitable
Reference is made to the Recommendation on a standard method
for establishing compliance with the requirements for
cross-flooding arrangements in passengers ships, adopted by the IMO
byresolution A.266(VIII), as may be amended.
information concerning the use of equalization devices shall
besupplied to the master of the ship.
2.7.6.1 Tanks and compartments taking part in suchequalization
shall be fitted with air pipes or equivalent meansof sufficient
cross-section to ensure that the flow of water intothe equalization
compartments is not delayed.
2.7.6.2 In all cases, si is to be taken as zero in those
caseswhere the final waterline, taking into account sinkage, heel
andtrim, immerses:
.1 the lower edge of openings through whichprogressive flooding
may take place andsuch flooding is not accounted for in
thecalculation of factor si. Such openings shallinclude air-pipes,
ventilators and openingswhich are closed by means of
weathertightdoors or hatch covers; and
.2 any part of the bulkhead deck in passengerships considered a
horizontal evacuationroute for compliance with the Rules for
theclassification of ships, Part 17 Fire pro-tection.
2.7.6.3 The factor si is to be taken as zero if, taking
intoaccount sinkage, heel and trim, any of the following occur
inany intermediate stage or in the final stage of flooding:
.1 immersion of any vertical escape hatch inthe bulkhead deck
intended for compliancewith the Rules for the classification
ofships, Part 17 Fire protection;
.2 any controls intended for the operation ofwatertight doors,
equalization devices,valves on piping or on ventilation ducts
in-tended to maintain the integrity of water-tight bulkheads from
above the bulkheaddeck become inaccessible or inoperable;
.3 immersion of any part of piping or ventila-tion ducts carried
through a watertightboundary that is located within any
com-partment included in damage cases contrib-uting to the attained
index A, if not fittedwith watertight means of closure at
eachboundary.
2.7.6.4 However, where compartments assumed floodeddue to
progressive flooding are taken into account in the dam-age
stability calculations multiple values of sintermediate,i may
becalculated assuming equalization in additional flooding
phases.
2.7.6.5 Except as provided in 2.7.6.3.1, openings closedby means
of watertight manhole covers and flush scuttles,small watertight
hatch covers, remotely operated sliding wa-tertight doors, side
scuttles of the non-opening type as well aswatertight access doors
and hatch covers required to be keptclosed at sea need not be
considered.
2.7.7 Where horizontal watertight boundaries are fittedabove the
waterline under consideration the s-value calculatedfor the lower
compartment or group of compartments shall beobtained by
multiplying the value as determined in 2.7.1.1 bythe reduction
factor vm according to 2.7.7.1, which representsthe probability
that the spaces above the horizontal subdivisionwill not be
flooded.
2.7.7.1 The factor vm shall be obtained from the formula:vm = v
(Hj,n,m,d) - v (Hj,n,m-1,d)
where:
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RULES FOR THE CLASSIFICATION OF SHIPS 9PART 5
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Hj,n,m is the least height above the baseline, inmetres, within
the longitudinal range ofx1(j)x2(j+n-1) of the mth horizontal
boundarywhich is assumed to limit the vertical ex-tent of flooding
for the damaged compart-ments under consideration;
Hj,n,m-1 is the least height above the baseline, inmetres,
within the longitudinal range ofx1(j)x2(j+n-1) of the (m-1)th
horizontalboundary which is assumed to limit thevertical extent of
flooding for the damagedcompartments under consideration;
j signifies the aft terminal of the damagedcompartments under
consideration;
m represents each horizontal boundarycounted upwards from the
waterline underconsideration;
d is the draught in question as defined in2.2.6; and
x1 and x2 represent the terminals of the compart-ment or group
of compartments consideredin 2.6.1.
2.7.7.2 The factors (Hj,n,m,d) and (Hj,n,m-1,d shall be
ob-tained from the formulas:
v(H, d) = ( )8.7dH , if (Hm-d) < 7.8 [m];
v(H, d) = ( )
+7.4
8.72.08.0 dH in all other cases,
where:v (Hj,n,m,d) is to be taken as 1, if Hm coincides with
the
uppermost watertight boundary of the shipwithin the range
(x1(j)x2(j+n-1)); and
v (Hj,n,0,d) is to be taken as 0.In no case is vm to be taken as
less than zero or
more than 1.
2.7.7.3 In general, each contribution dA to the index A inthe
case of horizontal subdivisions is obtained from the for-mula:
dA = pi [v1smin 1+( v2- v1) smin 2++(1- vm-1) smin m]where:
vm = the v-value calculated in accordance with2.7.7.1;
smin = the least s-factor for all combinations ofdamages
obtained when the assumeddamage extends from the assumed dam-age
height Hm downwards.
2.8 PERMEABILITY
2.8.1 For the purpose of the subdivision and damagestability
calculations of this Section of the Rules, the perme-ability of
each general compartment or part of a compartmentshall be as
follows:
Spaces Permeability
Appropriated to stores 0.60
Occupied by accommodation 0.95
Occupied by machinery 0.85
Void spaces 0.95
Intended for liquids 0 or 0.95*
* Whichever results in the more severe requirement
2.8.2 For the purpose of the subdivision and damagestability
calculations of this Section of the Rules, the perme-ability of
each cargo compartment or part of a compartmentshall be as
follows:
Spaces Permeabilityat draught dsPermeabilityat draught dp
Permeabilityat draught dl
Dry cargo spaces 0.70 0.80 0.95
Container spaces 0.70 0.80 0.95
Ro-ro spaces 0.90 0.90 0.95
Cargo liquids 0.70 0.80 0.95
2.8.3 Other figures for permeability may be used ifsubstantiated
by calculations.
2.9 SPECIAL REQUIREMENTSCONCERNING PASSENGER SHIP
STABILITY
2.9.1 A passenger ship intended to carry 400 or morepersons
shall have watertight subdivision abaft the collisionbulkhead so
that si=1 for the three loading conditions on whichis based the
calculation of the subdivision index and for a dam-age involving
all the compartments within 0.08L measuredfrom the forward
perpendicular.
2.9.2 A passenger ship intended to carry 36 or morepersons is to
be capable of withstanding damage along the sideshell to an extent
specified in 2.9.3. Compliance with this Headis to be achieved by
demonstrating that si, as defined in 2.7 , isnot less than 0.9 for
the three loading conditions on which isbased the calculation of
the subdivision index.
2.9.3 The damage extent to be assumed when demon-strating
compliance with 2.9.2 is to be dependent on both N asdefined in
2.4, and Ls , as defined in 2.2, such that:
.1 the vertical extent of damage is to extendfrom the ships
moulded baseline to a posi-tion up to 12.5 m above the position of
thedeepest subdivision draught as defined in2.2, unless a lesser
vertical extent of dam-age were to give a lower value of si ,
inwhich case this reduced extent is to beused;
.2 where 400 or more persons are to be car-ried, a damage length
of 0.03 Ls but not lessthan 3 m is to be assumed at any
positionalong the side shell, in conjunction with apenetration
inboard of 0.1B but not lessthan 0.75 m measured inboard from
theship side, at right angle to the centreline atthe level of the
deepest subdivisiondraught;
.3 where less than 400 persons are carried,damage length is to
be assumed at any po-sition along the shell side between
trans-verse watertight bulkheads provided thatthe distance between
two adjacent trans-verse watertight bulkheads is not less thanthe
assumed damage length. If the distancebetween adjacent transverse
watertightbulkheads is less than the assumed damagelength, only one
of these bulkheads shall be
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10 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
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considered effective for the purpose ofdemonstrating compliance
with 2.9.3;
.4 where 36 persons are carried, a damagelength of 0.015 Ls but
not less than 3 m isto be assumed, in conjunction with a
pene-tration inboard of 0.05B but not less than0.75 m; and
.5 where more than 36, but fewer than 400persons are carried the
values of damagelength and penetration inboard, used in
thedetermination of the assumed extent ofdamage, are to be obtained
by linear inter-polation between the values of damagelength and
penetration which apply forships carrying 36 persons and 400
personsas specified in previous sub-items .4 and .2.
2.10 SYSTEM CAPABILITIES AFTER AFLOODING CASUALTY ON
PASSENGER SHIPS
2.10.1 ApplicationThis regulation applies to passenger ships
con-
structed on or after 1 July 2010 to which regulation II-2/21
ofthe SOLAS Convention as amended by MSC 216(82) applies.
2.10.2 Availability of essential systems in case offlooding
damage
A passenger ship shall be designed so that thesystems specified
in regulation II-2/21.4 of the SOLAS Con-vention as amended by MSC
216(82) remain operational whenthe ship is subject to flooding of
any single watertight com-partment.
2.11 DOUBLE BOTTOMS INPASSENGER SHIPS AND CARGO SHIPS
OTHER THAN TANKERS
2.11.1 A double bottom shall be fitted extending fromthe
collision bulkhead to the afterpeak bulkhead, as far as thisis
practicable and compatible with the design and properworking of the
ship.
2.11.2 Where a double bottom is required to be fitted theinner
bottom shall be continued out to the ship's sides in such amanner
as to protect the bottom to the turn of the bilge. Suchprotection
will be deemed satisfactory if the inner bottom is notlower at any
part than a plane parallel with the keel line andwhich is located
not less than a vertical distance h measuredfrom the keel line, as
calculated by the formula:
h = B/20
However, in no case is the value of h to be lessthan 760 mm, and
need not be taken as more than 2,000 mm.
2.11.3 Small wells constructed in the double bottom inconnection
with drainage arrangements of holds, etc., shall notextend downward
more than necessary. A well extending to theouter bottom is,
however, permitted at the after end of the shafttunnel. Other wells
(e.g. for lubricating oil under main engines)may be permitted by
the Register if satisfied that the arrange-ments give protection
equivalent to that afforded by a doublebottom complying with this
regulation. In no case shall thevertical distance from the bottom
of such a well to a plane co-inciding with the keel line be less
than 500 mm.
2.11.4 A double bottom need not be fitted in way ofwatertight
tanks, including dry tanks of moderate size, pro-vided the safety
of the ship is not impaired in the event of bot-tom or side
damage.
2.11.5 Any part of a passenger ship or a cargo ship thatis not
fitted with a double bottom in accordance with 2.11.1and 2.11.4
shall be capable of withstanding bottom damages,as specified in
2.11.7, in that part of the ship.
2.11.6 In the case of unusual bottom arrangements in apassenger
ship or a cargo ship, it shall be demonstrated that theship is
capable of withstanding bottom damages as specified in2.11.7.
2.11.7 Compliance with 2.11.5 and 2.11.6 is to beachieved by
demonstrating that si , when calculated in accor-dance with 2.7, is
not less than 1 for all service conditionswhen subject to a bottom
damage assumed at any positionalong the ship's bottom and with an
extent specified in .2 belowfor the affected part of the ship:
.1 Flooding of such spaces shall not renderemergency power and
lighting, internalcommunication, signals or other emergencydevices
inoperable in other parts of theship.
.2 Assumed extent of damage shall be as fol-lows:
For 0.3 L from theforward perpendicular
of the ship
Any other part of theship
Longitudinalextent
1/3 L2/3 or 14.5 m,whichever is less
1/3 L2/3 or 14.5 m,whichever is less
Transverse ex-tent
B/6 or 10 m, which-ever is less
B/6 or 5 m, whicheveris less
Vertical extent,measured fromthe keel line
B/20 or 2 m, which-ever is less
B/20 or 2 m, which-ever is less
.3 If any damage of a lesser extent than themaximum damage
specified in .2 would re-sult in a more severe condition, such
dam-age should be considered.
2.11.8 In case of large lower holds in passenger ships,the
Register may require an increased double bottom height ofnot more
than B/10 or 3 m, whichever is less, measured fromthe keel line.
Alternatively, bottom damages may be calculatedfor these areas, in
accordance with 2.11.7, but assuming an in-creased vertical
extent.
2.12 PASSENGER SHIPS CARRYINGGOODS VECHILES AND
ACCOMPANYING PERSONNEL
2.12.1 This Head applies to passenger ships designed oradapted
for the carriage of goods vehicles and accompanyingpersonnel.
2.12.2 If in such a ship the total number of passengerswhich
include personnel accompanying vehicles does not ex-ceed 12 +
Ad/25, where Ad = total deck area (square metres) ofspaces
available for the stowage of goods vehicles and wherethe clear
height at the stowage position and at the entrance tosuch spaces is
not less than 4 m, the provisions of 7.12 of theRules for the
classification of ships, Part 3 Hull Equipment in
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RULES FOR THE CLASSIFICATION OF SHIPS 11PART 5
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respect of watertight doors apply except that the doors may
befitted at any level in watertight bulkheads dividing cargospaces.
Additionally, indicators are required on the navigationbridge to
show automatically when each door is closed and alldoor fastenings
are secured.
2.12.3 The ship may not be certified for a higher numberof
passengers than assumed in 2.12.2, if a watertight door hasbeen
fitted in accordance with this Head.
2.13 INTERNAL WATERTIGHTINTEGRITY OF PASSENGER SHIPS
ABOVE THE BULKHEAD DECK
2.13.1 The Register may require that all reasonable
andpracticable measures shall be taken to limit the entry andspread
of water above the bulkhead deck. Such measures mayinclude partial
bulkheads or webs. When partial watertightbulkheads and webs are
fitted on the bulkhead deck, above orin the immediate vicinity of
watertight bulkheads, they shallhave watertight shell and bulkhead
deck connections so as torestrict the flow of water along the deck
when the ship is in aheeled damaged condition. Where the partial
watertight bulk-head does not line up with the bulkhead below, the
bulkheaddeck between shall be made effectively watertight.
Whereopenings, pipes, scuppers, cables etc. are carried through
thepartial watertight bulkheads or decks within the immersed partof
the bulkhead deck, arrangements shall be made to ensure
thewatertight integrity of the structure above the bulkhead
deck.
2.13.2 All openings in the exposed weather deck shallhave
coamings of ample height and strength and shall be pro-vided with
efficient means for expeditiously closing themweathertight. Freeing
ports, open rails and scuppers shall befitted as necessary for
rapidly clearing the weather deck ofwater under all weather
conditions. Minimum required dimen-sions of these openings are
stated in the International Conven-tion on Load Lines 1966 and
Protocol of 1988, as amended.
2.13.3 The open end of air pipes terminating within
asuperstructure shall be at least 1 m above the waterline whenthe
ship heels to an angle of 15, or the maximum angle of heelduring
intermediate stages of flooding, as determined by
directcalculation, whichever is the greater. Alternatively, air
pipesfrom tanks other than oil tanks may discharge through the
sideof the superstructure. The provisions of this paragraph
arewithout prejudice to the provisions of the International
Con-vention on Load Lines in force.
2.13.4 Sidescuttles, gangway, cargo and fuelling portsand other
means for closing openings in the shell plating abovethe bulkhead
deck shall be of efficient design and constructionand of sufficient
strength having regard to the spaces in whichthey are fitted and
their positions relative to the deepest subdi-vision draught.
2.13.5 Efficient inside deadlights, so arranged that theycan be
easily and effectively closed and secured watertight,shall be
provided for all sidescuttles to spaces below the firstdeck above
the bulkhead deck.
Refer to the Recommendation on strength and security and
locking
arrangements of shell doors on ro-ro passenger ships, adopted
bythe IMO by resolution A.793(19).
2.14 INTEGRITY OF THE HULL ANDSUPERSTRUCTURE, DAMAGE
PREVENTION AND CONTROL ONRO-RO PASSENGER SHIPS
2.14.1.1 Subject to the provisions of .2 and .3 of this
item, all accesses that lead to spaces belowthe bulkhead deck
shall have a lowest pointwhich is not less than 2.5 m above
thebulkhead deck.
.2 Where vehicle ramps are installed to giveaccess to spaces
below the bulkhead deck,their openings shall be able to be
closedweathertight to prevent ingress of waterbelow, alarmed and
indicated to the navi-gation bridge.
.3 The Register may permit the fitting of par-ticular accesses
to spaces below the bulk-head deck provided they are necessary
forthe essential working of the ship, e.g. themovement of machinery
and stores, subjectto such accesses being made watertight,alarmed
and indicated on the navigationbridge.
2.14.2 Indicators shall be provided on the navigationbridge for
all shell doors, loading doors and other closing ap-pliances which,
if left open or not properly secured, could, inthe opinion of the
Register, lead to flooding of a special cate-gory space or ro-ro
space. The indicator system shall be de-signed on the fail-safe
principle and shall show by visualalarms if the door is not fully
closed or if any of the securingarrangements are not in place and
fully locked and by audiblealarms if such door or closing
appliances become open or thesecuring arrangements become
unsecured. The indicator panelon the navigation bridge shall be
equipped with a mode selec-tion function harbour/sea voyage so
arranged that an audiblealarm is given on the navigation bridge if
the ship leaves har-bour with the bow doors, inner doors, stern
ramp or any otherside shell doors not closed or any closing device
not in the cor-rect position. The power supply for the indicator
system shallbe independent of the power supply for operating and
securingthe doors.
2.14.3 Television surveillance and a water leakage de-tection
system shall be arranged to provide an indication to thenavigation
bridge and to the engine control station of any leak-age through
inner and outer bow doors, stern doors or anyother shell doors
which could lead to flooding of special cate-gory spaces or ro-ro
spaces.
2.15 ASSIGNING, MARKING ANDRECORDING OF SUBDIVISION LOAD
LINES FOR PASSENGER SHIPS
2.15.1 In order that the required degree of subdivisionshall be
maintained, a load line corresponding to the approvedsubdivision
draught shall be assigned and marked on the ship'ssides. A ship
intended for alternating modes of operation may,if the owners
desire, have one or more additional load lines as-signed and marked
to correspond with the subdivision draughtswhich the Register may
approve for the alternative service con-figurations. Each service
configuration so approved shall com-
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12 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
ply with Heads 2.4 and 2.9 independently of the results
ob-tained for other modes of operation.
2.15.2 The subdivision load lines assigned and markedshall be
recorded in the Passenger Ship Safety Certificate, andshall be
distinguished by the notation P1 for the principal pas-senger
service configuration, and P2, P3, etc., for the alterna-tive
configurations. The principal passenger configuration shallbe taken
as the mode of operation in which the required subdi-vision index R
will have the highest value.
2.15.3 The freeboard corresponding to each of theseload lines
shall be measured at the same position and from thesame deck line
as the freeboards determined in accordancewith the International
Convention on Load Lines in force.
2.15.4 The freeboard corresponding to each approvedsubdivision
load line and the service configuration, for which itis approved,
shall be clearly indicated on the Passenger ShipSafety
Certificate.
2.15.5 In no case shall any subdivision load line mark beplaced
above the deepest load line in salt water as determinedby the
strength of the ship or the International Convention onLoad Lines
in force.
2.15.6 Whatever may be the position of the subdivisionload line
marks, a ship shall in no case be loaded so as to sub-merge the
load line mark appropriate to the season and localityas determined
in accordance with the International Conventionon Load Lines in
force.
2.15.7 A ship shall in no case be so loaded that when itis in
salt water the subdivision load line mark appropriate to
theparticular voyage and service configuration is submerged.
2.16 DAMAGE CONTROLINFORMATION
2.16.1 There shall be permanently exhibited, or readilyavailable
on the navigation bridge, for the guidance of the offi-cer in
charge of the ship, plans showing clearly for each deckand hold the
boundaries of the watertight compartments, theopenings therein with
the means of closure and position of anycontrols thereof, and the
arrangements for the correction of anylist due to flooding. In
addition, booklets containing the afore-mentioned information shall
be made available to the officersof the ship.
2.16.2 Watertight doors in passenger ships permitted toremain
open during navigation shall be clearly indicated in theship's
stability information.
2.16.3 General precautions to be included shall consistof a
listing of equipment, conditions, and operational proce-dures,
considered by the Register to be necessary to maintainwatertight
integrity under normal ship operations.
2.16.4 Specific precautions to be included shall consistof a
listing of elements (i.e. closures, security of cargo, sound-ing of
alarms, etc.) considered by the Register to be vital to thesurvival
of the ship, passengers and crew.
2.16.5 In case of ships to which damage stability re-quirements
of the Heads 2.4 to 2.9 of this Part of the Rules ap-ply, damage
stability information shall provide the master a
Refer to the Guidelines for damage control plans and
information
to the master (MSC.1/Circ.1245).
simple and easily understandable way of assessing the
shipssurvivability in all damage cases involving a compartment
orgroup of compartments.
2.17 PERIODICAL OPERATION ANDINSPECTION OF WATERTIGHT
DOORS, ETC., IN PASSENGER SHIPS
2.17.1 Drills for the operating of watertight
doors,sidescuttles, valves and closing mechanisms of scuppers,
ash-chutes and rubbish-chutes shall take place weekly. In ships
inwhich the voyage exceeds one week in duration a completedrill
shall be held before leaving port, and others thereafter atleast
once a week during the voyage.
2.17.2 All watertight doors, both hinged and power op-erated, in
watertight bulkheads, in use at sea, shall be operateddaily.
2.17.3 The watertight doors and all mechanisms and in-dicators
connected therewith, all valves, the closing of which isnecessary
to make a compartment watertight, and all valves theoperation of
which is necessary for damage control cross con-nections shall be
periodically inspected at sea at least once aweek.
2.17.4 A record of all drills and inspections required bythis
regulation shall be entered in the log-book with an explicitrecord
of any defects which may be disclosed.
2.18 PREVENTION AND CONTROL OFWATER INGRESS, ETC.
2.18.1 All watertight doors shall be kept closed
duringnavigation except that they may be opened during navigationas
specified in 2.18.3 and 2.18.4. Watertight doors of a widthof more
than 1.2 m in machinery spaces as permitted by 7.12of the Rules for
the classification of ships, Part 3 HullEquipment may only be
opened in the circumstances detailedin that regulation. Any door
which is opened in accordancewith this paragraph shall be ready to
be immediately closed.
2.18.2 Watertight doors located below the bulkheaddeck having a
maximum clear opening width of more than 1.2m shall be kept closed
when the ship is at sea, except for lim-ited periods when
absolutely necessary as determined by theRegister.
2.18.3 A watertight door may be opened during naviga-tion to
permit the passage of passengers or crew, or when workin the
immediate vicinity of the door necessitates it beingopened. The
door must be immediately closed when transitthrough the door is
complete or when the task which necessi-tated it being open is
finished.
2.18.4 Certain watertight doors may be permitted to re-main open
during navigation only if considered absolutely nec-essary; that
is, being open is determined essential to the safeand effective
operation of the ship's machinery or to permitpassengers normally
unrestricted access throughout the passen-ger area. Such
determination shall be made by the Registeronly after careful
consideration of the impact on ship opera-
Refer to the Interim Explanatory Notes to the SOLAS Ch. II-1
Subdivision and Damage Stability Regulations,
MSC.1/Circ.1226
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RULES FOR THE CLASSIFICATION OF SHIPS 13PART 5
2013
tions and survivability*. A watertight door permitted to
remainthus open shall be clearly indicated in the ships stability
in-formation and shall always be ready to be immediately
closed.
2.18.5 Portable plates on bulkheads shall always be inplace
before the ship leaves port, and shall not be removedduring
navigation except in case of urgent necessity at the dis-cretion of
the master. The necessary precautions shall be takenin replacing
them to ensure that the joints are watertight.Power-operated
sliding watertight doors permitted in machin-ery spaces in
accordance with 7.12 of the Rules for the classifi-cation of ships,
Part 3 Hull Equipment shall be closed beforethe ship leaves port
and shall remain closed during navigationexcept in case of urgent
necessity at the discretion of the mas-ter.
2.18.6 Watertight doors fitted in watertight bulkheadsdividing
cargo between deck spaces in accordance with with7.12 of the Rules
for the classification of ships, Part 3 HullEquipment shall be
closed before the voyage commences andshall be kept closed during
navigation; the time of openingsuch doors in port and of closing
them before the ship leavesport shall be entered in the
log-book.
2.18.7 Gangway, cargo and fuelling ports fitted belowthe
bulkhead deck shall be effectively closed and secured wa-tertight
before the ship leaves port, and shall be kept closedduring
navigation.
2.18.8 The following doors, located above the bulkheaddeck,
shall be closed and locked before the ship proceeds onany voyage
and shall remain closed and locked until the ship isat its next
berth:
.1 cargo loading doors in the shell or theboundaries of enclosed
superstructures;
.2 bow visors fitted in positions as indicated in.1;
.3 cargo loading doors in the collision bulk-head; and
.4 ramps forming an alternative closure tothose defined in
sub-items .1 to .3 inclu-sive.
2.18.9 Provided that where a door cannot be opened orclosed
while the ship is at the berth such a door may be openedor left
open while the ship approaches or draws away from theberth, but
only so far as may be necessary to enable the door tobe immediately
operated. In any case, the inner bow door mustbe kept closed.
2.18.10 Notwithstanding the requirements of 2.18.8, theRegister
may authorize that particular doors can be opened atthe discretion
of the master, if necessary for the operation ofthe ship or the
embarking and disembarking of passengerswhen the ship is at safe
anchorage and provided that the safetyof the ship is not
impaired.
2.18.11 The master shall ensure that an effective systemof
supervision and reporting of the closing and opening of thedoors
referred to in 2.18.8 is implemented.
2.18.12 The master shall ensure, before the ship proceedson any
voyage, that an entry in the log-book is made of thetime of the
last closing of the doors specified in 2.18.13 and thetime of any
opening of particular doors in accordance with2.18.14.
Refer to the Guidance for Watertight Doors on Passenger
Ships
which may be opened during Navigation, MSC.1/Circ.1380
2.18.13 Hinged doors, portable plates, sidescuttles,gangway,
cargo and bunkering ports and other openings, whichare required by
this Head to be kept closed during navigation,shall be closed
before the ship leaves port. The time of closingand the time of
opening (if permissible under these regulations)shall be recorded
in officially prescribed log-book.
2.18.14 Where in a between-decks, the sills of any of
thesidescuttles referred to in 7.2 of the Rules for the
classificationof ships, Part 3 Hull Equipment are below a line
drawn par-allel to the bulkhead deck at side and having its lowest
point1.4 m plus 2.5% of the breadth of the ship above the waterwhen
the ship departs from any port, all the sidescuttles in
thatbetween-decks shall be closed watertight and locked before
theship leaves port, and they shall not be opened before the
shiparrives at the next port. In the application of this item the
ap-propriate allowance for fresh water may be made when
appli-cable.
.1 The time of opening such sidescuttles inport and of closing
and locking them beforethe ship leaves port shall be entered in
pre-scribed log-book.
.2 For any ship that has one or more sidescut-tles so placed
that the requirements of item2.18.15 would apply when it was
floating atits deepest subdivision draught, the Regis-ter may
indicate the limiting mean draughtat which these sidescuttles will
have theirsills above the line drawn parallel to thebulkhead deck
at side, and having its lowestpoint 1.4 m plus 25% of the breadth
of theship above the waterline corresponding tothe limiting mean
draught, and at which itwill therefore be permissible to depart
fromport without previously closing and lockingthem and to open
them at sea on the re-sponsibility of the master during the
voyageto the next port. In tropical zones as definedin the
International Convention on LoadLines in force, this limiting
draught may beincreased by 0.3 m.
2.18.15 Sidescuttles and their deadlights which will notbe
accessible during navigation shall be closed and secured be-fore
the ship leaves port.
2.18.16 If cargo is carried in such spaces, the sidescuttlesand
their deadlights shall be closed watertight and locked be-fore the
cargo is shipped and such closing and locking shall berecorded in
officially prescribed log-book.
2.18.17 When a rubbish-chute, etc. is not in use, both thecover
and the valve required by Section 7 of the Rules for
theclassification of ships, Part 3 Hull Equipment shall be
keptclosed and secured.
2.19 SPECIAL REQUIREMENTS FORRO-RO PASSENGER SHIPS
2.19.1 Special category spaces and ro-ro spaces shall
becontinuously patrolled or monitored by effective means, suchas
television surveillance, so that any movement of vehicles inadverse
weather conditions and unauthorized access by pas-sengers thereto
can be detected whilst the ship is underway.
2.19.2 Documented operating procedures for closingand securing
all shell doors, loading doors and other closingappliances which,
if left open or not properly secured, could, in
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14 RULES FOR THE CLASSIFICATION OF SHIPSPART 5
2013
the opinion of the Register, lead to flooding of a special
cate-gory space or ro-ro space, shall be kept on board and posted
atan appropriate place.
2.19.3 All accesses from the ro-ro deck and vehicleramps that
lead to spaces below the bulkhead deck shall beclosed before the
ship leaves the berth on any voyage and shallremain closed until
the ship is at its next berth.
2.19.4 The master shall ensure that an effective systemof
supervision and reporting of the closing and opening of
suchaccesses referred to in 2.19.3 is implemented.
2.19.5 The master shall ensure, before the ship leavesthe berth
on any voyage, that an entry in the log-book, as re-quired by
2.18.13, is made of the time of the last closing of theaccesses
referred to in 2.19.3.
2.19.6 Notwithstanding the requirements of 2.19.3, theRegister
may permit some accesses to be opened during thevoyage, but only
for a period sufficient to permit through pas-sage and, if
required, for the essential working of the ship.
2.19.7 All transverse or longitudinal bulkheads whichare taken
into account as effective to confine the seawater ac-cumulated on
the ro-ro deck shall be in place and secured be-fore the ship
leaves the berth and remain in place and secureduntil the ship is
at its next berth.
2.19.8 Notwithstanding the requirements of 2.19.7, theRegister
may permit some accesses within such bulkheads tobe opened during
the voyage but only for sufficient time topermit through passage
and, if required, for the essentialworking of the ship.
2.19.9 In all ro-ro passenger ships, the master or thedesignated
officer shall ensure that, without the expressed con-sent of the
master or the designated officer, no passengers areallowed access
to an enclosed ro-ro deck when the ship is un-der way.
2.20 PREVENTION AND CONTROL OFWATER INGRESS, ETC., IN CARGO
SHIPS
2.20.1 Openings in the shell plating below the deck lim-iting
the vertical extent of damage shall be kept permanentlyclosed while
at sea.
2.20.2 Notwithstanding the requirements of item 2.20.3,the
Register may authorize that particular doors may be openedat the
discretion of the master, if necessary for the operation ofthe ship
and provided that the safety of the ship is not im-paired.
2.20.3 Watertight doors or ramps fitted internally subdi-vide
large cargo spaces shall be closed before the voyagecommences and
shall be kept closed during navigation; thetime of opening such
doors in port and of closing them beforethe ship leaves port shall
be entered in the log-book.
2.20.4 The use of access doors and hatch covers in-tended to
ensure the watertight integrity of internal openingsshall be
authorized by the officer of the watch.
2.21 TIMBER DECK CARGO IN THECONTEX OF DAMAGE STABILITY
REQUIREMENTS
2.21.1 For ships carrying timber deck cargoes whichhave to
fulfil the damage stability requirements of this part ofthe Rules,
stability information shall include, among otherdamage stability
related issues, a curve of minimum operatingmetacentric height (GM)
versus draught or maximum allow-able vertical centre of gravity
(KG) versus draught which cov-ers the requirements in 1.5.1.3.8 of
the Rules for the classifica-tion of ships, Part 4 Stability.
2.21.2 To ensure the buoyancy of timber deck cargo canbe
justifiably credited in damage stability calculations, the
in-tegrity of the lashed timber deck cargo shall comply with
theprovisions of Chapters 3 and 4 of the CODE OF SAFE PRAC-TICE FOR
SHIPS CARRYING TIMBER DECK CARGOES,1991 (Resolution A.715(17)).
2.21.3 The height and extent of the timber deck cargoshall be in
accordance with Chapter 3.2 of the CODE OFSAFE PRACTICE FOR SHIPS
CARRYING TIMBER DECKCARGOES,1991, and shall be at least stowed to
the standardheight of one superstructure.
2.21.4 The permeability of the timber deck cargo is notto be
less than 25% of the volume occupied by the cargo up toone standard
superstructure.2.21.5 Unless instructed otherwise by the Register,
thestability information for ships with timber deck cargoes shallbe
supplemented by additional curve(s) of limiting GM (or KG)covering
the timber draught range.
2.21.6 The above described curve(s) applicable for con-ditions
with timber deck cargo is/are to be developed as de-scribed in
1.5.1.6 of the Rules for the classification of ships,Part 4
Stability, and considering timber deck cargo at thedeepest timber
subdivision draught and at the partial timbersubdivision draught
only.
2.21.7 The limiting GM shall be varied linearly betweenthe
deepest timber subdivision draught, and between the partialtimber
subdivision draught and the light service draught re-spectively.
Where timber freeboards are not assigned the deep-est and partial
draughts shall relate to the summer load line.2.21.8 When
considering the vertical extent of damage,the upper deck may be
regarded as a horizontal subdivision (inaccordance with 2.7.7.1 of
this part of the Rules). Thus whencalculating damage cases are
limited vertically to the upperdeck with the corresponding v
factor, the timber deck cargomay be considered to