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STABILITY REQUIREMENTS

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Presumed to be to design your vessel with intact stability characteristics to ... MBD DAY SAILER/RACER. As 'pleasure craft' no statutory stability requirements apply ... – PowerPoint PPT presentation

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Title: STABILITY REQUIREMENTS


1
STABILITY REQUIREMENTS
  • Rob Gehling
  • Principal Adviser Technical Marine Standards
  • Maritime Safety Environmental Strategy
  • AMSA, Canberra

2
YOUR TASK
  • Presumed to be to design your vessel with intact
    stability characteristics to meet the appropriate
    statutory criteria - and ultimately prepare trim
    stability booklet as would be required for
    submission to a regulatory authority

3
YOUR AIM!
  • If under AMSA jurisdiction, to provide the Master
    with such information satisfactory to the
    Administration as is necessary to enable him by
    rapid and simple processes to obtain accurate
    guidance as to the stability of the ship under
    varying conditions of service
  • Refer SOLAS II-1/22.1
  • Load Lines Protocol (1988) reg. 10(2)(b) similar
  • Appendix 2 of Marine Orders Part 12 defines what
    is satisfactory to AMSA
  • Other jurisdictions (eg. State, Military) have
    similar, if sometimes less stringent requirements

4
MY BACKGROUND
  • 3 years as Naval Architect in Drawing Office of
    large shipyard, preparing and gaining approval
    for stability booklets
  • 12 years in AMSA and its predecessors, assessing
    and approving stability booklets
  • Australian delegate to IMOs Sub-Committee on
    Stability, Load Lines and Fishing Vessels Safety
    (SLF) since 1988, taking specific interest in
    operational intact stability issues
  • Recently elected as Vice-Chairman of SLF

5
JURISDICTION
  • Determined by ship type and trading pattern
  • Military DoDs own rules but are often guided
    by commercial rules which they may make mandatory
    (ref. s.3, Navigation Act 1912)
  • Trading ship (ref. s.2(a), Navigation Act) -
    State requirements (USL Code) for intra-state
    voyages incl charter boats, but AMSA (Marine
    Orders/SOLAS) for inter-state and international
    service
  • Fishing vessel or fishing fleet support vessel
    (ref. s.2(b)/(ba), Navigation Act) State
    requirements (USL Code) unless on international
    voyages, then AMSA
  • Pleasure craft (ref. s.2(d), Navigation Act) -
    State Boating laws re equipment but refer AYF and
    relevant parts of AS.1799 re design and
    construction

6
DEFINITIONS
  • Passenger ship (SOLAS) is ship which carries more
    than 12 passengers
  • Cargo ship (SOLAS) is any ship which is not a
    passenger ship
  • Special purpose ship (Special Purpose Ship Code)
    is a mechanically self-propelled ship which by
    reason of its function carries more than 12
    special personnel (persons who are not passengers
    or crew and who are in board in connection with
    the special purpose of the ship or special work
    being carried out aboard the ship, number
    includes any passengers)

7
CODES
  • Offshore Supply Vessel (OSV) Guidelines
  • Intact and damage stability requirements
  • Mobile Offshore Drilling Unit (MODU) Code
  • Includes intact damage stability
  • High-Speed Craft Code (2000)
  • Alternative to SOLAS construction/equipment
    /certification requirements, includes intact
    damage stability criteria
  • Special Purpose Ship Code
  • Modifies SOLAS for SPSs, includes intact damage
    stability criteria
  • Uniform Shipping Laws (USL) Code
  • Used by State/NT authorities, stability mainly
    intact

8
IMO INTACT STABILITY CODE
  • Adopted in November 1993 through res. A.749(18)
    and has since been amended by res. MSC.75(69)
  • Intended to be a consolidation of requirements
    and guidance information adopted by IMO (eg. res.
    A.167(ES.IV), A.168(ES.IV), A.206(VII),
    A.268(VIII) Codes for specific vessel types)
  • Non-mandatory but now under review again with
    view to some parts being made mandatory
  • Useful reference but not implemented by Australia
    (refer Marine Orders Part 12) because of problems
    with weather criterion among other things

9
TYPICAL TRIM STABILITY BOOKLET AS PER MO.12
  • General stability-related info
  • vessel particulars, draft mark diagram, immersion
    angle heeling lever diagrams
  • Info for Master and officers
  • Instructions stability criteria
  • Worked example of stability condition calculation
  • Calculations for typical / worst loading
    conditions
  • Supporting data/tables/graphs
  • Tank plan table, tank calibrations, hydrostatic
    tables, KN tables, nomenclature, inclining report
  • NOTE Actual required content varies with ship
    type

10
STABILITY CRITERIA LANDING CRAFT
  • Statutory Authority is Dept of Defence, so
    following info relates to hypothetical (?)
    application of commercial criteria
  • Criteria are at 6.2.2 and 6.2.3 of Appendix 2 to
    Marine Orders Part 12, most likely using
    6.2.3(k), or 8.C.16 of USL Code
  • Allows for maximum GZ to occur at angles between
    15deg. and 25deg, but requires higher area under
    GZ curve to 30deg. than normal IMO criteria
  • Note that criteria not to vary between load
    conditions

11
STABILITY CRITERIA MBD DAY SAILER/RACER
  • As pleasure craft no statutory stability
    requirements apply
  • But refer AYF stability requirements(?)
  • Refer yacht stability requirements(?) of AS.1799
    Small Pleasure Boats Code
  • Not mandatory but have effect under consumer
    protection and trade practices law
  • Statutory stability requirements could apply if
    vessel put into survey for commercial operations
    (eg. harbour sailing)
  • USL Code section 8.C.12 implemented by State
    authorities and also called up by Marine Orders
    Part 12 (not AMSA jurisdiction!)

12
STABILITY CRITERIA NWBS DAY TRIP BOAT
  • Apply relevant criteria from section 8.C.1 of USL
    Code
  • Assuming vessel is under State jurisdiction (not
    AMSA)
  • Could use criteria of 2.3 to 2.5 of 2000 HSC Code
  • Call-up standards of Annexes 7 and 8 of Code,
    depending on whether craft is monohull or
    multihull
  • Note that 1.1 of Annex 8 to the 2000 HSC Code
    calls up the Severe wind and rolling criterion
    from the IMO Intact Stability Code
  • Absence of adjustments to tabulated factors to
    apply to HSC renders such application difficult

13
STABILITY CRITERIA NWBS DAY TRIP BOAT (CONT)
  • Note that Table 2.3.4 of 2000 HSC Code provides
    for some inter-changeability between the
    requirements of Annexes 7 and 8
  • Eg. trimarans stability is similar to monohulls
    but amahs of can be tailored to meet the
    specified stability criteria
  • CFD may soon enable compliance with 2.4 to be
    verified by calculation but trials required for
    now
  • Intact stability criteria currently being
    researched as major part of review of 2000 HSC
    Code

14
AUSTAL MONOHULL CREW/SUPPLY VESSEL
  • Mexican flag and high service speed would
    normally pose questions
  • But these are answered by specification of IMO
    Code on Intact Stability (IS Code)
  • Severe Weather Criterion NOT required
  • Note 2000 HSC Code could not be applied as HSC
    Code requires high-speed criterion to be met at
    displacement of maximum operational weight
  • Consider using 4.5.6 of IS Code in place of 3.1.2
  • Offshore cargo handling probably precludes
    fitting passenger cabin above cargo deck

15
DAMAGE STABILITY
  • (Not part of brief for this presentation but
    generally results in relevant operational
    information being included in Trim Stability
    Booklet)

16
ANY QUESTIONS????
17
DAMAGE STABILITY SOLAS MARPOL
  • SOLAS Ch. II-1 Part B provides deterministic
    requirements for subdivision of passenger ships,
    Res. A.265(VIII) is probabilistic alternative
  • SOLAS reg.II-1/8-1 covers probabilistic
    subdivision and damage stability of ro-ro
    passenger ships
  • SOLAS Ch.II-1 Part B-1 provides for probabilistic
    subdivision damage stability for dry cargo
    ships of Lgt80m unless covered by deterministic
    criteria
  • MARPOL Annex I specifies oil tanker subdivision
    damage stability requirements incl. double-hulls

18
DAMAGE STABILITY SOLAS/MARPOL-RELATED CODES
  • International Bulk Chemical (IBC) Code gives
    requirements for chemical carriers
  • note that where a chemical carrier can carry
    petroleum grades in addition to noxious liquid
    substances in bulk, MARPOL Annex I also applies
  • International Gas Carrier (IGC) Code gives
    requirements for liquefied gas carriers
  • Other Codes cover existing ships unnecessary to
    list here

19
NOTE RE PROBABILISTIC DAMAGE STABILITY
  • Res. A.265 (IX) (1973) is probabilistic
    alternative to SOLAS Ch.II-1 damage stability
    requirements
  • now applied to ro-ro passenger ships through
    SOLAS reg. II-1/8-1
  • Amendments to SOLAS Ch. II-1 scheduled for
    adoption in May to harmonise probabilistic
    method for passenger cargo ships (flood length)
  • Probabilistic principles likely to be extended to
    Load Line and MARPOL Conventions damage
    stability
  • MARPOL Annex I oil outflow and guidelines for
    double-hull equivalence are already probabilistic

20
INTACT STABILITY DATA -DAMAGE STABILITY LINK
  • A given ship at a given displacement and trim
    will have a limiting intact KG at which it meets
    any damage stability criterion
  • Tracking this data over a range of intact
    displacements and trims gives a series of
    limiting KG curves within which the ship must be
    operated to maintain compliance with the
    criterion
  • Such curves are most useful to the Master when
    integrated into the intact stability booklet
  • preferably on the same page as similar limiting
    KG information for intact stability criteria

21
OTHER ASPECTS OF STABILITY
22
SHIPS FOR DRY BULK CARGOES
  • The most important criterion for such ships is in
    relation to ships which may carry grain, which
    must comply with the International Grain Code
    which is given mandatory effect in SOLAS reg.
    VI/9
  • Most bulk carriers are designed to comply with
    this Code even if they are intended to engage in
    the iron ore and coal trades commercially
    important in terms of both resale features and
    being able to accept grain cargoes when they
    arise
  • Involves provision of Grain Stability Data
  • For specialised bulk cargoes, Bulk Cargoes Code
    should be checked for any extra requirements
  • Eg. transportable moisture limits, extra
    watertight integrity / bilge requirements, gas
    sniffing (coal)

23
TIMBER CARGOES
  • Many Handy-size bulk carriers are arranged for
    carriage of timber on deck (clear side-decks,
    stanchions)
  • 1966 Load Line Convention Annex I, Ch. IV
    provides for assignment of lumber load lines
  • stability requirements are as per 4.1 of Intact
    Stability Code which in turn calls up the Code of
    Safe Practice for Ships Carrying Timber Deck
    Cargoes

24
SUMMARY
  • It is essential to establish the jurisdiction and
    regulatory environment in which the ship will
    operate at the outset
  • This varies between your selected projects
  • AMSA intact stability requirements generally
    build on basic IMO stability criteria, HSC is
    exception
  • Looking beyond intact stability, relevant intact
    stability criteria related to cargoes and the
    operational linkage between intact and damage
    stability should not be overlooked

25
ANY QUESTIONS????
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