Agreement concerning specific stability requirements for ro-ro passenger ships undertaking regular scheduled international voyages between or to or from designated ports in North West Europe and the Baltic Sea:Annex 2 Stability requirements pertaining to the Agreement

Annex 2 Stability requirements pertaining to the Agreement

Geldend

Documentgegevens:

Geldend vanaf 01-04-1997

Redactionele toelichting: Deze bijlage is gecorrigeerd via een rectificatie (Trb. 1999, 62).
Bronpublicatie:: 28-02-1996, Trb. 1997, 72 (uitgifte: 21-03-1997, kamerstukken/regelingnummer: -)
Inwerkingtreding: 01-04-1997
Bronpublicatie inwerkingtreding:: 28-02-1996, Trb. 1997, 72 (uitgifte: 21-03-1997, kamerstukken/regelingnummer: -)
Vakgebied(en): Internationaal publiekrecht / Verdragenrecht
Vervoersrecht / Personenvervoer algemeen

Preamble

Application

In accordance with this Agreement, passenger ships with ro-ro cargo spaces or special category spaces as defined in regulation II-2/3 of the International Convention for the Safety of Life at Sea, as amended, shall comply with the provisions of this Agreement not later than at the first yearly inspection following the date of compliance prescribed below, according to the value of A/Amax as defined in the annex to the Calculation Procedure to Assess the Survivability Characteristics of Existing Ro-Ro Passenger Ships When Using a Simplified Method Based Upon resolution A.265 (VIII), developed by the Maritime Safety Committee at its fifty-ninth session in June 1991 (MSC/Circ.574):

Value of A/Amax	Date of Compliance
Less than 85%	1 April 1997
Less than 90%	31 December 1998
Less than 95%	31 December 1999
Less than 97.5%	31 December 2000
97.5% or higher	31 December 2001 but in any case not later than 1 October 2002

Stability Standard

1

In addition to the requirements of SOLAS regulation II-1/8, ro-ro passenger ships shall comply, subject to the provisions of paragraph 2, if applicable, with the following:

.1.

the provisions of paragraphs 2.3 regulation 8 shall be complied with when taking into account the effect of a hypothetical amount of sea water which is assumed to have accumulated, on the first deck above the designed waterline of the ro-ro cargo space or special category space as defined in regulation II-2/3 assumed to be damaged (referred to as ‘the damaged ro-ro deck’ hereinafter). The other requirements of regulation 8 need not be complied with in the application of the stability standard1) contained in this Agreement. The amount of assumed accumulated sea water shall be calculated on the basis of a water surface having a fixed height above:

a) the lowest point of the deck edge of the damaged compartment of the ro-ro deck, or

b) when the deck edge in way of the damaged compartment is submerged then the calculation is based on a fixed height above the still water surface at all heel and trim angels;

as follows:

0.5 m if the residual freeboard f_r) is 0.3 m or less;

0.0 m if the residual freeboard (f_r) is 2.0 m or more; and

intermediate values to be determined by linear interpolation, if the residual freeboard (f_r) is 0.3 m or more but less than 2.0 m;

where the residual freeboard (f_r) is the minimum distance between the damaged ro-ro deck and the final waterline at the location of the damage in the damage case being considered without taking into account the effect of the volume of assumed accumulated water on the damaged ro-ro deck;

.2.

when a high-efficiency drainage system is installed, the Administration may allow a reduction in the height of the water surface in accordance with the guidelines to be developed by the Organization2);

.3.

for ships in geographically defined restricted areas of operation, the Administration may reduce the height of the water surface determined in accordance with subparagraph 1 substituting such height of the water surface by the following:

.3.1.: 0.0 m if the significant wave height (h_s) defining the area concerned is 1.5 m or less;
.3.2.: the value determined in accordance with subparagraph 1 if the significant wave height (h_s) defining the area concerned is 4.0 m or above;
.3.3.: intermediate values to be determined by linear interpolation if the significant wave height (h_s) defining the area concerned is 1.5 m or more but less than 4.0 m;
provided that the following conditions are fulfilled:
.3.4.: the Administration is satisfied that the defined area is represented by the significant wave height (h_s) which is not exceeded with a probability of more than 10%; and
.3.5.: the area of operation and, if applicable, the part of the year for which a certain value of the significant wave height (h_s) has been established are entered into the certificates;

and

.4.

as an alternative to the requirements of subparagraph .1 or subparagraph .3, the Administration may exempt application of the requirements of subparagraph .1 or subparagraph .3 and accept proof, established by model tests carried out for an individual ship in accordance with the model test method developed by the Organization3), annexed to this document justifying that the ship will not capsize with the assumed extent of damage as provided in paragraph 4 of regulation 8 in the worst location being considered under paragraph 1.1 in an irregular seaway, and

.5.

reference to acceptance of the results of the model test as an equivalence to compliance with subparagraph .1 or subparagraph .3; the value of the significant wave height (h_s) used in the model tests shall be entered into the ship's certificates.

.6.

the information supplied to the master in accordance with paragraphs 7.1 and 7.2 of regulation 8, as developed for compliance with paragraphs 2.3 to 2.3.4, shall apply unchanged for ro-ro passenger ships approved according to these requirements.

2

For assessing the effect of the volume of the assumed accumulated sea water on the damaged ro-ro deck in paragraph 1, the following provisions shall prevail:

.1.

a transverse or longitudinal bulkhead shall be considered intact if all parts of it lie inboard of vertical surfaces on both sides of the ship, which are situated at a distance from the shell plating equal to one-fifth of the breadth of the ship, as defined in regulation 2, and measured at right angles to the centreline at the level of the deepest subdivision load line;

.2.

in cases where the ship's hull is structurally partly widened for compliance with the provisions of this regulation, the resulting increase of the value of one-fifth of the breadth of it is to be used throughout, but shall not govern the location of existing bulkhead penetrations, piping systems, etc., which were acceptable prior to the widening;

.3.

the tightness of transverse or longitudinal bulkheads which are taken into account as effective to confine the assumed accumulated sea water in the compartment concerned in the damaged ro-ro deck shall be commensurate with the drainage system, and shall withstand hydrostatic pressure in accordance with the results of the damage calculation. Such bulkheads shall be at least 4 m in height unless the height of water is less than 0.5 m. In such cases the height of the bulkhead may be calculated in accordance with the following:

B_h = 8h_w

where B_h = bulkhead height, and

h_w = height of water

In any event,the[lees: event, the] minimum height of the bulkhead shall be not less than 2.2 m. However, in the case of a ship with hanging car decks, the minimum height of the bulkhead shall be not less than the height to the underside of the hanging car deck when in its lowered position.

.4.

For special arrangements such as, e.g., full width hanging decks and wide side casings, other bulkhead heights may be accepted based on detailed model tests;

.5.

The effect of the volume of the assumed accumulated sea water need not be taken into account for any compartment of the damaged ro-ro deck, provided that such a compartment has on each side of the deck freeing ports evenly distributed along the sides of the compartment complying with the following:

.5.1.: A ≥ 0.3 l
where A is the total area of freeing ports on each side of the deck in m²; and
I is the length of the compartment in m;
.5.2.: the ship shall maintain a residual freeboard of at least 1.0 m in the worst damage condition without taking into account the effect of the assumed volume of water on the damaged ro-ro deck; and
.5.3.: such freeing ports shall be located within the height of 0.6 m above the damaged ro-ro deck, and the lower edge of the ports shall be within 2 cm above the damaged ro-ro deck; and
.5.4.: such freeing ports shall be fitted with closing devices or flaps to prevent water entering the ro-ro deck whilst allowing water which may accumulate on the ro-ro deck to drain; and

.6.

when a bulkhead above the ro-ro deck is assumed damaged, both compartments bordering the bulkhead shall be assumed flooded to the same height of water surface as calculated in paragraphs 1.1 and 1.3 above.

Appendix Model test method

1. Objectives

In the test provided for in paragraph 1.4 of the stability requirements pertaining to the agreement, the ship should prove capability to withstand a seaway defined in paragraph 3 hereunder in the worst damage case scenario.

2. Ship model

2.1.

The model should copy the actual ship for both outer configuration and internal arrangement — in particular of all damaged spaces, having an effect on the process of flooding and shipping of water. The damage should represent the worst damage case defined for compliance with paragraph 2.3.2 of SOLAS regulation II-1/8 ( SOLAS 90). An additional test is required at a level keel midship damage, if the worst damage location according tot[lees: to] SOLAS 90 is outside the range ± 10% Lpp from the midship. This additional test is only required when the ro-ro spaces are assumed to be damaged.

2.2.

The model should comply with the following:

.1.

length between perpendiculars (Lpp) is to be at least 3 m;

.2.

hull is to be thin enough in areas where this feature has influence on the results;

.3.

characteristics of motion should be modelled properly to the actual ship, paying particular attention to scaling of radii of gyration in roll and pitch motions. Draught, trim, heel and centre of gravity should represent the worst damage case;

.4.

main design features such as watertight bulkheads, air escapes, etc., above and below the bulkhead deck that can result in asymmetric flooding should be modelled properly as far as practicable, to represent the real situation;

.5.

the shape of the damage opening shall be as follows:

.5.1.: rectangular side profile with a width according to SOLAS regulation II-1/8.4.1 and unlimited vertical extent;
.5.2.: isosceles triangular profile in the horizontal plane with a height equal to B/5 according to SOLAS regulation II-1/8.4.2.

3. Procedure for experiments

3.1.

The model should be subjected to a long-crested irregular seaway defined by the JONSWAP spectrum with a significant wave height Hs, defined in paragraph 1.3 of the stability requirements and having peak enhancement factor γ and peak period Tp as follows:

.1.: Tp = 4√Hs with γ = 3.3; and
.2.: Tp equal to the roll resonant period for the damaged ship without water on deck at the specified loading condition but not higher than 6√Hs and with γ = 1

3.2.

The model should be free to drift and placed in beam seas (90° heading) with the damage hole facing the oncoming waves. The model should not be restrained in a manner to resist capsize. If the ship is upright in flooded condition, 1° of heel towards the damage should be given.

3.3.

At least 5 (five) experiments for each peak period should be carried out. The test period for each run shall be of a duration such that a stationary state had been reached but should be run for not less than 30 min in full-scale time. A different wave realization train should be used for each test.

3.4.

If none of the experiments result in final inclination towards the damage, the experiments should be repeated with 5 runs at each of the two specified wave conditions or, alternatively, the model should be given an additional 1° angle of heel towards the damage and the experiment repeated with 2 runs at each of the two specified wave conditions. The purpose of these additional experiments is to demonstrate, in the best possible way, survival capability against capsize in both directions.

3.5.

The tests are to be carried out for the following damage cases:

.1.: the worst damage case with regard to the area under the GZ curve according to SOLAS; and
.2.: the worst midship damage case with regard to residual freeboard in the midship area if required by 2.1.

4. Survival criteria

4.1.: The ship should be considered as surviving if a stationary state is reached for the successive test runs as required in 3.3 but subject to 4.2.
4.2.: Angles of roll of more than 30° against the vertical axis, occurring more frequently than in 20% of the rolling cycles or steady heel greater than 20° should be taken as capsizing events even if a stationary state is reached.

5. Test approval

5.1.: It is the responsibility of the Administration to approve the model test programme in advance. It should also be borne in mind that lesser damages may provide a worst case scenario.
5.2.: Test should be documented by means of a report and a video or other visual record containing all relevant information of the ship and test results. A copy of the video and report should be submitted to the Organization, together with the Administration's acceptance of the test.

Toon alle voetnoten

Voetnoten

1).

Guidance notes on the standard to be developed.

2).

Refer to the ‘guidelines …’.

3).

Refer to the ‘model test method attached to this document’.