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NtS 255/1990 Intact Stability Requirements for Pontoons, Intended for the Carriage of Deck Cargoes
Geldigheid:23-05-1990 t/m Status: Geldig vandaag

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Notice to Shipping for amending Notice to Shipping no. 255/1990 (Intact Stability Requirements for Pontoons, Intended for the Carriage of Deck Cargoes)

The Head of the Shipping Inspectorate, Noting Article 67a, first paragraph, of the Ships Decree 1965;
Announces:

Article I
Notice to Shipping no. 255/1990 will read:

Article 1. General

1.1 Definitions
L : the length of the pontoon, described in Article 2, first paragraph, of Annex I, to the Ships Decree 1965;
B : the largest breadth of the pontoon, described in Article 2, fourth paragraph, of Annex I, to the Ships Decree 1965;
H : the moulded depth, described in Article 2, fifth paragraph, of Annex I, to the Ships Decree 1965;
Cb : the block coefficient, described in Article 2, seventh paragraph, of the Ships Decree 1965;
Dfw : displacement including shell and appendages in water with a density of 1.000 t/m3;
Dsw : displacement including shell and appendages in water with a density of 1.025 t/m3;
MCT : moment required for 1 cm total change of trim on the draught scales in water with a density of 1.025 t/m3;
LCB : longitudinal centre of buoyancy;
LCF : longitudinal centre of floatation;
KM : transverse metacentre above the baseline.

1.2 Application
The provisions of this Notice are applicable to pontoons, which:
a. are carried unmanned and towed;
b. carry only deck cargo;
c. have a block coefficient of 0.9 or greater;
d. have a B/D ratio of greater than 3.0; and
e. have no hatchways in the deck except hatchways with an opening of not more than 1.5 m2 capable of weathertight closure by means of gaskets and clasps, or small manholes capable of watertight closure.

Article 2. Lightweight checks
Instead of performing an inclining test, a lightweight check of the empty, ready-for-use pontoon and measuring the densities of the surrounding water may suffice in general, when the following conditions are met:
a. the centre of gravity of the empty, ready-for-use pontoon is assumed at deck level. A somewhat lesser height of the centre of gravity of the empty, ready-for-use pontoon above baseline (KG) can be accepted by the Head of the Shipping Inspectorate, on the basis of a submitted, detailed weight calculation of the pontoon;
b. the lightweight check is performed in the presence of an official of the Shipping Inspectorate. The weight of the empty, ready-for-use pontoon and the corresponding position of the longitudinal centre of gravity should be determined from the draughts and densities of the surrounding water.

Article 3. Stability information and calculations

3.1 The following information should be submitted for approval:
a. lines drawing;
b. hydrostatic curves containing: 1° D1 curve; 2° D2 curve; 3° M1 curve; 4° Xb curve; 5° Xa curve; 6° KM curve;
c. cross curves* for at least the angles of heel: 5, 10, 15, 20, 25, 30 and 45 degrees;
d. report of lightweight check, as well as a calculation of the weight of the empty, ready-for-use pontoon and the corresponding location of the longitudinal centre of gravity;
e. the assumed or calculated value of the location of the vertical centre of gravity of the empty pontoon;
f. a loading diagram, from which the maximally allowable vertical centre of gravity of the deck cargo above deck can simply be found for various displacements. Maximum KG curves or deadweight moment curves can also be accepted for this purpose; and
g. the calculations which form the basis of f.

3.2 Concerning the performance of calculations, as referred to under 3.1, the following applies:
a. except for timber deck cargoes as referred to under c. of this paragraph, no account should be taken of the buoyancy of deck cargoes;
b. the increase of weight due to water absorption by the deck cargo, or the increase due to ice accretion or due to trapped water in cargo, should be taken in consideration, where among others the following applies:
    1° the weight of a timber deck cargo increases due to absorption of water by timber by 10 per cent;
    2° the weight of a pipe deck cargo should be increased by the weight of the amount of water which can accumulate between and in the pipes. This amount is 30 per cent of the net volume of the space covered by the pipes and of the space between pipes; c. the buoyancy of timber deck cargoes may only be taken into account when the height of the deck cargo assumed in the calculation is not greater than the height of the deck cargo resulting from 3.1, under f., and:
      1° the deck cargo consists of loose sawn timber for which a permeability of 0.25 is assumed; or
      2° the deck cargo consists of packaged sawn timber of the same length (so-called longitudinal packages) for which a permeability of 0.50 is assumed; d. the calculations should be made for a range of draughts at least extending from the draught of the empty pontoon to the greatest allowed draught;
      e. as angle of heel, where the pontoon is flooded, should be taken the angle at which an opening not capable of watertight closure is immersed. A vent with an automatically operating closing device and a watertight man cover can be considered to be watertight in this respect.
      f. the effect of the wind heel should be taken into account. In performing wind heel calculations:
        1° the wind pressure should be constant, where a homogeneous distribution of the deck cargo over the total length of the pontoon should be assumed;
        2° the centre of gravity of the cargo should be assumed at a point mid-height of the homogeneously distributed cargo;
        3° the wind lever arm should be taken as the vertical distance between the point at half draught and the centre of buoyancy of the sideward wind heeling area of the deck cargo.
        Article 4. Stability criteria
        4.1 The area under the righting lever (GZ curve) up to the angle of maximum righting lever, should be at least 0.08 mrad.;
        4.2 The static angle of heel due to a uniformly distributed wind load of 0.54 kPa should not exceed an angle corresponding to half the freeboard for the relevant loading condition;
        4.3 the range of the area under the righting lever should at least be:
        • 20 degrees for pontoons with a length L of 100 m or less;
        • 15 + 0.1 x (150 - L) degrees for pontoons with a length L of more than 100 m, but less than 150 m;
        • 15 degrees for pontoons with a length L of 150 meter or more.

        Article 5.
        The technical standards or technical requirements laid down in this Notice are equated with equivalent technical standards or technical requirements, laid down by another member state of the European Union or a state which is party to the Agreement on the European Economic Area.

        Article II
        This Notice enters into force as of the second day after the date of the Government Gazette in which it is published.

        This Notice, together with its Explanatory Notes, will be published in the Government Gazette, in the Official Gazette of the Netherlands Antilles and in the Country Gazette of Aruba.

        The Head of the Shipping Inspectorate,
        H.G.H. ten Hoopen.


        * These data may also be submitted in the form of appropriate tables.


        Explanatory Notes
        This Notice to Shipping serves to again laying down the Notice to Shipping no. 234/1988 (Gov.Gaz. 1988, 142). The draft of that Notice was not notified in accordance with Article 8, first paragraph, of Directive no. 83/189/EEC of the Council of the European Communities of 28 March 1983 regarding an information procedure in the field of standards and technical regulations (PbEG L 109)*. In order to still comply with the obligation to notification, this Notice has been notified in draft to the Commission of the European Communities (see also Parliamentary proceedings II 1996/1997, 25 389).
        The text of this Notice is identical to the text of the original Notice, except for the following. In Article 5 a provision has been included regarding mutual recognition of technical standards and technical requirements. The draft Notice has been reported to the Commission of the European Communities (notification no. 97/0567/NL) on 14 August 1997, in compliance with Article 8, first paragraph, of the above-mentioned Directive no. 83/189/EEC. The draft Notice has been reported to the Secretariat of the World Trade Organization (notification no. G/TBT/Notif.97.576) on 1 October 1997, in compliance with Article 2, ninth paragraph, of the Agreement on Technical Trade Barriers (Trb. 1994, 235) established on 15 April 1994 in Marrakech. An announcement of the draft Notice is published in Gov.Gaz. 1997, 197.
        These notifications are necessary because the Notice contains technical provisions within the meaning of Directive no. 83/189/EEC, as amended, and as referred to in the afore-mentioned agreement. The Articles 3 and 4 can be indicated as technical provisions.
        These provisions, which are applicable without distinction to Dutch and imported pontoons intended for the carriage of deck cargoes, are necessary by virtue of an efficient protection of the public safety and the health and the life of persons. They are also proportionate to the purpose intended with these provisions. As far as this Notice contains quantitative import restrictions or measurements with the same effect within the meaning of Article 30 EC-Treaty, they are therefore justified for the protection of the above-mentioned interests.
        Within the scope of the notification pursuant to the Directive, the afore-mentioned provision with regard to mutual recognition is included in Article 5 in view of the harmonized application of technical provisions. The WTO notification procedure has not led to amendment of the draft Notice.

        The Head of the Shipping Inspectorate,
        H.G.H. ten Hoopen.


        * Most recently amended by Directive no. 94/10/EC of the European Parliament and the Council of the European Union of 23 March 1994 (PbEG L 100). An updated integral text of the Directive is published in PbEG 1997, C 78.
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