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IMSBC Code (S-1 to S-6)

Section 1 General Provisions

What is individual schedule?
Various aspects of cargoes currently shipped and carried in bulk, are given in the schedules for individual cargoes. User must understand that there can be extra information found from experience and research over and above these schedules. A broad information about properties of cargoes are given as schedule only for guidance. The current valid information is provided by the shipper on the physical and chemical properties, of the cargoes supplied.

What if a particular cargo is not included in the Code?
If a solid cargo which is not listed in appendix 1 to IMSBC Code, and is to be loaded, the shipper shall, provide the competent authority of the port of loading with the characteristics and properties of the cargo. The competent authority will assess the acceptability of the cargo for safe shipment. He, then shall provide to the Master an appropriate certificate stating the characteristics of the cargo and the required conditions for carriage and handling of this shipment. He shall also submit an application to the Organization, to include it into appendix 1.

Is the Code mandatory?
Although this Code is legally treated as a mandatory instrument under the SOLAS Convention the following provisions of this Code remain recommendatory or informative:

Section 11 Security provisions (except a few provisions);

Section 12 Stowage factor conversion tables;

Section 13 References to related information and recommendations;

Appendices other than appendix 1 (Individual schedules of solid bulk cargoes) and appendix 5 (Bulk Cargo Shipping).

Some of the definitions:

Angle of repose means the maximum slope angle of non-cohesive (i.e. free-flowing) granular material. It is measured as the angle between a horizontal plane and the cone slope of such material.

Bulk Cargo Shipping Name (BCSN) identifies a bulk cargo during transport by sea. When a cargo is listed in the IMSBC, the Bulk Cargo Shipping Name of the cargo is identified by capital letters in the individual schedules or in the index.

Cargoes which may liquefy means cargoes which contain a certain proportion of fine particles and a certain amount of moisture. They may liquefy if shipped with a moisture content in excess of their transportable moisture limit.

Competent authority means any national regulatory body or authority designated or otherwise recognized as such for any purpose in connection with this Code. The competent authority shall operate independently from the shipper.

Concentrates means materials obtained from a natural ore by a process of enrichment or beneficiation by physical or chemical separation and removal of unwanted constituents.

Flow moisture point means the percentage moisture content (wet mass basis) at which a flow state develops under the prescribed method of test in a representative sample of the material.It is explained in appendix 2.

Flow state means a state occurring when a mass of granular material is saturated with liquid to an extent that, under the influence of prevailing external forces such as vibration, impaction or ship’s motion, it loses its internal shear strength and behaves as a liquid.

GHS means the seventh revised edition of the Globally Harmonized System of Classification and Labeling of Chemicals, published by the United Nations as document

Group A consists of cargoes which may liquefy if shipped at a moisture content in excess of their transportable moisture limit.

Group B consists of cargoes which possess a chemical hazard which could give rise to a dangerous situation on a ship.

Group C consists of cargoes which are neither liable to liquefy (group A) nor to possess chemical hazards (group B).

High-density solid bulk cargo means a solid bulk cargo with a stowage factor of 0.56 m3 /t or less.

Materials hazardous only in bulk (MHB) means materials which may possess chemical hazards when carried in bulk other than materials classified as dangerous goods in the IMDG Code.

Moisture content means that portion of a representative sample consisting of water, ice or other liquid expressed as a percentage of the total wet mass of that sample.

Moisture migration means the movement of moisture contained in a cargo by settling and consolidation of the cargo due to vibration and ship’s motion. Water is progressively displaced, which may result in some portions or all of the cargo developing a flow state.

Non-cohesive material means dry materials that readily shift due to sliding during transport, as listed in appendix 3, paragraph 1, “Properties of dry bulk cargoes.Transportable moisture limit (TML) of a cargo which may liquefy means the maximum moisture content of the cargo which is considered safe for carriage in ships not complying with the special provisions provided for carriage. It is determined by the test procedures, as provided and is approved by a competent authority.

Section 2 Gen. loading, carriage and unloading precautions

Stresses When loading a high-density solid bulk cargo, particular attention shall be given to the distribution of weights to avoid excessive stresses. Shifting divisions and bins, of adequate strength, shall be erected if required.

Stability As far as practicable, high-density cargoes shall be loaded in the lower hold cargo spaces in preference to ‘tween-deck cargo spaces.

Precautions when loading and unloading Cargo spaces shall be inspected and prepared for the particular cargo which is to be loaded. Due consideration shall be given to bilge wells and strainer plates, for which special preparation is necessary, to facilitate drainage and to prevent entry of the cargoes into the bilge system. Because of the velocity at which some high-density solid bulk cargoes are loaded, special care may be necessary to protect cargo space fittings from damage. As far as practicable, ventilation systems shall be shut down or screened. Due consideration shall be given to minimize the extent to which dust may come into contact with moving parts of deck machinery.

Section 3 Safety of personnel and ship

Why some bulk cargoes, can cause poisoning, corrosive and asphyxiation hazards?
Some solid bulk cargoes are susceptible to oxidation, which may result in oxygen depletion, emission of toxic gases or fumes and self-heating. Some cargoes are not liable to oxidize but may emit toxic fumes, particularly when wet. There are also cargoes which, when wetted, are corrosive to skin, eyes and mucous membranes or to the ship’s structure.
Dust of some solid bulk cargoes may constitute an explosion hazard, especially while loading, unloading and cleaning.

What precautions must be taken to minimize such hazard?
Prior to entry into an enclosed space aboard a ship, appropriate procedures shall be followed taking into account the recommendations developed by the Organization. It is to be noted that, after a cargo space or tank has been tested and generally found to be safe for entry, small areas may exist where oxygen is deficient or toxic fumes are still present.
Emergency entry into a cargo space shall be undertaken only by trained personnel wearing self-contained breathing apparatus and protective clothing and always under the supervision of a responsible officer.

To minimize the chronic and acute risks associated with exposure to the dust of some solid bulk cargoes, the need for a high standard of personal hygiene of those exposed to the dust cannot be overemphasized. Precautions, including the use of appropriate breathing protection, protective clothing, protective skin creams, adequate personal washing and laundering of outer clothing, shall be taken as necessary.

Risk from dust of certain cargoes can be minimized by ventilating to prevent the formation of a dust-laden atmosphere and by hosing down rather than sweeping.
Ventilation shall be such that any escaping hazardous gases, vapours or dust cannot enter the accommodation or other interior spaces in hazardous concentrations. Due consideration shall be given to prevent escaping hazardous gases, vapours or dust from reaching enclosed work areas. Adequate precautions shall be taken to protect the personnel in these work areas. When a fumigant is used, such as phosphine gas, for fumigation-in-transit, due precautions are taken.  Gas concentration safety checks shall also be continued throughout the voyage at least at eight-hour intervals or more frequently if so advised by the fumigator-in-charge at all appropriate locations.

Section 4 Assessment of acceptability of consignments for safe shipment

What information must be included in respect of solid bulk cargo?
When a solid bulk cargo is carried by sea it shall be identified in the transport documentation by the BCSN. Cargo information shall be confirmed in writing and by appropriate shipping documents prior to loading. Following information shall be provided:

A.   The identification related information such as:
the BCSN; the cargo group (A and B, A, B or C); IMO class, if applicable; UN number, if applicable; total quantity; and the SF.

B    Physical behavior related information such as:
the need for trimming and procedures; angle of repose, if applicable; certificate on the moisture content of the cargo and its TML in the case of a concentrate or other cargo which may liquefy; and likelihood of formation of a wet base.

C   Chemical behavior related information such as:
toxic or flammable gases which may be generated; flammability, toxicity, corrosiveness and propensity to oxygen depletion; self-heating properties of the cargo; properties on emission of flammable gases in contact with water; radioactive properties; whether or not the cargo is classified as harmful to the marine environment; and any other information required by national authorities.

Information provided by the shipper shall be accompanied by a declaration.

Section 5 Trimming procedures

Why is trimming important?
reduces the likelihood of the cargo shifting;
minimizes the air entering the cargo; and
reduces exposed area.
Air entering the cargo could lead to spontaneous heating. The Master can ensure required trimming for the stability, taking into account the characteristics of the ship and the intended voyage.

Q. From the point of view of trimming or angle of repose, how are the cargoes categorized?
In respect of trimming, solid bulk cargoes can be categorized as cohesive or non-cohesive. The angle of repose is a characteristic of non-cohesive bulk cargoes. There are three categories:

1. Non-cohesive bulk cargoes having an angle of repose less than or equal to 30º
These cargoes, which flow freely like grain, shall be carried according to the provisions applicable to the stowage of grain cargoes. The bulk density of the cargo shall be taken into account when determining:
a. the scantlings and securing arrangements of divisions and bin bulkheads; and
b. the stability effect of free cargo surfaces.

2. Non-cohesive bulk cargoes having an angle of repose greater than 30° to 35° inclusive
These cargoes shall be trimmed according to the following criteria:
a. the unevenness of the cargo surface measured as the vertical distance (Dh) between the highest and lowest levels of the cargo surface shall not exceed B/10, where B is the beam of the ship in metres, with a maximum allowable Dh = 1.5 m; or
b.  loading is carried out using trimming equipment approved by the competent authority.

3. Non-cohesive bulk cargoes having an angle of repose greater than 35°
These cargoes shall be trimmed according to the following criteria:
a. the unevenness of the cargo surface measured as the vertical distance (Dh) between the highest and lowest levels of the cargo surface shall not exceed B/10, where B is the beam of the ship in metres, with a maximum allowable Dh = 2 m; or
b. loading is carried out using trimming equipment approved by the competent authority.

Section 6 Methods of determining the angle of repose

What are the different methods to find angle of repose?
There are various methods in use to determine the angle of repose for non-cohesive solid bulk materials explained in appendix 2 and are as follows:
1. Tilting box method: This laboratory test method is suitable for non-cohesive granular materials with a grain size not greater than 10 mm.
2. Shipboard test method: In the absence of a tilting box apparatus.

Explain how angle of repose of fine-grained materials (size less than 10 mm) is found by “tilting box method.
When measuring the angle of repose by this method, the material surface should initially be level and parallel to the test box base. The box is tilted without vibration and tilting is stopped when the product just begins to slide in bulk.
The box 60cm x 40cm with depth of 20cm. A framework, with arrangement of measuring angle has an open box on top.

The box is filled with the material to be tested by pouring it slowly and carefully from the lowest practical height into the box in order to obtain uniformity of loading. The excess material is levelled off with the aid of a straight edge. The tilting system is then activated and stopped when the material just begins to slide in bulk. The angle of the top of the box to the horizontal is measured by the protractor and recorded.

Is there any alternate method, which can be used on ships?
A sheet of paper is spread on the table. 10 L of the material to be tested is split into three subsamples and each is tested in the following way: Two thirds of the subsample (i.e. 2 L) is poured onto the sheet, producing a starting cone. The remainder of this subsample is then poured very carefully from a height of a few millimetres on top of the cone. The cone must be built up symmetrically. When measuring, care should be taken that the protractor does not touch the cone; otherwise this may result in sliding of the material and spoil the test. The angle has to be measured at four places around the cone, about 90° apart. This test should be repeated on the other two subsamples.

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