Carriage of solid bulk cargoes
Dry cargo trades
1.1. Dry bulk carriers
Dry bulk carriers, the workhorses of the sea, carry out the essential transport of the commodities without which our modern society would not be able to function. Theships and their crews, together with the companies that operate them, do not enjoy theglamour attached to other sectors of the industry more in the public eye; the bulkshipping sector does, however, provide a highly cost-effective service for which proper recognition is due.The bulk cargo business is, like most other shipping sectors, subjected tovariable demand and supply with the entailing fluctuations in freight rates. During thefirst decade of the 21
century, the business experienced peaks never seen before. Theboom was mainly driven by the China’s unsaturated craving for iron ore which createdpositive ripples all the way down the bulk carrier industry. However, no peak last forever and here at the beginning of the second decade of the 21
century the world is sufferingunder the credit crunch albeit fortunately with some optimism picking up.In 1993 the bulk carrier fleet consisted of approximately 5000 ships. In thebeginning of 2010 the number of bulk carriers was close to 7500, with another almost3200 new buildings expected to enter the market during the coming years. Not only isthe number of ships growing, today’s bulk carriers are generally significantly larger thantheir predecessors.The shipping industry in general was significant increase in the number of shipsin the last years, which
pressure in the space; and3. the increase in water pressure reduces the friction between cargo particlesresulting in a reduction in the shear strength of the cargo.
consists of cargoes which possess a chemical hazard which could giverise to a dangerous situation on a ship. Some of these materials are classified asdangerous goods and others are materials hazardous only in bulk (MHB). It is essentialto obtain current, valid information about the physical and chemical properties of thecargoes to be shipped in bulk, prior to loading.
consists of cargoes which are neither liable to liquefy (Group A) nor topossess chemical hazards (Group B).
2.3. Provision of information regarding cargo
Cargo information (
see Annex 1
) shall be confirmed in writing and by appropriateshipping documents prior to loading. The cargo information shall include:
the BCSN when the cargo is listed in the IMSBC Code. Secondary namesmay be used in addition to the BCSN;
the cargo group (A&B, A, B, or C);
the IMO Class of the cargo, if applicable;
the UN number preceded by letters UN for the cargo, if applicable;
the total quantity of the cargo offered;
the stowage factor;
the need for trimming and the trimming procedures, as necessary;
the likelihood of shifting, including angle of repose, if applicable;
additional information in the form of a certificate on the moisture content of the cargo and its transportable moisture limit in the case of a concentrateor other cargo which may liquefy;
likelihood of formation of a wet base (contains in IMSBC Code);
toxic or flammable gases which may be generated by cargo, if applicable;
flammability, toxicity, corrosiveness and propensity to oxygen depletion of the cargo, if applicable;
self-heating properties of the cargo, and the need for trimming, if applicable;
properties on emission of flammable gases in contact with water, if
radioactive properties , if applicable; and
any other information required by national authorities.
Definitions and terminologies associated with the carriage of bulk cargoes
Angle of Repose ( AOR)
This is maximum slope angle of non-cohesive (i.e. ,free flowing) granular material. It is measured as the angle between a horizontalplane and the cone slope of such material.The angle of repose will be in the range of 0o- 90o.Free flowing liquids will have zero AOR. Whereasmaterials with high density & high coefficient of friction will have the tendency to make large AOR.
Figure 1. Angle Of Repose (AOR)
Materials with large angle of repose will form large piles while with less angle of repose will tend to flatten up , making it more liable to shift and slide duringtransport. As far as solid bulk cargoes are concerned, the angle repose is required for non-cohesive substances only. For cohesive substances (which may stick together) , thevalue of AOR is not applicable.(2)
Bulk Cargo Shipping Name (BCSN)
It identifies a bulk cargo during transportby sea. When a cargo is listed in IMSBC Code, the Bulk Cargo Shipping Name of the cargo is identified by capital letters in the individual schedules or in the index.When the cargo is a dangerous good as per IMDG code, Proper Shipping Nameof that cargo is the Bulk Cargo Shipping Name.Each solid bulk cargo in this Code has been assigned a Bulk Cargo ShippingName (BCSN). When a solid bulk cargo is carried by sea it shall be identified in thetransport documentation by the BCSN. The BCSN shall be supplemented with theUnited Nations (UN) number when the cargo is dangerous goods.
(3) Bulk density
Means the weight of solids, air and water per unit volume. Bulkdensity is expressed in kilograms per cubic meter (kg/m3) , in general. It should
be noted that the void spaces in the cargo may be filled with air and water.
(4) Cargo space
Means any space in a ship designated for carriage of cargoes.
(5) Cargoes which may liquefy
Means cargoes which contain a certain proportionof fine particles and a certain amount of moisture. They may liquefy if shippedwith moisture content in excess of their transportable moisture limit.
Means materials other than non-cohesive materials.
Combination carriers (OBO or O/O)
a ship whose design is similar to aconventional bulk carrier but is equipped with pipelines, pumps and inert gasplant so as to enable the carriage of oil cargoes in designated spaces.
(8) Competent Authority
Means any national regulatory body or authoritydesignated or otherwise recognized as such for any purpose in connection withIMSBC Code.
Means materials obtained from a natural ore by a process of enrichment or beneficiation by physical or chemical separation and removal of unwanted constituents.
(10) Conveyor system
Means the entire system for delivering cargo from theshore stockpile or receiving point to the ship.
(11) Flow moisture point (FMP)
Means the percentage moisture content (wetmass basis) at which a flow state develops under the prescribed method of testin a representative sample of the material
(12) Flow state
Means a state occurring when a mass of granular material issaturated with liquid to an extent that, under the influence of prevailing externalforces such as vibration, impaction or ships motion, it loses its internal shear strength and behaves as a liquid.
(13) High-density solid bulk cargo
Means a solid bulk cargo with a stowagefactor of 0.56 m3/t or less.
(14) Incompatible materials
Means materials that may react da