IMSBC Code – IMDG Code Compliance Centre

Stowage and Segregation of Dangerous Goods on General Cargo Ships

In the last article, ‘Stowage and Segregation of Dangerous Goods on Container Ships’, dated 20^th May, we looked at the provisions of stowage of containerized dangerous goods on container ships. Let us look at the basic stowage and segregation provisions for carriage of dangerous goods in packaged from and in solid bulk form on general cargo ships.

Flammable gases or flammable liquids having a flashpoint of less than 23°C c.c, must be stowed on deck only, unless otherwise approved by the Administration and must be stowed at least 3 m from any potential source of ignition. Here possible sources of ignition may include open fires, machinery exhausts, galley uptakes, electrical outlets and electrical equipment including those on refrigerated or heated cargo transport units unless they are of certified safe type. For interpreting what is certified type, for cargo spaces, refer to SOLAS II:2/19.3.2 and for refrigerated or heated cargo transport units refer to Recommendation published by the international Electrotechnical Commission, in particular IEC 60079.

When explosives are loaded the compartments or holds and containers must be locked to pervert unauthorized access however when in emergency access to the locked places must be able to be gained without delay. If the cargo compartment floors are not fitted with closed boarded wood the loading/unloading equipment and process must ensure no sparks can occur. If the cargo gets wet all handling operations must be stopped unless specialist advise from shipper clears same. Personnel involved in cargo operations must be briefed prior work regarding the potential risks and necessary precaution. When explosives belonging to different compatibility groups are loaded they must be stowed not less than 6 meters from each other unless mixed loading is permitted between the involved compatibility groups as per section 7.2.7 of IMDG Code.

Non containerized flammable liquids packaged in plastics jerricans, plastics drums, plastics IBCs must always be stowed on deck. There are special requirements for stowage of FISHMEAL, UNSTABILIZED (UN 1374), FISHMEAL, STABILIZED (UN 2216, class 9) and KRILL MEAL (UN3497), SEED CAKE (UN 1386), AMMONIUM NITRATE BASED FERTILIZER, UN 2071 and certain other goods.

When feeds or other edible substances intended for consumption by humans or animals, foodstuff, is loaded it will require segregation ‘separated from’ toxic, radioactive and corrosive dangerous goods and Dangerous goods in other classes which has segregation reference in column 16 (16b in 37th amendment of IMDG Code).

There are four segregation rules for dangerous goods loaded in conventional way on board ships.

Away from: Effectively segregated so that the incompatible goods cannot interact dangerously in the event of an accident but may be transported in the same compartment or hold or on deck, provided a minimum horizontal separation of 3 metres, projected vertically is obtained.
Separated from: In different compartments or holds when stowed under deck. Provided the intervening deck is resistant to fire and liquid, a vertical separation, i.e. in different compartments, may be accepted as equivalent to this segregation. For on deck stowage, this segregation means a separation by a distance of at least 6 metres horizontally.
Separated by a complete compartment or hold from: Either a vertical or a horizontal separation. If the intervening decks are not resistant to fire and liquid, then only a longitudinal separation, i.e. by an intervening complete compartment or hold, is acceptable. For on deck stowage, this segregation means a separation by a distance of at least 12 metres horizontally. The same distance has to be applied if one package is stowed on deck, and the other one in an upper compartment.
Separated longitudinally by an intervening complete compartment or hold from: Vertical separation alone does not meet this requirement. Between a package under deck and one on deck, a minimum distance of 24 m, including a complete compartment, must be maintained longitudinally. For on deck stowage, this segregation means a separation by a distance of at least 24 metres longitudinally.

Segregation rules between containerized dangerous goods and those loaded in conventional ways are different. Dangerous goods stowed in the conventional way must be segregated from goods transported in closed containers in accordance with segregation provisions showed above except that for “away from” is required, no segregation between the packages and the closed cargo transport units is required; and where “separated from” is required, the segregation between the packages and the closed cargo transport units may be as for “away from”.

Segregation between Bulk dangerous goods and packaged dangerous goods must be in accordance with the table shown in section 7.6.3.5.2 of IMDG Code where all 4 segregation terms have different rules from those listed above.

For full details of the requirements of stowage and segregation of dangerous goods loaded on general cargo ships refer to chapter 7.6 of IMDG Code, individual entries in chapter 3.2 and IMSBC Code as applicable.

Danger of cargo liquefaction – Bulk Carriers

International Maritime Solid Bulk Cargo (IMSBC) Code categorizes cargoes into three groups, A, B & C:

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

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

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

Liquefaction property of group A cargo is a major concern on safety of ship and its crew. In 2010 vessels Jian Fu Star, Nasco Diamond, Hong Wei and Vinalines Queen sank resulting in total loss of 67 lives at sea. The cargo carried by these four ill-fated vessels was nickel ore.

When liquefaction takes place vessel at sea may experience cargo shifting resulting in sudden loss of stability and capsizing.

When does liquefaction occur? Liquefaction takes place if the moisture content in cargo is above the Transportable Moisture Limit (TML). Since Nickel ore is not listed by name in IMSBC Code the carriage of nickel ore must be within the scope of section 1.3 “Cargoes not listed in this Code”

Recommendations are submitted to Maritime Safety Committee for implementing binding rules for engagement of National Competent Authority together with qualified laboratories for assessment of moisture content, TML to ensure cargoes which may liquefy is not loaded if moisture content is above TML.

Quote from China’s submission to Maritime Safety Committee (MSC89)

“China, as the country of nationality of the 45 seafarers [who lost their lives], carried out the investigation immediately after the accidents. In view of the fact that the subject ships had sunk and the difficulty to obtain cargo samples from the port of loading, the investigation was mainly based on the interviews with the surviving seafarers.

According to the evidence available, the direct cause of these accidents was the loss of stability as a result of cargo liquefaction and shifting in bad weather. However, the cargo documentation provided to the masters indicated that the moisture content of the cargo samples was lower than the Transportable Moisture Limit (TML)”.

Japan: ClassNK – New Edition of “Guidelines for the Safe Carriage of Nickel Ore” (worldmaritimenews.com)
ClassNK Revises Guidelines Following Loss of MV Vinalines Queen (gcaptain.com)
Imsbc Code – Shipper’s Declaration

ALUMINIUM SMELTING BY-PRODUCTS

Aluminium is made mainly from bauxite ore. Australia is one of the biggest suppliers of bauxite ore in the world. Cost of production of aluminium is comparatively higher due to high energy consumption involved in the process.

Alcoa's Point Henry smelter - from the other side of Corio Bay - Geelong, Victoria, Australia

One of the byproducts of aluminium production is called “aluminium smelting by-products” This is typically a complex waste however can be used to extract more aluminium.

Aluminium smelting byproducts are reactive with water. When in contact with water it will generate hydrogen, acetylene, ammonia, phosphine and methane. These flammable gasses will easily ignite.

IMDG Code list this product as UN 3170, Class 4.3, ALUMINIUM SMELTING BY-PRODUCTS or ALUMINIUM REMELTING BY-PRODUCTS, Packing group II and III

Stowage requirement in IMDG Code states “Category B. Under deck in a mechanically ventilated space. Only to be loaded under dry weather conditions.

Cloudy weather in Singapore. Photo by Eric Bayona Faytaren

When this product is transported for disposal purpose then it will fall under BASEL Convention and proper shipping name must be preceded by word WASTE.

IMSBC Code states “Aluminium smelting by-products are wastes from the aluminium manufacturing process. Grey or black powder or lumps with some metallic inclusions. The term encompasses various different waste materials, which include but are not limited to: ALUMINIUM DROSS, SPENT CATHODES, ALUMINIUM SALT SLAGS, SPENT POTLINER, ALUMINIUM SKIMMINGS

Stowage factor (m3/t) : 0.82

IMSBC CODE – SHIPPER’S DECLARATION

Before loading of Solid Bulk Cargo the shipper must furnish information to the master or his representative about the cargo sufficiently in advance of loading to enable the precautions which may be necessary for proper stowage and safe carriage of the cargo to be put into effect.

Sample editable form is attached here.IMSBC DECLARATION

Angle of Repose

Bulk granular materials when poured on a flat surface will create a conical pile. The internal angle between the surface of the pile and the horizontal surface is called as ‘angle of repose’. Angle of repose is depended on the density, surface area, and the shapes of the particle also the coefficient of friction.

Antlion larvae’s sand pit works on critical angle of repose to catch its prey, see below image

IMSBC Code defines angle of repose as 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.

Angle of repose of UN 1942 AMMONIUM NITRATE is 27 deg to 42 deg

MHB in IMSBC Code

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

Below are MHBs listed in IMSBC Code with description and their hazardous nature.

BROWN COAL BRIQUETTES

Brown Coal (Lignite) Briquettes are manufactured by pressing dried brown coal particles into compressed blocks.

Briquettes are easily ignited, liable to spontaneous combustion and will deplete oxygen in cargo space.
CHARCOAL

Wood burnt at a high temperature with as little exposure to air as possible. Very dusty, light cargo. Can absorb moisture to about 18 to 70% of its weight. Black powder or granules.

May ignite spontaneously. Contact with water may cause self-heating. Liable to cause oxygen depletion in the cargo space. Hot charcoal screenings in excess of 55oC should not be loaded.

COAL

Coal (bituminous and anthracite) is a natural, solid, combustible material consisting of amorphous carbon and hydrocarbons.

Coal may create flammable atmospheres, may heat spontaneously, may deplete the oxygen concentration, may corrode metal structures. Can liquefy if predominantly fine 75% less than 5 mm coal.

DIRECT REDUCED IRON (A)

A metallic grey colloid material emanating from a densification process whereby the direct reduced iron (DRI) feed material is at a temperature greater than 650oC at time of moulding and has a density greater than 5.0 g/cm3. Fines (under 4 mm) not to exceed 5%.

Material may slowly evolve hydrogen after contact with water. Temporary self-heating of about 30oC may be expected after material handling in bulk.

This cargo is non-combustible or has a low fire-risk.

DIRECT REDUCED IRON (B)

Direct Reduced Iron (DRI) (B) is a metallic material of a manufacturing process formed by the reduction (removal of oxygen) of iron oxide at temperatures below the fusion point of iron.

Cold-moulded briquettes should be defined as those which have been moulded at a temperature of under 650oC or which have a density of less than 5.0 g/cm3.

DRI may react with water and air to produce hydrogen and heat. The heat produced may cause ignition. Oxygen in an enclosed space may be depleted.

FERROPHOSPHORUS

An alloy of iron and phosphorus used in the steel industry

May evolve flammable and toxic gases (e.g. phosphine) in contact with water.

This cargo is non-combustible or has a low fire-risk.

FERROSILICON

25% to 30% silicon, or 90% or more with silicon (including briquettes)

Ferrosilicon is an extremely heavy cargo.

In contact with moisture or water it may evolve hydrogen, a flammable gas which may form explosive mixtures with air and may, under similar circumstances, produce phosphine and arsine, which are highly toxic gases.

This cargo is non-combustible or has a low fire-risk.

FLUORSPAR

Yellow, green or purple crystals. Coarse dust.

This material may liquefy if shipped at moisture content in excess of their Transportable moisture limit. See section 7 of the Code. Harmful and irritating by dust inhalation.

LIME (UNSLAKED)

White or greyish-white in colour.

Unslaked lime combines with water to form calcium hydroxide (hydrated lime) or magnesium hydroxide. This reaction develops a great deal of heat which may be sufficient to cause ignition of nearby combustible materials. This is not combustible or has a low fire-risk corrosive to eyes and mucous membranes.

This cargo is non-combustible or has a low fire-risk.

LINTED COTTON SEED

Cottonseed with short cotton fibres adhering to the kernel after approximately 90% – 98% of the cotton has been removed by machine.

May self-heat and deplete oxygen in cargo space.

MAGNESIA (UNSLAKED)

Combines with water to form magnesium hydroxide with an expansion in volume and a release of heat. May ignite materials with low ignition temperatures. Similar to LIME (UNSLAKED) but is less reactive. Corrosive to eyes and mucous membranes.

This cargo is non-combustible or has a low fire-risk.

METAL SULPHIDE CONCENTRATES

Mineral concentrates are refined ores in which the valuable components have been enriched by eliminating the bulk of waste materials. Generally the particle size is small although agglomerates sometimes exist in concentrates which have not been freshly produced

.The most common concentrates in this category are: zinc concentrates, lead concentrates, copper concentrates and low grade middling concentrates.

Some sulphide concentrates are liable to oxidation and may have a tendency to self-heat, with associated oxygen depletion and emission of toxic fumes. Some materials may present corrosion problems.

When a Metal Sulphide Concentrate is considered as presenting a low fire-risk, the carriage of such cargo on a ship not fitted with a fixed gas fire extinguishing system should be subject to the Administration’s authorization as provided by SOLAS regulation II-2/10.7.1.4.

PEAT MOSS

Surface mined from mires, bogs, fens, muskeg and swamps. Types include moss peat, sedge peat and grass peat. Physical properties depend on organic matter, water and air content, botanical decomposition and degree of decomposition.

May range from a highly fibrous cohesive mass of plant remains which when squeezed in its natural state exudes clear to slightly coloured water, to a well decomposed, largely amorphous material with little or no separation of liquid from solids when squeezed.

Typically air-dried peat has low density, high compressibility and high water content; in its natural state it can hold 90 percent or more of water by weight of water when saturated.

Oxygen depletion and an increase in carbon dioxide in cargo and adjacent spaces.

Risk of dust explosion when loading. Caution should be exercised when walking or landing heavy machinery on the surface of uncompressed Peat Moss.

Peat Moss having a moisture content of more than 80% by weight should only be carried on specially fitted or constructed ships Dust may cause eye, nose and respiratory irritation.

PETROLEUM COKE (calcined or uncalcined)

Black, finely divided residue from petroleum refining in the form of powder and small pieces.

Uncalcined petroleum coke is liable to heat and ignite spontaneously when not loaded and transported under the provisions of this entry.

This cargo is non-combustible or has a low fire-risk.

PITCH PRILL

Pitch Prill is made from tar produced during the coking of coal. It is black with a distinctive odour. It is extruded into its characteristic pencil shape to make handling easier.

Cargo softens between 40ºC to 50ºC. Melting point: 105ºC to 107ºC

Melts when heated. Combustible, burns with a dense black smoke. Dust may cause skin and eye irritation. Normally this cargo has a low fire-risk. However powder of the cargo is easy to ignite and may cause fire and explosion. Special care should be taken for preventing fire during loading or discharging.

PYRITES, CALCINED (Calcined Pyrites)

Dust to fines, Calcined Pyrites is the residual product from the chemical industry where all types of metal sulphides are either used for the production of sulphuric acid or are processed to recover the elemental metals – copper, lead, zinc, etc. The acidity of the residue can be considerable, in particular, in the presence of water or moist air, where pH values between 1.3 and 2.1 are frequently noted.

Highly corrosive to steel when wet. Inhalation of dust is irritating and harmful. Cargo may

liquefy. This cargo is non-combustible or has a low fire-risk.

SAWDUST

Fine particles of wood.

Spontaneous combustion if not clean, dry and free from oil. Liable to cause oxygen depletion within the cargo space.

SILICOMANGANESE

Silicomanganese is an extremely heavy cargo, silvery metallic material with a grey oxide coating.

HAZARD

In contact with water may evolve hydrogen, a flammable gas that may form explosive mixtures with air and may, under similar conditions produce phosphine and arsine, which are highly toxic gases.

Cargo is liable to reduce oxygen content in a cargo space.

This cargo is non-combustible or has a low fire-risk

TANKAGE

The dried sweeping of animal matter from slaughterhouse floors. Very dusty.

Subject to spontaneous heating and possible ignition. Possibly infectious.

VANADIUM ORE

Dust may be toxic.

This cargo is non-combustible or has a low fire-risk

WOODCHIPS

Natural timber mechanically chipped into the approximate size of a business card.

This material possesses a chemical hazard. Some shipments may be subject to oxidation leading to depletion of oxygen and increase of carbon dioxide in cargo and adjacent spaces.

With moisture content of 15% or more this cargo has a low fire-risk. As the moisture content decreases the fire risk increases. When dry, woodchips can be easily ignited by external sources; are readily combustible and can ignite by friction.

WOOD PELLETS

The Wood Pellets are light blond to chocolate brown in colour; very hard and cannot be easily squashed. Wood Pellets have a typical specific density between 1,100 to 1,700 kg/m3 and a bulk density of 600 to 750 kg/m3. Wood Pellets are made of sawdust, planer shavings and other wood waste such as bark coming out of the lumber manufacturing processes. Normally there are no additives or binders blended into the pellet, unless specified. The raw material is fragmented dried and extruded into pellet form. The raw material is compressed approximately 3.5 times and the finished Wood Pellets typically have a moisture content of 4 to 8%. Wood Pellets are used as a fuel in district heating and electrical power generation as well as a fuel for small space heaters such as stoves and fireplaces.

Wood Pellets are also used as animal bedding due to the absorption characteristics. Such Wood Pellets typically have a moisture content of 8 to 10%.

Shipments may be subject to oxidation leading to depletion of oxygen and increase of

carbon monoxide and carbon dioxide in cargo and communicating spaces.

Swelling if exposed to moisture. Wood Pellets may ferment over time if moisture content is over 15% leading to generation of asphyxiating and flammable gases which may cause spontaneous combustion.

Handling of Wood Pellets may cause dust to develop. Risk of explosion at high dust concentration.

WOOD PULP PELLETS

The pellets are brown in colour; very hard and cannot be easily squashed. They are light and are about half the size of a bottle cork. The pellets are made of compacted woodchips.

This cargo possesses a chemical hazard. Some shipments may be subject to oxidation leading to depletion of oxygen and increase of carbon dioxide in cargo and adjacent spaces. With moisture content of 15% or more this cargo has a low fire-risk. As the moisture content decreases, the fire risk increases.

IMSBC Code Training (shashikallada.wordpress.com)
Another Hazardous Cargo, Another 22 Seafarers Lost at Sea (gcaptain.com)

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