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Hazardous cargoes -loading precautions

Dangerous goods on board

In the event of any dangerous goods or harmful substances being carried aboard the general cargo ship, reference to ‘The International Maritime Dangerous Goods (IMDG)’ code (volume 1, 2 and suppliment) should be consulted. Additionally, the Chemical Data Sheets contained in the Tanker Safety Guide (Gas and Chemical) issued by the International Chamber of Shipping may be appropriate. Such goods/substances must be classified, packaged and labelled in accord with the Merchant Shipping Regulations. Such trailers or vehicles should be given special consideration when being loaded and inspected for leakage prior to loading on the vessel. Such vehicles/containers should also be provided with adequate stowage that will provide good ventilation in the event of leakage whilst in transit, e.g., upper deck stowage, exposed to atmosphere is recommended as a general rule.

Deck Officers should pay particular attention to the securing of such transports to ensure negative movement of the unit. Special attention should also be given to the securing of adjacent units to prevent escalation of cargo shifting in a seaway.Tank vehicles may not necessarily be carrying hazardous goods, but any spillage of the contents could act as a lubricant on surrounding units and generate a major cargo shift on Ro-Ro vessels in heavy seas.

In the event that a cargo parcel/unit is found to be ‘leaking’ or have exposed hazards, the nature of the cargo should be ascertained and personnel kept clear of the immediate area until the degree of hazard is confirmed. In any event the unit should not be accepted for shipment and rejected until satisfactorily contained.

Where a hazardous substance is discovered at sea, to be a threat to personnel, full information should be sought as soon as possible.Any action taken would reflect on the nature of the substance and the emergency actions stipulated in carriage instructions. It may become prudent to seek additional instructions from the manufacturer of the substance and act accordingly.

The shipping procedure for hazardous/dangerous goods is as follows:

1. The shipper is responsible for obtaining the ‘Export Licences’ for the shipment.

2. The shipper would also be responsible for marking and labelling the goods to be shipped in accord with the IMDG Code.

3. The shipper would then be in a position to contact the Shipping Companies Agents and must provide:The Number of packages, their weight, the value, the volume, and any special requirements that may be required for the cargo.

4. Customs clearance would be required, and the goods may be liable to inspection.

5. The bill of lading is also liable to be endorsed, especially if packages are damaged and are rejected.

6. The goods would be listed in the ship’s manifest and on the ship’s cargo plan.

7. Ship’s Officers would check the details of the goods including the labelling, the respective UN Number, the condition of the package, together with any special stowage requirements prior to loading the cargo.

8. Throughout this procedure the Ship’s Master has the right to accept or reject the cargo prior to loading.

Once stowed on board the vessel the IMDG Code requirements would be followed throughout the period of the voyage.

Monitoring of Hazardous Cargoes:
Different operators monitor the shipment of Hazardous Goods in various ways but each vessel needs to be fully aware of the position of the cargo, its class and the emergency procedures that are involved if transport difficulties arise. Ferry operators tend to identify on a cargo stowage outline the position of the ‘special unit’, and the relevant details are recorded once it has arrived for shipment.

Emergency responses to spillage of dangerous goods : are contained in the IMO Medical First Aid Guide and the IMO Emergency Procedures for Ships Carrying Dangerous Goods (EmS). Both of these are available either as free-standing documents or incorporated into the International Maritime Dangerous Goods (IMDG) Code.

Recommendations on emergency action differ depending on where the goods are stowed and whether a substance is gaseous, liquid or solid. When dealing with incidents involving flammable gases or flammable liquids, all sources of ignition (eg naked lights, unprotected light bulbs, electric handtools) should be avoided.

Normally dangerous goods in packaged form can be handled without the use of special protective clothing or equipment. If the packaging has been damaged the contents may have spilt or leaked. Under these circumstances the emergency team may have to deal with toxic corrosive or flammable solids, liquids or vapours. Vapours may arise from a spilt substance itself or as a result of the reaction between spilt substances themselves and other materials. Eye protection should always be worn, and if hazardous dust may be encountered, respiratory protection should be used - where the substance offers a significant toxic hazard this should be self-contained breathing apparatus.

In general the recommendation is to wash spillages on deck overboard with copious quantities of water, and, where there is likely to be a dangerous reaction with water, from as far away as practicable. Disposal of dangerous goods overboard is a matter for judgement by the master, bearing in mind that the safety of the crew has priority over pollution of the sea. If it is safe to do so, spillages and leakages of substances, articles and materials identified in the IMDG Code as MARINE POLLUTANT should be collected for safe disposal. Absorbent material should be used for liquids.

Spillages collected with absorbent material and kept in plastic bags or other receptacles may need to be stowed safely for ultimate disposal ashore. Collection of spillages with absorbent material under deck may not be fully effective, and precautions for entry into enclosed spaces should be observed.

A careful inspection for structural damage should be carried out after dealing with spillages of highly corrosive substances.

Water is generally recommended as the fire fighting medium for most dangerous goods at sea. However, reference should be made to the relevant EmS schedules.

Where possible, a package should be removed from the vicinity of the fire. Where there is a possibility that the heat will cause a chemical or physical change in the substance, or affect the integrity of a package, leading to rupture and dispersal of the contents, keeping the packages cool may limit the hazard. Care should be exercised with those substances liable to polymerise, as this reaction can continue long after the removal of external heat.

For incidents under deck, the best course of fire fighting will usually be to batten down the hatch, exclude all ventilation and operate the fixed fire-fighting installation. Self-contained breathing apparatus should be worn when battening down the hatches or if there is any need to enter the space, for example after the fire is out.

For certain substances which are highly reactive with water, only the use of dry chemical fire extinguishers is recommended. This would not preclude the use of suitable powdered inert material if available in sufficient quantity. The only alternative is the use of copious quantities of water, which will have a cooling effect on the fire, although reacting with the substance.

Where an EmS advises against the use of foam, this does not preclude the use of special foams.

The general fire-fighting recommendations for a number of dangerous goods suggest that they should be jettisoned if there is a likelihood of their involvement in a fire. Where full or nearly full container loads or other units are concerned, this may be impractical, in which case everything possible should be done to prevent the spread of fire to those containers. If, despite preventive measures, fire seems likely to affect these containers, it should be borne in mind the contents may burn with explosive violence and personnel should be withdrawn accordingly.

Other useful articles :
  1. Transport of dangerous goods at sea

  2. No packaged dangerous goods may be offered for carriage or taken aboard any ship unless a dangerous goods declaration or marine pollutants declaration (or a combined declaration) has been given to the master or operator as per the the MS (Dangerous Goods and Marine Pollutants) regulations 1997 .
    More .....

  3. Hazardous cargoes -loading precautions /monitoring

  4. Check the details of the goods including the labelling, the respective UN Number, the condition of the package, together with any special stowage requirements prior to loading the cargo.
    More .....

  5. IMDG code

  6. IMDG code brief guideline & regulatory requirement
    More .....

  7. The documents of compliance (DOC)for carrying dangerous goods

  8. Document of Compliance (regulation 22) applies to: • passenger ships built on or after 1 September 1984; • cargo ships of 500gt or over built on or after 1 September 1984; and • cargo ships of less than 500gt built on or after 1 February 1992.
    More .....

  9. Gas detection equipment

  10. An appropriate instrument for measuring the concentration of gas or oxygen in the air must be provided together with detailed instructions for its use. The instrument must be of a type approved by a Certifying Authority, and the crew must be trained in its use..
    More .....

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