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Coal is a mineral resource with significant reserves, and accounts for many imports in Vietnam. Imported coal will be transported by sea, and during transportation, special attention and strict compliance with legal requirements are required to minimize risks and ensure safety for both humans and property.

I. Risks in the coal transportation process

1. Risk of fire and explosion

One of the challenges when transporting large quantities of coal is its potential for self-heating to the point of causing fires and explosions. The self-heating process begins with heat-releasing reactions, and when the heat production rate exceeds the rate of heat loss, it leads to an accelerated oxidation rate, increasing the likelihood of ignition and combustion. This often poses a serious challenge for vehicles transporting flammable fuel.

Factors contributing to coal self-heating and ignition include:

• Coal is in an oxygen-rich air environment
• Large fuel surface area, increasing the likelihood of oxidation reactions
• Suitable moisture environment
• Coal is contained in a thermal gap, preventing internal heat from dissipating

Moreover, both Bituminous coal and Anthracite coal emit methane gas, a highly flammable gas with a very low explosion limit in air (4.4%). Explosions often occur due to the ignition of methane in the cargo. Bituminous coal has a low methane content, while Anthracite coal can contain several times more.

2. Health and safety risks to human life

The explosive nature and harmful gases emitted from coal when burned pose a threat to the safety of sailors on ships. Sailors need to be familiar with and adhere to maritime safety rules. Furthermore, monitoring cargo transportation at sea is crucial. Cargo conditions should be closely monitored, with inspection details recorded in cargo logs and deck logs.

Coal is quite dusty, and prolonged exposure and inhalation of coal dust can have adverse health effects. Therefore, to mitigate the risk of coal dust, sailors need to be equipped with proper protective gear and clothing that meets safety standards.

3. Risk of vehicles

The intensity of coal loading and unloading is very high (thousands of tons per hour), causing a significant impact on the ship's cargo structures. Without preventive measures, this can lead to equipment damage or deformation of the ship's hull. When the cargo loading speed is high, coal being concentrated in one place causes localized stress on the structure, leading to deformation and shifting of the hull, potentially causing the ship to tilt.

When transporting coal at sea, it's essential to be aware of the maximum payload the vessel can carry to avoid unfortunate accidents such as shipwrecks due to overloading. Additionally, attention should be paid to evenly spreading coal during loading or trimming the cargo promptly and correctly.

II. Rules and requirements for safe coal transportation

SOLAS (International Convention for the Safety of Life at Sea) and the IMSBC Code (International Maritime Solid Bulk Cargoes Code) are regulations and rules to be followed for cargo transportation in general and coal transportation in particular via maritime transport.

1. Preparing necessary documents

According to SOLAS, coal is defined as a hazardous cargo in bulk with large quantities. In all documents related to the transportation of hazardous bulk cargo by sea, the correct term "bulk cargo shipping" must be used.

Each vessel carrying hazardous bulk cargo in large quantities must have a list/manifest of dangerous cargo on board, including their positions. Copies of these documents must be provided to the person or organization designated by the Port State Authority before departure.

2. Control cargo handling processes and compliance with requirements

Coal can self-heat or self-ignite, so appropriate preventive measures should be taken before transportation to minimize the fire risk.

Coal is a type of cargo regulated by the IMSBC Code. The Code requires shippers to provide cargo details, including moisture content, sulfur content, particle size, and information on whether the cargo emits methane gas. The Code also requires vessels to have:

• Oxygen, carbon monoxide, and methane measuring equipment
• Gas sampling tubes in all cargo holds
• A pH meter for water samples.

Additionally, the IMSBC Code recommends that vessels have equipment to measure cargo temperature, both during cargo handling and throughout the voyage, such as infrared thermometers.

In the event of a fire or progressing self-heating in the coal hold to a dangerous state, the vessel should:

• Close all ventilation to cargo holds
• Start cooling the affected cargo holds and consider heading to the nearest port for refuge
• Notify P&I immediately, as an emergency response from this organization may be necessary, including the presence of experts
• Ensure all spaces near the cargo holds are inspected before allowing personnel to enter and that no one enters confined spaces until it has been confirmed safe
• Provide the Shipowner and P&I with all temperature and gas monitoring records during the voyage

3. Equip gas detection and temperature measurement devices

The IMSBC Code requires vessels transporting coal to use gas detection equipment and train crew members. This equipment needs to be tested in gas-free spaces before entering enclosed spaces or cargo holds. Gas detection devices typically use electrochemical sensors to detect combustible gases and operate reliably in the atmosphere with over 15% oxygen. When oxygen is below 10%, measurements of combustibility using electrochemical sensors are unreliable. For vessels transporting coal, gas detectors with infrared sensors that do not require oxygen are a good choice to ensure accuracy.

The use of infrared thermometers can assist crew members in controlling the surface temperature of coal, ensuring that cargo is not loaded at temperatures above 55°C, which is considered unsafe according to the IMSBC Code recommendations.

III. Conclusion

Full implementation of safe coal transportation procedures is a mandatory requirement to prevent unfortunate incidents that could result in significant loss of life and property. As one of the largest coal importers in the Vietnamese market, Thuan Hai has established standardized infrastructure and facilities, along with an experienced operational team, to mitigate risks that may arise during the transportation, storage, and use of coal.