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Understanding Cargo Liquefaction: Risks and Prevention for Bulk Carriers

Can a solid cargo suddenly turn into a liquid, causing a ship to capsize? This phenomenon, known as cargo liquefaction, poses a hidden threat to bulk carriers.


As the maritime industry transports vast amounts of goods, understanding and preventing cargo liquefaction is crucial for maritime safety.


Liquefied cargo in a bulk carrier cargo hold

Cargo liquefaction happens when certain bulk cargoes, like iron ore fines and nickel ore, have too much moisture. When these cargoes are exposed to a ship's dynamic forces at sea, they can change from solid to liquid. This can compromise the ship's stability and lead to severe accidents. The sinking of the Bulk Jupiter in 2015, which killed 18 crew members, shows the devastating effects of cargo liquefaction.


To reduce the risks of cargo liquefaction, ship operators and marine surveyors need to understand its causes and prevention. Following international regulations, like the International Maritime Solid Bulk Cargoes (IMSBC) Code, is vital for bulk carrier safety. By using proper cargo testing, stowage, and monitoring, the industry can lower the risk of liquefaction-related accidents. This ensures the safe transport of goods globally.


Key Takeaways

  • Cargo liquefaction is a serious risk to bulk carriers, potentially leading to vessel instability and capsizing.

  • Bulk cargoes with high moisture content, such as iron ore fines and nickel ore, are most at risk of liquefaction.

  • The consequences of cargo liquefaction can be severe, as seen in the sinking of the Bulk Jupiter in 2015.

  • Following international regulations, like the IMSBC Code, is key to preventing liquefaction-related accidents.

  • Proper cargo testing, stowage, and monitoring are essential for maintaining bulk carrier safety and preventing cargo shift.


Introduction to Cargo Liquefaction

Cargo liquefaction is a critical risk for bulk carriers and their crews. It happens when solid cargo, like iron ore fines or nickel ore, turns liquid during transport. This is due to moisture and the ship's movement. The process, known as cargo liquefaction, can cause severe issues, including loss of stability, structural damage, and even sinking.





Grasping the cargo liquefaction definition and its dangers is vital for safe bulk carrier operations. When cargo liquefies, it can shift quickly, leading to sudden stability loss. This can result in capsizing or sinking, putting crew lives at risk and causing financial losses.


Definition of cargo liquefaction

Cargo liquefaction is when solid bulk cargo, like mineral ores, turns liquid due to moisture and external forces. This is mainly caused by moisture migration within the cargo. Water particles move from high to low concentration areas.


Cargo liquefaction occurs when the moisture content of a bulk cargo exceeds its Transportable Moisture Limit (TML). This is the maximum moisture level for safe transport without liquefaction risk.

Importance of understanding liquefaction risks in bulk carriers

Knowing about cargo liquefaction risks is crucial for maritime industry stakeholders. This includes ship owners, operators, crews, and port authorities. Understanding factors like moisture content, particle size, and cargo density helps prevent bulk carrier accidents.


Some key statistics show the gravity of cargo liquefaction incidents:


Statistic

Description

94 lives lost

M/V Mega Tars, M/V Sea Prospect, M/V Jian Fu Star, M/V Nasco Diamond, M/V Hong Wei, and M/V Vinalines Queen were totally lost ships with 94 lives lost during 1988-2005 due to cargo liquefaction.

44 seafarers lost

44 seafarers lost their lives in incidents involving M/V Jian Fu Star, M/V Nasco Diamond, and M/V Hong Wei, all carrying nickel ore from Indonesia to China.

100+ lives and 12 vessels lost

Cargo liquefaction has caused the loss of more than 100 seafarers' lives and twelve bulk carrier vessels in the last ten years, making it the most significant safety issue for bulk carriers.


To reduce liquefaction risks, following international regulations is key. The International Maritime Solid Bulk Cargoes (IMSBC) Code offers guidelines for safe cargo handling and transport. Proper cargo testing, monitoring, and stowage are also essential for vessel stability and safety during voyages.


The Risk of Cargo Liquefaction

Cargo liquefaction incidents are a major threat to the safety of bulk carriers and their crews. Certain bulk cargoes, like nickel ore and bauxite, can turn into liquids if they have too much moisture. This change, known as liquefaction, can cause the cargo to shift and destabilize the vessel. Such instability can lead to severe consequences.


Consequences of cargo liquefaction incidents

The effects of cargo liquefaction incidents are often severe. They can result in loss of life and property. When a bulk carrier experiences liquefaction, the cargo's sudden shift can cause the vessel to list heavily or even capsize. This puts the crew at risk of injury or death, and can lead to the total loss of the ship and its cargo. In addition to the human toll, cargo liquefaction incidents can have significant financial implications for shipping companies, insurers, and cargo owners.


Examples of bulk carrier accidents due to liquefaction

Several high-profile bulk carrier accidents have been attributed to cargo liquefaction in recent years. One such incident was the sinking of the Bulk Jupiter in January 2015, which resulted in the loss of 18 lives. The vessel, carrying 46,400 tonnes of bauxite, sank rapidly off the coast of Vietnam due to suspected liquefaction of the cargo. This tragedy highlights the need for increased awareness and stricter adherence to safety regulations when transporting potentially hazardous bulk cargoes.


Vessel Name

Year

Cargo

Fatalities

Bulk Jupiter

2015

Bauxite

18

Emerald Star

2017

Nickel ore

10

Nur Allya

2019

Nickel ore

25


Other notable incidents include the sinking of the Emerald Star in 2017 and the Nur Allya in 2019, both of which were carrying nickel ore and resulted in multiple fatalities. These accidents underscore the importance of proper cargo handling, accurate moisture content testing, and strict adherence to the International Maritime Solid Bulk Cargoes (IMSBC) Code to prevent future tragedies.


Importance of Marine Surveys in Preventing Liquefaction

Marine surveys are crucial in spotting and reducing the dangers of cargo liquefaction on bulk carriers. They offer a detailed look at the cargo's state, ensuring it meets safety standards and guidelines. Through careful cargo checks, marine surveyors are key in avoiding liquefaction incidents. This keeps the vessel and its crew safe.


Role of marine surveyors in assessing cargo conditions

Marine surveyors check the state of bulk cargoes before loading and during the journey. They perform detailed inspections to gauge the cargo's moisture level, a key factor in liquefaction risk. Using methods like the "Can Test," they evaluate liquefaction potential and advise the crew and operators.


A marine surveyor in protective gear, examining cargo using moisture content testing equipment

The International Maritime Solid Bulk Cargoes (IMSBC) Code mandates that liquefaction-prone cargoes have their Bulk Cargo Shipping Name (BCSN) and Transportable Moisture Limit (TML) determined. Marine surveyors ensure these criteria are met, keeping the cargo's moisture under the TML. This accurate assessment prevents liquefaction incidents, averting disasters like vessel loss and crew endangerment.


Compliance with safety regulations and industry guidelines

Marine surveyors are vital in upholding safety standards and guidelines for cargo liquefaction. They collaborate with ship operators, crew, and port authorities to ensure cargo loading and voyage procedures are correct. They also share knowledge on liquefaction prevention, like adjusting the vessel's balance and weather routing.


Following safety rules and guidelines is paramount, as shown by ongoing cargo liquefaction incidents. Marine surveyors enforce these regulations, making sure all involved in bulk cargo transport understand their duties and the risks of non-compliance.


Vessel Size

Accelerations during Liquefaction

Capesize (>125,000 DWT)

Considerably lower

Handymax (50 – 60,000 DWT)

Higher

Handysize (20 - 50,000 DWT)

Higher


In conclusion, marine surveys are essential in preventing cargo liquefaction on bulk carriers. Through thorough cargo inspections, moisture content assessment, and adherence to safety regulations, marine surveyors reduce liquefaction risks. This contributes significantly to maritime safety.


Safety Measures and Regulations for Cargo Liquefaction

The maritime industry has put in place various safety measures and regulations to tackle the risks of cargo liquefaction in bulk carriers. These steps aim to ensure the safe transport of solid bulk cargoes and prevent accidents at sea.


International Maritime Solid Bulk Cargoes (IMSBC) Code

The International Maritime Solid Bulk Cargoes (IMSBC) Code sets out detailed regulations for the safe handling and transport of solid bulk cargoes. The 2022 Edition of the IMSBC Code, with amendments 06-21 from IMO Res. MSC 500 (105), categorizes over 350 bulk cargoes by their shipping risk levels. It mandates compliance with SOLAS74 Reg VI/2-1, grouping solid bulk cargoes into three categories:

  • Group A: Cargoes with liquefaction risks

  • Group B: Cargoes with chemical hazards

  • Group C: Cargoes with other remaining hazards


The IMSBC Code details specific cargo handling  procedures. It requires shippers to provide accurate cargo information to the Master in advance, as stated in Section 4.3. The Master's role includes continuous moisture monitoring during loading. This ensures the cargo's moisture content stays within safe limits. It also involves preventing water ingress and ensuring proper cargo trimming.


Training and Awareness Programs for Crew Members

Regular crew training and awareness programs on cargo liquefaction risks are crucial for enhancing safety protocols on bulk carriers. These programs educate personnel on the dangers of transporting liquefiable cargoes and the preventive measures to be taken. Key aspects of these training programs include:

  1. Recognizing the characteristics of cargoes prone to liquefaction

  2. Understanding the importance of accurate cargo declarations and documentation

  3. Implementing proper cargo monitoring and sampling procedures

  4. Responding to emergency situations related to cargo liquefaction

By offering comprehensive training and awareness  programs, the maritime industry can ensure that crew members are well-prepared to handle the challenges of transporting solid bulk cargoes. This minimizes the risk of accidents at sea.


The ongoing emphasis on safety issues in the maritime industry highlights the importance of following regulations and guidelines, such as the IMSBC Code. It also underscores the shared responsibility between shippers, masters, and terminal representatives in ensuring the safe transport of solid bulk cargoes.

Safety Measure

Description

IMSBC Code

Comprehensive regulations governing the safe handling and transportation of solid bulk cargoes

Cargo Handling Procedures

Specific guidelines for cargo handling, including moisture monitoring and proper trimming

Crew Training

Regular training programs to educate crew members on cargo liquefaction risks and preventive measures

Safety Protocols

Implementation of safety protocols based on industry guidelines and best practices


Impact of Cargo Moisture Content on Liquefaction Risk

Moisture content is key in assessing the liquefaction risk of bulk cargoes during transport. Cargoes with fine particles and high moisture can liquefy if their moisture exceeds the transportable moisture limit (TML). This can cause stability problems and even lead to vessel capsize. The International Maritime Solid Bulk Cargoes (IMSBC) Code categorizes such cargoes as Group A. It requires that their moisture content not surpass the TML for safe loading.


Recent incidents of cargo liquefaction have been linked to high moisture levels in cargoes like iron ore fines, nickel ore, mineral concentrates, and bauxite fines. Poor testing methods, incorrect cargo descriptions, and pressure from shippers have contributed to these accidents. To mitigate moisture-related liquefaction, strict control measures are essential. This includes thorough testing and certification processes to ensure cargoes stay within safe moisture limits during transport.


A bulk carrier rocking dangerously in turbulent waters

The IMSBC Code emphasizes the shipper's responsibility to provide the master with accurate cargo information before loading. This includes a certificate of moisture content and TML for Group A cargoes. Masters must not load these cargoes without the required documentation. Terminal representatives also play a crucial role by ensuring ships receive cargo declarations as required by SOLAS Chapter VI. This facilitates safe loading and unloading operations.


"Wet nickel ore was involved in 4 out of the 5 fatal liquefaction events in the last decade, while bauxite accounted for the fifth incident."

Intercargo's long-term casualty report from 2013-22 reveals 26 seagoing bulker casualties. Five incidents and 70 fatalities were due to ships capsizing from cargo liquefaction. Wet nickel ore was responsible for 4 of these incidents, with bauxite being the fifth. These statistics underscore the need to keep cargo moisture content within the TML and implement effective moisture control measures to avoid such disasters.


Common Bulk Cargoes Prone to Liquefaction

Several bulk cargoes are at risk of liquefaction, threatening the safety of ships and their crews. Iron ore fines, nickel ore, bauxite, and mineral concentrates are among the most vulnerable. Classified as Group A under the International Maritime Solid Bulk Cargoes (IMSBC) Code, they demand special care and adherence to safety standards to avoid accidents.


Iron ore fines and nickel ore

Iron ore fines and nickel ore are frequently linked to liquefaction incidents. Originating from countries like Indonesia and the Philippines, they have caused several ship accidents. In 2010, the loss of three ships – Jian Fu Star, Nasco Diamond, and Hong Wei – all carrying nickel ore, resulted in 44 lives lost.


Bauxite and mineral concentrates

Bauxite, a key aluminum source, is also at risk of liquefaction. With about 100 million tons transported annually, certain types of bauxite are more prone due to their fine particle size. Mineral concentrates, produced from various ores, also fall into Group A and need careful handling to avoid liquefaction.


Cargo

Liquefaction Risk Factors

Key Statistics

Iron Ore Fines

High moisture content, fine particle size

Linked to several bulk carrier casualties

Nickel Ore

High moisture content, fine particle size

Loss of 3 bulk carriers in 2010, resulting in 44 deaths

Bauxite

High proportion of fine particles, dynamic separation

Annual transport volume of 100 million tons by sea

Mineral Concentrates

Varying particle sizes, moisture content

Classified as Group A cargoes under IMSBC Code


To reduce risks, strict adherence to safety rules, like the IMSBC Code, is crucial. This includes testing cargo moisture, ensuring it's below the Transportable Moisture Limit (TML), and following proper stowage and monitoring during transit. By addressing these challenges and taking precautions, the maritime sector can prevent liquefaction incidents and ensure crew safety.


Guidelines and Mitigation Strategies for Cargo Liquefaction

The maritime industry has developed guidelines and strategies to minimize cargo liquefaction risks. These measures focus on proper cargo stowage, continuous monitoring, and strict adherence to safety guidelines. By implementing these strategies, bulk carriers can significantly reduce the likelihood of liquefaction incidents. This ensures the safe transportation of potentially hazardous cargoes.


Proper stowage and cargo monitoring procedures

Effective liquefaction mitigation begins with proper cargo stowage. The International Maritime Solid Bulk Cargoes (IMSBC) Code provides specific guidelines for the safe stowage and transport of Group A cargoes, which are prone to liquefaction. These guidelines include:

  • Testing for moisture content (MC) and Transportable Moisture Limit (TML) within specific time frames and with proper documentation

  • Conducting the Can-test, a supplementary procedure to determine cargo safety by observing if the cargo starts to flow under agitation

  • Ensuring sampling and testing are conducted by accredited third-party laboratories within defined periods


In addition to proper stowage, cargo monitoring is crucial throughout the voyage. Regular cargo inspections and bilge well checks should be performed to detect any changes in cargo conditions that may indicate the onset of liquefaction. Weather logs and precautions during loading, including Can-testing, are essential for preventing liquefaction risks.


Adherence to industry guidelines and safety recommendations

To further mitigate the risks of cargo liquefaction, it is essential for ship operators and crew members to adhere to industry guidelines and safety recommendations. These include:

  • Following the IMSBC Code amendments, which have introduced changes to tackle issues related to sampling and testing of cargo to address potential hazards like liquefaction

  • Staying informed about the classification of various cargoes, such as nickel ore (Group A), bauxite (Group C with restrictions), and iron ore fines (Group A)

  • Taking immediate actions if liquefaction occurs during the voyage, such as contacting authorities, P&I Club, and considering a port of refuge


Updated guidelines by classification societies aim to raise awareness and suggest mitigating actions for liquefaction risks on ships carrying bulk cargoes. The American Club, for example, provides valuable information and guidance on the risks associated with liquefying bulk cargoes. It emphasizes the importance of awareness and compliance for safe transportation.


Cargo

Classification

Main Exporters

Nickel Ore

Group A (IMSBC Code Amendment 02-13)

Philippines

Bauxite

Group C (with restrictions)

Australia, Brazil, Guinea

Iron Ore Fines

Group A (IMSBC Code Amendment 03-15)

Philippines, Brazil, Australia, Ukraine, West Africa, India


By following these guidelines and mitigation strategies, the maritime industry can significantly reduce the risks of cargo liquefaction. Proper stowage, cargo monitoring, and adherence to safety recommendations are key to preventing the devastating consequences of liquefaction incidents.


Responsibilities of Shippers and Ship Operators

The safe transport of solid bulk cargoes, like those at risk of liquefaction, demands teamwork between shippers and ship operators. Shippers must provide precise and timely cargo documentation. This includes details on the cargo's moisture and Transportable Moisture Limit (TML). This data is critical for ship operators to perform detailed risk assessments and craft effective risk management strategies.


Ship operators, in turn, must ensure the vessel is fit for the cargo and that the crew is trained in handling it. They must also follow the guidelines of the International Maritime Solid Bulk Cargoes (IMSBC) Code. This Code, introduced by the International Maritime Organization (IMO) in January 2011, offers safety standards for solid bulk cargo transport.


Accurate cargo information and documentation

Shippers are crucial in preventing liquefaction incidents by offering detailed cargo information to ship operators. This information should cover:

  • Cargo type and characteristics

  • Moisture content and Transportable Moisture Limit (TML)

  • Stowage and handling requirements

  • Any special precautions or hazards associated with the cargo


Inaccurate or incomplete cargo documentation can lead to catastrophic outcomes. The sinking of vessels like Jian Fu Star, Nasco Diamond, Hong Wei, and Vinalines Queen in 2010, which resulted in 67 lives lost, is a stark reminder. Investigations showed that the cargo documentation provided was misleading, emphasizing the need for accurate data.

Iron ore liquefied

Implementing risk assessment and management plans

Ship operator duties include conducting comprehensive risk assessments based on the cargo documentation from shippers. These assessments must identify potential hazards, such as liquefaction, and outline suitable risk management strategies. Key components of a risk management plan include:

  1. Ensuring proper stowage and trimming of the cargo

  2. Monitoring cargo moisture content during loading and throughout the voyage

  3. Implementing cargo monitoring systems and alarms

  4. Training crew members in handling potentially liquefiable cargoes

  5. Establishing emergency response procedures in case of liquefaction incidents


ClassNK registered the world's first specialized vessel to carry solid bulk cargoes in compliance with the IMSBC Code's regulations. Retrofitting bulk carriers to confine liquefaction incidents within specific boundaries can cost shipowners around US$3 million.

Collaboration between shippers and ship operators is vital for the safe transport of solid bulk cargoes. By fulfilling their respective shipper responsibilities and ship operator duties, the industry can reduce the risks of cargo liquefaction. This effort aims to prevent loss of lives and assets at sea.


Conclusion

Cargo liquefaction poses a major threat to bulk carriers, their crews, and the maritime industry. Between 2008 and 2017, it led to the loss of 101 lives and 9 ships. This highlights the need for effective prevention measures and strict regulatory compliance. The devastating consequences of liquefaction incidents are evident in the losses of vessels like the Nur Allya, Emerald Star, and Harita Bauxite.


To combat these risks, the maritime industry must embrace best practices and follow international regulations. The International Maritime Solid Bulk Cargoes (IMSBC) and the Safety of Life at Sea (SOLAS) Convention are crucial. They offer guidelines for the safe handling, stowage, and transportation of high-risk bulk cargoes like iron ore fines, nickel ore, and bauxite.


Bulk carrier safety hinges on several factors. These include proper cargo inspection, accurate moisture content assessment, and strict loading limits. Implementing robust risk assessment and management plans is key. Promoting awareness and training among crew members and fostering a safety culture are also vital. This approach can help reduce liquefaction incidents and protect the well-being of those on bulk carriers.


In summary, preventing cargo liquefaction is essential for bulk carrier safety. It requires the collective effort of all maritime industry stakeholders. By adopting best practices, adhering to regulations, and prioritizing crew and vessel safety, we can ensure a safer, more sustainable maritime future.


FAQ

What is cargo liquefaction?

Cargo liquefaction occurs when a solid bulk cargo turns into a liquid due to moisture and ship movement. This can happen because of the ship's motion, vibration, and wave impact. It can significantly reduce the vessel's stability, potentially causing it to capsize.


Why is understanding cargo liquefaction risks crucial for bulk carriers?

Bulk carriers must understand liquefaction risks to safely transport goods across oceans. Knowing the factors that lead to liquefaction, like moisture content, helps implement preventive measures. This minimizes the chance of accidents at sea.


What are the consequences of cargo liquefaction incidents?

Cargo liquefaction incidents have caused many ship sinkings, leading to loss of life, vessels, and cargo. The sinking of the Bulk Jupiter in 2015 off Vietnam's coast is a prime example. It was due to high moisture content in bauxite, highlighting the severe consequences.


How do marine surveys help prevent cargo liquefaction?

Marine surveys are key in identifying liquefaction risks by assessing cargo conditions and safety compliance. Surveyors check the moisture content of bulk cargoes to gauge liquefaction likelihood. They also provide insights into cargo handling to reduce risks.


What safety measures and regulations are in place for cargo liquefaction?

The International Maritime Solid Bulk Cargoes (IMSBC) Code classifies cargoes to manage liquefaction risks. Safety measures include proper cargo handling, monitoring moisture levels, and following industry guidelines. Crew training is crucial to enhance safety protocols.


How does cargo moisture content impact liquefaction risk?

High moisture content in bulk cargoes can cause cargo shifting and potentially capsize the ship. Strict moisture control is necessary. This includes thorough testing and certification to ensure cargoes stay within safe moisture limits during the voyage.


What are some common bulk cargoes prone to liquefaction?

Iron ore fines, nickel ore, bauxite, and mineral concentrates are prone to liquefaction, posing risks to ship stability. These Group A materials are high-risk and require strict handling and monitoring to prevent accidents.


What guidelines and mitigation strategies exist for cargo liquefaction?

Classification societies have updated guidelines to raise awareness and suggest mitigating actions for liquefaction risks. Preventive measures include proper stowage, cargo monitoring, and following safety recommendations from industry guidelines, such as the American Club.


What are the responsibilities of shippers and ship operators in preventing cargo liquefaction?

Shippers must provide accurate and appropriate information about the cargo to the ship's master or representative in advance. Ship operators must ensure safe loading and carriage of cargo, adhering to the IMSBC Code and SOLAS regulations. They must also implement risk assessment and management plans.


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