Seaworthiness Management of Bulk Carriers during the Transportation Process from the Perspective of Bauxite Performance

Abstract

The seaworthiness of a ship plays a critical role in ensuring the safety of life and property and the prevention of marine pollution. One meaning of seaworthiness is the fundamental ability to sail safely to a destination, as well as being fit and ready for cargo. The parameters of seaworthiness have been expanded with the introduction of new maritime regulations. The entry of the 2019 amendments to the IMSBC Code into force has brought significant changes to bulk carriers with cargo that may liquefy at sea. Using examples from history, as well as an understanding of the environmental conditions of the oceans that ships are subject to, the seaworthiness of bauxite carriers was examined critically. First, the concept and doctrine of seaworthiness were clarified considering the existing transportation technology. Then, the spirit of the 2019 amendments to the IMSBC Code was applied to the seaworthiness of a bauxite carrier, showing that it demonstrated dynamic instability. Beyond that, from a transportability performance perspective, an extensive discussion was provided concerning the major correlation related to seaworthiness. Finally, practical recommendations were given on keeping a ship seaworthy before and during the process of bauxite transportation.

1. Introduction

The maritime industry continues to see a considerable increase in the number of maritime incidents involving the loss of cargo, ships, and human life. Today, merchant ships have become increasingly complex, with various systems being equipped to make them more efficient, safer, and easier to operate. However, this has also made the concept of seaworthiness more complex and confusing. The standards and requirements of seaworthiness have caused widespread debate and even disputes.

The narrow sense of seaworthiness is usually from the perspective of the ship structure and design, rarely considering other aspects. Based on the implementation of international conventions and other relevant regulations, the concept of seaworthiness has been extended. For example, Zhang [1] investigated the relationship between crew factors and ship seaworthiness under the Maritime Labour Convention, 2006 (MLC 2006). In a broad sense, the seaworthiness of a ship refers to its ability to carry cargo out of the wharf and transport cargo safely. As a result, crew factors, environmental factors, management factors, ship factors, and cargo factors should be considered component factors of ship seaworthiness. However, until now, there has not been any research on the seaworthiness of ships specifically focusing on the characteristics of the cargo.

Solid bulk cargoes have special physical and chemical properties. They are easy to couple with carriers during the shipping process. For example, some cargoes may liquefy and undermine the stability and safety of the ship. The disaster of the M.V. Bulk Jupiter had a profound impact on the industry. It was a Handymax carrier with 46,400 Tons of bauxite that capsized and sank with 18 crew members on 2 January 2015 [2]. A series of efforts were undertaken by the industry to improve the safety of bauxite transportation in the following years. The 2019 amendments of the International Maritime Solid Bulk Cargoes Code (IMSBC Code), entering into force on 1 January 2021, represent a significant outcome of the industry collaboration. However, it remains to be seen if the 2019 amendments deliver their intended objectives.

This paper aims to critically examine the seaworthiness of bauxite carriers related to the 2019 amendments. For this purpose, the following objectives are achieved:

• Reviewing the development of the doctrine of seaworthiness in maritime law, in particular the important role of cargo property in ensuring the seaworthiness of ships;
• Examining the implications of implementing the 2019 amendments of the IMSBC Code, particularly its role in improving the safety of bulk bauxite carriers;
• Analysing the extension of the meaning of seaworthiness under the impact of the IMSBC Code, in particular the changes to standards under the new requirements of the 2019 amendments;
• Assessing the criticisms of this extension and the major obstacles existing in law and practice.

2. Literature Review

Between 1988 and 2019, a total of 25 accidents were recorded in bulk carriers due to the liquefaction of the cargo, and 19 of the recorded accidents resulted in capsizing as the ships lost their stability [3,4]. Considering that these accidents were caused by cargoes that may liquefy, many researchers have explored the transportation safety of bulk carriers in relation to the interaction between mineral ore and its carriers.

Related to the loading conditions and behaviour during transportation, the performance of mineral cargoes is an important factor in the seaworthiness of bulk carriers, as shown by previous accidents caused by the liquefaction of the cargo in bulk carriers [5]. Cargo liquefaction is a direct result of the correlation between the parameters of the moisture content (MC) inside the cargo and the movement of the ship, manoeuvring to respond to weather conditions at sea. The only available parameter used to prevent liquefaction from occurring is the transportable moisture limit (TML). At present, simulation experiments of cargo characteristics are usually carried out to reveal the disaster mechanism of cargo characteristics from the perspective of engineering safety. Munro M.C. [6] examined the collective causes of the liquefaction of solid bulk cargoes to prevent the ingress of water into the cargo during transportation, loading, and storage. Through a review of the three test methods stated in the 2013 IMSBC Code, Munro M.C. [7] found that none of them were suitable for evaluating iron fines. To further refine the modified Proctor/Fagerberg test (MPFT) to determine the TML of iron ore fines, Munro M.C. [8] investigated 23 incidents originating from bulk cargoes that liquefied during transportation and caused the loss of human life and industry assets, and they proposed improving the modified Proctor/Fagerberg test (MPFT) to determine the TML of iron ore fines. Ju L. [9] developed a liquefaction model to predict the ship’s stability and evaluate potential hazards during the marine transport of solid bulk cargo. Sakar C. [10] analysed the liquefaction risk and the other fundamental causes resulting from the capsizing of bulk carriers using an integrated risk assessment method with the integration of interpretive structural modelling and fuzzy Bayesian networks. Improper loading, a lack of cargo care, and insufficient knowledge arising from human error play a critical role in cargo liquefaction. For the preparation before the cargo loading stage, Zhang D.H. [11] proposed a revised evidential reasoning approach to cope with the complex decision making in cargo stowage plans. In order to reduce the risk of capsizing and reclaim the stability of a Handymax bulk carrier with nickel ore, Lee H.L. [12] developed a response plan for a liquefaction incident that would redistribute homogeneous stowage. Based on an overview of the behaviour of iron ore cargoes during marine transportation, Mohajerani [13] explored the reasons behind some listing and capsizing incidents and implemented some possible solutions and recommendations to reduce cargo shift. Based on a 3D simulation, Wu W. quantified the risk of cargo liquefaction roughly, quickly, and dynamically [14]. Airey D.W [15] used a fully coupled dynamic finite element analysis, simulated cyclic loading, and simultaneous consolidation and drainage, and then obtained the destructive factors of the stability of the ship and cargo.

Shipping practice shows that liquefaction is a phenomenon triggered by ship movements, where solid bulk cargo produces high-density, viscous liquid in the hold. Liquefaction can occur in iron ore or nickel ore due to excessive dynamic loading, vessel vibration, and rough seas. However, the Global Bauxite Working Group found that bauxite does not simply liquefy, even under worst-case shipping conditions [16]. The instability of bauxite is referred to as dynamic separation, and its influence is fundamentally different from that of liquefaction [17]. Both liquefaction and dynamic separation are caused by excessive moisture in the bauxite cargo, particularly the presence of highly fine particles that tend to absorb more water than granular particles, which may cause liquefaction [18]. The performance of liquefaction and dynamic separation, called dynamic instability, destroys the stability of a ship and can even cause it to capsize [19]. Bauxite properties are similar to those of traditional liquid cargo. If the moisture content is not properly controlled, it can release moisture to form a free surface, such as that in group A, which can reduce the stability of the ship and even cause it to capsize. Although bauxite was recorded as group C within the 2019 amendments to the IMSBC (yet the bauxite powder is classified as group A in the IMSBC Code due to the moisture content of which is generally approximately 15%) [20], it has garnered attention since the M.V. Jupiter accident at the beginning of 2015. Before that, none of the incidents onboard bauxite bulk carriers resulted in losses to vessels or crew members since 2 July 2013, according to information from the North P&I Club. Hence, as a key factor in the accident, the relationship between the transportability of bauxite and the seaworthiness of ships ought to be a serious area of consideration.

According to research in the literature, the earliest research paper on bauxite transportation safety was in 1978. Anon [21] discussed the development of and changes in efficient bauxite-handling equipment and transport ship types. Miyazawa and Masaru [22] developed a special bauxite transport vessel based on the hydrodynamic effect of shallow water along the northeast coast of Australia through model tests of resistance, self-propulsion, wake measurement, and a cavitation test. Portella et al. [23] applied the innovative concept of “single pour, single pass” drainage and loading synchronization to a bauxite carrier with 80,000 DWT to reduce the unacceptable stress superposition on the hull structure during single-hold loading and to ensure structural safety in the ship’s operation. Research on bauxite liquefaction has also been published in recent years. From the perspective of maritime management practice of bauxite shipping safety, Wu J. [24] proposed a high-density slurry effect to evaluate the stability risk of bauxite carriers. Chen Z. [25] gave several suggestions to ensure the strengthening of bauxite shipping safety management. As a sample, Gebeng bauxite was further researched under the IMSBC Code by Hasan M. [18], and an understanding of several properties, including particle size distribution, moisture content, and specific gravity, was gained. Wu J. [26] examined the transportation process of a bauxite carrier using the Markov chain method at different stages of loading, unberthing, departure, and sea navigation, and then revealed the risk evolution of the solid bulk cargoes with potential liquefaction during the bauxite shipping process. Wu J. [27] developed an approach to reasoning about risk performance with a hidden Markov model and a prewarning system for the improvement of bauxite shipping process safety.

In general, although there have been studies on the subject of the dynamic instability of bauxite at sea, there are few systematic investigations into the management of seaworthiness in the study of the ocean transportation of bauxite. This paper mainly focuses on improving the understanding of the risk of the liquefaction of bauxite that may occur during shipment by interpreting the 2019 amendments of the IMSBC Code. A method of securing the seaworthiness of ship operation is proposed to comply with the standards under the IMSBC Code. The research defines several parts to clarify the definition of seaworthiness and describes seaworthiness in terms of shipbuilding, related equipment, cargo loading, maritime problems, customs and procedures, cargo management, and external inspection. In the following sections, a discussion and some recommendations concerning seaworthiness are provided from the preshipment stage and the shipping stage to the operation stage during the process of transportation.

3. Interpretation

3.1. Definition of Seaworthiness

The concept of seaworthiness derives from the ancient concept of a maritime contract, which refers to the obligation of ship owners to provide seaworthy ships to fulfil the maritime mission of carrying cargo. It can be traced back to Act X of the Oleron of 1176, Article 1 of the law of Hanse Towns of 1197, and item 12 of Part 3 of the Marine Ordinances of Louis XIV of France 1681 [28]. In marine insurance, seaworthiness had its origins in common law at least at the beginning of the 19th century.

Despite its important role in maritime law, there is a lack of a unified definition of seaworthiness [1]. The most in-depth definition of ships’ seaworthiness is found in the final report of 1873 from the Royal Commission on Unseaworthy Ships. Thus far, there is no precautionary approach to completely achieve ship safety at sea, as this requires the application of advanced technology in the construction, equipping, and stowage of ships, and uninterrupted attention and vigilance during the voyage; otherwise, the ship is unseaworthy. Although this consensus was based on the level of technology at that time, its implications are still of great significance today. Subsequently, in Lyon v. Mells, a British jurisprudence, Lord Ellenborough, further defined seaworthiness as follows: for each contract of carriage of cargoes, the law implied that the contract contained a clause that the carrying vessel would be (sufficiently) strong and fit for maritime transport provided to the public by the shipowner. According to Section 39(4) of the Marine Insurance Act of 1906, “A ship is deemed to be seaworthy when she is reasonably fit in all respects to encounter the ordinary perils of the seas of the adventure insured”.

However, no specific statutory definition has received universal recognition in the maritime industry. Meanwhile, in the judicial field, maritime courts have to define seaworthiness on a case-by-case basis [29]. For instance, seaworthiness in some US and English cases was defined as the “condition in which a ship should be enabled to encounter whatever perils of the sea a ship of her kind, and laden as she is, may fairly be expected to encounter in performing the voyage concerned”. Additionally, for Australian courts, the seaworthiness of a vessel is that it must be “fit to encounter the ordinary perils of the voyage” or “in a fit state … to encounter the ordinary perils of the voyage insured”, where the state of fitness must depend on the whole nature of the adventure.

Seaworthiness may be defined as the state of a vessel in such a condition, with such equipment, and manned by such a master and crew, that normally, the cargo can be loaded, carried, cared for, and discharged properly and safely on the contemplated voyage [30].

3.2. Description of Seaworthiness

Seaworthiness firstly refers to the seaworthiness of the ship itself, followed by the seaworthiness of the crew and cargo. The seaworthiness of the ship itself is known as technical seaworthiness. Technical seaworthiness refers to the navigation capability of the ship. In a narrow sense, seaworthiness requires that the ship be designed and constructed to resist the usual dangers in the sea for the contracted voyage. In a broad sense, seaworthiness relates not only to the physical properties of the ship, but also to other areas, such as manning and cargo worthiness. The following three requirements must be met: Firstly, the design, construction, and equipment of the ship shall fulfil the requirements of shipbuilding and specifications of the ship survey and obtain the corresponding qualification certificate. Second, it must be equipped with indispensable crews, ship equipment, and supplies. Third, cargo stowage shall satisfy the requirements of relevant conventions, codes, and regulations. The following is a detailed analysis of ship construction, equipment, and cargo stowage.

3.2.1. Design, Construction, and Equipment

The ship must have the hull, equipment, and machinery necessary to complete the scheduled voyage, which are the main aspects of the ship’s navigation capacity. The physical properties and structural conditions of ships are valued by ship surveyors. With the increase in a ship’s age, the properties of the hull and machinery are relatively worsened, and its unseaworthy factors increase gradually.

The ship shall carry the corresponding certificates of the ship and crew. The qualified technical certificates of the ship are the formal standard and legal basis for maritime adjudicators to judge its seaworthiness. Generally, if the certificates are valid, the ship is seaworthy. If the actual situation of the ship does not conform with the certificates, that is, the ship fails to comply with the requirements of various certificates and relevant laws and regulations, then the ship becomes unseaworthy. Generally, there is a positive correlation between the degree of severity of the incidents and the level of compliance of the cargo-carrying vessels with international standards [31]. Therefore, maritime judges must examine the essential requirements of seaworthiness.

A ship’s certificate of cargo worthiness for solid bulk cargo is such a certificate of seaworthiness, which schedules the bulk cargo shipping names, including the names listed in group A. This certificate can be issued by the classification society, following the amendment of chapters VI and VII of the International Convention for the Safety of Life at Sea, 1974 (SOLAS Convention), and the notice of enforcement of the IMSBC Code, upon the ship owner’s application for approval of the ship’s structure and equipment to meet the relevant requirements. International bulk carriers generally hold certificates of fitness for solid bulk cargo, including bulk carriers and ore carriers. For sea-going ships engaged in domestic voyages carrying bulk cargo without a certificate of fitness, the maritime authorities examine whether the bulk carrier is marked in the certificate of seaworthiness, safety certificate of construction, or safety certificate (international vessel), and non-bulk carriers shall not be approved.

In the shipping practice of nickel ore, fine iron ore, bauxite, and other cargoes that may liquefy, Handysize bulk carriers are mostly used. Due to this type of ship not having the structure design of an ore carrier for heavy cargo, the cargoes that may liquefy create a great risk during shipping. In terms of general cargo, ships and dry bulkers have the highest level of recurrent accidents [32]. For bulk carriers that do not meet the requirements of fitness, it is necessary to modify or optimize the ship structure to reduce the shipping risk.

In terms of stability, according to the Rules for Construction of Sea-Going Ships Engaged on Domestic Voyages, 2006, and Rules for the Classification of Sea-Going Steel Ships, 2012, bulk carriers, ore carriers, and combined vessels with a length of 150 m or above should be equipped with approved loading manuals and loading instruments as required. According to the Rules for the Classification of Sea-Going Steel Ships [33], all bulk carriers with a length of less than 150 m should be equipped with a stowage instrument that provides the ship’s stability data to meet the corresponding requirements. If a nonbulk carrier has a typical load condition of a solid bulk cargo and its stability calculation results conform to the loading manual, the ship can be considered to be fit for specific cargoes [34].

In 1978, scholars discussed high-efficiency loading and unloading equipment and applicable ship types based on the characteristics of bulk bauxite [21]. In 1986, Miyazawa Masaru et al. from Japan designed a specific bauxite carrier based on the characteristics of the shallow waters off the northeast coast of Australia [22]. In May 2019, the world’s first 300,000 DWT bauxite carrier MV Orion finished its first voyage to Yantai, China [35]. In December 2019, the Shanghai Merchant Ship Design and Research Institute and China Ship Design & Research Center Co., Ltd. developed a 330,000 DWT bauxite carrier considering the impact of bauxite on the structural arrangement and capacity of the cargo hold [36].

3.2.2. Cargo Stowage

Seaworthiness not only means that the ship itself is seaworthy, but also includes the safe shipping and discharge of all cargo to the port of destination. Therefore, the carrier must guarantee the cargo worthiness of the ship and ensure the reception, carriage, and preservation of cargoes. It is stipulated in the Hague Rules that if the ships’ reception, carriage, and preservation of cargoes do not meet the requirements of relevant conventions, codes, and regulations, they shall be deemed unseaworthy. The carrier shall do a good job ensuring the cargo worthiness of the hold, the reasonable stowage of cargo during loading and unloading, and the proper preservation of cargo during the voyage.

The seaworthiness of the cargo hold means that the equipment of the loading is well equipped to meet the requirements of the cargo shipped. The carrier shall treat the cargo hold according to the characteristics of the different cargo and its requirements for transportation and preservation to ensure that it is fit for receiving, storing, and transporting the cargo, including checking that the cargo hold is clean, dry, and odourless; that the sewage and ventilation lines are unimpeded; and that the hatch cover is watertight. According to the provisions of Hague Rules, Visby Rules, and Maritime Law of China, cargo holds, refrigerating and cool chambers, and other places carrying parts shall be fit and safe for the reception, carriage, and preservation of cargo.

Reasonable stowage has a great influence on the seaworthiness of the ship and the safety of the cargo. Stowage operation includes making full use of the ship’s capacity for loading, ensuring the safety of the ship’s strength and stability, and ensuring an appropriate draught difference. For example, an overload can endanger the ship’s stability and decrease the reserve buoyancy and antisinking ability, and in cases of bad weather and seas or improper operation, it is easy for the ship to capsize, run ground, or cause other accidents. Therefore, overloading also makes the ship unseaworthy.

3.2.3. The Extension of the Concept

In a narrow sense, seaworthiness is a fundamental ability of the ship to navigate safely to its destination, including fitness and readiness. It is regulated in a wide range of areas in the maritime business, such as the carriage of goods by sea, marine insurance, ship charters, shipbuilding businesses, etc. Seaworthiness is an implied warranty of the shipowner, the breach of which results in the loss of insurance coverage under marine insurance law [37]. A ship might be considered seaworthy between the insurer and the shipowner but unseaworthy between the shipowner and the shipper of a particular cargo [38].

Seaworthiness is not an absolute concept but a relative one that is dependent on the particular context and facts. Seaworthiness is relative to the nature of the ship, to the particular voyage, and even to the particular stage of the voyage the ship is on [1]. According to the requirements related to the carriage of goods by sea in the Hague/Hague–Visby Rules, the carrier should exercise due diligence to make the ship seaworthy both before and at the beginning of the voyage. In the law relating to seafarers’ employment contracts, such as the Insurance Act of 2015, it is defined as follows: “the policyholder promises to perform or prohibit certain acts, to meet certain conditions, or to affirm or deny the existence of certain facts”. This is because the relevant court rules are hardly strict in relation to existing collateral, and they do not take into account the significance or severity of violations. According to the Maritime Labour Convention, 2006, the ship on which seafarers are employed to work onboard shall be seaworthy. Additionally, this right was legally recognized in Section 458 of the UK Merchant Shipping Act (MSA) of 1894, which proposed the terms of seaworthiness in law and fact. Protection and indemnity (P&I) clubs, such as the London P&I Club and the UK P&I Club, have released various bulletins and cautions to their members in relation to past incidents and recent events, including those that could potentially have caused dangerous loading conditions of the mineral cargoes.

3.3. Application of Seaworthiness

3.3.1. Seaworthiness before and at the Beginning of the Voyage

Seaworthiness is the general rule governing a ship’s departure. Maritime transport has a higher danger than other forms of transport, and damage to the ship and its cargo can occur when the carrier does not respond quickly to the dangers at sea. Due to the ship’s isolation, if it has any defects and cannot be repaired quickly, it can endanger the safety of the cargo. Therefore, the ship must be able to identify the usual hazards foreseen during the voyage, deal with the inherent risks to cargo, and deliver it to the destination safely and on time.

Paragraph 1 in Article 3 of the Hague rules specifies that the carrier is required to determine the following with the necessary care: whether the ship is seaworthy before or at the time of departure; the availability of adequate and competent seafarers, equipment, and supplies; the suitability of the cargo holds, refrigerated and cooled chambers, and other parts for safe reception, carriage or preservation with the necessary care or disposal. Paragraph 1 in Article 47 of the Maritime Law of China 1992 states that the carrier shall, before and at the beginning of the voyage, exercise due diligence to make the ship seaworthy, properly manned, equipped, and supplied, and to make the holds refrigerated and cooled and other parts fit and capable for the safe reception, carriage, and preservation of cargo.

A ship’s seaworthiness in the narrow sense highlights three aspects of the ship’s performance: floatation ability, navigation ability, and carriage ability. First of all, the ship body must be seaworthy; that is, the hull must be strong and watertight, all equipment must be in good condition, and the ship type and ship size must be appropriate to resist the usual weather and seas. Furthermore, the requirements for seaworthiness vary with seasons, route risks, and cargo types. To complete a specific voyage, the carrier needs to provide different types of ships, the strength and structure of which should respond to the general risks, which refers to weather, seas, and other common conditions in the contract voyage and the particular season.

3.3.2. Seaworthiness during a Voyage

With the progress of navigation technology, the carrier undertakes the obligation of continuous care for ship seaworthiness after departure. Article 14 of the United Nations Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea (hereinafter referred to as the “Rotterdam Rules”), adopted on 12 December 2008, extends the period of care taken to seaworthiness from “before and at the beginning of the voyage” to the whole voyage. The Rotterdam Rules are not in force internationally; however, they can be used for reference. According to Article 10 of the International Management Code for the Safe Operation of Ships and Pollution Prevention (ISM Code), the shipping company shall establish relevant procedures to ensure that the ships are seaworthy at all times. That is to say, regardless of whether the ship is sailing or not, the company has a continuous obligation to ensure proper maintenance of the ship and equipment, crew manning, and other aspects. This requirement breaks through the period of seaworthiness in the Hague–Visby Rules; however, it keeps up with that of the Hamburg Rules. Therefore, the seaworthiness during a voyage covers both the objective contents (hull seaworthiness, crew seaworthiness, and cargo space seaworthiness) and the subjective contents (whether the carrier exercises due diligence to make the ship seaworthy).

4. Discussion

4.1. New Requirement of the IMSBC Code

4.1.1. Evolution of the IMSBC Code

With the prosperity of maritime trade in the early days, bulk carriers carrying minerals, coal, and grain became the mainstream of maritime trade. Due to bad weather, such as strong winds and waves at sea, it is easy to form a free surface level and capsize the ship. Therefore, the International Maritime Organization (IMO) formulated these rules to ensure the safe maritime transportation of solid bulk cargo. As per Chapter VI in the SOLAS Convention, as amended, the mandatory provisions were set to govern the carriage of solid bulk cargo. These provisions were extended in the IMSBC Code, which was adopted on 4 December 2008, and entered into force on 1 January 2011. Figure 1 shows the evolution of the IMSBC Code.

4.1.2. The 2019 Amendments of the IMSBC Code

According to the current version of the IMSBC Code, as bauxite is not listed in group A, it cannot be supervised strictly as cargo that may liquefy. However, after the disaster of the M.V. Bulk Jupiter at the beginning of 2015, some proposals to revise the relevant provision of bauxite in the IMSBC Code were put on the agenda. The IMO recommends that the captain, based on experience and relevant certificate documents, may refuse to carry the cargo if the carrying of such cargo may fail to ensure the absolute safety of the voyage; if the captain has decided to carry it, necessary measures must be taken to ensure the safety of the vessel. In the 2019 amendments of the IMSBC Code, a new individual schedule for BAUXITE FINES as a group A cargo was adopted at the 101st session of the Maritime Safety Committee of the IMO.

With the new amendment of the IMSBC Code coming into force on 1 January 2021, the ship had to perform the proper and prudent operation and management of the bauxite. The IMSBC Code modified the above two rules, directly clarifying the shipper’s responsibility in determining the acceptable moisture limit and the time interval of the moisture content sampling test, and extending the period of the checking test to the end of loading, effectively preventing the shirking of responsibility before the shipowner, shipper, and carrier, and controlling the cargo risk at the source. The IMSBC Code sets out requirements for the carrier of cargoes that may liquefy and the cargo ship with a gross tonnage of fewer than 500 tons. In addition to the general requirements for the technical condition of the ship, special equipment for trimming, certification, and documents from the ship survey agency shall be required for ships carrying cargo whose moisture content exceeds its TML. Furthermore, the operational ability of crews is clearly defined: for crews working on ships carrying solid bulk cargo, the maritime authority shall take the necessary measures to ensure that they meet the requirements of the IMSBC Code. For example, adequate measures shall be taken to prevent liquids from entering the cargo space in which these solid bulk cargoes are stowed during the voyage. Masters shall be cautioned about the possible danger of using water to cool these cargoes while the ship is at sea. Operational inspections from the port state control (PSC) may examine whether crews are aware of the safety requirements of the IMSBC Code.

4.2. Cargo Transportation in the IMSBC Code

4.2.1. Cargo Transportability

The primary aim of the IMSBC Code is to facilitate the safe stowage and shipment of solid bulk cargo by providing information on the dangers and instructions on the procedures associated with the shipment of certain types of solid bulk cargo. The IMSBC Code categorizes solid bulk cargo into three groups. Group A consists of cargo that may liquefy if shipped with moisture content (MC) over the transportable moisture limit (TML). Natural and transportation characteristics of group A cargo include a certain proportion of fine particles and a certain amount of moisture. The TML stipulates that the applicable moisture of the cargo must be measured within 6 months before loading. However, in the case of any change in the composition and nature of the cargo for any reason, the sampling and test time for retesting and requiring the determination of the moisture content shall be close to the time of loading and shall not exceed 7 days. In the case of rain or snow, tests should be carried out to ensure that the moisture content of the cargo is below the TML.

Some requirements of concentrates or other cargoes which may liquefy are listed in the IMSBC Code. These cargoes shall only be accepted for loading when the actual moisture content of the cargo is less than the TML. However, such cargo may be accepted for loading on specially constructed or fitted cargo ships, even when their moisture content exceeds the TML. When a concentrate or other cargoes that may liquefy are carried, the shipper shall provide the ship’s master or their representative with a signed certificate of the TML and a signed certificate or declaration of the moisture content. Therefore, having an MC below the TML before loading is the mandatory standard of the IMSBC Code for the transport of solid bulk cargoes that may liquefy.

In the case of cargo that may liquefy, transportability must be considered for the ships that are legally permitted to carry such cargo. In shipping practice, the information and certificate provided by the shipper often differ from the reality of the cargo to be loaded. The inspector commissioned by the master or the shipowner should refuse to sign any document that requires them to confirm that the cargo is safe and transportable. The IMSBC Code provides that the shipper should confirm the safety or the transportability of cargoes and that the signature of such documents would prejudice the carrier’s right to claim against the shipper in subsequent accidents. Nevertheless, the carrier needs to take further measures to verify the actual transportability of the cargo.

4.2.2. Bauxite Transportability

The 2019 amendments of the IMSBC Code require the shipowners to maintain the proper documentation of bauxite submitted by the shipper, such as the TML certificate and the moisture content certificate. Nevertheless, it is still necessary to further verify the actual moisture content of the goods on-site. The current check test for approximately determining the possibility of cargo flows onboard a ship or at the dockside is the Can test, which was designed to examine the surface for free moisture or fluid conditions. If free moisture or a fluid condition appears, it generally means that the shipment is not safe. However, the Can test is just an auxiliary method other than a laboratory test. Therefore, it is rather rash to accept the shipment of cargo based on its Can test results when the cargo has arrived. Arrangements should be determined to have additional laboratory tests conducted on the material before it is accepted for loading [39].

The suggestion to the captain of the bauxite carrier from the IMO is essentially to enforce the right to refuse transportation, the fundamental foundations of which are from the contract or law. The Hague–Visby Rules give the carrier the right to refuse dangerous goods or to dispose of them if they become dangerous (liquefy). The right to refuse transportation can be a contractual right, provided that the content of the contract has an agreement on it. The principle of freedom of the contract allows both parties to agree on the cargo that can be transported. For instance, the carrier may refuse to transport the cargo provided by the shipper if the cargo does not conform to the contract. In the meantime, the right to refuse transportation is a legal right under a specific legal basis that can be found in the contract law, maritime law, and relevant regulations on transportation management. The carrier should take all measures to meet the requirements of relevant rules before exercising the right of the refusal of carriage. According to the provisions of sections four and eight of the IMSBC Code, the carrier should first determine a reasonable judgment on the actual moisture content of the bauxite. If the carrier fails to determine a judgment and the inspection of the cargo’s adaptability but conducts a sampling inspection on the shipped cargo, then judges it to be harmful to the seaworthiness of the ship according to the inspection results, and then decides to refuse transportation, it is not justified that they exercise the right to refuse transportation.

The next part discusses the seaworthiness of ships from the perspective of bauxite shipping characteristics. The main related factors include relevant international rules, technical and management measures related to cargo, and relevant external supervision activities, as shown in Figure 2.

4.3. Ship Seaworthiness Considering Cargo Management

4.3.1. Ship Seaworthiness

In the maritime charter contract, the shipowner must ensure a ship’s seaworthiness unless explicitly stipulated. The carrier’s duty to pay attention to the ship’s seaworthiness is essential in terms of public interest, such as the protection of sailors and passengers and the security of ships and cargo, which can be stated to be valuable national assets.

First, the structure of the hull should be sufficiently watertight, robust, reliable, and safe to overcome the risks that may be encountered in navigation, and a fire suppression system should be equipped. Second, the carrier must conduct necessary inspections and repairs by experts before leaving the port to ensure the ship’s safe voyage of mechanical devices, lighting, generators, and other auxiliary equipment necessary for freezing. Third, the proper nature of the shipment generally requires that the shipment is maintained in good condition considering the convenience of unloading, the need or convenience for storage and handling, and the safety of the ship at each port of call. Fourth, the ship must be cleaned so that the carrier is suitable for receiving, transporting, and storing the shipment to prevent contamination of other shipments from odours, dirt, rust, insects, and seawater, and to prevent rot or infectious diseases caused by bacteria through thorough disinfection. Fifth, in order to safely carry out the voyage, the carrier must board an appropriate number of crew members, and the crew members must possess a marine license, have sufficient experience and ability in sailing work, and be mentally and physically healthy. Sixth, the necessary supplies, such as sufficient and reasonable excess adequate fuel, food, drinking water, and medicine, shall be loaded at the port of departure to complete the voyage. Finally, the documents to be kept on the ship must include a list of fast ports, a charter contract, a bill of lading, a ship nationality certificate, a ship inspection certificate, a marine list, a sailing log, a safety facility certificate, and a disinfection certificate.

4.3.2. Seaworthiness and Cargo Worthiness

The judge in the case of Silvia [40] stated that “conformation of seaworthiness depends on whether the ship is reasonably fit for transporting the cargoes promised to transport”. This view was accepted by later generations; it emphasizes that a ship’s seaworthiness should take into account its ability to adapt to the carriage of the cargo. Thereafter, for the first time, the case of Ciampa and Others v British India Steam Navigation Co., Ltd. [41] formally proposed that cargo worthiness should be one of the requirements of ship seaworthiness. Cargo worthiness specifies that the cargo’s location shall be always fit for safe carriage and that the carrier shall exercise care to ensure the seaworthiness of the ship with a genuine, appropriate, and qualified effort to fulfil the obligations set out in Paragraphs 1 (1), (2), and (3) of Article 3 of the Hague Rules. This means that the carrier, as a possessor of the ship with the usual skills and with due diligence, takes reasonable measures required in the particular circumstances of each voyage. Exercising due diligence is manifested as regular inspection and maintenance. It should be emphasized that the obligation of seaworthiness is a unilateral obligation of the carrier, which shall not ask the shipper to confirm the seaworthiness of the ship, thereby attempting to circumvent the liability if the shipper knows that the ship is unseaworthy.

4.3.3. Seaworthiness and Preservation of Cargo

As for the uniform provisions in international maritime law, the insurer shall not be liable for compensation for the loss of the ship, goods, freight, or other costs due to the unseaworthiness of the insured ship, and it does not apply the exemption clause or enjoy the limitation of liability. Therefore, the premise for the maritime court to judge the liability of the ship in the maritime case is to first confirm the acts and omissions of the ship during the period from the time of loading to the completion of unloading, to determine whether the carrier has exercised due diligence to make the ship seaworthy, including the preservation of cargo.

Article 48 of the Maritime law of China and paragraph 2 in Article 3 of the Hague Rules provide that the carrier shall properly and carefully load, carry, stow, transport, preserve, and discharge cargo. Therefore, the key to the carrier’s obligation to manage cargo is “proper” and “prudent”. “Proper” usually refers to technical requirements and the operation of equipment and procedures. It requires the carrier to adopt a reasonable and safe working procedure fit for the carriage, depending on the particular circumstances of the shipment and the transport practice. It means that the carrier, crew, and other employees shall apply the knowledge and skills normally required or specifically required for the carriage of cargoes during the process of cargo management, such as guidelines for cargo working developed by the shipping company [42]. “Prudent” is usually a requirement for attitude and responsibility. It requires the carrier, crew, or other employees to pay the necessary attention to the obligation of management during the process of shipping and to find and reasonably solve the problems in all aspects of the transportation of a specific voyage or specific cargo type in time. For example, Portella Ricardo b. et al., from Brazil, proposed a loading strategy named “single-pour, single-pass” in 2011 to reduce the unacceptable stress superposition of the hull structure during the single-hold loading of an 80,000 DWT bauxite carrier to ensure the structural safety of the ship during operation [23].

4.4. Ship Seaworthiness under External Supervision

Since the mandatory implementation of the ISM Code in 2002, it has had a great impact on ship seaworthiness and the carrier’s obligation to make the ship seaworthy. Additionally, after the 2019 Amendments of the IMSBC Code, it directly clarified that the shipper should take more responsibility for the cargo before loading and to control the risk of the cargo from the source. In terms of the crew’s competency in making the ship seaworthy, the maritime safety authorities would inspect the operation ability and emergency ability of the PSC’s inspection activity, especially carrying cargo properly and responding to liquefaction with prudence.

4.4.1. Ship Survey

A ship survey is a technical survey conducted to prove that the technical status of the ship meets the requirements of relevant laws, codes, and regulations to ensure safe ship operation and to avoid damaging the marine environment. The purpose of the operational survey is to ensure that the ship remains seaworthy by performing various professional surveys on the operational ship, including an initial survey, a periodic survey, an annual survey, and a dock survey. The operational ship always needs to complete a closed-loop process of “seaworthiness-unseaworthiness or problem found-repair or correction survey or audit seaworthiness”. Although the operational survey is also a periodical activity, it ensures the ship’s technical and managerial seaworthiness in different periods and ranges. The administrative seaworthiness survey provides a good supplement to and strengthens the technical seaworthiness survey, which focuses on the safety to life and pollution prevention. The statutory survey combined with the technical and administrative surveys plays a key role in the maritime safety governance of ship seaworthiness.

4.4.2. Ship Endorsement

No matter the PSC inspection, flag state safety inspection, or ship survey within a certain window of time, the ship does not have to be inspected or surveyed every time it is in a port. The endorsement of the visa of ships entering or leaving a port is an administrative measure to approve the current or recent actual seaworthiness of the ship before a new voyage. Ship endorsement can be considered one of the activities of ship safety inspection in the broad sense. Without endorsement, the ship has not obtained the legal qualification for navigation. The ship would be unseaworthy without the certification of the form and substance of seaworthiness. To put it formally, the endorsement ensures the safety of the port, ship, cargo, human life, and property. Meanwhile, in essence, the ship’s visa refers to the maritime authority’s inspection and approval of the ship’s technical safety condition before departure, the requirements of which are consistent with the seaworthiness conditions of the ship. Figure 2 shows the relationship between the two factors for seaworthiness.

4.4.3. Ship Safety Inspection

Although a ship safety inspection involves many aspects of a ship’s seaworthiness, its meaning is slightly different from “ship seaworthiness” in maritime law. According to the Hague Rules and Maritime Law of China, the judgment of a ship’s seaworthiness is based on whether the ship can resist the expected risks encountered during the voyage. This requirement was proposed to protect the reasonable interests of the shipowner or the insurer in the maritime transportation and does not involve the contents of ensuring the safety of human life and preventing pollution from the ship.

While the seaworthiness required in a ship’s safety inspection also concerns meeting the intended purpose of the ship, it is more concerned with ship safety and pollution prevention, including ship structure, equipment, and crew quality. The PSC inspection, together with the flag state inspection, plays an important role in ensuring ship safety and seaworthiness.

One of the most severe actions in response to deficiencies found in PSC inspection is the detention of ships, which is a measure imposed on ships with serious deficiencies that prohibit them from leaving port, enforcing repairs, and meeting the requirements of seaworthiness. The maritime authorities of maritime countries are paying more and more attention to the transportation safety of the solid bulk cargo that may liquefy. In recent years, 457 of the 21,100 defects found in ship safety inspections conducted by the Ningbo Maritime Administration of China were related to the transportation of cargo that could liquefy, accounting for 2.16%. For instance, many defects in the probe failure of the water ingress alarm system were found in many bulk carriers of international navigation with more than a 10,000 gross tonnage and a ship age of 15 years and above, according to the special inspection report carried out by the China maritime safety authorities from 15 June 2017 to 31 December 2017 [43].

5. Recommendations

5.1. Seaworthiness Management Framework for Logistics Chain of Bauxite

Considering the 2019 amendment of the IMSBC Code, the seaworthiness management of bauxite ocean transportation ships is a systematic project that requires the safety and quality management of the whole chain and the whole process. In addition to the transportability management of bauxite and the cargo worthiness management of ships, the following items should be involved in the whole logistics chain: bauxite production enterprises, shippers, carriers, terminal handling enterprises, transportation administrative authorities, and third-party organizations. Figure 3 shows the framework of sea worthiness management for bauxite carriers.

In the whole logistics chain management, different bodies undertake corresponding responsibilities at each link. For shippers, sufficient, objective, and scientific cargo information and certificates must be provided for group A cargo with an IMSBC code, a qualification can be determined with instructions from the P&I Club, or through the selection of a surveyor; in particular, for barge cargo in Malaysia and Indonesia, the qualification must be determined through the selection of a crew with strict compliance with certification and laboratory cargo sample testing. For the carrier, before transportation, these responsibilities refer the duties and responsibilities of supercargo or the superintendent for matching or reconfirming the name of the charterer and the actual name of the IMSBC Code, as well as confirming the receipt of a third-party certificate of conformity rather than checking the appearance of the moisture content in the cargo. During the loading and transportation, if there were problems on the cargo, the captain at this time would be responsible for the supervision of the condition of the cargo.

For the transportation administrative authority, both the port administrative authority and the maritime administration play an important role in safety supervision. Taking China as an example, the regulations on the safety management of waterborne solid bulk cargo stipulate that the maritime administration is responsible for the safety supervision and management of the ship’s transportation of solid bulk cargo that may liquefy within its jurisdiction. However, the port administrative authority is responsible for the safety supervision and management of the loading, unloading, and storage of solid bulk cargo that may liquefy in the port under its jurisdiction. To ensure the safety of the carriers, the maritime administration has to extend the safety management requirements that the port, shipping agency, inspection agency, and other institutions must implement, resulting in the absence of the port administration and the overstepping of the maritime administration. Therefore, it is necessary to pay special attention to the coordination and management between the industry and government agencies and to clarify their logic and responsibilities. In particular, maritime administrations shall fulfil their responsibilities for maritime safety supervision and strictly control the navigation, ship management, crew management, risk prevention, and ship inspection management. They shall also define the duties of the captain and the crew to achieve the purpose of clarifying the division of responsibilities between them and the maritime administrative agency. Therefore, the division of responsibility should be clearer.

5.2. Due Diligence Operation of Seaworthiness in the Loading Process

To prevent ship sway and the endangerment of the safety of the hull structure, the cargo hold stowage plan should be properly developed following the specifications of the carrier. Both of the on-site verification of loading and the constant monitoring aim to keep the bulk carriers seaworthy for the bauxite shipping. In addition to carrying out corresponding self-inspections on general ship safety inspection items and bulk-carrier-exclusive safety inspection items, the following items should be listed in the self-inspection list according to the characteristics of solid bulk cargoes that may liquefy, including, but not limited to, bauxite:

• The moisture content is kept below the transportable moisture limit.
• The cargo working plan is effectively implemented.
• Loading shall not be carried out during a period of precipitation unless otherwise specified.
• The loading schedule and distribution of cargo is mastered to avoid excessive trim, roll, and overload.
• During the loading, all hatches not in use are closed. After loading, the hatch is closed and covered and kept weather-tight.
• Even loading must be kept to ensure the stability and seaworthiness of the carrier before sailing.

5.3. Properly Management of Cargo during the Shipping Process

5.3.1. Intelligent Monitoring of Cargo Liquefaction

Bulk carriers must install a water ingress alarm system in the cargo hold according to SOLAS 74-2002 Amended/CXII/R12. In addition to monitoring the water tightness of ballast tanks, the system also monitors the moisture released from the cargo to the bilge during navigation and starts the sewage well’s drainage device in time.

The alarm system can only detect the water level below 2 m and provide an early water level alarm. If the drainage is effective, the water level falls below the warning level, the risk of liquefaction is still under control for ship safety, and the alarm disappears within a short time. However, if the drainage is ineffective, the crew is unaware of the alarm or hears the alarm but did not respond, or the alarm system failed, the water level would rise over 2 m in more serious cases, and, at this time, the alarm system would be unable to provide further warning of liquefaction. After the liquefaction of bauxite or other cargo that may liquefy, moisture would shift from the bottom of the cargo hold to the upper space, and the low-height ingress alarm system would not be able to play an effective role. Additionally, it should be noted that the loading and unloading operations have a major risk of damaging the detection device, which could cause alarm failure or falsification.

The low reliability of the alarm system is detrimental to the seaworthiness of ships during the bauxite shipping process. Therefore, bauxite shall be under proper and prudent preservation, including the use of supplementary means to monitor the liquefaction state. The cargo hold’s liquid level detector is an effective means of supplementary monitoring. The detector is also known as a liquid level radar, and it can monitor the clearance height of the liquid level until the hatch cover in real time and then judge the water level height and measure the degree of cargo liquefaction. Another supplementary monitoring technology is laser scanning [16] or image recognition, which can be used to regularly observe the surface morphology of the cargo before sailing and the cargo stack during the shipping process, thus, estimating the degree of liquefaction. This kind of liquefaction monitoring system was applied in a very large ore carrier (VLOC) to improve the safety of navigation. By monitoring the height of mineral precipitation in the cargo hold and the change in cargo heap form [44], the liquefaction degree provides timely feedback to the crew to preprocess the problems of liquefaction, affecting the ship’s stability.

5.3.2. Prevention and Mitigation of Cargo Liquefaction

Intelligent monitoring may be inaccurate in a few cases. At such a time, the crew on duty should be sent to determine a judgment by observing the cargo based on their experience. At this time, the inspection crew must be required to have a certain level of ability. However, in special circumstances, in order to protect the safety of the life of the crew, the cargo cannot be manually checked. In addition, if the monitoring device detects any danger, an alarm sounds. However, once the officer on duty is unaware of the danger, the accident may still occur if the correct measures are not taken in time due to stress, assumptions, or a lack of knowledge, perhaps because of the influence of the surrounding environment or personal reasons, or even if the danger is perceived. Therefore, not only should an intelligent monitoring system of liquefaction be implemented, but also the subsequent intervention of cargo liquefaction. It is generally considered that the period within 10 h after departure is a dangerous period for the cargo stack. The master can use reliable measures to delay and prevent the liquefaction of the cargo. If a lower moisture content than the TML, the opening of the hatch cover, ventilation and airing, sampling, and inspection should be performed in the anchorage to avoid the dangerous situation of cargo liquefaction in the early days of the sailing process [45].

5.3.3. Emergency Drill for Cargo Liquefaction

The use of extreme caution to mitigate these risks should be further supplemented with improvement measures and a full awareness of the hazards to the seafarer and ship caused by transporting liquefied solid cargo in bulk carriers. These steps must be taken to establish an emergency response plan for cargo liquefaction and to carry out regular emergency drills for the maritime transportation of cargoes that may liquefy, including systematic response measures for moisture shifting, particle movement, cargo heap deformation, and the degree of liquefaction. In particular, crews should become familiar with the regularity of variations in the ship’s attitude motion from large-angle rolling to capsizing and sinking due to the serious liquefaction of cargo. A scientific and accurate judgment should be determined on the dangerous situation and the abandonment of the ship would need to be announced at the right moment. Based on the angles of the heel and the angle of the trim owing to cargo liquefaction before the declaration of the abandonment order, it is beneficial to learn from the method of determination of the stability parameters and the position of the ship during the flooding of the cargo hold [46].

If there is a short time from the awareness of the great danger to the sudden capsizing of the ship, the crew cannot take any measures to save the ship and cannot even abandon the ship effectively, resulting in a major loss of the ship and crew. To avoid the danger caused by the immediate capsizing of the ship, or the sudden large-angle heeling from one side to the other without immediate capsizing, the ship should be abandoned decisively when the loss of the ship is inevitable, to ensure a rapid, safe, and orderly evacuation and reduce casualties. The effectiveness of the abandonment depends on the continuous monitoring of liquefaction, the ability to detect early danger and sounding the alarm, the ability to judge the residual stability of the ship, and the decision making to abandon ship.

6. Conclusions

The paper critically examined the seaworthiness of bauxite bulk carriers under the 2019 amendments of the IMSBC Code, which had a significant commercial effect of improving productivity and efficiency. This was accomplished by increasing and giving a legal backbone to the standards of due diligence and eventually decreasing the chances of unseaworthy Handy carriers with liquefaction being sent to the sea, as well as reducing the risk of maritime incidents on ships and cargo, and, most importantly, preventing the loss of seafarers on board. Through the discussion of the concept of seaworthiness in maritime technology in terms of the different aspects of ship construction, equipment, and cargo stowage, as well as an analysis of the development of the doctrine of seaworthiness in maritime law, especially the relationship between seaworthiness and cargo worthiness, cargo transportability, the preservation of cargo, and external supervision based on the scope of application of seaworthiness, it was found that PSC inspections, ship surveying, and ship endorsement are the keys to the external guarantee of ship seaworthiness. Additionally, the paper then explored the implications of introducing the doctrine of seaworthiness in the 2019 amendments of the IMSBC Code based on a correlation analysis between the ship operation and ship seaworthiness based on bauxite liquefaction characteristics.

The paper found that it is crucial for the ship to remain seaworthy throughout the whole logistics chain of bauxite for the safety of life, the ship, and the marine environment. The due diligence operation of seaworthiness in the loading process and the proper management of cargo during the shipping process can keep the ship seaworthy. This paper provided some suggestions to ensure the seaworthiness of bauxite carriers, which involves ensuring cargo worthiness, cargo transportability, and competency for the seafarer. The intelligent monitoring of cargo liquefaction, the prevention and mitigation of cargo liquefaction, and emergency drills for cargo liquefaction are recommended measures to keep seaworthiness during the shipping process. These prudent practices are of great significance for preventing accidents and clarifying legal liability once there is a civil dispute related to the contract and the careful placement of cargoes to ensure the safety of the ship.

It should be noted that some regrets appeared in the interpretation of seaworthiness. The IMO, the IMSBC, Charter Party, and Marine Insurance legal terms vary in meaning or expression depending on the context, so when applying related laws and regulations to specific cases, the law should be interpreted correctly. Even if the terms and phrases used in the two related laws were the same, the meaning may be different, or the same meaning may be used with different terms, so if the law is not properly interpreted in its application to specific issues, which may cause errors. Interpreting the law is based on and begins with literary interpretation. Literary interpretation is “an interpretation that focuses on the text and terms of the law and has a general meaning of the article”. “Interpretation of the law” is a theoretical and technical action that clarifies the concept of norms. It is necessary to adopt appropriate theories and methods to clarify the connotations and differences in the application of different terms.

The authors tried to interpret the definition of seaworthiness in detail, but were limited by the applicable legal environment and the ship operation scene. This paper focused on discussing the technical connotation of seaworthiness under the framework of the IMSBC, so it did not carry out an excessively detailed identification in judicial aspects. A comparative study should be conducted on this insurance issue raised by the reviewers in another paper. In this regard, this paper still needed further theoretical and applied research combined with legal practice. Beyond that, it examined the relationship between ship seaworthiness and cargo custody in the ore port yard, to further widen and deepen the basic idea of seaworthiness in terms of the orientation of the value of safety.