The international convention for the safety of life at sea: highlighting interrelations of measures towards effective risk mitigation

Safety is often described as freedom from unacceptable risk. The International Maritime Organization (IMO) since its establishment has consistently been working towards mitigation of risks at sea by implementing measures through specific legal Instruments. The IMO’s principle Instrument with this focus is the International Convention for the Safety of Life at Sea, 1974, as amended (SOLAS). By identifying and examining a wide range of risks that must be addressed in order to ensure the safe operations of ships at sea, the chapters of SOLAS provide the necessary mitigation measures. This paper goes on to discusses three specific risks among those being mitigated by SOLAS, which are a) structural integrity and stability related risks; b) fire risk and c) navigational risk. The reason for this choice is quite simple: analysis of past statistics from shipping incidents databases clearly indicates that these risks are recorded with the highest numbers; with statistics testifying that navigational risk is linked to the greatest number of accidents. A conclusion clearly standing out is that the various measures being put forward by SOLAS and the associated supporting Codes work in a complementary manner and together have provided a positive contribution towards the safety of personnel, environment and property. ARTICLE HISTORY Received 17 December 2020 Accepted 18 January 2021


Background
In the course of human history, shipping activities have always been vital for supporting trade. It is also a rather self-explanatory fact that at any point of time the building characteristics and equipment of ships are heavily reliant on the vessels' "intended" mission, and most importantly, upon the technology applications available to support these quite complex activities. It is not a coincidence that during the so-called industrial revolution, dependency on shipping increased because of the ships ability to transport high volumes of goods and in a very cost-effective manner, especially when considering the benefit of "economics of scale" (Heaver 2002). However, as sea-going vessels were increasing in size and complexity, it also become obvious that coordinated effort to endure the safety at sea were needed. It is indicative that the absence of an effective Convention to regulate the safety of shipping in this period 1 was probably one of the factors which resulted in the death of more than 1500 out of 2224 passengers and crew on-board the passenger liner RMS Titanic, when it collided with an iceberg on 15 April 1912. No matter the grief for the numerous lives lost at sea, that maritime disaster had a positive impact: it opened the way for the adoption of International Convention for the Safety of Life at Sea (SOLAS) (Dalaklis 2017). Following a path of continuous improvement since that point in time, the wider regulatory framework under the auspices of the International Maritime Organisation (IMO) has resulted in a safer, cleaner and more sustainable shipping industry that is capable to effectively deal with the global economy needs. The main purpose of this paper is to discuss the aforesaid evolution in IMO's framework to enhance safety at sea, facilitate its better understanding and especially highlight the interrelating approach deployed for the various Conventions and Codes supporting this. Following this brief introductory section, the berth/evolution of IMO is discussed next. Then, the focus is shifted towards the main Convention dealing with safety at sea, SOLAS. The methodology deployed to serve risk mitigation by SOLAS is presented in section 4. An analysis of measures used to deal with the most "threatening" types of risk is conducted in sections 5-6, along with identification of their interrelations. Finally, conclusions are provided.

Evolution of the IMO
In 1948, an international conference in Geneva adopted a Convention formally establishing IMO (the original name was the Inter-Governmental Maritime Consultative Organization or IMCO, but the name was changed in 1982 to IMO). The IMO Convention entered into force in 1958, and the new Organisation met for the first time the following year. Since its inception, in 1959, the Organization (ΙΜΟ) has exerted every effort to protect human life at sea. The purposes of the IMO, as summarised by Article 1(a) of its Convention, are: ". . . to provide machinery for cooperation among Governments in the field of governmental regulation and practices relating to technical matters of all kinds affecting shipping engaged in international trade; to encourage and facilitate the general adoption of the highest practicable standards in matters concerning maritime safety, the efficiency of navigation and prevention and control of marine pollution from ships". The Organization is also empowered to deal with administrative and legal matters related to these purposes. IMO's first task was to adopt a new/updated version of the International Convention for the Safety of Life at Sea, the most important of all treaties dealing with maritime safety; this was achieved in 1960 (IMO 2020b). IMO has used the concept of continuous development, keeping abreast to the advancement in technologies to ensure that relevant measures have been incorporated in this Convention to mitigate existing or newly identified risks. Accordingly, significant amendments in 1929, 1948, 1960 and 1974 have developed the Convention into the current International Convention for the Safety of Life at Sea, 1974, as amended (SOLAS 1974. SOLAS 1974 was adopted on 1 November 1974 2 (IMO 2020b).

SOLAS 1974: Amendments' procedure
Article VIII of the SOLAS 1974 Convention states that amendments in the Convention can be made via two different avenues (IMO, 2014a). The first one is after (formal) consideration within IMO. Amendments proposed by a Contracting Government must be circulated at least six months before their consideration by the Maritime Safety Committee (MSC), which may refer discussions to one or more IMO Sub-Committees. Amendments are adopted by a two-thirds majority of Contracting Governments present and voting in the MSC. It is also interesting to note that Contracting Governments of SOLAS 1974, whether or not Members of IMO are entitled to participate in the consideration of amendments in the so-called "expanded MSC". The second way is via a dedicated Conference. This Conference (of Contracting Governments) is called when a Contracting Government requests the holding of a Conference and at least one-third of Contracting Governments agree to hold the Conference. Amendments are adopted by a twothirds majority of Contracting Governments present and voting.
In the second method of updating/changing SOLAS 1974 (Conference), as well as in the case of the expanded MSC, amendments (other than those to Chapter I) are deemed to have been accepted at the end of a set period of time following communication of the adopted amendments to Contracting Governments, unless a specified number of Contracting Governments object. The length of time from communication of amendments to "deemed acceptance" is set at two years unless another period of time (which must not be less than one year) is determined by the two-thirds of Contracting Governments at the time of adoption. Amendments to Chapter I are considered as accepted after positive acceptance by two-thirds of Contracting Governments; amendments enter into force six months after their "deemed acceptance". The minimum length of time from circulation of proposed amendments through entry into force is therefore 24 months (circulation: six months, adoption to deemed acceptance date: 12 months minimum; deemed acceptance to entry into force: six months).
However, a resolution adopted in 1994 ensures that an accelerated amendment procedure can be used in exceptional circumstances, allowing for the length of time from communication of amendments to "deemed acceptance" to be shortened to just six months in exceptional circumstances and when this is so decided by a Conference. In practice to date, the expanded MSC has adopted most amendments to SOLAS 1974, while Conferences have also been held on several occasions (notably to adopt whole new Chapters to SOLAS 1974, or to adopt amendments proposed in response to a specific incident). Instead of requiring that an amendment shall enter into force after being accepted by, for example, two-thirds of the Parties, the tacit acceptance procedure provides that an amendment shall enter into force on a specified date unless, before that date, objections to the amendment are received from an agreed number of Parties.

Focus of SOLAS 1974
SOLAS 1974 is the principle Instrument by the IMO, which focusses on human life protection during shipping activities (Vassalos et al. 2010). SOLAS 1974 applies to all passenger ships and cargo ships over 500 GT engaged on international voyages (unless provided otherwise in the Convention). The MSC (and its six sub-committees 3 ) of IMO deal with matters on maritime safety and the amendments to SOLAS 1974 (Beckman and Sun 2017). The structure of the SOLAS 1974 leads from Chapter one, which includes the specifications of types of vessels on which the Convention applies and follows by providing necessary definitions used with the Instrument. Chapter 1 also contains the details on the requisite inspection and survey regime towards maintenance of statutory certificates on-board vessels. These elements are followed by the chapters elaborating on various risks addressed by SOLAS 1974. The structure and a brief overview of salient features of SOLAS 1974 are summarized in Figure 1.
It may be observed from Figure 1 that SOLAS 1974 does not work in isolation, but it utilises Codes empowered by the Convention. These Codes serve to effectively mitigate specific risks identified in the Convention, while keeping the Convention generic and at the same time more compact.

Risk mitigation in SOLAS 1974
Arnaud, as cited in Ale, Burnap, and Slater (2015), has defined risk as a set of two parameters, namely, the potential of an occurrence in tandem with the outcome of an incident. Furthermore, safety is often described as freedom from unacceptable risk (Hollnagel 2016). Management of risks associated with shipping operations is a very effective way to ensure safety of life at sea; this is the main objective of SOLAS 1974 and very evident in the introduction to its Articles. 4 Even though many of the amendments to SOLAS 1974 are "additional" measures towards risk mitigation, these amendments have on occasions been a responsive measure, i.e., legislation by disaster due to accidents/incidents (Dalaklis 2020). As per O'Neil (1991) as cited in Mitrouss (2004), IMO started transitioning from being reactive to marine disasters and becoming proactive in the 1990s by starting to utilise methodologies to anticipate and prevent accidents. Accordingly, the adoption of Guidelines for Formal Safety Assessment (FSA), was such a proactive move by IMO 5 ensuring that an analytical and methodical technique in risk management was incorporated into their rule-making process ( Figure 2) (IMO 2002). Risks cannot be wholly mitigated but are managed using FSA methodology by IMO to ensure that the risks are kept to 'As Low As Reasonably Practicable (ALARP) (Figure 3) (Pedersen 2010).

Types of Risks
The risks being managed in SOLAS 1974 may be categorised into the following (non-exhaustive) list of eleven (11) different (but, interrelated) types (Figure 4).
A certain number of these risks are also addressed in other IMO Instruments such as MARPOL 6 and STCW, 7 with the issue of shipboard operations standing out, but with different objectives when compared to SOLAS 1974. Additionally, some of these risks and their management are interlinked within different SOLAS 1974 chapters under the specific provisions. 8 Furthermore, the risks being managed in SOLAS 1974 can be also be categorised into two stages based on its handling stage, as described in Table 1. SOLAS 1974, through its legislation, has ensured that risks are managed by "properly sharing" between the four main stakeholders: Ship-owner, Flag State, Classification Society (Class) and Port State. This sharing ensures that a safety net is created through Survey, Audit, Inspection and Examination to verify that the provisions of SOLAS 1974 are being complied with and therefore ensure that risks are sufficiently and efficiently managed. Further, certificates specified in MSC.1/Circ.1586 are issued by a competent authority after the Survey/Audit/Inspection/Examination to a vessel to formally testify "compliance" with the requirements of the Convention (Dalaklis 2020).

Three very influential risks addressed in SOLAS 1974
Risks do not exist in isolation but are, at times, interlinked. When an incident occurs due to a particular primary risk acting out, the following sequence of events may result in a secondary risk manifesting itself. For example, a navigational risk which is manifested due to a collision incident may also result in a structural damage. The most influential (three) risks addressed in SOLAS 1974 is best possible to be identified by analysing past statistics of accidents.
As per a relevant report by EMSA (2019), out of 23,073 incidents/casualties which occurred between 2011 and 2018 ( Figure 5), the navigational incidents represented 54.4% of the total, consisting of collisions (26.2%), contact (15.3%) and grounding/stranding (12.9%), followed by incidents/casualties due to fire & stability/structural integrity. This exactly same trend is also observed in other databases with a similar purpose (Kristiansen 2013). Due to particular emphasis placed by IMO (and SOLAS 1974) on Roll-on/roll-off Passenger (ROPAX) and passenger 9 vessels, statistics indicate that passenger vessel losses constitute a minute fraction in comparison of losses of cargo vessels which is at 40% for the period 2009 to 2018 ( Figure 6) (AGCS 2019). This paper is, therefore, focussing on common risks addressed in SOLAS 1974 for all types of vessel irrespective of its mission in the following sub-sections, by providing an overview of structural integrity and stability, as well as fire risk. A detailed analysis of navigational risk is provided in section 6, considering that this is the risk associated with the largest number of accidents.   Figure 7 presents the chapters in SOLAS 1974 addressing "Structural Integrity & Stability" as Primary & Secondary Risk. The importance of this risk is evident from the fact the sea is indeed a very dangerous place and the common saying that a ship itself is the best available "lifeboat" for the crew while conducting the voyage. Ensuring safety at sea is made possible via the mitigation of all "primary and secondary" risks by SOLAS 1974; this holistic approach is based on identifying all risks interrelations and then ensuring that vessels are being designed with resiliency to encounter the perils of the seas (Barker and Campbell 2000). For example, a fire incident can compromise the vessel's structural integrity, and SOLAS 1974 Chapter II-2, which deals with fire risk, also has risk management Table 1. Categorisation of risk mitigated in SOLAS 1974 based on its handling stage (created by the authors).

Structural integrity and stability related risk
Categorisation of risk mitigated in SOLAS based on its handling stage

Construction stage
Operation Stage The construction stage is when risks are managed during shipbuilding in the ship design, construction and/or equipment fitment stage by complying with the requirements of SOLAS provisions.
Operation stage is when risks are dealt during the routine operations by the ship crew and/or by necessary shore support by complying with the requirements of SOLAS provisions. The risks dealing with structural stability and integrity, fire, navigational risks, lifesaving appliances, High speed craft, Nuclear Ships, etc. are generally mainly dealt in the construction stage.
The risks dealing with cargo (grain code, etc), Shipboard operations (ISM Code), maritime security (ISPS Code), cybersecurity (ISM Code) are being dealt mainly in the operational stage.
Note: Many of the risks have elements which need to be addressed in both the construction and operation stage. To cite an example, SOLAS under chapter II-2 Part E "Operational Requirements" deals with the method of mitigating and managing the risks of fire for example by conducting training and drills using the operational method whereas most of the other Parts in chapter II-2 are addressed when ships are in the construction stage. provisions of the secondary risk of structural elements due to fire. 10 SOLAS 1974 Chapter II-1 11 Regulation 3-1 requires ships to be designed, built and maintained in compliance with a classification society's 12 structural, mechanical and electrical specifications. This results in effective micro risk management as the classification society is involved from the stage of ship design up to the end of the ships life when recycled.
Furthermore, under Chapter II-1 Regulation 3-10, the introduction of Goal-based ship construction standards (GBS) for bulk carriers and oil tankers, as incorporated under Res. MSC.290(87) in 2003, was a positive move by IMO. GBS allowed ship designers to overcome the disadvantages of prescriptive regulations which were on bases of past experiences and therefore redundant in some instances due to its failure to take into consideration future design challenges (IMO 2020a). Chapter II-1 which in coordination Chapter XII (bulk Carriers) and codes such as SPS, MODU, INF, IGF, IBC, Polar & Grain contain further measures such as provisions for subdivision, intact stability including special requirements for ships, double bottom requirements and structural requirements, etc., which are applicable for cargo ships and passenger ships (unless specified otherwise). Further, the subdivision and damage stability provisions of SOLAS 1974 under Chapter II-1part B regulations 4-7 and IMO Resolution A.265 (VIII), as an equivalent to Chapter II-1 part B regulation 7, allow for evaluating the stability of ships in case of damage. These regulations impose requirements on subdivision arrangements and also compartmentalise the vessel by providing for the allowable length of the compartments 13 to ensure that the ship is safe without submerging the margin line when two consecutive compartments are flooded (Puisa et al. 2013).

Fire risk
The reason why fire risk incidents numbers are high is that ships most commonly operated within an environment where the three elements constituting a fire triangle 14 are present, increasing such exposure to this risk. Casualties from fire incidents are low even though the numbers of incidents are high, and the main reason for this is the rigorous way the SOLAS Convention manages the risk of Fire. For example, the Ch. II-2 15 of SOLAS 1974 (Figure 8) deals with mitigating fire risk by focusing on the location where the fire originates and thereafter containing, controlling and extinguishing it in case of an outbreak (Vassalos et al. 2010).
Regulation 2 of Chapter II-2 specifies five safety objectives with regards to a fire which is prevention, reduction to risk to life, reduction to the risk of damage, contain, control and suppress the fire and provide easy means of escape from spaces on fire.
The various codes, as listed in Figure 10, also address fire risks for the specific type of ship, especially at the construction stage. This risk mitigation is achieved by constructional requirements, detection and alerting requirements, fitment of equipment for extinguishment, specifying materials which are fire protective/ retardant for ships construction, etc.
Safely Return to Port (SRtP) is a very crucial concept introduced by amendments to SOLAS 1974 via MSC Resolution 216(82), aimed at increasing passenger ship safety by making it compulsory for new passenger ships over 120 m in length or with three or more Main Vertical Zones. This amendment provides "safe areas" for passengers and "essential services" to allow it to safely return to port after a fire or flooding incident, provided that the casualty threshold is not reached. The Goal-based standards 16 (GBS) methodology to serve the identification of SRtP according to the provisions of SOLAS 1974 has incorporated innovative methods by bringing in cost-effective designs at the same time optimising passenger ship operations by bringing in more safety standards (Cangelosi et al. 2018).

Navigational risk
As evident from statistics of past marine incident databases, the navigational risk is at the forefront of attention, especially when considering that a very extended number of incidents is linked to this specific risk. This risk is most often associated with consequences such as collision, grounding or contact damage. Incidentally, the collision of RMS Titanic with an iceberg on the ill-fated night was also linked to a navigational risk. Figure 9 presents the chapters in SOLAS 1974 addressing "Navigation" as Primary & Secondary Risk.
Further aspects dealing with navigational risk being addressed by IMO is discussed next. 13 Termed floodable length. 14 The Fire triangle three sides represent heat, fuel, and an oxidizing agent (usually oxygen) required to sustain a fire. 15 Chapter II-2 -Fire protection, fire detection and fire extinction 16 According to IMO's official website: "Goal-based standards (GBS) are high-level standards and procedures that are to be met through regulations, rules and standards for ships. GBS are comprised of at least one goal, functional requirement(s) associated with that goal, and verification of conformity that rules/ regulations meet the functional requirements including goals. In order to meet the goals and functional requirements, classification societies acting as recognized organizations (ROs) and/or national Administrations will develop rules and regulations accordingly. These detailed requirements become a part of a GBS framework when they have been verified, by independent auditors and/or appropriate IMO organs, as conforming to the GBS" . . .

Holistic approach to safety of navigation by IMO
The non-exhaustive measures in regulations of SOLAS 1974 that serve the purpose of mitigating navigational risk through its various Chapters are summarised in Table 2. These measures clearly indicate that the SOLAS 1974 Convention is a quite forward-thinking legislation in terms of incorporating technological advances as it is evident from its various amendments in the course of time. Effectively adapting to technological changes and new innovations is especially true in terms of SOLAS 1974 Chapter V, as various provisions in the Convention ensure that the navigational bridge of ships (irrespective of type or size) is fitted with a series of devices and systems that improve the quality of navigation and therefore contribute into the mitigation of risks such as collision, grounding or contact damage.
Furthermore, the 81st session of the MSC agreed on the process of developing a regulatory framework for e-navigation, 17 taking well into account the expected in the future technological advances in shipping. The Correspondence Group on e-navigation of the NCSR subcommittee produced a roadmap called the e-navigation strategy implementation plan (SIP) in 2014. The FSAderived SIP aims at reaching five specific e-navigation  solutions 18 (IMO 2018). Once formulated and incorporated into SOLAS 1974 amendments, this regulation will go a long way towards further improving navigational safety. E-navigation also needs consideration towards integration with the so-called "net-centric" 19 functionality of technological equipment and systems towards optimisation of processing of high-quality data and information coming from them, which can further improve response to navigational risks . Furthermore, the International Safety Management (ISM) Code, 20 which was introduced as a result of RORO ferry Herald of Free Enterprise sinking that resulted in the death of 193 persons, ensures safe shipboard operations by following standardised procedures as well as ensuing responsibilities are shared between the ship and shore personnel (Mukherjee 2007). These procedures include but are not limited to Bridge Team management, Planned Maintenance System for equipment/machinery/structure, etc. SOLAS 1974, therefore, addresses the Human Element aspect of the risks through the ISM Code for all the risks ( Figure 4) including risks of navigation, fire as well as structural integrity and stability.

Conclusion
The SOLAS Convention, which has its origin a couple of decades before the IMO's establishment is a constantly evolving legislation; today 165 member States party to the Convention 21 and there is a coverage of 99.04% of the gross tonnage of the world's merchant fleet (IMO 2020c). For any IMO Instrument, the critical aspect is legislation by the Member State followed by Implementation and Verification. The success in this regard is evident from statistics as SOLAS 1974 has resulted in a reduction in the number of marine casualties/incidents over the years. IMO specifically through its MSC and member states have ensured that SOLAS 1974 has evolved to become more proactive for example through the GBS methodology, the timely introduction of the Polar Code (Dalaklis 2017), shifting the focus towards cybersecurity, etc. Additionally, the regulatory scoping exercise of IMO Instruments to evaluate preparedness for Maritime Autonomous Surface Ships that was initiated in 2017 is another positive step in this direction (Ringbom 2019).
However, risks cannot be wholly eliminated/extinguished, but with the help of various mitigation measures can be kept to the ALARP level. With ongoing technological advances, electronically aided collisions could be recorded in the future as another navigation risk. When considering the "ordinary" distractions from numerous equipment on the ship's bridge, human errors associated with failure to interpret the information accurately, or even lack of training and inability to maintain proper navigational watch, now there is a need to deal with "new distractions", such as looking/answering a smartphone phone. Such an evolving issue would need to be constantly addressed as most of the navigational incidents are clearly linked to human errors. Even though SOLAS 1974 is associated with very strict safe manning provisions under Chapter V regulation 14, the number of personnel involved with navigational watchkeeping task is most commonly maintained to the absolute minimum; this approach is deployed to keep costs down, but when factoring in issues like fatigue and/or information overload from the bridge equipment can result into devastating effects. Here the issue of effective training, working in unison with the further built-up of certain "soft skills" can provide the solution.
At the same time, the positive impact of introducing FSA has resulted in risks being studied before legislating in relation to new technologies and therefore mitigating these risks by introducing countermeasures in SOLAS 1974. Additionally, the early introduction of concepts such as e-navigation and net-centric functionality of technological equipment and systems can further help in the alleviation of the risks related to navigation. Such positive measures have contributed towards ensuring the safety of life at sea and at the same time facilitate the Organisation 22 to "uphold its leadership role as the global regulator of shipping, promote greater recognition of the sector's importance and enable the advancement of shipping, whilst addressing the challenges of continued developments in technology and world trade; and the need to meet the 2030 Agenda for Sustainable Development".