containerships-wang.pdf

Marine Policy 25 (2001) 143}157

Formal safety assessment of containerships

J. Wang��*, P. FoinikisMarine Engineering (Risk Assessment), School of Engineering, Liverpool John Moores University, Byrom Street,

Liverpool L3 3AF, UK

Received 1 September 2000; received in revised form 4 January 2001; accepted 5 January 2001

Abstract

Following an introduction to containerships, formal safety assessment and its development in the shipping industry are described.Containership accident statistics are studied and discussed. This is followed by a description of containership characteristics anda proposed formal safety assessment methodology for containerships. Further development in formal safety assessment in the contextof containership safety is "nally discussed in detail. � 2001 Elsevier Science Ltd. All rights reserved.

Keywords: Containership; Containership safety; Formal safety assessment; Ship safety

1. Introduction

Due to a rapidly expanding world trade, the tradi-tional multi-purpose general-cargo liner became increas-ingly labour and cost intensive. A system was required toaccommodate the needs of physical distribution, a systemthat would o!er convenience, speed, safety and above alllow cost. By this system, goods should be able to bemoved from manufacturer to "nal distribution usinga common carrying unit, compatible with both sea andland legs of transportation. The result was expected to bethat all costly and complicated transhipment operationsat seaports would be eliminated. The whole process re-sulted in the development and introduction of the`freight containera, a standard box, "lled with commodi-ties, detachable from its carrying vehicle, and as easy tocarry by sea as by air, road and rail. The beginning of thecontainer era was marked with the sailing of the `con-tainer tankera `MAXTONa on 26th April 1956 fromNewark N.J. to Houston, loaded with 58 containers [1,2].

During the "rst years of containerisation, transporta-tion was carried out with modi"ed tankers or dry cargovessels, broadly accepted as the 1st generation ofcontainer ships [2,3]. It was not until 1965 that the "rst

� Internet: http://www.eng.livjm.ac.uk/research/groups/morg/* Corresponding author. Tel.: #44-151-231-2245; fax: #44-151-

231-2453.E-mail address: [email protected] (J. Wang).

orders for purpose built cellular vessels were placed,forming the 2nd generation of container vessels. Thesewere the `Bay Classa ships of 1600 TEUs capacity. In thelate 1970s the 3rd generation appeared increasing thesizes up to Panamax and capacities up to 3000 TEUs.Following the increasing demand for tonnage but with-out being prepared to lose the Panama Canal #exibilitythe industry moved to the development of the 4th genera-tion of container vessels, keeping the Panamax dimen-sions and increasing the capacity up to 4200 TEUsrepresented by the `Econ Classa ships [2,3].

Further development in the shipbuilding industry andthe need for the creation of `economies of scalea resultedin the appearance of the 5th generation of containerships, the Post-Panamax in the 1980s [2]. A recent re-search in the container sector of the shipping industryindicates that the world fully cellular containership #eetincreased to more than 3500 vessels with a total carryingcapacity exceeding 4.6 million TEUs in 1999 and with anaverage annual growth rate up to 11.1% as shown inFig. 1 [4]. It is also noteworthy that the growth rate ofpost-Panamax containerships is the largest of all thecontainership sizes, amounting up to 26.3%.

Although there were not many major casualties, interms of loss of lives, resulting from accidents involvingcontainerships, this particular ship type has more of itsfair share of losses due to incidents involving cargo dam-age, personal injury, collision, ship structural failure andpollution. Major accidents in the last decade include the

0308-597X/01/$ - see front matter � 2001 Elsevier Science Ltd. All rights reserved.PII: S 0 3 0 8 - 5 9 7 X ( 0 1 ) 0 0 0 0 5 - 7

Fig. 1. World fully cellular containerships in TEUs.

total loss of the `C/V Pioneer Containera in 1994 due toa collision in the South China Sea, the loss of the `C/VRiver Guraraa in 1996, the extensive damages su!ered bythe `C/V Toyama Maerska in 1997 due to a collisionwith a Gas Carrier in the Singapore Strait, the loss of the`C/V MSC Carlaa in 1998 which broke in two in badweather conditions, and the extensive damages su!eredby the `M/V APL Chinaa in 1999 due to severe badweather conditions. Statistics indicate that incidents in-volving containerships account up to about 7% of thetotal.

In terms of incident categories containerships di!erfrom most other ship types in that shore error accountsfor a high percentage of all major incidents. The result isan equally high percentage of cargo damage. Althoughcontainerships follow the same pattern as the majority ofcargo vessels, as far as the types of damages are con-cerned, they do di!erentiate in various aspects. Therelative statistics available show that the percentage ofincidents is higher in newer containerships, decreasing asthey age, while in other cargo ship types, higher incidentrates occurs at their middle age. The same statistics showthat a high percentage of all incidents caused by humanerror, was due to shore based personnel error, which isfar higher than other cargo ship types. As far as ship sizeis concerned the smaller ships of this type are betterplaced with fewer incidents.

Other operational characteristics of containerships,such as the fact that they very rarely travel in ballastcondition and the few opportunities for overnight stay atports, contribute to the overall performance of thesevessels and their operators. At this point, it should bestressed out that although a relatively large amount ofdetailed data exists, organisations such as classi"cationsocieties, as well as private shipping companies possess-ing them are reluctant to release them. This is mainlyattributable to the high competition in the market. Onthe other hand, government agencies are either not readyyet to dedicate the necessary resources for data collec-tion, or the time period for which relevant governmentprojects are run is not su$cient to produce reliable data.

Following the investigation on the disaster of the`Herald of Free Enterprisea of 6th March 1987,

the House of Lords issued `Lord Carver's Reporta [5].The whole report and its concept was promptly andwidely embraced by the UK Maritime and CoastguardAgency (MCA), by introducing in 1993 the `Formal ShipSafety Assessmenta as a proposal to the InternationalMaritime Organisation (IMO) [6,7]. Following a periodof deliberations, the IMO "nally in 1997 broadly accep-ted Formal Safety Assessment (FAS) for ships as a poten-tially helpful tool in the rule-making process and issuedthe relevant circular [8]. What was needed, however, wasproof of the theory's feasibility for the various types ofships available. The task of testing the theory and itsfeasibility in the industry was assigned to the UK MCA,which proceeded to the application of FSA initially tohigh-speed passenger ships. The product of the applica-tion was successful, leading to the submission of a rel-evant report by the UK MCA to the IMO. The feasibilitystudy of the FSA application to bulk carriers has alsobeen carried out and the "nal results are expected to beproduced in December 2000 [9].

The shipping community, being traditionally conser-vative in adopting new methods and technologies, in itsgreat majority has yet to openly express its views on FSA.Shipping companies, in general, maintain a waitingpolicy on the subject, possibly reluctant to expose them-selves to premature expenses. Nevertheless, there areexceptions with the most notable ones P&O Nedlloydand Neptune Oriental Lines (NOL), which have startedusing scienti"c methods for risk prediction and manage-ment establishing new specialist departments within theirorganisations for that purpose [10].

The general concept, however, of FSA has entered thewider maritime sector, with classi"cation societies likeLloyds Register of Shipping (LR), DNV and Ger-manisher Lloyd (GL), proceeding to individual researchand providing services. On the other side of the AtlanticOcean, in the USA, the US Coast Guard (USCG) hasapplied `Risk Based Decision-Making Guidelinesa inorder to improve its management system [11] and at-tempts to pass variations of the FSA in a competitivemanner towards its British counterpart. Indicative of theabove is the simplistic methodology followed in a testcase produced on risk assessment on passenger vessels inco-operation with the US Passenger Vessel Association(PVA) [12].

2. Containership accident statistics

In order to carry out any kind of safety analysis, eitherqualitative or quantitative, it is essential to obtain re-liable failure data. It is admitted that qualitative riskanalysis requires less detailed statistical failure data,compared to Quantitative Risk Assessment (QRA) [13].The existence of a certain amount of relative data is,however, considered to be necessary, in either case, in

144 J. Wang, P. Foinikis / Marine Policy 25 (2001) 143}157

Fig. 2. Distribution of incidents per ship type.

Fig. 3. Incident categories involving containerships.

order to enable us to determine the probability of occur-rence and the extent of the consequences of a hazardousevent.

The amount of data available will also determine thechoice of the risk analysis methods (qualitative or quant-itative) that could more suitably be incorporated in thewhole process of the FSA. Accident statistics on a genericvessel type can be obtained from the following sources:

1. Field experience (historical data) including:1. 1.1. Data collection programmes by government

agencies.1. 1.2. Data collection programmes by classi"cation so-

cieties.1. 1.3. Data collection programmes by insurance com-

panies and P&I Clubs.1. 1.4. Statistics maintained by private shipping com-

panies.2. Agreed judgmental estimates of experts.

As far as "eld experience is concerned, there is a two-folded problem. On one hand, great attention should bepaid on the data resources, as the various databases donot always use the same base for data analysis. This isattributable to the fact that di!erent bodies look intosafety issues from di!erent prospective, facilitating theirown interests. On the other hand, there is the problem ofdata accuracy. The available information on a certainsubject varies with the vessels' working environment.Such factors generally add uncertainties to risk assess-ment thus reducing the con"dence in it and can only beovercome by expert judgement. Equally varying are therisk criteria set around the world, as they depend mostlyon local regulators. This gives them a large amount ofin#exibility, making it impractical to use them, especiallyin cases where there is a high level of uncertainty.

Classi"cation societies and P&I Clubs can be a veryuseful source of failure data mainly because of the largeamount of vessels each one represents. Data, however,from these organisations should be critically evaluatedbefore used or combined with others. Classi"cation so-cieties tend to look into safety, mainly from the viewpoint

of compliance with the various sets of rules in force. Onthe other hand, P&I Clubs tend to deal with the matterfrom the viewpoint of "nancial losses due to lack of safetyand are not immediately interested in the regulatoryaspect of loss prevention. A recent research carried outby one of the world's leading P&I Clubs, the UK P&IClub [14] and possibly the most complete one publiclyavailable, shows that for the 10-year period from 1989 to1999 incidents involving containerships account up to7% of the total as shown in Fig. 2.

In terms of incident categories, containerships di!erfrom most other ship types in that show error accountsfor up to 21% of all major incidents. The result is a fairlyhigh percentage of cargo damage, 54%, as comparedwith the overall percentage of the Club. All the values ofincident categories are shown in Fig. 3 while the totalnumber of incidents is 273 for the period 1989}1999 [14].

In terms of ship size and age, the 10-year study showsthat the smaller ships of this type are better placed. 87%of the major incidents have occurred on containershipsabove 10,000 grt as shown in Fig. 4. Equally interesting isthe fact that 44% of incidents involving containershipshave occurred on ships of less than 10 years of age asshown in Fig. 5 [14]. The human error factor in incidentsinvolving containerships is shown to be in decline, fol-lowing two peak periods in 1988 and 1991 as shown inFig. 6 [14].

Administrations tend to look into marine casualtiesfrom the viewpoint of `reportable incidentsa within their

J. Wang, P. Foinikis / Marine Policy 25 (2001) 143}157 145

Fig. 4. Distribution of incidents as per ship's size (in grt).

Fig. 5. Distribution of incidents as per ship's age.

Fig. 6. Containership-o$cer/crew error-frequency trend.

jurisdiction which results to a di!erentiation in the rel-evant numbers, as the sample of vessels considered issmaller than that of P&I Clubs and classi"cation socie-ties. Furthermore, due to their orientation towards shipsafety and environmental protection, areas such as cargodamage and third party liability (i.e. "nes) are not con-sidered. Nevertheless, results of such data are equallyuseful for the identi"cation of major problematic areas ofthe various ship types although in many case there maybe a di!erence between the data from classi"cation socie-ties and government agencies.

3. Formal safety assessment of containerships

Formal Safety Assessment (FSA) is a new approach tomarine safety, which combines the techniques developedfor risk and cost bene"t assessment. The bene"ts ofadopting FSA as a regulatory tool were very accuratelypointed out by UK MCA and can be summarised in thefollowing [6]:

� A consistent regulatory regime, which addresses allaspects of safety in an integrated way.

� Cost e!ectiveness, whereby safety investment is tar-geted where it will achieve the greatest bene"t.

� A proactive approach, enabling hazards that have notyet given rise to accidents to be properly considered.

� Con"dence that regulatory requirements are in pro-portion to the severity of the risks and

� A rational basis for addressing new risks posed by everchanging technology.

The main FSA framework consists of the following "vesteps [6,8]:

� The identi"cation of the hazards.� The assessment of the risks associated with those haz-

ards.� Ways of managing the risks.� Cost bene"t assessment of the options and,� Decisions on which options to select.

The "rst three involve the use of risk assessment tech-niques, while the fourth one is, as stated, cost bene"tassessment. The "fth step is nothing else but the logicaloutcome of the cost bene"t assessment.

3.1. The generic containership

The generic model of containership needs to be de-veloped according to IMO's Interim Guidelines [8]taking into consideration the particular systems andcharacteristics required for the transportation of con-tainerised cargo. The relevant study carried out by theUK MCA on High Speed Passenger Craft [15] as well asthe one currently being carried out on Bulk Carrier o!eran equally useful guide for the development of our gen-eric model.

The generic containership is not a `typicala vessel buta hypothetical one consisting of all technical, engineer-ing, operational, managerial and environmental (phys-ical, commercial and regulatory) networks that interactduring the transportation of containerised cargo. Thisgeneric model can be broken down to its component andmore detailed levels. Thus the generic container ship cantake the form shown in Fig. 7.

Breaking down the model to the four basic levelsof the containership operation produces the `generic


Fig. 7. The component levels of the generic model of containership.

Fig. 8. The generic engineering and technical system.

engineering and technical system modela (Fig. 8) [9], the`generic personnel sub-systema (Fig. 9), the `generic op-erational and managerial infrastructurea (Fig. 10), andthe `generic environment of operationa (Fig. 11).

Containerships follow the general pattern that all in-ternationally trading cargo ships do, but they di!erenti-ate in various aspects, of which, the primary ones appearto be as follows:

(i) Structure: The structure of a containership is typi"edby holds longitudinally divided in two sections (fore andaft), each being able to accommodate one 40 ft unit ortwo 20 ft ones in length. Holds are "tted with vertical `Lashaped guides (cell guides) used to guide and secure theunits into their storage position. Internally containership

holds are box shaped surrounded by ballast, fuel tanksand void spaces.

(ii) Strength and stability: Containerships like mostcargo vessels are equipped with means to calculate stabil-ity, shear-forces (SF) and bending moments (BM). Thedi!erentiating feature of containerships is the additionalneed for the calculation of torsion moments (TM). Thisneed is generated by the uneven distribution of cargoes incases where the vessel is partly loaded proceeding tovarious ports before completing its loading.

The existence of deck cargo reduces the stability of thevessel and calls for increased inherent or design stabilityof the vessel itself. It is not an uncommon phenomenonthat a `Metacentric Heighta (GM) is 6.5 m for a Pa-namax size containership in `light shipa condition. Theuse of high-speed diesel engines increases the fuel con-sumption rate, which imposes the need for large fueltanks, usually located at, or close to, the mid-section ofthe vessels. Thus, as fuel is consumed bending momentsand shearing forces are increasing. It is noteworthy thatmany modern containerships are equipped with real-timestress monitoring equipment allowing for automated cor-rection of excessive values using ballast.

(iii) Cargo and ballast operations: This is one of themain di!erences between containerships and other cargovessels. Loading and unloading cargo operations arecarried out simultaneously and at very high rates. Thecargo loaded and discharged is calculated based on thevalues declared by the shippers for each unit and byweighing the units upon their arrival at the terminal gate.Cargo operations are normally pre-planned by terminalpersonnel in simulated conditions and are subject to


Fig. 9. The generic personnel sub-system.

Fig. 10. The generic organisational & managerial infrastructure.

evaluation and acceptance by the ship's personnel. Real-time follow-up of the operation is carried out bothonboard and ashore and the "nal "gures of stability,stresses and cargo quantities are then calculated.

(iv) Manoeuvrability, power and propulsion: Container-ships are generally "tted with thrusters (bow and/orstern) and in several cases active rudders. This coupledby the advanced hydrostatic features (i.e. block co-e$cient) of these vessels, results in a high level ofmanoeuvrability at all speed levels. High speeds, never-theless, tend to reduce the time available for reaction by

operators, adversely a!ecting the human reliability inclose quarters situations.

(v) The cargoes carried: The majority of the cargoescarried are usually of high value, as opposed to bulkcarriers and crude oil tankers, which tend to carry rawmaterial of lower values. Containerised cargoes come insmall parcels, while bulk cargoes (dry or liquid) come inlarger ones. Goods travelling in a sealed containerproduce a problem of uncertainty as far as the character-istics of the cargo (i.e. quantity, quality security andinherent hazards) are concerned. The information for


Fig. 11. The generic environment of operation.

such features is received by the documents accompanyingthe sealed unit and is rarely crosschecked. Only in casesof suspected existence of undeclared dangerous goodsdoes the law provide for ship personnel to demand in-spection of the unit's contents.

Again due to the high loading rates and pressure intime, most of the paperwork is received `in good faithaand the burden of avoiding and in the worse case com-bating hazardous situations falls on the ship personnel.Cases of undeclared hazardous substances as well aspoorly maintained containers and tanks, have been iden-ti"ed but rarely reported to the authorities, followinga compromising agreement between carriers and cargoowners [10,16].

(vi) Cargo recipients (consignees): Another di!erencethat containerships have is the one connected withthe cargo recipients (consignees). Unlike other shiptypes (i.e. bulk carriers, tankers) the number of cargoconsignees is highly increased. Even within the sameunit there may be more than one of recipients.This fact, combined with the high value of the cargoescarried and their hazardous nature increases boththe exposure of the carriers for possible damage andthe di$culty in co-ordination and co-operation, bet-ween ship and cargo owners, during contingencysituations.

(vii) Ports and terminals: Container-handling portsand terminals follow a distinct path, as far as theirgeneral layout and organisation are concerned.Container terminals have the ability to concurrentlycarry out loading and discharging operations, whileterminals handling bulk cargoes tend to be specia-lised loading or discharging ones. In cases wherebulk carrier terminals can handle both loading anddischarging, the two operations are never carried outsimultaneously.

3.2. Formal safety assessment of containerships

By considering the characteristics of containerships,a formal safety assessment framework is described indetail in the context of containerships.

3.2.1. Hazard identixcation (HAZID)The aim of this step is to identify the hazards related to

a speci"c problematic area and generate a list of them,according to their likelihood of occurrence and the sever-ity of their consequence towards human life, propertyand the environment, in order to provide the base or thereference point for the next step. The following assump-tions are applied:

� The containership average lifetime: 25 years� The average number of operational days per year: 330� Operational hours per day: 24� Major maintenance frequency: 1 every 2.5 years

(30 months).

The most popular expression used for the whole pro-cess of hazard identi"cation is called `brainstormingatechnique. This technique involves trained and experi-enced personnel combining their knowledge to identifythe hazards through various approaches, such as thefollowing [17]:

� Preliminary Hazard Analysis (PHA).� Failure Mode and E!ects Analysis (FMEA).� Hazard and Operability (HAZOP) study.

The accident categories identi"ed with regard to thecontainerships' operation include:

� Contact and/or collision.� Explosion and "re (including #ame and heat).� External hazards (i.e. heavy weather).� Flooding.� Grounding and/or stranding.� Hazards related to hazardous substances (including

leakage, noxious fumes, etc.).� Loss of hull integrity.� Machinery failure (including electronic devices, navi-

gation equipment and safety systems).� Hazards related to loading/discharging operations

(including ballast operations).� Cargo damage.� Hazards related to human errors.

The containership's compartments include:

� Navigation Bridge.� Cargo Spaces.� Engine Room.


Fig. 12. Example proposed of risk matrix table.

� Void Spaces.� Tunnels.� Upper Deck Areas.� Crew Accommodation.� Galley.� Provisions' Storage Spaces (including Bonded Stores).

The operational phases of a containership include:

� Design*construction*commissioning.� Entering and leaving port.� Berthing and unberthing.� Cargo and ballast operations.� Coastal navigation.� Open sea navigation.� Planned maintenance (day-to-day onboard).� Major maintenance (dry docking).� Decommissioning.

Once the hazards are identi"ed with respect to each ofabove accident categories, compartments and opera-tional phases, it is essential that they are `screeneda sothat they can be properly evaluated and the trivial onesto be excluded from further investigation. The screeningtechnique evaluates hazards in terms of both frequenciesof occurrence `Fa and the severity of their consequences`Sa. Accordingly severity `Sa ranges from minor injuries,property and environmental damage up to those with`catastrophica consequences [8,15].

Using the `Risk Matrix Approacha [6,18,19], the com-bination of frequency and severity rankings is used forthe estimation of the `Risk Ranking Numbera (RRN),which is used to categorise risks according to their im-portance. By pursuing this approach, important risks areidenti"ed and forwarded for further analysis while trivialones can be disregarded. An example of the `Risk MatrixTablea and its associated explanatory notes, as theycan be applied to containerships, can be seen in Figs. 12and 13.

3.2.2. Risk assessmentFollowing the study of the escalation of the basic

or initiating events to accidents and their "nal outcomes,it is necessary for an `in#uence diagrama to be construc-ted, in order to study how the regulatory, commercial,technical and political/social environments in#uence

each accident category and eventually quantify thesein#uences with regard to human and hardware failure aswell as external events [9,15,19,20]. In general, an `in#u-ent diagrama is a combination of fault trees and eventtrees. Each in#uence diagram is required to de"ne the`besta and `worsea cases for each factor a!ecting theparticular accident category under review. The wholeprocess must cover each of those systems/compartmentsand include the escalation of the accident as well as themitigation aspects such as evaluation of people, marinepollutants' containment, etc. Again the various opera-tional phases of the ship have to be taken into considera-tion and generic data or expert judgements to be used.A list of ship's systems/compartments and operationalphases can be shown in Fig. 14.

Each `frequency-consequencea curve determines thePotential Loss of Life (PLL) for the particular sub-category. By summing the product of frequency and sev-erity across all event tree outcomes, the PLL for thewhole accident category can be estimated.

3.2.3. Ways of managing risksThe aim at this stage is to propose e!ective and practi-

cal `Risk Control Measuresa (RCMs) to high-risk areasidenti"ed from the information produced by the riskassessment in the previous step [6,17}19,21]. At thisstage the implementation costs and potential bene"ts ofrisk control measures are not of concern. In general, thereare three main characteristics according to which RCMsare evaluated and which can be summarised as follows[19]:

� Those relating to the fundamental type of risk reduc-tion like the preventative measures forming `safetybarriersa not allowing an incident to progress.

� Those relating to the type of action required (i.e. engin-eering or procedural).

� Those relating to the con"dence that can be placed inthe measure (single or redundant, active or passive)

Reducing the likelihood of occurrence and/or the se-verity of the consequences of hazards can achieve riskreduction. There are three main methods used for riskreduction, namely the management, engineering and op-erational ones [17,19].

Managerial solutions involve activities related to themanagement of each organisation. The main objective ofsuch activities is the development of a safety culture,while the key factor for their success is e!ective commun-ication.

Engineering solutions involve the design and/orconstruction of the ship. Engineering solutions have theinherent advantages that can be clearly identi"able(i.e. introduction of double hull in oil carriers) andaddress hazards in the early stages of a vessel's life.Nevertheless, large-scale engineering solutions su!er


Fig. 13. Example of proposed key to risk matrix table.

Fig. 14. Vessel's compartments and operational phases.

from lack of historical data on design aspects, inability offull-scale experimentation as well as of modi"cation orreplacement once vessels are in operation [21].

Operational solutions involve the development andintroduction of appropriate procedures for carrying out`risk-criticala tasks, as well as improving the e!ectivenessof personnel in these tasks. Thus safety procedures, safeworking practices, contingency plans and safety exercises(drills) can be included. Such solutions address e$cientlyhuman error factors and ensures the existence of uni-formity of the adopted safety standards.

The identi"ed measures with the same e!ect, or ap-plied to the same system, can then be grouped in RCMsand it is up to the experts to estimate the e!ectivenessof each RCM. The development of casual chainsprovides a helpful tool for identifying and eventuallyselecting the appropriate RCMs [19]. The identi"cationof RCMs can, then, be carried out at the nodes ofeach casual chain. Selected RCMs can then be forwardedto the 4th step, where their cost e!ectiveness will beevaluated.

3.2.4. Cost}benext assessmentSelected RCMs must also be cost-e!ective (attractive)

so that the bene"t gained will be greater than the "nan-cial loss incurred as a result of the adoption [8,6,17,19].Therefore this step is aiming at identifying the bene"tsfrom the reduced risks and the associated costs for eachRCM. Attention is necessary to be drown to the fact thatthe evaluation of costs and bene"ts should initially be

carried out for the overall situation and then for thevarious parties concerned and a!ected by the problem inconcern. The parties a!ected are commonly referred to as`Stakeholdersa [6,19,20].

There are limitations in carrying out cost}bene"t anal-ysis. The limitations come from imperfect data and un-certainty. It must also be pointed out that cost}bene"tanalysis, as suggested for use in FSA is not a precisescience, but it is only a way of evaluation. Thus it cannotbe used mechanistically, but only as a consulting instru-ment in decision making.

Each RCO, which has been forwarded from step 3,needs to be evaluated in accordance with the costs forits implementation and maintenance through thevessel's lifetime, as well as the bene"ts received forthe same period. This evaluation is required to be carriedout in two levels, primarily for the overall situationand then for each of the parties concerned and/or a!ec-ted (Stakeholders) by the problem under review[8,9,15,19].

A `base casea is required to be incorporated as a refer-ence for the comparisons that will follow. The base casere#ects the existing situation, covering all levels of asso-ciated risks arising from a particular activity prior to theimplementation of any RCM. The RCM costs, bene"tsand the `Cost of Unit Risk Reductiona(CURR value) canbe estimated by comparing the base case with the onewhere the RCM is implemented.

The CURR value can be determined by dividing the`Net Present Valuea(NPV) of the option's costs and


Fig. 15. The ALARP principle.

bene"ts by the combined reduction in mortality andinjury risks [19,20].

Having estimated all costs}bene"ts and cost unit re-duction levels of each RCM, for both the overall situ-ation and for each particular accident category, the nextrequirement is to list the "ndings with regard to theirsigni"cance to the various stakeholders and their relativevalues.

3.2.5. Decision makingThe "nal step of FSA is `decision makinga, which

aims at giving recommendations and making deci-sions for safety improvement taking into considera-tion the "ndings during the whole process. Thusthe pieces of information generated in all four previoussteps are used in selecting the risk control option whichbest combines cost e!ectiveness and an acceptable riskreduction, according to the set `risk criteriaa by theregulators.

It is equally admitted, however, that the application ofabsolute numerical risk criteria may not always beappropriate, as the whole process of risk assessmentinvolves uncertainties. Furthermore, opinions on accept-able numerical risk criteria may di!erentiate betweenindividuals and societies with di!erent cultures, experi-ence and mentalities. Thus setting rigid numerical riskcriteria may prove the whole decision-making processin#exible [19]. A numerical value could be de"ned as theupper tolerable/acceptable limit, which should not beexceeded in any circumstances. Below this limit, a more#exible formula could be used in order to ensure thegreater risk reduction possible. Such formula may beused to determine whether or not risks are toler-able/acceptable and whether or not they need to be

reduced to `As Low As Reasonably Practicablea(ALARP). A graphical representation of the ALARPprinciple is shown in Fig. 15.

The RCMs that could "nally be adopted would be theones that best balance reduction in PLL with cost-e!ec-tiveness for the whole situation as well as for the particu-lar stakeholders.

4. Testing, evaluation and recommendations

4.1. A test case

Following the detailed analysis of the FSA meth-odology of containerships, a test case study is requiredin order to demonstrate its feasibility. A full-scaletrial application would, however, be too large in volumefor this paper. Therefore, the test case is limited toone accident category only, namely `"rea. In addition,mainly owing to insu$ciency of su$cient historicaldata assumptions may be employed, based on theexpert judgement deriving from the experience in the"eld.Step 1: Having identi"ed the accidents, the causes are

then grouped in terms of human error, hardware failures,external events, etc. The `"rea accident sub-categories arelisted as follows:

� Navigation Bridge.� Cargo Spaces.� Engine Room.� Void Spaces.� Tunnels.� Upper Deck Area.


Fig. 16. Fire rankings, using the `risk matrix approacha*expert judgement.

� Crew Accommodation.� Galley.� Provisions' Storage Spaces (including Bonded Stores).

The screening process is carried out using the `RiskMatrix Approacha. The "nal ranking for the accidentcategory of `"rea, takes the form as presented in Fig. 16.Step 2: In this step the PLL and its distribution

through the in#uence diagram will be determined.An illustration of the in#uence diagram for the accidentcategory of `"rea can be seen in Fig. 17. Below theaccident category level the structure is a graphicalrepresentation of the accident sub-category, including allthe combinations of relevant contributing factors foreach accident sub-category. Above the accident categorylevel the structure is an event tree representation ofthe development of the accident category to its "naloutcome.

The study can then continue in order for the regula-tory, commercial and social/political in#uencing envi-ronments, for each accident category, to be deliberatedand eventually quanti"ed with regard to human andhardware failures and external events. The outcomes areshown in Fig. 18.Step 3: The table constructed for the accident category

of `"rea is shown in Fig. 19. From Fig. 19, it can beenseen that the areas requiring less consideration areclearly identi"able, and appear to be the `ProvisionStoresa and `Upper Deck Areasa. For each of the re-maining areas (sub-categories) casual chains need to beconstructed and RCMs to be identi"ed at the nodes ofeach chain.

RCMs according to their e!ect to the system underconsideration are then grouped. The RCMs will next beevaluated, taking into account their e!ectiveness withinthe event trees or in#uence diagrams, rather than theircost, utilising once more expert judgements. The moste!ective RCM(s) can afterwards be forwarded to the nextstep.Step 4: The most preferable means that for the

cost}bene"t analysis model construction is the use of

nested computer spreadsheets to calculate the costs andbene"ts for each selected RCM. The quanti"cation of thecosts and bene"ts is to be achieved in terms of NetPresent Value (NPV), which can be converted intoa CURR value.

The above procedure is essential to be carried out forthe overall situation as well as for each particular acci-dent category. The CBA outcomes can then be listedaccording to their signi"cance to the various stake-holders.Step 5: In this step "nal decisions are made, taking into

account each individual RCMs CURR value and PLLreduction capabilities, as determined and listed by thesafety analysts.

4.2. Evaluation of the FSA requirements and proposalsfor improvement

FSA can be feasibly applied to containerships, pro-vided that several areas, which cause uncertainties, arefurther deliberated. These areas in#uence both the gen-eral principles of FSA and the speci"c requirements forcontainerships, either directly or indirectly. The mostprominent ones are analysed and alternative suggestionsare described as follows

4.2.1. The brainstorming techniqueAlthough the knowledge and expertise of the people

involved in the brainstorming technique is absolutelyrespectable, certain safety aspects may be overlookedas it might be considered `naturala from their pointof view, while to a person outside the profession itmight be something completely new and thus causingconcern.

Since by de"nition the `brainstorming sessionaought to be structured to encourage the unfetteredthinking and participation of the people involved,the contribution by people with less expertise in thesubject would be a positive one, as they might bringup safety issues, which otherwise would have beenoverlooked.


Fig. 17. Risk contribution tree for "re.

4.2.2. Need for interaction with other industries' safetyand quality management systems

FSA for ships in general and for containerships inparticular, should develop the ability to interact withregulatory bodies responsible for land-based operations.Sharing the relevant data of non-compliance with estab-lished safety and quality standards for shore-based in-dustries would eliminate a considerable percentage of theuncertainty created in this direction.

4.2.3. Human elementAnother important factor to be taken into considera-

tion is human element. Problems like di!erences in lan-guage, education, training, mentality, etc. have increasedover the past years, especially with the introduction ofmulti-national crews. Such problems largely contributeto marine casualties. On the other hand, crew reductions

have increased the workload of operators, which in con-nection with the reduced opportunities for port stay andrecreation (especially with containerships) equally in-creases the probabilities for errors.

It becomes apparent that FSAs success largely de-pends on two essential conditions. The "rst condition isthe development of a safety culture at all levels of theindustry's infrastructure, from company managers tovessel operators. The second one is the inclusion into theFSA framework itself of further guidance on how humanfactors would be integrated in a feasible manner.

4.2.4. The availability and reliability of dataPrimarily, great attention should be paid on the data

resources, as the various databases do not always use thesame platform for data analysis. This is attributable tothe fact that di!erent organisations look into safety issues


Fig. 18. Incident database for "re.

Fig. 19. Cumulative table for "re sub-categories.

from a di!erent prospective, which facilitates their owninterests. In order to overcome the problems created bythe availability and reliability of failure data, interna-tional co-operation and co-ordination are required withthe intention that a new global database will be estab-lished, controlled and updated by an International Regu-latory Body (i.e. IMO). Such a database should be easilyaccessible by both Administrations and Analysts/Researchers providing reliable data with de"ned param-eters upon which the incoming information has beenprocessed.

As far as containerships are concerned, the task of datacollection and processing appears to be relatively easierthan in other ship types. This is attributable to the factthat containerships and their owning/operating com-panies form a part of a multi-modal transportationnetwork and therefore are highly computerised. Thenecessary infrastructure therefore exists. With theadequate adaptations the existing infrastructure canbe feasibly utilised for the purpose of FSA and failuredata can be easily collected, processed and communic-ated both internally (i.e. company head o$ces, branchesand ships) and externally (i.e. central international andnational databanks, other industrial bodies).

4.2.5. Risk criteriaLarge variations also exist in the risk criteria,

set around the world, as they depend mainly on local

regulators. Up to today, all e!orts are being made byadministrations individually, without any co-ordinationamong them. Considering that internationally tradingvessels move constantly from one jurisdiction to another,it becomes apparent that this lack of co-ordination isbound to produce further confusion to the industry,which does not seem willing to accept it.

The establishment of universally acceptable risk cri-teria for ships can be achieved through a compromisebetween qualitative and quantitative "gures. Thus a nu-merical value could be de"ned and agreed as the uppertolerable/acceptable limit, which should not be exceededin any circumstances. Below this limit, a more #exibleformula could be used in order to ensure the greater riskreduction possible. Such a formula may be used to deter-mine whether or not risks are tolerable/acceptable andwhether or not they need to be reduced to ALARP.

4.2.6. Cost}benext analysisThe use of cost}bene"t analysis as a platform on which

a given option is "nally selected for implementation is anappealing proposal. In practice, however, it can be quitecomplicated, especially in cases where human livesare involved. The fact that ships are manned with multi-national crews, usually o$cers from developed countriesand crews from developing ones, and obliged to tradein all parts of the world creates a di$culty in selectingthe proper human life value for cost}bene"t analysis.


Furthermore, the use of di!erent values on di!erent na-tionalities would have an adverse and undesirable e!ecton both international relations and working conditionsonboard ships.

A feasible solution to this problem would, once more,involve an international agreement on a reliable methodof estimating the current value of human life. The inter-national regulatory bodies should not only be respon-sible for the initial deliberations, but also for the constantfollow up of the international economic, political andsocial trends that in#uence that value.

5. Conclusion

This paper has attempted a critical evaluation of theFSA framework as it applies to containerships. A testcase was used to demonstrate the feasibility of the de-scribed approach.

It becomes apparent that there is still plenty of spacefor improvement on containership safety. Areas on whichsuch improvement can be achieved include, but not lim-ited to, the vessels' strength and stability, "re-"ghting andlife-saving equipment, human reliability and informationavailability, reliability and interchange. Such areas aredescribed as follows:

5.1. The containership hull stresses

Mainly due to their con"guration and the increaseddemand for full capacity utilisation, coupled by the sub-sequent increase in the vessels' sizes, containerships facethe problem of increased structural stresses (i.e. bendingmoments, searing forces and torsion). The establishmentof objectives aiming at the advancement of practicaldesign strategies towards containership structures, opti-mal for both the operator and the operating environ-ment, is considered crucial. Further research and testingtowards that direction will greatly contribute to the rule-based treatment of the containership structural strengthin the context of FSA.

In addition to the above, stress monitoring both in`harboura and òpen-seaa conditions, would providea useful tool for the safe operation of large containershipsproducing information on both the current structuralstress levels of the vessel and any possible deviations fromthe pre-calculated "gures. Thus, `Real Time StressMonitoring Systemsa, should not be considered òp-tionala, but become compulsory for containership sizesof `Panamaxa (3000 TEU) and above.

5.2. The containership xre-xghting and life-savingequipment

The high concentration of dangerous goods with vary-ing properties implies that apart from adequate contin-gency procedures containerships need to be "tted with

the appropriate combating equipment. The available fail-ure data do not show considerable fatalities, seriousinjuries or damage to the environment in such emergencysituations.

The traditional combating methods (i.e. "xed andportable "re "ghting arrangements) and material (i.e.sea-water, chemical foam, CO

�and personal protective

equipment) which are used today are not designed toprotect from conditions involving corrosive, toxic andbiochemical substances or a chain reaction causing ex-tensive "re and/or explosion. Since the introduction ofspeci"ed combating materials for each particular type ofcargo would not prove to be cost-e!ective, the introduc-tion of advanced escape/evacuation systems and proced-ures should be considered.

Today the types of escape vehicles (i.e. lifeboats and liferafts) used on containerships follow the general pattern ofdry cargo vessels, without taking into consideration thepossibility of existence of corrosive, toxic or biochemicalenvironments. Excluding their capacity, the choice of thetype of lifeboats or life rafts is left on the shipping com-pany's discretion. The compulsory inclusion, of protec-tively located and easily accessible lifeboats with `totallyencloseda, `free falla, `self-rightinga and àir tighta func-tions, equipped with èxternal sprinkler systema (as usedin Oil and Gas Carriers) for all containerships carryingdangerous goods would provide adequate protection tothe evacuees.

5.3. Human element

Considering the relevant statistics and failure data inhand, the human element appears to be the prominentfactor for containership failures. The distribution of ap-proximately 1 : 5 (21%) between shore based and shipoperating personnel, suggests that the problem in hand isa multi-sided one.

Primarily, there is the need for adequate training ofship personnel, specialising in the containership opera-tion. Containerships should cease to be considered assimple `general dry cargo vesselsa, as dictated by theirparticular characteristics. Such characteristics includethe increased ship speed, the long list of dangerouscargoes carried (e.g. explosives, biochemical, toxic, cor-rosive, nuclear, etc.) and the often-marginal structuralstrength exploitation. The above suggest that personnelserving on containerships should be adequately quali"ed,with knowledge and skills exceeding the general oneso!ered by the various Nautical Academies. A similarrequirement exists today for personnel serving on Oiland Gas Carriers. Thus, specialist courses and seminarsshould be introduced providing containership personnelwith the adequate theoretical and practical knowledgeand the necessary documentation.

Other factors that diversely a!ect human reliabilityare the reduced port turnaround and the increased


sea-passage time of this ship type. Containerships in veryrare occasions have the opportunity for overnight stay inport, reducing the chances for crew recreation and thusincreasing personal stress and fatigue. Measures such asin-built swimming pools, gymnasiums and recreationrooms and the introduction by the IMO of limits onthe maximum amount of daily working hours per crew-member, where actually implemented, had little e!ectin reducing crew stress and fatigue. Reductions in thecontractual service time of crewmembers rest on eachindividual shipping company's discretion. It is believedthat further consideration should be given to the matterand international agreement be achieved.

Attention should also be paid on the required quali-"cations for shore-based personnel, as well as on thecorrect implementation of the relevant legislation regard-ing the proper inspection and documentation of thecargoes from the point of production to the point ofloading. Better policing of the whole network will reduceincidents, which may prove to be disastrous for humanlives, the environment and other property. Such incidentsinclude, but not limited to, undeclared dangerous goodspacked in inadequate containers, inaccurate or deliber-ately altered container weights and numbers, forgedmanifests and poorly if at all maintained reefer con-tainers with inadequate settings.

5.4. Information availability, reliability and interchange

Many of the weaknesses existing today in the shippingindustry in general and the container sector in particular,would have been remedied if there had been an adequate#ow of information amongst the parties concerned. Con-tainerships and their owning/operating companies forma part of a multi-modal transportation system, whichbases its successful function on an integrated logisticssystem and an electronic data interchange network.Thus, each company's existing infrastructure could easilybe adapted to carry out the additional task of collection,processing, storing and interchange of safety informationincluding failure rates at all sections.

It could also interact with regulatory bodies outsidethe shipping industry, responsible for land-based opera-tions, and share the relevant data of non-compliance withestablished safety and quality standards for shore-basedindustries. This would eliminate a considerable percent-age of errors attributable to factors not related to con-tainer shipping.

Until today, ship safety has been subject to sets ofprescriptive rules and established good practices. Mattersare usually resolved in an intuitive manner by ship per-sonnel. The constantly evolving ship technology and thenew hazardous cargoes carried impose new hazards inone form or another and call for equally advanced safetymeasures with the ability to follow up and adapt to theabove evolutions. Possibly, the most illustrative example

of fast evolution is the containership sector of the indus-try. Within only 44 years of life, containerships havemoved from 58 to up to 7000 TEU per vessel, from 13 to27 Knots and from simple dry general cargo to refrig-erated, corrosive, toxic, explosive, biochemical, nuclearand other ones.

References

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[8] IMO. IMO/MSC Circular 829, interim guidelines for the applica-tion of formal safety assessment to the imo rule-making process.London: IMO, 1997.

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[14] UK P&I CLUB. Analysis of major claims*ten years trends inmaritime risk, London, 1999.

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[20] Billington C.J. Managing risks in ports. Managing risk in ship-ping. London: The Nautical Institute, 1999. p. 57}69.

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