Applications of risk-based approaches in the maritime industry started in the early 1960s with the introduction of the concept of probabilistic ship damage stability. The book is introduced by an overview of risk-based approaches to the maritime industry in Chap.
An Enhanced Design Process
How Did It Start?
- Probabilistic Damage Stability
- Offshore Industry
- Structural Reliability Analysis
- Alternative Design and Arrangement for Fire Safety (SOLAS II.2/17)
- Alternative Design for Oil Tankers (MARPOL Annex I-4/19)
- Special Craft
- Formal Safety Assessment
- Selected Recent Research Activities
- Recent Regulatory Developments
Although the aim is to demonstrate an equivalent level of structural resistance, the procedure is quite strict and many details, such as the generation of finite element models, material properties and structural failure criteria, are fixed. The guidelines provide the framework for the assessment and oil flow performance of the alternative design.
A High-Level Introduction to Risk-Based Design and Approval
Linking Risk-Based Design and Approval
This deterministic approach is not really goal-based and is not related to risk-based planning. The GBS, when based on an SLA, uses the IMO approach to risk acceptance to define the level of acceptable reliability at any level (ship, ship function, system, subsystem or component).
How Risk-Based Design and Approval Work Together
Each partial risk can be calculated using risk models such as event trees or Bayesian networks. In this context, it should be noted that an additional objective of risk-based design is to increase ship design knowledge at an early stage of design, thereby facilitating the advancement of decision-making.
What is Needed to Make Risk-Based Design and Approval Work?
Regulatory Framework
For really challenging and larger risk-based design projects, the quantitative part of the risk assessment is most likely carried out before the letter of intent and therefore well before preliminary approval. Ideally, yards should aim to have all issues affecting the design and approval process resolved before applying for approval.
Design Framework and Tools
With the available advanced tools, a risk analysis on important aspects can be carried out cost-effectively before a letter of intent is signed. As new constraints and objectives in risk-based design are added to the optimization problem, parametric ship models are also needed.
Qualified Engineers
In general, fault trees can be used for system analysis, event trees and Bayesian networks in FSA studies, and risk models expressed by mathematical formulas for rapid design optimization.
SAFER EURORO I (1997) Design for Safety: An Integrated Approach to Safe European RoRo Ferry design, EU funded project, Contract ERB-BRRT-CT97-5015, www.safer-euroro.org. SAFETY FIRST (2000) Design for Safety – Ship Fire Engineering Analysis Package, EU Funded Project, Contract G3RD-CT www.safer-euroro.org.
Risk-Based Ship Design
Methodological Approach to Risk-Based Ship Design
- Introduction
- The Ship Design Process
- Rules-Based Design
- Risk-Based Design
This has in turn led to the development of a formal state-of-the-art design methodology (risk-based design) that supports and nurtures a safety culture paradigm in the ship design process by addressing safety. A possible high-level general representation of the ship design process is shown in Fig.
Ris k-b ase d d esig n
Contemporary Developments
Specifically, in May 2000, the Secretary-General of the IMO called for a critical review of the safety of large passenger ships, noting that it “deserves due consideration whether the SOLAS requirements, several of which were drafted before some of these large ships were built, adequately address all the safety aspects of their operation - especially in emergency situations. The term "safe return to port" has been widely accepted in discussions of this framework, which addresses all the basic elements, prerequisites for quantifying the level of safety (life cycle risk) of a ship at sea.
IMO (SLF 47/48) Passenger Ship Safety
Scope of Work
Vulnerability to flooding (dynamic ship survivability analysis) for all statistically possible collision and grounding cases.
Total Risk (Safety Level)
- Flooding Survivability Analysis
- Fire Safety Analysis
- Post-Accident Systems Availability Analysis
- Evacuation and Rescue Analysis
The ability to estimate the probability of time to rollover (in fractions of a second) can be a very important tool to aid decision-making in emergencies, especially. The parameters f(TBHD) and F(Tflash) are estimated based on the average temperature in the fire space and the flash temperature of the contents of the adjacent space, respectively.
Concluding Remarks
Left: Temperature at 1.5 m height from floor level for a large public space at 4 minutes after ignition (Horvat et al. 2007) Right: Human injury analyzes for the same scenario (Guarin et al. 2007a).
RBD Case Story: Large Passenger Vessel
- Building Blocks of Risk-Based Design
- Advanced Evacuation Simulation
- Flooding Risk Assessment Background
- Fire Risk Assessment Background
- Early Implementation Results
- Flooding Survivability Analysis
- Fire Safety Analysis
- Safety Level
In the scenario considered, the fire originates on the forward starboard side of the lower deck, as illustrated in figure. Assessment of the risk to the ship's occupants in night and day scenarios (FSS code).
Regulatory Framework
Introduction
Today, the term 'Risk-Based Regulation' tends to be used alongside the term 'Goal-Based Standard' (GBS), which is a more recent initiative also at the IMO (and a term known somewhere another, where a regulatory reform is debated. ). The prescriptive requirements (in the Codes, Rules and Regulations) then need to be verified to meet the objectives and functional requirements and the ship itself needs to be verified in accordance with the Codes, Rules and Regulations.
Formal Safety Assessment .1 Historical Background
- Purpose of FSA
- Application-General
In the offshore industry, the use of risk analysis has been required since 1986 in Norway and in the UK since 1992 as a result of the Piper Alpha accident. In 1993, during the 62nd session of the IMO Maritime Safety Committee (MSC), the UK's Maritime and Coastguard Agency (MCA) (then MSA) proposed a standard five-step risk-based approach called the Formal Safety Assessment (FSA). . .
What is FSA?
Quick solutions were therefore preferred and an assessment of the costs and benefits of such solutions was not normally carried out. The FSA approach, on the other hand, systematically analyzes the various options available to control the risk, and also assesses both the costs and the benefits of those options if they are implemented.
Development of Risk Assessment and FSA
- Risk Assessment ‘Solo Watch-keeping During Period of Darkness’
- FSA – High Speed Craft
- FSA – Helicopter Landing Area on Cruise Ships as a Safety Measure
- FSA for Bulk Carriers
- Initial Studies
- Bulk Carrier FSA Studies at IMO
- Decision Making
- The Risk Control Options and the Decisions
- Note on the Decision-Making Related to Double Side Skin for Bulk Carriers
- Ongoing FSA on Electronic Chart Display and Information System
- Other Ongoing FSA Studies
Paragraph§6 of Norway and ICCL, (1997) summarizes how the FSA was carried out, namely: "The FSA was carried out with counter-. The IMO reads: "The committee noted that the cost-effectiveness of a helipad in terms of the cost of implementation divided by the expected number of additional lives saved (i.e., ICAF,4 the implicit cost of averting one death) is $37 million and that, recognizing the uncertainty in the assessment of both risk-benefit and cost, the group agrees that ICAF can range from about 12 to 73,000 million USD.'.
Discussion on FSA .1 FSA Work
- FSA Methods
- Open Issues
- Risk Acceptance Criteria
- The FSA Process
The FSA guidelines are quite specific about the format of safety risk acceptance criteria in relation to loss of life. A number of risk issues with large cost implications have been put on the agenda over the past two years, regardless of AMF studies.
Conclusions on FSA
In the IMO decision-making process, this criterion was considered and all risk control options with the cost of averting fatalities below USD 3 million were implemented. Most risk analysts see the FSA process as a method for coordinating all activities related to the decision-making process.
Goal Based Standards
- Definition of GBS
- Tier I: Goals
- Tier II: Functional Requirements
The structural parts of the ship must have a design that is compatible with the purpose of the space and ensures a certain degree of structural continuity. The design fatigue life shall not be less than the design life of the ship and shall be based on the environmental conditions in II.2 (final quote).
Risk Acceptance
- Methods to Justify Criteria
Risks that are less than in current building regulations can be accepted Compare with well-informed decisions made in democratic forums. Risk associated with the construction of the national natural gas power plant is hardly acceptable.
Decision Parameters
The cost of each risk management option should be presented along with the effect on the six items above. The costs of reducing the risk of injury and ill health should be presented (see discussion below).
Risk Evaluation Criteria
For each type of individual risk (i.e. the risk to an individual person) the risk of death, injury and ill health must be presented separately. For each of the social risk assessment criteria, results must be presented separately and aggregated.
Explicit Risk Evaluation Criteria – Individual Risk of Death, Injury and Ill Health for Passengers, Crew
- Purpose
- Background
- Individual Risk Criteria
- Comparison with Historical Data
If this is the case, the total individual risk for some ship types may be almost unacceptable. Similar evaluation criteria can be developed for individual risks of injury and ill health through comparison with other industries and transport.
Explicit Risk Evaluation Criteria – Societal Risk to Life for Passengers, Crew and third Parties
- Purpose
- Background
- Method
- Examples of Criteria and Comparison with Data for Some Ship Types
- Third Parties
- Cost Benefit and Cost Effectiveness Assessment
- Purpose
- Background
- Risk of Injuries and Ill Health
The social risk associated with the activity can be accepted depending on the importance of the activity for society. As noted above, an FSA may implicitly or explicitly address the risk of injury and ill health.
Environmental Risk Evaluation Criteria
Therefore, there has been no detailed discussion of environmental risk criteria based on real analyses. They concluded that the historical data currently available are insufficient to assess the environmental risk of oil tankers or to demonstrate the appropriateness of the proposed ALARP area.
The resulting ALARP limits make maritime oil transport effectively unacceptable, as spills of more than 1000 tonnes are in the intolerable range. The A1 scenario family develops into three groups that describe alternative directions for technological change in the energy system.
Risk Criteria for Use in Risk Based Design
The description of the risk-based regulatory regime within the maritime sector refers to the IMO Guidelines for Formal Safety Assessment. This shows that FSA can also be used to structure a risk and target-based regulation.
Risk-Based Approaches in the Context of the Regulatory Regime
Such a risk-based and targeted approach can be applied at any level, from the general ship safety level downwards. The envisaged future regulatory regime will facilitate the adoption of innovative ship designs that deviate from the prescribed rules.
General Procedure for Establishing Risk Criteria at Lower Level
UK (1998a) Formal Safety Assessment - Report of the Intersessional Correspondence Group on Helicopter Landing Areas (HLA). MSC 70/4/Add.1 and 'Additional information to support the official safety assessment of bulk carriers' MSC 70/INF.14.
Risk-Based Approval
Introduction
- Why Do We Need an Approval Procedure Related to Risk-Based Design
- Present Approval Process – A Prescriptive Procedure
- Risk-Based Approval Process – The Future Procedure
This second variant of risk-based ship design can be called “risk-based design optimization” to distinguish it from the first. Both types of risk-based design philosophy mentioned above require the same technology and framework that reflects and arises from the introduction of safety as an objective in the design process, as illustrated in the figure below.
Acceptance of the Alternative Design
- Safety Equivalent Provisions in SOLAS 74, ICLL 66 and STCW 95
- SOLAS II-2/17 Related to Fire Safety
- Future Regulations Allowing for Alternative Designs
- SOLAS II-1 Related to Damage Stability
- SOLAS 2009 Will Replace SOLAS 90
- High-Speed-Craft Code Requirements for Selected Systems
- Different Acceptance Criterion Philosophies
- Risk Evaluation Criteria at IMO
- Risk Acceptance Criteria for Main Ship Functions
- Cost-Effectiveness
- Risk Balance
At MSC82 a broadening of the safety equivalence for systems was agreed and this is documented in MSC/Circ.1212. It is well known that many ship functions contribute to the overall safety of the vessel.
Stakeholders in the Approval Process – How Do They Work Together?
- Design and Construction Phase
- Operational Phase
Designer: Involvement is concentrated in the design and construction phases, and the emphasis in qualification upgrades is on the application of risk-based design tools. However, all parties need an adjustment process, to a level of knowledge that corresponds to their type of involvement in the risk-based design.
How Do Risk-Based Design and the Associated Approval Work Together?
Note that this early design activity was introduced in the introduction as a risk-based design optimization. It is unlikely that any ship will be entirely risk-based in the near future.
Requirements to the Documentation Related to the Approval
- The Approval Matrix – An Easy Guideline
- Project Category
Traditional approaches to achieving security on board ships have involved adopting a number of complex and often unrelated requirements for the various components of the "ship" system. The value of each to the overall design goal is sometimes unknown, and the complementary or compensatory nature of these provisions cannot be quantified. In addition, test and analysis requirements may vary depending on the type approval authority's confidence in the project.
Approval of Ship Systems
- Acceptance
In the following, the alignment of the risk-based system approval process with the shipyard's main business process is illustrated in Fig. Determination of the interfaces to the global risk model (impact on ship functions and event trees).
Operating a Risk-Based Approved Ship
- On Board Documentation
- The International Safety Management Code
- Inspection of the Risk-Based Ship
- Owner’s Inspection
Supported by appropriate documentation, see above, the ship's risk-based elements will need to be understood prior to verification. Class survey, flag state inspection and maritime inspection must understand the risk-based nature of the ship.
Conclusions
As in many other industries, the responsibility lies with the owner to ensure that the information on board is correct. Management must also confirm that the officers and crew on board are aware of the ship's risk-based design and operational characteristics, which should be described in the safety management system, and verify that they have undergone appropriate training to ensure that these functions are not compromised.
