Approving Novel Concepts for Harsh Environments: A Classification Perspective

Transcription

1 Approving Novel Concepts for Harsh Environments: A Classification Perspective C. Baker, J. Ballesio, R. Basu, R. Conachey, E. Legland, C. Serratella, G. Wang American Bureau of Shipping (ABS) Presented at the Arctic Shipping 2006 conference held in St. Petersburg, Russia, April 24-26, 2006, and reprinted with the kind permission of the organizers of Arctic Shipping 2006 ABSTRACT Marine transportation of oil and gas from the Arctic will pose new challenges to the design and operation of ships. Many technology innovations are being studied and implemented to respond to these challenges, and extensive research and development is needed for managing risk associated with operating oil and gas carriers in the Arctic. The review and approval of novel concepts using risk-based methods provide a proactive approach to help identify unknown risks and use that information as a tool in decision-making. The review process includes identification of hazards and failure modes associated with the concept and a comparison of the level of risks with existing marine/offshore practice. The next stage involves moving forward with a project into detailed design and ultimately issuance of class approval. INTRODUCTION Due to the increasing demand of oil and natural gas in Europe and North America, the transportation of these commodities originating from Russia will grow considerably. Such transportation will traverse Arctic regions for which the marine industry has limited experience. On the other hand, classification rules and guides are largely of prescriptive nature, and have been historically established from principles of naval architecture, marine engineering and from the experience gained from past history and the existing marine fleet. They have proven satisfactory by service experience and systematic analysis, many of them for over a hundred years. The introduction of oil and gas carriers into the Arctic environment will involve combining several existing technologies into a new application. In many cases, the above leads to the use of novel concepts, which are defined as applications or processes that have no previous experience in the environment being proposed. In working with novel concepts these classes of concepts have been defined: Existing design / process / procedures in new or novel applications Existing design / process / procedures challenging the present boundaries/envelope of current offshore or marine applications New or novel design / process / procedures in existing application New or novel design / process / procedures in new or novel application Novel concepts are not inherently more risky. In fact, in many cases, they may prove in operation to pose less risk than prior technologies. However, when they are proposed initially, they often are thought of as high risk. For new concepts, the industry (particularly regulators, classification societies, investors, and other entities that share those risks) often perceive those risks as high. One way to help address those risk perceptions is to include as many of those stakeholders as practical in performing the novel concept review. New or novel concepts often do not have any classification rules, statutory regulations, or industry standards directly applicable to them, nor do they have any prior in-service experience. Therefore novel concepts require a different and more flexible approach to classification, including the use of Approving Novel Concepts for Harsh Environments: A Classification Perspective 45

2 new tools and techniques in order to determine if the concept provides acceptable levels of safety in line with current offshore and marine industry practice. Extensive research is necessary for managing risk and addressing hazards when novel concepts are to be deployed. In the early phases of novel technology development, there hazards include: Known hazards, Hazards whose effects are not totally understood, and Hazards that have not been recognized. Hazards that are unknown or not fully understood cannot be managed or mitigated appropriately, potentially resulting in major accidents. The American Bureau of Shipping (ABS) has developed a guidance document, the Guidance Notes on the Review and Approval of Novel Concepts [Ref. 1], in order to offer a methodology for requesting the classification of a novel design and facilitate its approval. This methodology relies heavily on risk assessment techniques. Risk-based methods provide a proactive approach to help identify unknown risks and use that information as a tool in decision-making. This paper describes a risk-based decision-making (RBDM) approach and also highlights some examples where a degree of novelty exists when considering oil and gas transportation and handling in an Arctic environment. In its more complex applications, an RBDM review process may call for full-scale application of risk assessment methodologies, including quantitative frequency assessment, detailed consequence analysis, and comprehensive risk evaluation. However, at the novel concept stage, there is generally not enough information to provide the input those methods require. This paper addresses performing the kind of review needed at early stages in development of a conceptual design. RISK-BASED DECISION MAKING The steps of an RBDM process are illustrated in Figure 1. The first step is for the team to structure the decision that needs to be made. As with many sequential processes, the first step in an RBDM process is critical. If it does not go right, there is little hope for the steps that follow. In the novel concepts review process described in this paper, structuring the decision involves defining the questions that, if answered, would help the decision-makers make a better decision. Examples of those questions include: What aspects of this project pose significant risks? Of those risks, which of them can be addressed effectively by design measures? Do existing codes, standards, and regulations apply to the aspects of the novel concept that are important to controlling the significant risks? What aspects of the technology that are not specified by current codes, standards, rules, and regulations need to be specified, accomplished, and verified? These kinds of questions can be evaluated in a risk assessment (i.e., Step 2 in the RBDM process) using techniques such as a hazard identification (HAZID) study, change analysis, hazard and operability study or any of several other techniques described in the ABS Novel Concepts Guideline. Such risk assessments generally serve to document the pertinent existing risk mitigation and management measures. This allows the novel concepts review team to identify those areas that could be fruitful for new risk management efforts (Step 3). 46 Approving Novel Concepts for Harsh Environments: A Classification Perspective

3 Decision Structure Risk Assessment Risk Management Impact Assessment Risk Communication Figure 1 Risk-Based Decision-Making Process Impact assessment in a RBDM process (Step 4) can consist of re-analysis of the technology after new risk management measures are designed or can be an on-going process that provides verification that the design intent of the risk management measures was achieved. Risk communication in the novel concepts review process is important because it serves to provide risk information to the regulators, classification society, and financial community. Having these entities accept the risk management approaches selected for the novel concept project as valid is an important part of getting them to play their role in making the project successful. This step is shown in Figure 1 as occurring concurrently with the other steps. The best way to make that happen is to involve the important stakeholders in implementing the RBDM process. The basis for an effective RBDM application is to perform as little analysis as is necessary to provide the information needed by decision makers. This leads to very focused risk analysis efforts, including the use of approaches such as change analysis, relative ranking, and other qualitative techniques in many cases. If required, more detailed quantitative studies can be performed; however, this is seldom necessary, (or even possible) at the conceptual stage. Those studies are reserved for when they are more valuable (i.e., when detailed engineering efforts have developed adequate information to consider). NOVEL CONCEPTS REVIEW PROCESS As stated previously, a novel concept review needs to be able to contribute to the development of a novel project without requiring extensive information, at least for the initial stages of the project. Figure 2 illustrates the review processes that involve increasingly detailed information the further into project development the concept goes. The figure provides a general overview showing that as more engineering, testing, and/or risk assessments are conducted for the concept, the level of confidence increases as the concept performance approaches the required performance limits. The performance limits may include required reliability, function, safety, strength etc. Some of the typical risk techniques and engineering steps that would be expected during the development of a new concept are shown along the concept evolution route. As more engineering and/or testing is conducted a better understanding of the system parameters and behavior can be achieved. Note that the knowledge being gained during the concept development does not stop at the end of detailed design. Particularly with novel concepts, it is important that information continues to be gathered during the construction and operation phases of a project. Approving Novel Concepts for Harsh Environments: A Classification Perspective 47

4 AIP Phase ABS TECHNICAL PAPERS 2006 Engineering / Operation Target Performance Risk Assessment ABS Uncertainty Uncertainty Concept Idea / Design Basis HAZID / Change Analysis Conceptual Design Whatif Engineering Prototype Development and Testing Detailed Design Increasing Confidence Increasing Confidence HAZOP FMEA Fault Tree/ Event Tree Reliability Analysis Class Approval Phase Increasing understanding of system parameters and behavior Construction Installation / Operation Required performance limits of system Increasing understanding of system risks Survey Figure 2 Novel Concepts Review Process [Ref. 1] During the concept evolution, risk assessment will be conducted to ensure risks related to the concept are being identified, managed during the development, and are within tolerable ranges by the completion of detailed design. The risk assessments have been arranged in general order of complexity and required concept development. However, there are instances where more detailed risk assessment techniques are conducted during earlier stages of the concept development. At the far right side of the figure, the general classification/certification phases are noted. It is important to note that this is a generalized figure of the concept evolution and there may be overlap between specific engineering step progression as well as different timing of the application of the risk assessment techniques than shown on the figure. Most of the novel concepts reviews that ABS has performed have been oriented to helping the project team achieve an Approval in Principle (AIP) from the classification society. AIP status provides project management and external personnel evaluating the project with confidence that the concept is one that can proceed successfully through the classification process, assuming that the issues identified in the concepts review are addressed and the conditions communicated as part of the AIP package are met. NOVEL FEATURES: CHALLENGES IN ARCTIC TRANSPORTATION The following sections of this paper describe some of the key issues to consider in the marine transportation of oil and gas in Arctic environments. Also covered is the approach that ABS follows for the classification of vessels operating in this environment. Oil and gas transportation in an Arctic environment brings many hazards and operational issues that if not considered carefully, could potentially lead to undesired incidents and catastrophic accidents. 48 Approving Novel Concepts for Harsh Environments: A Classification Perspective

5 This section will highlight some of the issues that need special consideration for Arctic transportation. 1. Safety of Hull Structure The hull structures of ice-going ships are built to Ice Class Rules. The Finnish Swedish Ice Class Rules (FSICR) have been the common industry standard for decades for Baltic shipping, for vessels designed for operation in first year ice conditions. Other rules such as the established Russian Ice Class Rules are applied to vessels designed for operation in multi-year ice. IACS is working towards adopting a new set of Polar Ice Class Rules to unify the requirements to meet higher safety standards and changing demands of trading in the Arctic. Robust Design: Unique design scenarios are encountered when considering hull structural design in the Arctic environment. Climate and sea conditions in the Arctic region are harsh. Compared with the winter Baltic Sea environment, the Arctic environment is more extreme during the winter months. Vessels may also confront thicker ice. Infrastructure support is very limited and there are few icebreakers available in this region to support oil or gas transportation. Arctic conditions call for additional and unique scenarios to be considered in the design of oil and gas carriers. Oil and gas carriers operating in most areas of the Arctic may require a certain level of ice-breaking capability which is not typically necessary in the Baltic Sea. Suitability of Containment Systems: One of the major concerns for LNG carriers is whether existing LNG containment systems are suitable for Arctic operation. Existing Ice Class Rules have established design guidance for hull structures in an ice belt, design of external hull surfaces that will encounter ice, and typically specify local ice loads for designing shell structures. Some Ice Class Rules specify additional hull girder bending loads for vessels that may be raised by an ice pack. In this regard, the consideration of the design adequacy and longevity of the various LNG containment systems as they are exposed to transmission of these loads through the hull structure needs to be considered. Vibratory ice loads will need to be considered for LNG containment system design. Though they do not directly encounter ice floating in sea, the LNG containment systems may feel the vibratory excitations from ice that are transmitted through hull structures and their response to this type of loading is not well understood. Global extreme ice loads may also need to be considered for LNG containment system design. During the Arctic winter, a vessel may ram into large ice ridge or floating ice, and the consequential deceleration of the vessels may pose new threats to the LNG containment systems. There are very limited studies on this scenario and data collection and further investigation is needed. Classification societies are actively applying the latest technology in addressing ice strengthening designs for large ice-going commercial ships. Such efforts of tackling new challenges to hull designs that have virtually no experience base have led, for example, to the release of the ABS Guidance Notes on Ice Class [Ref. 2] that provide formalized procedure for side structure designs. Extending the Size Envelope: Other than the aforementioned unique design scenarios, global extreme ice loads and vibratory ice loads, technical challenges also exist regarding the design guidance provided by the current Ice Class Rules. These rules are based on experiences of previous ice-going vessels, many of which are smaller ships with transverse framing systems. The marine industry has very limited experience in operating large oil and gas carriers in the winter Baltic Sea, and only limited experience in continuously operating oil and gas carriers in the winter Arctic environment. Impacts of extending the current Ice Class Rules to Arctic Operation are yet to be seen and may need consideration via a novel concept approach. Approving Novel Concepts for Harsh Environments: A Classification Perspective 49

6 2. Propulsion and Auxiliary Machinery Issues The machinery on vessels operating in very low ambient temperatures (such as -30C or less) may be subject to unusual operational events not occurring at higher temperatures. A Failure Mode Effects Analysis (FMEA) conducted early in the design evolution on various machinery and systems will help in identifying additional features or equipment/system design changes necessary to prevent failures from occurring or to mitigate consequences, if failure occurs. Operating Environment and Need for Special Features: A vessel with diesel engines installed for propulsion and electricity generation may encounter situations in which the engines are unable to fire because of the low temperature of the combustion air fuel mixture may fail to allow auto ignition when compressed in the engine cylinders. On the other hand if auto ignition is able to occur in the engine cylinders, the engine cylinder design pressure limits may be exceeded because more air can enter the cylinder due to the cold air s higher specific density. To prevent the failure mode of an engine being unable to fire, a special feature may be required, such as incorporating a combustion air pre-heater. The pre-heating may be accomplished through the use of electric or steam heating or using the diesel s jacket water waste heat. Additional safeguards for the pre-heater are necessary to ensure pre-heating is continuous. For the case of electric pre-heating, the electric power supply must be continuous so redundant electric generating capacity must be made available. For the case of steam heating, the boiler must be fitted with features to ensure continuous operation such as emergency electric power for the boiler controls, redundant boiler feedwater pumps, etc. If jacket water waste heat is used, redundant pumps for the heat exchanger may be necessary depending on the design arrangements. To prevent cylinder overpressure failure or, in other words, the engine producing too much power, overpressure protection can be achieved by installing a charge air bypass. To prevent cylinder overpressure failure which leads to the engine producing too much power, overpressure protection can be achieved by installing a charge air bypass between the turbocharger compressor outlet to the turbocharger turbine inlet along with a charge air waste gate on the engine s air receiver and an exhaust waste gate from the turbocharger turbine inlet to the turbocharger turbine outlet. By opening the bypass or waste gates, the quantity of charge air to the engine cylinders can be reduced thereby preventing cylinder overpressure. The arrangement can also be used to improve turbocharger performance and fuel efficiency at low engine loads when the vessel is operating in ice. Machinery arrangements may be required to be modified as a result of low ambient temperatures. For example, in many cases, combustion air for diesel engines is taken directly from the machinery space. In very cold climates this arrangement will cause the machinery space s temperature to become too low, possibly affecting equipment function and personnel comfort and ability to perform maintenance. Therefore, the combustion air needs to be directly supplied to the diesel engines through duct work. The added advantage of this ducting arrangement is the combustion air temperature can be better controlled. 3. Winterization of systems associated with the safe operation of LNG carriers Venting is one of the key issues essential to maintaining LNG cargo tanks integrity due to the boiloff of gas evaporating from the tanks. Normally, there are elaborate measures to ensure boil-off gas utilization at all times in places like the boilers on conventional ships but more recently using it in diesel engines or gas turbines. The gas from the tanks is compressed and heated before discharged to the machinery spaces. Hence the gas lines are not insulated. Therefore, there may be a need to consider the effect of temperature drop of the gas being supplied to machinery spaces. Ice Accretion/Formation: The adverse effects of ice loads on the relief valves and the PV valves in the vapor lines on deck must be specially considered during normal operation and cargo loading. 50 Approving Novel Concepts for Harsh Environments: A Classification Perspective

7 Both the design and operational procedures for the relief valves must be carefully considered. These systems may possibly require the use of heat tracing to ensure they are available and functional when called upon. Emergency shutdown valves at the manifold and at the tanks are for safeguarding against various emergency events during loading and discharging. These valves are on deck and are required to be fail closed type. These valves are critical in the safety chain on LNG carriers hence it is essential that their operation is guaranteed at all weather temperatures on deck. Harsh Environments: One of the key issues is that LNG is transported at -163 deg C, and elaborate efforts are made in the ship design to ensure that the liquid remains at this temperature, i.e. the liquid does not start to warm up since any slight increase in temperature will result in more boil-off. The volumetric ratio between liquid and gas is 1:600, and the pressure will rise rapidly if this vapor is not allowed to escape. When heating all the valves and equipment mentioned above, to ensure their functionality in the Arctic environment and other low temperature environments, there is always a chance of creating vapor traps which may impair the operation of these valves. It is therefore essential to have some means of temperature control to keep this equipment free of ice but also not create heat transfer into the LNG being transported. In addition, the trade-off among the beneficial effects of a colder ambient temperature on the boil-off rate, the need for heating some equipment to ensure functionality and the heat gain into the system from same, and the increased sloshing, which may occur in harsh wave environments causing more boil-off, need to be carefully considered. Loading Operations: LNG ships, because of the limitation of the design of the loading arms, are required to be ballasted or de-ballasted simultaneously when cargo is being transferred. Also, all cargo tanks are loaded simultaneously. This will require ballast water to be taken on board, and may require heating of the ballast tanks just sufficiently to prevent freezing but while also considering at the same time any excessive temperature rise in ballast space will affect the cargo boil-off rate through the inner hull. Further typical water spray operations used during offloading may require heating of the water spray to prevent freezing or the hull structure in way of the cargo manifold. This may require some heating equipment be installed in the ballast space to prevent ice build up as a result of water spray. There are several issues relating to safety systems and the functionality and suitability of such systems during operations in low temperature environments. Current classification rules and statutory requirements stipulate specific fire detection and fire extinguishing systems to be installed in areas exposed to the weather. Examples of such arrangements on deck are dry powder and water deluge for the poop front to cool down the accommodation block. Even if the lines are heated, the water deluge system will in many cases be ineffective. Due to the layout of currently used on LNG carriers, these designs have a greater exposed deck area. The additional deck-plating is either curved to cover the Moss type spheres or as an integrated part of the containment system for both the MKIII and No 96 membrane tanks. This exposed deck plating must be designed in such a way as to withstand the additional load due to snow accumulation and ice build-up caused by spraying. Other exposed deck plating must be able to resist any dynamic loads due to sliding of the snow form the inclined decks or dropped ice. The snow build-up and ice accumulation is also an additional hazard for operations by crew on the deck, particularly the passageway on each side of the vessel. Visibility: The summer fog, mainly at coastal regions and around islands in the western part of the Barents Sea, the winter snowstorms and the darkness are major factors of reduced visibility in the Arctic Regions. The overall arrangement of an LNG carrier and the inability of bridge personnel to Approving Novel Concepts for Harsh Environments: A Classification Perspective 51

8 see directly in front of the vessel due to the containment system height above deck, may necessitate the use of special features such as cameras and other devices to assist in navigation. 4. Emergency, Evacuation, and Rescue The Arctic and polar environments present many significant challenges to the design and use of emergency, evacuation, and rescue devices. Much of the hardware devised for such use is designed for more temperate climates, and Arctic deployment presents dilemmas. Fire mains can freeze. Use of free fall life boats, in ice conditions, may have lamentable results. Materials (such as used in life vests) become brittle. Working devices (such as sheaves, blocks, and davits) can freeze in place refusing to move. Presented in this section are Arctic and polar risks associated with use of emergency, evacuation, and rescue devices Life Saving Equipment (LSE): Arctic conditions lead to many special considerations and risks related to life saving equipment, including: The presence of ice on the sea surface may inhibit deployment of life rafts and rescue boats, and also in making distance from a ship in distress The presence of ice on deployment mechanisms such as davits that may interfere with lowering of boats and rafts Crew survival/rescue time in life boats and rafts in Arctic temperatures is limited The thermal insulating qualities of immersion suits Operability of escape chutes, hatches, chutes, and doors, in conditions of ice and snow may be limited. Equipment Deployment: Launching life boats and rafts offer numerous risks: Entrance to boat stations can be obstructed by snow and ice De-icing equipment (steam hoses) may freeze Freezing of hinges, lashes, gaskets, brake guide wires, and sheaves Snow and ice on winches may interfere with their use Ice on hooks, latches and hydrostatics release couplings may interfere with their use Freezing of winches Frozen surface to which a boat is deployed (and hence laid over of her shear) Fire Fighting Equipment: Significant risks are associated with fire fighting equipment, the most significant being the potential freezing of fluids in lines, thereby depriving crew of the use of the firefighting systems. Specific risks include: Freezing of fire water hoses, piping, nozzles, etc. Fire mains are charged and pressure is maintained with a topping-off pump. At 30 degrees, this may have to be changed and the fire mains drained until needed. Portable fire extinguisher storage may be obstructed or frozen Fire dampers may freeze in the stowage position (generally closed in temperate climates) 5. Human Factors There are significant implications on human capability when working in cold weather environments, and working under these conditions can be highly hazardous to a person s health. These implications present significant operational and design concerns for Arctic and polar operations of commercial ships, among them: Personal protection from exposure to cold Treatment of weather related medical emergencies (hypothermia, frost bite) Operating convoys of ships Availability of crew with requisite skills, knowledge, and abilities Cargo handling (loading and unloading). 52 Approving Novel Concepts for Harsh Environments: A Classification Perspective

9 Risks Related to Personal Protection: Human response to cold varies according to ambient temperature, period of exposure, level of protection (clothing, immersion suits, parkas, mittens, etc.), and individual differences due to age, health, and other factors. The list of potential injuries and issues for occupational work in cold environments is lengthy. Two significant cold weather related health concerns are hypothermia and frost bite. Hypothermia is a rapid, progressive mental and physical collapse due to the body s warming mechanisms failing to maintain normal body temperatures. Frost bite is damage to tissue during cold exposure, commonly caused by freezing of the tissue and surrounding area. Risk and Treatment of Weather Related Medical Emergencies: Given that Arctic and polar regions are typically remote from modern and comprehensive medical treatment facilities, and given that both hypothermia and frost bite can present significant health risks (including death), the risk to humans due to inadequate medical treatment may be severe. For either, those risks include: Performance decrements on the part of crew, potentially leading to human error and accidents Transient, temporary disability and health hazards (hyperthermia not leading to death or frost bite) Permanent disability (due to frost bite, including amputations of limbs) Hypothermic or gangrenous death. Risks in Operating and Communicating within Convoys: These risks are associated with operating as a convoy of cargo ships and an ice breaking ship. A principal risk of operating as a convoy steaming in a single ice channel is run-down collisions. Sufficient distance between ships is needed to allow for following and lead ships speed corrections, while sufficient proximity ( closeness ) may be required in order to prevent an ice channel from closing. Timely, accurate, and precise communications among all ships in a convoy are necessary to maintain the appropriate distances and speeds. Also required are mariners with sufficient convoy and ice operations knowledge, skills, and abilities to understand voice and other signals, and to then mediate an appropriate ships response. Specific risks to safe convoy operations include: Language barriers, garbled or unintelligible voice signals Conditions of ice dictating proximal closing distances Insufficient experience and training to interpret and comply with command communication and signals Handling characteristics of the ships forming the convoy. Risks Related to Crew Availability and Skills: Ships operating in Arctic and Polar regions have a long history. However, the extent of the operation is on the verge of dramatic growth. There is also a long history of operating crude and gas carriers - there is not, however, a long history of these types of ships operating in Arctic conditions. The growth may lead to insufficient numbers of adequately skilled and experienced mariners. There are potential risks that: Ships may sail understaffed, especially ice-experienced Masters and Mates Ships, especially LNG ships, may sail with inexperienced crew lacking sufficient experience and training. Risks in Cargo Handling: Cargo ships are active places. Much of this activity is performed on deck, and much of it is maintenance related. Exposing crew to occasionally very low ambient temperatures, commensurate with a potential for moderate to high winds speed over deck, is inadvisable. During transit of an LNG, terminal to terminal, no deck presence by humans is generally needed. During cargo loading/unloading, however, people are generally needed to hook up piping to the ships manifold, and to then monitor the manifold connection point for the duration of cargo transfer. This can be about a 12 hour operation. It may be that the monitoring task can be achieved remotely using closed-circuit television. Approving Novel Concepts for Harsh Environments: A Classification Perspective 53

10 MANAGING RISKS FOR ARCTIC TRANSPORTATION Due to the issues identified above, and more generally, due to the lack of experience in marine transportation in an Arctic environment, the management of risks should follow a more comprehensive and systematic approach. Additionally, new vessels designed for trade in this harsh environment will bring a series of novel ideas and concepts for which no industry standards, statutory regulations or classification rules will be fully applicable. For the classification point of view, the assessment of these novel concepts can be performed by a combination of engineering analysis and risk assessments. The ABS Guidance Notes on Review and Approval of Novel Concepts were developed to offer owners and designers a new methodology for requesting the classification of a novel design and to facilitate its approval. They are intended to cover proposed applications that have not been proven in the maritime or offshore industry and would therefore be considered novel for those environments. The methodology combines engineering analysis, field testing and risk assessments to compensate for the lack of prescriptive classification rules, in order to determine if the concept provides acceptable levels of safety in line with current offshore and marine industry practice. Design companies, when exploring the possibilities of a new technology or concept are looking for some confirmation that the design is feasible and will be capable of attaining classification. As stated in the opening paragraphs above the ABS Guidance Notes offers the Approval In Principle (AIP) as a first milestone in the road for classification of novel concepts. The benefit of gaining AIP is that the client can obtain a document issued by a knowledgeable independent marine and offshore society as evidence of preliminary acceptability of the concept for classification to provide to regulatory bodies and project partners. It confirms that there are no significant impediments to further the development of the concept. The Guidance Notes divide the class approval process into the following stages: Determine Approval Route Approval In Principle (concept development phase) Approval Road Map Final Class Approval (detailed design/construction/commissioning phase) Maintenance of Class (implementation/operational phase) The process that the client and ABS would follow to achieve these milestones is outlined in Fig. 3. This process involves ABS and the client working together to accomplish the following: Determine Approval Route: As a first step, the approval route to achieve AIP needs to be determined. This will involve the client and ABS meeting to discuss the concept, its purpose, its novel features and where it deviates from traditional approaches, the proposed operating envelope and the potential impact of the concept on other systems or components. Agreement will be reached as to the best methods to assess risk in the AIP phase as well as the appropriate level of engineering analysis. AIP and Approval Road Map: As a minimum, the goal of achieving AIP should be the identification of all hazards and failure modes applicable to the novel concept application along with suitable support information demonstrating the control of these hazards and failure modes are feasible. Throughout this phase, as the concept is being evaluated, an Approval Road Map will be defined which will lay out conditions to achieving full approval. The road map will define clearly the approach needed from a risk assessment and engineering analysis standpoint to justify those novel aspects not covered by existing rules, codes and standards. Final Class Approval: This phase covers typical class approval submittals comprised of typical drawings, specifications, calculation packages and support documentation, along with submissions of those items outlined in the Approval Road Map. Upon completion of this stage, the potential hazards 54 Approving Novel Concepts for Harsh Environments: A Classification Perspective

11 and failure modes for the novel features will have been assessed versus agreed-upon acceptance criteria to a level of confidence necessary to grant full class approval to the design. Maintenance of Class: As a final condition of class approval, ABS will determine the necessary additional conditions assigned to the maintenance of class via additional survey scope or frequency of attendance, condition monitoring, required maintenance and inspection techniques to maintain levels of monitoring assumed in the design phase which may have been necessary to achieve various design parameters, and finally as a means to verify assumptions and predictions made throughout the process. Client New/ Novel Concept Conceptual Design Detailed Design Const. & Install. Operations Initial Request to Approve Concept Conceptual Engineering & Risk Assessment Submittals Detailed Engineering & Risk Assessment Submittals Survey During Construction Survey During Operation ABS Determine Approval Route Approval In Principle Approval Road Map Final Class Approval Maintenance of Class Figure 3: Novel Concept Approval Process [Ref. 1] Risk Assessments Risk assessments at the conceptual stages of a novel concept are part of the requirement to obtain AIP. The specific requirements for risk assessments are based on the degree of novelty of the application. At a minimum, a qualitative risk assessment on the new concept will be required. In general for the concept development phase, a design basis, preliminary engineering and possibly testing results are available for use in the risk assessments. A qualitative risk assessment technique is generally the most suited method at this concept design phase. There are various qualitative risk techniques that can be applied, such as HAZID (Hazard Identification), What-if and HAZOP (Hazard and Operability Analysis). However, the most appropriate technique depends on the available concept design information and type of system being proposed. Conducting a qualitative risk assessment involves a team brainstorming session that provides a unique forum for designers, operational and safety personnel, as well as ABS representatives, to discuss the concept in a structured manner. Prior to conducting a qualitative risk evaluation, the organization proposing the novel concept has to submit information on what method will be used, what subject matter experts will participate and what scope the assessment will have. Additionally, a risk ranking methodology or risk matrix must be submitted and approved by ABS. After AIP has been assigned, there may be the need to perform more detailed, but more focused, risk assessments to assure that the risks identified in earlier phases are properly managed. Such assessments may involve quantitative risk assessments, such as fault trees and event trees in order to attain the necessary level of accuracy. Approving Novel Concepts for Harsh Environments: A Classification Perspective 55

12 CONCLUSIONS The increasing needs for oil and gas transportation in Arctic regions will bring the requirement to extend the envelope of current technologies. The systematic and detailed use of risk analyses techniques to compensate for the lack of industry experience will aid the project teams in ensuring that key design and operations issues as touched upon above are addressed. ABS has the guidance, tools and processes in place to meet this challenge. This paper has described some of the important and unique issues that need to be considered for Arctic marine transportation of oil and gas as well as an approach to support the classification of these novel concepts. To meet the industry need for safer ice-going oil and gas carriers, ABS has developed guidance on hull designs and cold weather operations, and is continuing the development of other key technologies that will support the current innovations. REFERENCES 1. American Bureau of Shipping, (June 2003), Guidance Notes on the Review and Approval of Novel Concepts, ABS 2003, Houston, USA 2. American Bureau of Shipping, (April 2005), Guidance Notes On Ice Class, ABS 2005, Houston, USA 3. American Bureau of Shipping, (to be published in 2006), Guide on Cold Weather Operations, internal draft April 2006, Houston, USA 4. M. Mahmood, A. Revenga, Design Aspects of Winterized and Arctic LNG Carriers: A Classification Perspective, OMAE 2006, to be presented 4-9 June 2006, Hamburg, Germany 5. E. Legland, D. Diettrich, R. Conachey, C. Baker, G. Wang, Operation of Arctic LNG carriers: conditions, crew and cargo, GASTECH 2006, to be presented 4-7 December 2006, Abu Dhabi, UAE ACKNOWLEDGEMENT The authors would like to acknowledge the valuable comments from Dr. Kirsi Tikka. 56 Approving Novel Concepts for Harsh Environments: A Classification Perspective