ABS - Low Temperature Operations

Interest in ice-class tankers has been steadily

rising as oil export from Russias Northern regions

becomes increasingly viable. According to industry

analysts, this interest, coupled with a regulatory-driven

accelerated phase-out of older ships, will result in the ice

class tanker fleet growing by 18 million dwt by 2008. There are

currently around 500 high ice class ships in service or on order.

While about 70 percent of the present ice fleet is under 20,000 dwt,

the trend is towards larger capacities, accompanying growing

confidence in large vessel behavior in heavy ice conditions.

TABLE OF CONTENTS

ABS Issues Guidance for Vessels Operating in Low Temperature Environments 2

Managing the Risks Associated with Arctic Shipping 4

Managing Ballast in Very Cold Temperatures 6

Russias Energy Reserves Lure Ships and Offshore Units into the Arctic 7

Critical Issues to Consider in Developing Polar Class LNG Carriers 8

The Double-Acting Tanker 11

Further Ice Research Activities at ABS 12

Regulatory Oversight for Arctic Shipping 14

IACS Develops Unified Requirements for Polar Ice Class 16

Remodeled Rig Exploits Sakhalins Riches 17

The First Arctic Tanker 18

P A G E 2 L O W T E M P E R A T U R E O P E R A T I O N S P O L A R C L A S S G U I D A N C E

Vast reserves of oil and gas are expected to beexploited in the Russian Arctic including theBarents Sea, the Pechora Sea and the Kara Sea.

There are also new gas fields being developed on theYamal Peninsula. There is a need for large tankers andLNG carriers to transport the gas and oil that will beproduced from these far northern locations.

Vessels operating in the Arctic region are exposed to a number of unique demands. The presence of firstyear and multi year ice imposes additional loads on thehull, propulsion system and appendages. Low tempera-tures impact the ship, and the cold, the lack of lightand visibility affect the crew. However, current opera-tional experience in the Arctic is limited to much small-

er vessels thanthose that areenvisaged.

All this, inaddition tothe probabilitythat new own-ers and opera-tors withoutoperationalexperience inthese harshconditionswill enter the

market, impose a need for guidance for these ownersand operators as well as for shipyards building vesselsfor cold weather service.

To help address these challenges, ABS has produced the Guide for Vessels Operating in Low TemperatureEnvironments. Guidance is provided for the preparationof vessels and other marine structures and their crewfor operation in harsh environments. This Guide doesnot include requirements related to hull strengtheningand machinery requirements which are covered byexisting ice class Rules. Vessels designed and equippedin accordance with the requirements of this guide areeligible for a special class notation, but the applicationof the requirements is optional.

Each Section of the Guide has a correspondingAppendix providing additional resource material to aidthe designer/owner in understanding and meeting the

Guides requirements. Issues related to personnel safetyand training are also covered. Supplementary informa-tion related to special weather conditions and vesseloperating considerations are included.

Materials, Welds and CoatingsSuitable materials for low temperatures are mandatoryfor proper functioning of the hull structure and equip-ment. This section of the Guide provides requirementsfor material classes to be used in the hulls structuralmembers, material grades for the design service temper-ature, material testing temperatures and alternativerequirements for higher strength steels. Coatingsrequirements, together with additional guidance oncoating selections for various parts of the vessel, arelisted.

Hull Construction and EquipmentFresh water, ballast and fuel oil tanks should be carefully placed or fitted with heating equipment toavoid the chance of the tanks contents freezing or leaking into the environment. The vessels bow should be designed to reduce the effects of spray from freezing and collecting on the bow area. Bridgewings and deck houses should be specially designed or enclosed to protect equipment and crew. Vessel stability should take into account the effects of icebuild-up on the hull.

Vessel Systems and MachineryThe effects of cold air can have unintended effects onsystems and machinery. Accordingly, the combustion air system is required to be routed directly to the primemovers to avoid exposing machinery and crew to theambient temperature. Additional heating of lube oilmay be needed for equipment located in the machineryspace.

Deck equipment should be provided with heaters forreliable operation. Piping systems need to be providedwith gaskets and hoses suitable for low temperaturesalong with arrangements to drain piping to preventfreezing damage. The accomodation heating systemshould be supplemented with additional heating unitsand insulation for crew comfort.

Fire fighting and protection systems components are to be specially located to prevent freezing or providedwith heating. In the event of an emergency, the emer-

ABS Issues Guidance for Vessels Operating in Low Temperature Environments

P A G E 3L O W T E M P E R A T U R E O P E R A T I O N S P O L A R C L A S S G U I D A N C E

gency source of power is to be increased to provideheating for selected spaces for crew protection.

Safety SystemsOperations in cold climates require additional equip-ment to receive weather reports, special radar to makecontact with ice, and lights suitable for the cold. Lifeboats should be enclosed and specially designed tooperate in the cold. Additional features should beincluded such as heating and communications equip-ment. Launching equipment should be designed toavoid the effects of freezing ice. Immersion suits arenecessary for crew survival.

Specific Vessel RequirementsSome vessel types require additional consideration forlow temperature operation because of their specialdesign or operational features. Additional requirementsare included for LNG carriers, ore carriers, tankers, andsupport vessels.

Crew ConsiderationsWorking in cold weather can impact the crew unlessproper preparations are made to equip the vessel andthe crew for operation in the cold, dark and icy condi-tions. Clothing and work station design requirements arelisted in the Guide. The Appendix lists supplementalinformation addressing human physiological responsesto cold, maximum allowable work times, and clothingand personal protective equipment recommendations.

Training and Related DocumentationTraining and manning are both important considera-tions for vessels operating in cold climates as specialskills are necessary if they are to be accomplished safelyand efficiently. The Guide provides information on thetype of training needed as well as the documentationrequired onboard.

Weather ConditionsExtremely low temperatures, and the associated forma-tion of ice dominate operations in polar and sub-polarregions. In low temperatures, any precipitation will bein the form of snow, freezing rain, sleet or ice pellets.Visibility in any of these conditions can be very limitedand ice build-up can produce a range of hazards. Iceaccumulation due to spray is most likely in air tempera-tures below 2C, and wind speeds of above 20 knots(10 m/s). It will worsen as wind speeds increase beyondthis and in higher sea states.

In very low temperatures, sea ice can form quite rapidlyonce the water temperature itself falls below 0C. Shipswith little or no ice capability can find themselves at

risk if caught in these conditions, which are most likely to occur towards the onset of winter.

Most ships can be put at risk by ice movement, which can occur rapidly under high wind or currents.Conditions reported on ice charts or by remote imagerycan change quickly, particularly the reported positionsof the ice edge and the location of leads through the pack. It is important for mariners to be able to recognize the conditions in which such changes canoccur and signs of the proximity of ice. Additionalinformation is provided in the Guide describing theweather conditions likely to be encountered in the cold regions.

Vessel OperationsLow temperatures require additional tasks to permitequipment to function or to conduct vessel operations.Owners/operators are responsible for operational guide-lines and keeping these guidelines updated. The Guideprovides guidance on vessel operations related to eachsection of the Guide addressing design considerations(deck machinery and safety equipment).

Flag Administrations Contact ListAdministrations have additional requirements whenoperating in their waters. A list of administration contacts is provided as an aid.

ABS NotationsA vessel designed, equipped, built, surveyed andcrewed in accordance with the requirements of the Guide for Vessels Operating in Low TemperatureEnvironments will be eligible for the notationCCO+(TEMP). The ambient temperature for which the vessel is designed will be listed in the parentheses(e.g. (-30C)). The notation will be listed in the ABS Record.

If vessel operation in a cold climate will be delayed, the Guide offers flexibility and cost savings to theowner in that crew training and installation of certainloose equipment for use only in cold climates can bedeferred. For these cases a notation CCO(TEMP) willbe provided. This notation signifies the major equip-ment necessary for cold climate operation is installedand surveyed. When cold climate operation is planned,the additional Guide requirements can be compliedwith, a surveyor notified and the notation can be changed to CCO+(TEMP).

P A G E 4

New vessels designed for trade in the harsh Arcticenvironment will bring a series of novel ideasand concepts for which no industry standards,statutory regulations or classification rules will be fullyapplicable. From the classification point of view, theassessment of these novel concepts can be performedby a combination of engineering analysis and riskassessments.

The ABS Guidance Notes on Review and Approval ofNovel Concepts were developed to offer owners anddesigners a new methodology for requesting the classi-fication of a novel design and to facilitate its approval.They are intended to cover proposed applications thathave not been proven in the maritime or offshoreindustry and would therefore be considered novel forthose environments.

The methodology combines engineering analysis, fieldtesting and risk assessments to compensate for the lackof prescriptive classification rules to determine if theconcept provides acceptable levels of safety, in line withcurrent offshore and marine industry practice.

Design companies, when exploring the possibilities of a new technology or concept, are looking for some con-firmation that the design is feasible and will be capableof attaining classification. The ABS Guidance Notes

offer the Approval InPrinciple (AIP) as a

first step towards classifi-cation of novel concepts.

The benefit of gaining AIP isthat the client can obtain a docu-

ment issued by a knowledgeable inde-pendent marine and offshore society as evi-

dence of preliminary acceptability of the con-cept for classification to provide to regulatory bodies

and project partners. It confirms that there are no sig-nificant impediments to further develop the concept.

The Guidance Notes divide the class approval processinto 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)

This process involves ABS and the client workingtogether to accomplish the following:

Determine Approval Route: As a first step, the approvalroute to achieve AIP needs to be determined. This willinvolve the client and ABS meeting to discuss the concept, its purpose, its novel features and, where itdeviates from traditional approaches, the proposedoperating envelope and the potential impact of the concept on other systems or components. Agreementwill be reached as to the best methods to assess risk in the AIP phase as well as the appropriate level ofengineering analysis.

AIP and Approval Road Map: As a minimum, the goal ofachieving AIP should be the identification of all hazardsand failure modes applicable to the novel concept appli-cation along with suitable support information demon-strating the control of these hazards and failure modesis feasible. Throughout this phase, as the concept isbeing evaluated, an Approval Road Map will be definedwhich will lay out conditions to achieving full approval.The road map will define clearly the approach neededfrom a risk assessment and engineering analysis stand-

L O W T E M P E R A T U R E O P E R A T I O N S P O L A R C L A S S G U I D A N C E

Managing the RisksAssociated with Arctic Shipping


Novel Concept Approval Process

New/

Novel

ConceptClient Conceptual

Design

Detailed

Design

Const.

&

Install.

Oper-

ations

Detailed

Engineering &

Risk

Assessment

Submittals

Survey

During

Construction

Survey

During

Operation

Conceptual

Engineering &

Risk

Assessment

Submittals

Initial

Request to

Approve

Concept

ABSDetermine

Approval

Route

Approval

In

Principle

Approval

Road

Map

Final

Class

Approval

Maintenance

of

Class

point to justify those novel aspects not covered byexisting rules, codes and standards.

Final Class Approval: This phase covers typical classapproval submittals comprised of typical drawings,specifications, calculation packages and support docu-mentation, along with submissions of those items out-lined in the Approval Road Map. Upon completion ofthis stage, the potential hazards and failure modes forthe novel features will have been assessed versusagreed-upon acceptance criteria to a level of confidencenecessary to grant full class approval to the design.

Maintenance of Class: As a final condition of classapproval, ABS will determine the necessary additionalconditions assigned to the maintenance of class throughadditional survey scope or frequency of attendance,condition monitoring, required maintenance andinspection techniques to maintain levels of monitoringassumed in the design phase which may have been nec-essary to achieve various design parameters and, finally,as a means to verify assumptions and predictions madethroughout the process.

RISK ASSESSMENTSRisk assessments at the conceptual stages of a novelconcept are part of the requirement to obtain AIP. Thespecific requirements for risk assessments are based onthe 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 designbasis, preliminary engineering and possibly testingresults are available for use in the risk assessments. Aqualitative risk assessment technique is generally themost suited method at this concept design phase. Thereare various qualitative risk techniques that can beapplied, such as HAZID (Hazard Identification), What-

if and HAZOP (Hazard and Operability Analysis).However, the most appropriate technique depends onthe available concept design information and type ofsystem being proposed.

Conducting a qualitative risk assessment involves a team brainstorming session that provides a uniqueforum for designers, operational and safety personnel,as well as ABS representatives, to discuss the concept in a structured manner. Prior to conducting a qualita-tive risk evaluation, the organization proposing thenovel concept has to submit information on whatmethod will be used, what subject matter experts will participate and what scope the assessment willhave. 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 verify that the risks identified in earlierphases are properly managed. Such assessments mayinvolve quantitative risk assessments, such as fault trees and event trees, in order to attain the necessarylevel of accuracy.

The systematic and detailed use of risk analyses tech-niques to compensate for the lack of industry experi-ence will aid the project teams developing new designsfor operation in the Arctic and similar harsh environ-ments in identifying and addressing key design andoperations issues.

ABS has the guidance, tools and processes in place tomeet this challenge and satisfy the industrys need fornew generations of safe polar class oil and gas carriers.ABS has developed guidance on hull designs and coldweather operations and is continuing the developmentof other key technologies that will support the currentinnovations.


Ballast water in side or hopper tanks above thewaterline in vessels operating in very cold envi-ronments may freeze, starting at the top of thetank and at the side walls. In new designs, it is advis-able to minimize the amount of ballast carried high inthe vessel, especially in stand-alone tanks. Even in caseswhere the tank itself does not freeze completely, valveand suction line freezing can occur.

In extremely cold regions, thick ice formation or com-plete blockage within air and vent pipes has also beennoted. The extent of freezing will depend on the tem-peratures encountered, on the duration of the voyage;and the salinity of the ballast water. Fresh or brackishwater will freeze more easily so, higher salinity seawater should be used where voyage routing and local or regional environmental regulations allow.

It is highly unlikely that any sizeable tank will freezesolid as the ice itself acts as an insulating layer reducingthe rate of heat transfer. However, ice represents aweight that may not be dischargeable when the vessel is loading, reducing deadweight capacity.

If ice chunks fall from the tank sides after the dischargeof the liquid ballast, they may damage coatings or com-ponents. The ABS Guide for Vessels Operating in LowTemperature Environments requires ballast tanksarranged with the top of the tank located above thelightest operating draft to be provided with arrange-

ments to prevent freezing of the ballast water. Forexample, bubble systems have been used satisfactorilyin temperatures as low as -30C. Below this tempera-ture, heating coils are required to be fitted in accor-dance with the Guide.

Seawater systems draw their supply from the seaaround the vessel and should be designed to reduce the risk that inlets will become blocked by ice beingingested by the systems or forming within them. This can be accomplished by:

Location placing sea chest and sea bays low in the vessel and away from ice flow lines;

Configuration using weirs, strainers and other means to separate ice from the water;

Heating normally by re-circulating hot waterfrom cooling systems into the inlet areas.

The most cost-effective solution will depend on thetype of vessel and the nature of the service. Specificguidance for the design of sea box/bays, including special considerations for piping and valves, is provided in the Guide. However, ice may still accumulate during periods alongside in cold cond-itions and so it will still be advisable to provide heating/water recirculation to deal with possible freeze-up and associated problems during start up.Therefore, several example heating and cooling arrangements are included in the ABS Guide.

Managing Ballast in Very Cold Temperatures

SEA BAY

HEAT TRACEO/B VALVESWL

STEAM LINEFOR DE-ICING


WL


AND ICE CLEARING

ACCESS HATCH

Heat Tracing and Freeze up Prevention Strategies


Russia is the worlds second largest oilexporter and its largest exporter of natural gas. In 2005 Russian oil exports are estimat-ed to have ranged between 5.38 and 5.52 millionbpd, up 7.4 percent from 2004, with projectedgrowth to 5.8 million bpd in 2007 and 6.2 millionin 2015. Most of those new exports are expectedto move through terminals in ice infested waters.

Russias terminal at Primorsk in the Gulf ofFinland, for example, now exports more than 55 million tons of oil a year, according to theInternational Energy Agency. Adding exportsthrough Estonia and other Baltic ports, the figureapproaches 100 million tons. The Russian gov-ernment predicts exports from the Primorsk andSt. Petersburg area terminals will exceed 160 million tons/year by 2010.

But Russias plans to dramatically increase north-ern exports over the next five years and beyondhas begun raising environmental concerns amongits neighbors in the Baltic Sea, worried about theconsequences of a possible future oil spill.

And so Russia is also looking at developing an oil export terminal near Murmansk, the most

northerly ice free port in the world, and using theNorthern Sea Route for eastward transport alongthe Siberian coast, through the Bering Strait andinto the Pacific Ocean. There are also proposals,such as those associated with the Shtockmanproject in the Barents Sea, to set course westwardacross the Arctic Ocean bringing oil or LNG tothe US East Coast.

The challenge for the international maritimeindustry is to deliver the technological supportneeded to underpin these vital energy projects. To make the Northeast and Northwest Passagesregular shipping lanes requires a new, polar iceclass. Some industry experts predict that, withinfive years, some 50 such specialized tankers willbe needed to handle the oil projected to move out of Northern Siberia.

Also due for development is the giant Shtockmangas field that lies in Arctic waters some 500 milesoff the northern coast of Russia which is plannedto come on stream by 2011 with much of the gasdestined for US markets. New rigs, productionunits and support vessels will be needed to han-dle the special challenges of developing these iceinfested offshore energy fields.

Russias Energy Reserves Lure Ships and Offshore Units into the Arctic


Gas transportation in an Arctic environmentbrings many hazards and operational issues that,if not considered carefully, could potentially leadto undesired incidents and catastrophic accidents. Someof the issues that need special consideration during thedevelopment of the proposed new generation of PolarClass LNG carriers include:

ROBUST DESIGN

The Finnish Swedish Ice Class Rules (FSICR) havebeen the common industry standard for decades forvessels designed for operation in first year ice condi-tions as found in the Baltic. Other rules such as theestablished Russian Ice Class Rules are applied to ves-sels designed for operation in multi-year ice. IACS isworking towards adopting a new set of Polar Ice ClassRules to unify class and industry requirements to meetthe higher safety standards and changing demands oftrading in the Arctic.

Technical challenges also exist regarding the designguidance provided by the current Ice Class Rules. These rules are based on experiences of previous ice-class vessels, many of which are smaller ships than are envisaged for future Arctic operation, withtransverse framing systems. The marine industry hasvery limited experience in operating large gas carriersin harsh environments. Impacts of extending the current Ice Class Rules to Arctic Operation are yet to be seen and may need consideration using a novelconcept approach.

ABS is actively applying the latest technology to theissue of ice strengthening for large commercial ships.These efforts have resulted in the release of the ABSGuidance Notes on Ice Class that provide formalized procedures for side structure designs.

SUITABILITY OF CONTAINMENT SYSTEMS

One of the major concerns for LNG carriers is whether existing LNG containment systems need modification for Arctic operation. Existing Ice ClassRules have established design guidance for hull structures in an ice belt, design of external hull surfaces that will encounter ice and typically specifylocal ice loads for designing shell structures. Some Ice Class Rules specify additional hull girder bendingloads 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 should also be considered for LNGcontainment system design. Though they do not direct-ly encounter floating ice, the LNG containment systemsmay feel the vibratory excitations from ice that aretransmitted through hull structures and their responseto this type of loading is not well understood.

Global extreme ice loads may also need to be consid-ered for LNG containment system design. During theArctic winter, a vessel may ram into large ice ridges orfloating ice, and the consequential deceleration of thevessel may pose new threats to the LNG containmentsystems. There are very limited studies on this scenarioand data collection and further investigation is needed.

PROPULSION AND AUXILIARY MACHINERY ISSUES

The machinery on vessels operating in very low ambi-ent temperatures (such as -30C or less) may be subjectto unusual operational events not occurring at highertemperatures. A Failure Mode Effects Analysis (FMEA)conducted early in the design evolution on variousmachinery and systems will help in identifying addi-tional features or equipment/system design changesnecessary to prevent failures from occurring or to mitigate consequences if failure occurs.

A vessel with diesel engines installed for propulsionand electricity generation may encounter situations inwhich the engines are unable to fire because of the lowtemperature of the combustion air fuel mixture mayfail to allow auto ignition when compressed in theengine cylinders. On the other hand, if auto ignition isable to occur in the engine cylinders, the engine cylin-der design pressure limits may be exceeded becausemore air can enter the cylinder due to the cold airshigher specific density.

To prevent the failure mode of an engine being unable tofire, a special feature may be required such as incorpo-rating a combustion air pre-heater. The pre-heating maybe accomplished through the use of electric or steamheating or using the diesels jacket water waste heat.

To prevent cylinder overpressure failure which leads to the engine producing too much power, overpressureprotection can be achieved by installing a charge airbypass between the turbocharger compressor outlet tothe turbocharger turbine inlet along with a charge airwaste gate on the engines air receiver and an exhaustwaste gate from the turbocharger turbine inlet to theturbocharger turbine outlet. The arrangement can alsobe used to improve turbocharger performance and fuel efficiency at low engine loads when the vessel is operating in ice.

Critical Issues to Consider inDeveloping Polar Class LNG Carriers


Machinery arrangements may be required to be modified as a result of low ambient temperatures. For example, in many cases, combustion air for dieselengines is taken directly from the machinery space. In very cold climates this arrangement will cause themachinery spaces temperature to become too low, possibly affecting equipment function and personnelcomfort and ability to perform maintenance. The combustion air should be directly supplied to the diesel engines through duct work. The added advantageof this ducting arrangement is the combustion air temperature can be better controlled.

LNG CARGO TANK VENTING

Venting is one of the key issues essential to maintainingLNG cargo tanks integrity due to the boil-off of gasevaporating from the tanks. Normally, there are elabo-rate measures to ensure boil-off gas utilization at alltimes in places like the boilers on conventional shipsbut more recently using it in diesel engines or gas tur-bines. The gas from the tanks is compressed and heatedbefore being discharged to the machinery spaces. Hencethe 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 requirecareful consideration during normal operation andcargo loading. These systems may possibly require the use of heat tracing to maintain functionality.Emergency shutdown valves at the manifold and at the tanks are critical in the safety chain on LNG carriers. It is essential that they operate at all weathertemperatures on deck.

HEAT TRANSFER

When heating the cargo related valves and equipmentto maintain functionality in the Arctic environment,there is always a chance of creating vapor traps whichmay impair the operation of these valves. Somemeans of temperature control should beprovided to keep this equipment free ofice that does not create heat transferinto the LNG being transported.

In addition, the trade-off amongthe beneficial effects of a colderambient temperature on theboil-off rate, the need forheating some equipmentto maintain function-ality and the heatgain into the sys-tem from same,and theincreasedsloshing,

which may occur in harsh wave environments causingmore 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 simultane-ously. This will require ballast water to be taken onboard, and may require heating of the ballast tanks just sufficiently to prevent freezing while also consider-ing that any excessive temperature rise in the ballastspaces will affect the cargo boil-off rate through theinner hull. Further typical water spray operations used during offloading may require heating of the water spray to prevent freezing of the hull structure in way of the cargo manifold. This may require someheating equipment be installed in the ballast space to prevent ice build up as a result of water spray.

SAFETY SYSTEMS

There are several issues relating to safety systems and the functionality and suitability of such systemsduring operations in low temperature environments.Current classification rules and statutory requirementsstipulate specific fire detection and fire extinguishingsystems 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 cooldown the accommodation block. Even if the lines are heated, the water deluge system will in many cases be ineffective.

Due to the layout typically used on LNG carriers, thesedesigns have a large exposed deck area. The additionaldeck-plating is either curved to cover the Moss typespheres or as an integrated part of the containment system for both the MKIII and No 96 membrane tanks.This exposed deck plating should be designed in such a way as to withstand the additional load dueto snow accumulation and icebuild-up caused by

The unique double-acting LNG carrier.

Even its bridge is different, designed

so the ship can be easily conned

whether moving ahead or astern.

P A G E 1 0 L O W T E M P E R A T U R E O P E R A T I O N S P O L A R C L A S S G U I D A N C E

spraying. Other exposed deck plating should be able to resist any dynamic loads due to sliding of the snowfrom the inclined decks or from dropped ice.

The snow build-up and ice accumulation is also anadditional hazard for crew operations on the deck, particularly the passageway on each side of the vessel.

VISIBILITY

The summer fog, mainly in coastal regions and aroundislands in the western part of the Barents Sea, the winter snowstorms and the darkness are major contrib-utors to reduced visibility in the Arctic region. Theoverall arrangement of an LNG carrier and the inabilityof bridge personnel to see directly in front of the vesseldue to the containment system height above deck, maynecessitate the use of special features such as camerasand other devices to assist in navigation.

LIFE SAVING EQUIPMENT (LSE)

Arctic conditions lead to many special considerationsand risks related to life saving equipment, including:

The presence of ice on the sea surface may inhibitdeployment of life rafts and rescue boats, and alsoin making distance from a ship in distress

The presence of ice on deployment mechanismssuch 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 and doors in conditions of ice and snow may be limited.

EQUIPMENT DEPLOYMENT

Launching life boats and rafts comprise numerous risks:

Entrance to boat stations can be obstructed bysnow and ice

De-icing equipment (steam hoses) may freeze

Freezing of hinges, lashes, gaskets, brake guidewires and sheaves

Snow and ice on winches may interfere withtheir use

Ice on hooks, latches and hydro-static release couplings may interfere with their use

Freezing of winches

Frozen surface to which a boat is deployed

FIRE FIGHTING EQUIPMENT

Significant risks are associ-ated with fire fightingequipment, the most

significant being the potential freezing of fluids in lines,thereby depriving crew of the use of the fire fightingsystems. 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 -30C, this may have to be changed and the fire mainsdrained until needed.

Portable fire extinguisher storage may be obstructed or frozen

Fire dampers may freeze in the stowage position

HUMAN FACTORS

There are significant implications on human capabilitywhen working in cold weather environments and working under these conditions can be highly hazardous to a persons 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)

RISKS IN CARGO HANDLING

During cargo loading/unloading people are generallyneeded 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 themonitoring task can be achievedremotely using closed-circuit television.

ABS-classed LNG carrier

Polar Eagle operates in the Alaska to Japan

LNG trade.

After a century of developing ice class vessels, anew development literally turns things aroundand revolutionizes navigation in ice-covered seas. Typically, icebreaking batters the crew as much as itdoes the ship. Now, a new concept, developed by AkerArctic Technology, eliminates the ramming and lets aship plow steadily through even the heaviest ice. It iscalled the double-acting ship and it involves drivingstern-ahead in ice, using an Azipod podded propulsionsystem and a propeller that pulls the ship instead ofpushing it.

Two such tankers are on order for Sovcomflot atSamsung Heavy Industries. They will be built jointly toABS and Russian Register class requirements. The con-cept has also been selected by the US Coast Guard foran icebreaker for the upper lakes, the Mackinaw, nowbuilding under ABS survey at Marinette Marine inWisconsin.

The improved ice breaking capability has to do with theflow from the propeller. The propeller stream acts like a large pump, flushing the hull and reducing friction.Even with deep ice ridges, the propeller mills the iceand flushes it away.

Though similar discoveries were made in the 19th century, and some icebreakers were fitted with bow propellers to help get through the ice, the concept was

largely forgotten. Having rediscovered the flushing propeller concept, Aker Arctic introduced the technolo-gy within a small river icebreaker for the Danube. Thencame two icebreakers for the Caspian Sea, an icebreakerfor the Norwegian arctic islands of Spitsbergen and,most recently, two aframax tankers for service in theBaltic.

According to Aker Arctic, the power requirement for a standard aframax tanker to break through ice 60 cmthick would be more than 35 MW. A standard aframaxhas about 13 MW of power meaning it can only operatein less than 20 cm of ice yet a double-acting tankerwith 13 MW power can break 1.2 m ice. With 16 MWthe tanker can break 1.6 m ice without ramming.

Now the double-acting concept is set to break newground. With the gas fields of the Russian northbelieved to account for a quarter of all known globalreserves, there is considerable interest in alternate tech-nologies for bringing it to market. As pipeline proposalsappear too expensive, the discussion has turned to LNGtransport, for which Aker Arctic has developed a dou-ble-acting LNG carrier design.

The company believes the double-acting design canmake gas transport from the Arctic competitive. Thedesign is distinguished by a patented integrated hullstructure, which features a strength deck arching overits spherical Moss tanks.

P A G E 1 1L O W T E M P E R A T U R E O P E R A T I O N S P O L A R C L A S S G U I D A N C E

The Double-Acting Tanker


Further Ice Research Activities at ABS

The industry has already started preparing for opera-tions in the Arctic. To provide guidance for theapplication of the Finnish Swedish Ice Class Rules(FSICR) to large commercial vessels, the FinnishMaritime Administration has developed the Guidelinefor the Application of the Finnish Swedish Ice Class Rules.These Rules accept an alternative design if verified bydirect calculations.

To fill the gap between requirements and design, ABSpublished the ABS Guidance Notes on Ice Class (ABS2005), which describes a complete set of procedures forice-strengthening design using the latest nonlinear FEMmethodology. This demonstrates that powerful toolssuch as nonlinear FEMhave great potential in solving sophisticated design issues. As shown in Figure 1, nonlinear FEM can capture the permanent deformationssustained in the side shellof a vessel operating in ice.

Advanced technology alsodemonstrates its power inidentifying potentially criti-cal structural members.Figure 2 shows the resultsof a recent study of a side

Figure 1. Permanent deformation (or dent) in ice damaged side shell predicted by using nonlinear FEM

stringer in the ice belt. Option 2 refers to the sidestringer thickness designed with the assistance of FEManalysis. FMA 2005 is the required side stringer thick-ness following the latest Finnish Maritime Admin-istration (FMA) Guidelines. This example shows thepotential of nonlinear FEM analyses in identifying critical structural members. It is expected the applica-tion of nonlinear FEM in rule development and structural design will increase in future.

Propulsion power and propeller strength are the twomost critical issues for ship propulsion in ice. The high ice resistance and large ice loads on the propellerblade make the propulsion design more challenging


for ice class ships. ABS has developed comprehensiveprocedures to assess the powering for ice navigationand propeller strength and related issues such as bladecavitation and vibration.

A systematic approach is proposed by ABS for an ice powering estimate by taking into consideration the ice resistance model test results, the propeller performance under a slow ship speed and the engineperformance at a heavy load condition.

A case study for an IA (PC7 for Polar Class ships)Aframax-size tanker shows that the required enginepower can be largely reduced compared to the power

required by the FSICR rule formulae if the propelleris appropriately designed along with the use of amore accurate ice resistance value.

Table 1 summarizes the comparison between theresults for the combination of

1. FSICR ice resistance value and power require-ment;

2. FSICR ice resistance value and the ABSapproach for power requirement and;

3. the model test value for ice resistance and theABS approach for power.

When comparing these results with a typical enginepower rating for non-ice tankers, it is noted thatinstead of a typical VLCC tanker engine required byFSICR, a typical Aframax tanker engine can be usedfor this IA class Aframax tanker.

Side Stringer Thickness of IA Suezmax Tanker

FMA

200

4

FMA

200

5

No

n-i

ce-s

tren

then

ed

Op

tio

n 1

Op

tio

n 2

0

5

10

15

20

Req

uir

ed W

eb T

hic

knes

s (m

m)

Figure 2. Nonlinear FEM analyses help identify critical structures.

Engine Power

Reduction compared to FSICR power

FSICR

22,000 kW

FSICR - IceResistance

ABS approachPower

18,631.8 kW

15.31%

Model Test - IceResisteance

ABS approachPower

13,098.2 kW

40.5%

Table 1. Comparisons of the power reductions for Aframax-size tanker

Engine power for non-ice tankers


Safety and environmental standards for ships operating in cold climates and ice covered watersinclude international regulations, regional regula-

tions as well as classification requirements. Industry is looking for broader guidance and is requesting amore unified approach to the requirements for thedesign and operation of ships for service in the Arctic.Additionally, concern for the environment can beexpected to promote regulations that address emissions,contamination from water ballast and other ship-sourced pollution.

Although some limited experience exists based on operations in the western end of the Russian Arctic,there is little experience or knowledge of the likelyimpact of shipping activity on the ecology of this undeveloped region. Given the short summer and low temperatures throughout most of the year, the level of bio-metabolism is expected to be extremely low, so that any ecological disturbance may require a much longer period to recover to its normal statecompared to warmer regions of the world. It is possible that more stringent regional requirements may become effective beyond the international requirements of the International MaritimeOrganization (IMO).

Vessels traveling in the Northern Sea Route (NSR), the Arctic region north of Russia, are regulated at

two levels: international regulations framed by theInternational Maritime Organization (IMO), andregional regulations issued by the Russian authorities.

International Regulatory Requirements

To promote the safety of navigation and to prevent pollution from ship operations in Arctic ice-coveredwaters, the Marine Safety Committee (MSC) andMarine Environment Protection Committee (MEPC) of IMO approved the Guidelines for Ships Operating in Arctic Ice-Covered Waters in October 2002, as anaddition to the mandatory and recommendatory provisions contained in existing IMO instruments.

IMO Guidelines define special measures for safety of life and protection of the environment in the Arcticregion. The Guidelines harmonize different nationalrequirements relating to hull structure, equipment, navigation and operation for different types and sizes of ships that may travel in the Arctic ice-covered waters.

The IMO Guidelines are mainly divided into threeparts: the design and construction of hull structure and machinery; specific equipment requirements for a low temperature environment, including fire safetyequipment, life-saving appliances and navigationalequipment; and operational guidelines, such as opera-tional control, the operating and training manuals,crewing and emergency equipment.

IMO Guidelines refer to the IACS UnifiedRequirements (UR) for Polar Class for

structural design and construction.The IACS Polar Class UR

are intended to harmonizethe ice class require-

ments of various

Regulatory Oversight for Arctic Shipping


classification societies and MaritimeAdministrations. The IMOGuidelines are recommendatory ratherthan mandatory for vessels traveling in the Arcticice-covered waters.

Regional Regulatory Requirements

The NSR is governed on two main levels of the Russiangovernment: federal and regional.

The Northern Sea Route Administration (NSRA), an agency of the Russian Ministry of Transportation,manages the entire stretch of the route from west toeast. The responsibility of NSRA includes implementa-tion of state supervision over the rational use of theNSR; organization of Arctic navigation, taking measuresto ensure the safety of navigation on the lanes of theNSR and on the lanes of adjacent areas; taking meas-ures to prevent and eliminate consequences of pollutionto the marine environment and the northern coast of Russia, and supervision of vessels and offshoreinstallations for this purpose which might be a potential source of pollution.

The regional governments are responsible for improvingthe transportation and economic infrastructure in theirregions for effective support of the commercial feasibili-ty of the route.

To secure safety of navigation and prevent pollution ofthe marine environment from ships, NSRA has devel-oped the Guide for Navigation through Northern SeaRoute to regulate the traffic in the NSR and the Barentsand Bering Sea areas covered by ice. The Guide outlines the navigational-geographical and hydro-meteorologicaldescription of the NSR, including the natural environ-ment such as sea ice distribution, geographical settingand regional climate, and ice navigation such as charts, routes, aids to navigation, communications and convoying.

It references Regulations for Navigation on the Seaways of the NSR and Regulations for Ice-breaker-

Assisted Pilotage of Vessels on the NSR whichinclude navigation, operation and ice-breaker-assistedpilotage requirements and other safety regulations. The Guide also provides nautical charts and sailinginstructions for all Arctic areas.

As to the structural design and construction, equipment and supply requirements, the Guide refers to the Requirements for Design, Equipment, and Supply of Vessels Navigating the NSR to addressthese issues. As reported by Central Marine Researchand Design Institute (CNIIMF), the requirements fordesign and equipment in the Guide are identical tothose of the Rules for Classification and Construction ofSea-Going Ships of the Russian Maritime Register ofShipping (RMRS).

ABS has a bilateral technical pact and dual class agreement with RMRS.

All ships planning to travel to frozen Russian ports during wintertime with an ice class lower than admissi-ble by the port authority need an Ice Certificate to enterthe ice-covered ports. The Ministry of Transportation of the Russian Federation authorizes CNIIMF to issuean Ice Certificate for vessels that describes their abilityto operate in ice.

Regulatory development in this area is ongoing. TheNorthern Sea Route Administration is drafting new versions of its Guide for Navigation through the NorthernSea Route and the referenced regulations for navigation,design, equipment and other issues to address newtechnical and legal developments. A new Russian law,equivalent to the Oil Pollution Act of the US, is expect-ed to impact the design and operation of vessels transit-ing the NSR.


Requirements of ice loads and scantlings varyamong the currently available ice class rules. This reflects different design scenarios, conceptsand ice mechanism assumptions embedded in the iceclass rules of the different societies.

Ice Class Rules establish design requirements for hullstructures in an ice belt where the external hull surfaceswill encounter ice. Strength requirements are specifiedfor shell plating, frames (including local and main sup-porting members), and bulkheads. Some Ice ClassRules specify additional hull girder bending loads forvessels that may be raised by an ice pack. The strengthrequirements are accompanied with material require-ments and abrasion/corrosion allowance.

For machinery, quite varied engineering practices anddesign philosophies have been used in the developmentof the various ice class rules.

To establish greater consistency, IACS is currentlyworking toward adopting a new set of UnifiedRequirements for Polar Class Ships (PCS). These willunify the ice class rules as well as respond to the needfor a technical complement to the IMO Guidelines forShips Operating in Arctic Ice-Covered Waters.

A system of Polar Classes has been developed to designate different levels of capability for vessels navigating in certain areas at a certain time of the year in ice-covered water. Seven ice classes are proposed in the requirements, namely, PC1, PC2, PC3, PC4, PC5, PC6, and PC7.

Through cooperation with the Finnish MaritimeAdministration (FMA), the two lowest IACS polarclasses (PC7/PC6) have been developed to align withthe highest Baltic Ice Class (1A and 1A super). Tomaintain this alignment extensive calibration and validation for the ice load formulae were performed bythe project team members from the five class societies(ABS, DNV, GL, LR, and RMRS), Canadian Transportand FMA.

Three Unified Requirements (UR) developed so farinclude:

UR I1, Polar Class Descriptions andApplications

UR I2, Structural Requirements for Polar Class Ships

UR I3, Machinery Requirements for Polar Class Ships

IACS develops Unified Requirements for Polar Ice Class


Sakhalin Energy has tapped into a billion-barrel oilfield using an ABS classed production unit andFSO in some of the harshest offshore conditionsin which industry is currently operating. The Pilton-Astokhskoye field off Russias Sakhalin Island, lies inthe stormy Okhotsk Sea north of Japan.

Production is handled by the ABS classed Molik Paq. It has been supported by the specially built, ABS classed FSO OKHA, delivered from Daewoo in 1999.Daewoo also handled the modification and refitting ofthe Molik Paq, a unit originally built as a drilling rigdesigned to withstand the tough multi-year ice of theNorth American Arctic off the northern coast of Alaska.In its new role as a production unit, the Molik Paqmust combat moving sheet ice and deep ice rubble in an area of the world prone to earthquakes as well as severe seas.

The conversion involved extensive upgrades and a massive construction project. It required, among otherthings, substantial new topsides equipment to changeits working capability from oil exploration to oil pro-duction from 36 sub sea wells. The units new operatingdepth of 50m is nearly double that for which it wasoriginally designed. When operating in the Beaufort Seait stood in 25m water depth on a raised berm that hadbeen dredged on the seabed. The increased operational

Remodeled Rig Exploits Sakhalins Riches

height was achieved by adding a space to the unitsbase. This was built in four parts totaling more than14,000 tons of new steel.

Held in place by the base filled with 350,000 tons ofsand and protected against ice scour by a further27,000 tons of rock piled about its perimeter, Molik Paqhas delivered outstanding service since its re-commis-sioning in late 1999.


In one of historys biggest privately funded experi-ments, the ABS-classed tanker Manhattan wonimmortality as the first commercial ship to break

through the Northwest Passage.

In 1969, four shipyards, an international team of maritime experts and three major oil companies pitted their considerable technical, creative and financial resources against the monolithic might of nature. Their goal: to take a tanker through thedaunting, deadly Northwest Passage.

For 500 years, the Northwest Passage had tempted merchant adventurers with its promise of a seaway connecting the Atlantic and Pacific oceans across theice-choked top of North America. Turning the Passageinto a commercial route remained a dream until oilwas discovered on Alaskas North Slope in 1968.

The question of whether to export oil from PrudhoeBay via pipeline or ship sparked a nationwide debateand inspired the project leader, Humble Oil andRefining (a subsidiary of Esso), to develop a new kind of ship: the icebreaking oil tanker.

They knew the perfect vessel for the job: the SS Manhattan. Built in 1962 at Bethlehem Steel and classed by ABS, the Manhattan possessed a unique, transitional structure that bridged an evolutionary moment in ship design. Developed during the change from empirical, experienced-based design to first-principals engineering aided by computers, the ship combined the daring size of the future with the conservativerobustness of the past.

The Manhattan was the only twin-screw tanker over100,000 dwt in the world at the time. With 43,000shaft hp it had considerably more horsepower per ton displacement than any other major merchant ship. Its short tank length gave a substantially morerigid structure than found in more modern designs, and its scantlings were so heavy much more than one finds in tankers of similar size today that the bottom plating, deck, and upper hull structures were of normalized, or heat-treated steel, which by naturehas very favorable low-temperature characteristics.

The ConversionIn December 1968, a team from Wrtsil approachedEsso and offered to share everything they knew abouticebreaking. It was an unusual offer since Wrtsil was the world leader in icebreaking technology and had built 60 percent of the of the worlds icebreakingfleet.

The experiment lasted 20 months from start to finish.Wrtsil advised the project every step of the way, from vessel conversion to testing and finally to themodeling and design of future ships for NorthwestPassage service.

The Manhattan took everyone into the unknown, shipyard, scientist and expert alike. When the projectwas approved, very little was actually known about the extent of the work needed to ready the ship forArctic service. Only one yard, Sun Shipbuilding inChester, Pennsylvania was willing to take on the task, which had been tendered only as extensive modification requiring strengthening the hull and

The First Arctic Tanker


installing an icebreaking bow, propellers and rudderprotection.

Still, the job was so big that no single shipyard couldfinish it within the required time frame and, at Sunssuggestion, the project was divided among four. The493-ft aft section stayed at Sun for modification.Newport News took the 122-ft forward section andNumber One cargo tank. The 264-ft midbody went toAlabama Dry Dock at Mobile. The new icebreaking bowwas to be built in two sections, the 56-ft after section atSun and the 69-ft forward section at Bath Iron Works inMaine. In each yard, work was done under the watchfuleyes of ABS surveyors.

Transverse bulkheads were strengthened by the addition of doublers, installed in way of the weldedconnections of horizontal girders, while heavy I-beamswere placed at every web frame across the width

of the ship. A nine-foot-wide, sloping steel belt, like a great, triangular blister, was added

to the ships sides to increase strength anddeflect the deadly pressure ice typical to the region. The ice belt helped the vessel on the second voyage, when the sloping sides caused the ice boulders to tumble back and away onto the floe.

Other modifications included: adding a helideck;renewing the shafting with higher strength mate-rials; attaching a shearing coupling in the shaft-

ing to protect the low-pressure turbine rotoragainst the shock of ice loads;

installing underwaterrudder guards andhigher-strength pro-pellers; building adouble hull for the

machinery and steering gear rooms; reinforcing all machinery for stability; and installing a special liquid-phase heating system that circulated heated oil to warm the deck machinery. Experience provedevery modification to have been necessary.

The most distinctive aspect of the Manhattan was the new bow. A design never before seen, it still influences icebreaker design. Its fore part was sloped at 18 degrees, curving gently down to the bottom,where it was plumb.

Another lasting innovation of the Manhattan was the forward shoulder, the place where the bow section met the parallel body of the ship. It was made severalmeters wider than the hull, to cut a wide swath throughthe ice and reduce friction on the vessel. (When adopted for later-generation icebreakers, the feature was called a reamer.)

The VoyageManhattans first voyage gave her a place in explorationhistory. As much publicity event as discovery mission,the late summer voyage took 126 people 45 crew, the rest mostly scientists, journalists and politicians on a thrilling 4,400-mile journey into one of the last frontiers. The adventure was closely followed on thefront pages of every major newspaper, riveting readerswith images of ambitious man against inscrutablenature.

Polar pack ice can exceed 3 meters thick and roamsabout in vast floating plains miles across. Crashing into each other, the floes form huge rubble hills andundersea ridges that can reach 30 meters deep. To pass through such ice, a traditional icebreaker rams,rides up, and breaks through as the ship presses


down. The ship broke ice thicker than any ship in history.

Manhattan carried no cargo on this voyage; its tankswere filled with water to simulate loading. In Alaska,the ship picked up a symbolic barrel of oil, returning to New York a merchant hero.

Esso sent the ship on a second voyage the followingApril, to test itself against Arctic winter ice. There, itencountered ice that was so tough the ship couldnteven enter the Northwest Passage. Instead, it wentto Pond Inlet near the top of Baffin Island, wherethe investigators conducted their icebreaking testsand gathered additional data.

The ship was heavily instrumented, with straingauges throughout the hull and the most mod-ern electronics available, housed in a 50-ft

container on deck. Afterwards, a model of theManhattan was built and tested in Wrtsils newIce Model Basin. Built specifically to support theManhattan Experiment, the basin opened thedoor for ice technology exchange betweenSoviet and Finnish scientists a lesser-knownpart of the Manhattans legacy. Voyage datawere compared with model tests and calcu-lations to calibrate the basin and its testresults, with the information serving asthe basis for Wrtsil and Esso to designthe ice-class tankers of the future.

The experiment showed conclusivelythat it would be technically and economically feasible to do year-round marine transportation intankers through the NorthwestPassage.

Mission

The mission of ABS is to serve the public interest as well as the needs of our clients by promoting the security of life, property and the natural environment primarily through the development andverification of standards for the design, construction and operationalmaintenance of marine-related facilities.

Quality & Environmental Policy

It is the policy of ABS to be responsive to the individual and collectiveneeds of our clients as well as those of the public at large, to providequality services in support of our mission, and to provide our servicesconsistent with international standards developed to avoid, reduce or control pollution to the environment.

All of our client commitments, supporting actions, and servicesdelivered must be recognized as expressions of Quality. We pledge to monitor our performance as an on-going activity and to strive for continuous improvement.

We commit to operate consistent with applicable environmentallegislation and regulations and to provide a framework forestablishing and reviewing environmental objectives and targets.

TX 6119 05/06 4000

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Documents

ABS - Low Temperature Operations