Marine technical assistance - Shaft alignment studies and analysis
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BUSINESS CHALLENGE Proper shaft alignment is a key issue on ships, especially on large vessels such as containerships, bulks, tankers and gas-carriers. Any wrong alignment of the shaft can result in undesirable vibrations, higher operating costs or worse. Damage to the stern-tube bearings or other key parts of the vessel's propulsion equipment could result in the ship being immobili sed. SOLUTION What are shaft alignment studies and analysis? Bureau Veritas offers shipbuilders and ship owners a complete set of services regarding rational shaft alignment. The shaft alignment studies and related analyses must be chosen taking into account the type of ship, the shaft arrangement and the required degree of accuracy. They include theoretical studies and practical operation. What are the key benefits? • Avoid undesirable vibration and its effects. • Prevent costly repairs and immobilisation of the vessel. • Ensure operating the line shafting in the best running conditions for its optimal behaviour, particularly in the stern tube area. • Improve efficiency of the whole propulsion system, including the main engine and eventual gear box. WHY CHOOSE BUREAU VERITAS ? Reputation ■ Founded in 1828, Bureau Veritas was one of the first classification societies and a founding member of IACS (International Association of Classification Societies, gathering the 10 leading classification societies in the world). Network ■ The worldwide BV network has more than 1,000 high qualified marine surveyors, specialised in the implementation of safety, security, and protection of environment rules and standards, operating in 420 survey stations in 140 countries. Speed of response ■ Bureau Veritas provides a single convenient point of contact to each client, and a large autonomy to its local managers for plan approval, surveys and issue of certificates. Efficient IT tools ■ Bureau Veritas' own VeriSTAR system is a powerful and sophisticated tool that facilitates the efficient management of safety and quality. It integrates all the elements of ship operation to provide timely and cost-effective solutions across a broad range of classification services. In addition to Shaft Alignment studies & analysis, Bureau Veritas offers a wide range of related services. • Classification of ships and off-shore units • Statutory and non-statutory certification • Other technical assistance • Training RELATED SERVICES Marine technical assistance - Shaft alignment studies and analysis Ensuring optimum propeller shaft performance and helping avoid costly problems
Transcript of Marine technical assistance - Shaft alignment studies and analysis
BUSINESS CHALLENGEProper shaft alignment is a key issue on ships, especially on large vessels such as containerships, bulks, tankers and gas-carriers. Any wrong alignment of the shaft can result in undesirable vibrations, higher operating costs or worse. Damage to the stern-tube bearings or other key parts of the vessel's propulsion equipment could result in the ship being immobilised.
SOLUTIONWhat are shaft alignment studies and analysis? Bureau Veritas offers shipbuilders and ship owners a complete set of services regarding rational shaft alignment.The shaft alignment studies and related analyses must be chosen taking into account the type of ship, the shaftarrangement and the required degree of accuracy. They include theoretical studies and practical operation.
What are the key benefits? • Avoid undesirable vibration and its effects.• Prevent costly repairs and immobilisation of the vessel.• Ensure operating the line shafting in the best running conditions for its optimal behaviour, particularly
in the stern tube area.• Improve efficiency of the whole propulsion system, including the main engine and eventual gear box.
WHY CHOOSE BUREAU VERITAS ? Reputation ■ Founded in 1828, Bureau Veritas was one of the firstclassification societies and a founding member of IACS (InternationalAssociation of Classification Societies, gathering the 10 leadingclassification societies in the world).
Network ■ The worldwide BV network has more than 1,000 high qualifiedmarine surveyors, specialised in the implementation of safety, security, andprotection of environment rules and standards, operating in 420 surveystations in 140 countries.
Speed of response ■ Bureau Veritas provides a single convenient point ofcontact to each client, and a large autonomy to its local managers for planapproval, surveys and issue of certificates.
Efficient IT tools ■ Bureau Veritas' own VeriSTAR system is a powerful andsophisticated tool that facilitates the efficient management of safety andquality. It integrates all the elements of ship operation to provide timely andcost-effective solutions across a broad range of classification services.
In addition to Shaft Alignment studies& analysis, Bureau Veritas offers awide range of related services.
• Classification of ships and off-shore units
• Statutory and non-statutorycertification
• Other technical assistance• Training
RELATED SERVICES
Marine technical assistance - Shaft alignmentstudies and analysisEnsuring optimum propeller shaft performance and helping avoid costly problems
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CONTACTFor details about this service, please contact Bureau Veritas Marine Division - Serge KoroleffBy phone: +33 1 42 91 33 63 - Fax: +33 1 42 91 33 95By e-mail: [email protected]
FOR MORE INFORMATIONplease visit:
www.veristar.com
OUR APPROACHTheoretical studiesRational Alignment Analysis. The conventional study which considers thebearings as infinitely rigid includes the following items:
• Basic calculations with influence coefficients of bearings.• Rational distribution of reactions in way of bearings including gear
shaft bearings.• Boring out of stern tube and bushes.• Details or practical operations of alignment allowing realisation of
calculated rational alignment.Elastic Alignment Analysis. This complementary study may be carriedout according to the results obtained previously. This analysis which takesinto account the elasticity of bearing material and hull structuredeformation, gives the following information:
• Distribution of reactions• Deflection of material• Deflection of hull structure
Influence of oil film. In addition, influence of oil film may be taken intoaccount. This approach permits to determine the following:
• Distribution of pressure • Distribution of reaction • Oil film thickness
in relation to rpm, shaft alignment, structure elasticity, and propellerforces and moments.
Practical operationSurvey during mounting. This survey consists mainly of checking whatenables us to achieve the theoretical rational alignment study.
• Checking of relative position of bores and their predetermined slopes.• Checking of coupling conditions to fit the intermediate bearing.• Checking of coupling conditions for positioning the reduction gear or
main engine.Jack up test. This test enables us to determine the real reaction in way ofaccessible bearings and verify their influence coefficients.
• Intermediate bearings.• Fwd bush or aft bearing of shaft reduction gear (in relation with the
shaft arrangement).Alignment checking. The results of alignment checking by optical checkor laser methods are analysed and compared with the boring conditionscalculated for the involved line shafting (ship newly built or in repair). Thelaser method also enables to verify the line shafting alignment conditionswithout disconnecting the shafts, the main engine or the gear shaft.
FAQWhat do you have more than other classification societies inproviding shaft alignment analysis?At Bureau Veritas we have among the best specialists in the world inthe field of shaft alignment analysis. They have been recognised assuch in the industry for more than 25 years. In addition, our hightechnology analytical and modeling tools are second to none.
CLIENT REFERENCESBureau Veritas has earned theconfidence of many leadingcompanies in the marine sector,including:
• Shipyards: Aker Yards, Dalian,DSME, Fincantieri, Hyundai, IHI,Mitsubishi, Samsung, SWS,Universal.
• Marine Equipment Manufacturers:Bao Steel, Caterpillar, FFEHoldings, Hyundai, Man, Mitsui,Mittal Steel, POSCO, Reintjes,Schneider, Wartsilä.
• Ship owners: Anangel, Boskalis,Broström, Cardiff Maritime, CMA-CGM, Dynacom, GroupeBourbon, Dredging International,Enterprises Shipping & Trading,Exmar, Jan De Nul, Louis Dreyfus,Maersk, MSC, Nisshin, Norden,Tsakos.
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