Increases in the tonnage of tankers, LNG carriers, and container vessels accompanied by increases in the powers of propulsion plants have led to incompatibility between the deflections of the hull and the line-shafting stiffness. This incompatibility is at the origin of the harmful influences exerted on main gears by external effects, including: deformability of the hull girder and double-bottom structure; flexibility of thrust foundations and rocking of thrust bearings; improper shafting and turbine alignment; and thermal expansion. Strain-gage, displacement, and vibration measurements on the journals of shafting and gears have given evidence of the existence of these harmful external influences. The solution adopted for different types of gearing and thrust bearing designs have produced positive results. Previous experience together with modern finite-element calculation techniques on speedy computers have made it possible to proceed with preliminary calculations that furnish the alignment data for satisfactory installation of main gears and shafting. These modern calculation methods have served to explain some phenomena recently encountered on gears and shafting of VLCC vessels which were caused by the influence of ship's structure.

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  • Corporate Authors:

    Society of Naval Architects and Marine Engineers

    601 Pavonia Avenue
    Jersey City, NJ  United States  07306-2907
  • Authors:
    • Volcy, G C
    • Budd, WIH
  • Publication Date: 1975-10

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Filing Info

  • Accession Number: 00127593
  • Record Type: Publication
  • Source Agency: Society of Naval Architects and Marine Engineers
  • Files: TRIS
  • Created Date: Dec 3 1975 12:00AM