The main items of engine overhaul are concerned with pistons and main bearings and since the usual duration of the dry-dock period for hull overhaul is sufficient for only half the pistons to be examined and repaired, efforts are being made in Japan to achieve a four-year interval between major engine overhauls, which are preferably carried out in dry dock. Tests with this objective have been in progress since 1973 on a Mitsui B & W 6K84EF engine rated (m.c.r.) at 15,500 bhp at 114 rpm, installed in the 36,000-dwt tanker Toei-Maru. Because bearing failures have been virtually eliminated since the adoption of the overlaid crosshead bearing as standard, the tests have been confined mainly to measurements of cylinder and piston-ring wear. The former has been considerably reduced by substituting "Takalloy"--a boron cast iron--for the more commonly used titanium-vanadium cast iron for the cylinder-liner material. Takalloy is now used as standard in all Mitsui B & W engines. After three years of operation the wear rates of cylinder liners and piston rings were, respectively, 0.02 to 0.93 mm and 0.05 to 0.15 mm per 1000 hours. These satisfactory results were achieved by careful attention to the fuel-cleaning and cooling-water systems, and the type and purification of the lubricating oil; the methods adopted and the desirable objectives of each are described. Order from BSRA as No. 49,465.

  • Corporate Authors:

    Marine Engineering Society in Japan

    Osaka Building, 1-2-2 Uchisaiwai-Cho, Chiyoda-Ku
    Tokyo 100,   Japan 
  • Authors:
    • Yamamoto, O
    • Danjho, Y
  • Publication Date: 1978-3

Media Info

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Filing Info

  • Accession Number: 00188739
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Mar 14 1979 12:00AM