On ships of the Viborg class, built by the Warnow Shipyard (East Germany) (length 140 m, beam 19.95 m, displacement 17,900 tons), increased vibrations of the main engine (MAN K9 70/120 A5 diesel, 8150 HP, 130 RPM) and certain machines in the engine room is observed; this results in damage to the structural elements and machinery of virtually all the ships of this class. The principal types of damage observed on these ships are: fracture of the bearings of gas turbine-driven superchargers; pitting corrosion of main-engine bushings and cylinders, rupture of stanchions supporting the turbine exhaust pipe; rupture of the oil lines ahead of engine cylinders due to vibrations of the diesel-powered generating set. Moreover, on certain ships of this class there occurs considerable vibration of the piping of air conditioning system, steam lines leading to heaters in the separator department and the refrigeration-plant compressor, etc. Following prolonged tests of the main ship in the Viborg series, the Viborg, by the TsNIIMF (Central Scientific Research Institute of the Maritime Fleet) in May 1968 the principal cause of the vibrations was unambiguously traced to the unbalanced inertial forces of the main engine. Measurements of vibrations as a function of engine RPM showed that the vibration amplitudes increase in direct proportion to RPM. This is largely due to the fact that in East Germany the norm for the permissible amplitude of engine vibrations is less stringent (0.5 mm) than that allowed in the USSR by the USSR Ship Registry (0.25 mm). The principal corrective measures that can be taken consist in dismantling most of rigid couplings linking the main engine to the accessories (superchargers, platforms, manifolds and other elements most susceptible to vibration) and mounting the accessories on autonomous footings. As for the vibrations of diesel-powered generating sets, whose amplitude reaches as much as 1.52 mm compared with the 0.25 mm permitted by the norm, here the most effective counter-measure is replacement of the sets.

  • Corporate Authors:


    Leningrad,   USSR 
  • Authors:
    • Gavrilov, M N
  • Publication Date: 1967

Media Info

  • Features: Figures; Tables;
  • Pagination: p. 57-65
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00014612
  • Record Type: Publication
  • Source Agency: Joint Publications Research Service
  • Report/Paper Numbers: Russian
  • Files: TRIS
  • Created Date: Aug 12 1973 12:00AM