BUREAU VERITAS AND GAS CARRIERS. 3. FREE AND FORCED VIBRATIONS ON GAS CARRIERS

Owing to the simultaneous increase of LNG tanker dimensions and their propulsive-plant outputs, the problem of the influence of hull deformations and ship vibrations on the behaviour of these sophisticated ships is of the utmost importance. Over the past 15 years Bureau Veritas has carried out numerous investigations on the causes of the different technical problems encountered on different types of ships, including gas carriers. The troubles met were found to be mainly due to two types of phenomena: 1. The propulsive plants began to be influenced by external phenomena, the most prevalent being deformability of the steelwork due to loading conditions, as well as to sea state and its influence on the smooth relationship between lineshafting, gearing, crankshaft and their supports. 2. More and more frequent appearance of various vibratory phenomena affecting propulsive plants as well as hull steelwork, superstructures, etc. The most urgent question, however, with respect to ship vibration phenomena concerns the forced vibrations of the various parts of the hull steelwork and especially of the engine room, very often situated well aft in the hull girder. To investigate these phenomena effectively it was necessary to devise a clear, flexible, and rapid method of dealing with these problems, which is known as the CAF system. This system comprises an assembly of automated tasks which can be interconnected one with the other, conceived in parallel with several computer programs. The calculations carried out for the different types of vibration are described and illustrated.

• Supplemental Notes:
  • Proceedings held in Paris, September 30-October 3, 1975. For further information, see MRIS Abstract #20 157838.
• Corporate Authors:

  GASTECH 75 LNG & LPG Technology Congress

  Paris,   France 
• Authors:
  • Volcy, G C
  • Masson, J C
• Publication Date: 1975

Media Info

• Pagination: 9 p.

Subject/Index Terms

• TRT Terms: Chemical tankers; Design; Hulls; Liquefied gases; Liquefied natural gas; Structural analysis; Vibration
• Old TRIS Terms: Hull structural analysis; Hull vibration
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00157839
• Record Type: Publication
• Source Agency: British Ship Research Association
• Files: TRIS
• Created Date: Aug 15 1977 12:00AM