FIELD MEASUREMENT OF VERY LARGE CRUDE CARRIER (VLCC) MOORING LOADS

The proper mooring system design for very large crude carriers (VLCCs) is necessary to assure safe loading or unloading operations. The design of a conventional pier mooring system involves the predictions of static wind and current loads acting on the tanker using theoretical analysis and/or model test data. In order to verify these prediction procedures, Exxon Research and Engineering Co. conducted a series of experimental studies at two tanker piers handling vessels up to 280,000 deadweight tons. The experimental studies utilized two of the earliest operating mooring load monitoring systems for VLCC piers. The force in each mooring line was monitored and recorded during the measurement period. Fender deflections and environmental conditions such as wind and current were also recorded. From the measured mooring line and fender force data, the resultant load acting on the tanker can be evaluated. The resultant load is then compared with the design load based on the measured environmental condition. In addition, the experimental study included the recording of the tanker dynamic response when subject to natural wind. This experimental study demonstrated that industry wind and current load data (OCIMF Prediction of Wind and Current Loads on VLCCs) are adequate in predicting the static wind and current load acting on a moored tanker. It further indicated that analytical procedures based on theory and small scale model studies are applicable in prototype situations. However, more research would be beneficial in understanding the dynamic response of a moored VLCC while subjected to natural wind. Better understanding of this phenomenon could result in more efficient/economical mooring systems for large tankers.

  • Supplemental Notes:
    • Proceedings of the Eleventh Annual OTC Held in Houston, Texas April 30-May 3, Volume 1.
  • Corporate Authors:

    Offshore Technology Conference

    6200 North Central Expressway
    Dallas, TX  USA  45206
  • Authors:
    • Fang, S
  • Publication Date: 1979

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Filing Info

  • Accession Number: 00195852
  • Record Type: Publication
  • Source Agency: Offshore Technology Conference
  • Report/Paper Numbers: Volume 1 Proceeding
  • Files: TRIS
  • Created Date: Jul 31 1979 12:00AM