This paper presents an application of a patent technique (the patent number is ZL94 20404.2 in China) called Fan Weathervane Multi-point Counterweight Mooring (FWMCM). The feature of the technique is to apply the weathervane effect of the single point mooring system and additionally install the counterweight to conventional multi-point mooring system to reduce the mooring load and the occupied water-area. This new system may be utilized even in severely limited water-area for discharging of product oil and liquid goods economically. The FWMCM system technique had been utilized in a engineering project at Long Men Harbor in Qinzhou Bay, Guangxi province, China, which was an ideal selection for this project. There were two oil transfer terminals that adopted the type of FWMCM system in this project; one is for 50,000-ton terminal with 4 million-ton annual transfer capacity, and the other is 20,000-ton terminal with 3 million-ton annual transfer capacity. Computer simulation and tank model tests had been carried out, the results had shown that the FWMCM system was a novel and advanced mooring system.
The traditional fix jetty dock were mostly utilized to handling oil storage before the appearance of the single point mooring system in late 1950s in the field of large terminal of oil storage and handling in the sea. Nevertheless, the conventional multi-point mooring system technique is still an choice for mooring systems in the sea. The Traditional fix jetty scheme has the advantages of being direct connection between the jetty and the tanker, convenience in transportation and operation, but it suffers from the defects of being large investment, long construction period and poor stand capability to environment loads. The single point mooring system has the characteristic of weathervane, which always keeps the moored oil tanker at the least combined load position in wind, waves and current.
