Electrical Hazard Protection of Tank Vessels While Moored to Shore Facilities

摘要

The scope of this task is limited to tanker/terminal operations involving the transfer of liquid flammable cargoes. A literature search and review has been conducted to collect available information pertinent to the electrical hazards related to the ship to shore transfer of flammable cargoes. The literature search revealed that a great amount of work has been accomplished in the area of static charge hazards, however very little has been done to characterize the nature of stray currents. It has not been feasible to produce mathematical stray current models using the available literature. A review of current practices of various operators was accomplished, mostly by observation and interview. Specific documents dealing with electrical hazards were not available at the terminals. The personnel involved with cargo transfer at the terminals are, in general, only vaguely aware of the nature and hazards of stray currents and static charges. Instrumentation was designed and fabricated for the measurement of stray currents. The instrumentation will measure voltage, current, and the capability of the tanker/terminal circuit to produce an arc when the circuit is opened. The measurement of stray current was accomplished at several terminals. In some cases, significantly high current flows capable of producing arcs were observed between the tanker and terminal. In one case, the presence of two bonding cables and a connected loading arm did not prevent arcing. (Author)