Spillage and Leakage

One of the main issues that “The International Convention for the Prevention of Pollution From Ships (MARPOL Convention)” primarily takes account of is prevention and prohibition of the accidentally spilled fuel, oily wastes and ballast water into the sea.

Oil spills during routine bunkering operations may cause a number of significant pollution claims and raise concerns as to the spillages resulting from a lapse of awareness during critical aspects of the bunkering operation or a basic failure to follow defined procedures.

Empirical analysis shows that bunker fuel commonly escaped through the air vents of the bunker tanks.  In most cases the quantities involved were substantial enough to breach savealls and plugged scuppers, resulting in escape of fuel from the confines of the vessel into the marine environment.

The circumstances leading to each incident were often different.  Bunker spills can of course also result where external factors impinge on the vessel’s operation.  Notwithstanding external factors, the following were commonly identified as causative in the incidents reviewed:

•Failure to close completely a valve to a tank which had completed loading its nominated quantity of fuel.  During filling of adjacent tanks, bunker fuel continued to enter the first completed tank unnoticed, eventually exceeding tank capacity;
•Failure to adhere to the stipulated maximum loading rate contained in the vessel’s bunker plan and agreed prior to operations.  As a consequence of excessive rate of supply, air pockets collected in the top frames of the tank.  When the fuel reached its optimum level in the tank, fuel was forcefully blown out through the air vents;
•Failure to adhere to recognized procedures for topping off tanks.  During topping off a valve was closed against the flow of one of two receiving tanks.  The flow rate was not reduced sufficiently and the increased pressure to the adjacent receiving tank resulted in overflow.
•Failure to monitor the progression of loading at adequate intervals resulting in overflow.

Bunkering is only one facet of a vessel’s dynamic operating schedule, but is categorized as a critical operation. Stemming bunkers commands careful planning, co-ordination and co-operation between all parties involved from the point of ordering until completion of the delivery.  Commercial schedules can impose immense pressure on owners and a vessel’s crew to stem bunkers within limited time periods.  However, non-compliance with recognized operating procedures in a vessel’s Safety Management System during bunker operations has the potential to result in substantial costs, penalties and even greater delay where spillage occurs as a consequence.  In some jurisdictions accidental spillage of bunker fuel can also result in criminal charges.

In accordance with the risks mentioned above, all hoses, joints, connections, pumps and tanks should be regularly controlled by the shippers and charterers. Bunkerist is determined on coordinating the activities they conduct with all their business partners on complying with this issue.