The USCG said that after a noted decrease in loss of propulsion (LOP) incidents, there has been a recent increase in the number of reported LOP incidents on deep draft vessels within the Eleventh Coast Guard District which covers the states of California, Arizona, Nevada, and Utah.
According to the alert, posted July 11, Coast Guard studies and review of marine casualties indicate that lack of maintenance and testing of certain systems, including fuel oil systems, is one of the leading causes of propulsion failures.
"Advanced planning and careful fuel system management are critical to safely switching fuels. This is especially important if fuel switching is not routine practice. Proper procedures, training, and maintenance are essential for vessels to safely switch between heavy/intermediate fuel oils and marine distillates," the USCG alert said.
Vessel operators, said the Coast Guard, also need to have a good understanding of their system requirements and limitations, and determine if any modifications may be necessary to safely switch between intended fuels.
"Extensive analysis of LPO incidents have revealed certain trends among vessels operating on marine distillate fuels," the alert said.
In order to manage risk and improve safety, vessel owners and operators should:
- Consult engine and boiler manufacturers for fuel switching guidance;
- Consult manufacturers to determine if system modifications or additional safeguards are necessary for intended fuels;
- Develop detailed fuel switching procedures;
- Establish a fuel system inspection and maintenance schedule;
- Ensure system pressure and temperature alarms, flow indicators, filter differential pressure transmitters, etc., are all operational;
- Ensure system seals, gaskets, flanges, fittings, brackets and supports are maintained and in serviceable condition;
- Ensure a detailed system diagram is available;
- Conduct initial and periodic crew training;
- Exercise tight control when possible over the quality of the fuel oils received;
- Complete fuel switching well offshore prior to entering restricted waters or traffic lanes; and
- Test main propulsion machinery, ahead and astern, while on marine distillates.
- Monitor for accelerated wear of engine/fuel system components and evaluate maintenance period intervals;
- Ensure fuel viscosity does not drop below engine manufacturer’s specifications;
- Ensure proper heat management of fuel systems to maintain minimum viscosity values;
- Make appropriate fuel rack adjustments to account for potential fuel pressure differentials between residual fuel oils and marine distillates;
- Determine speed limitations for stopping the engine ahead and ordering an astern bell to ensure timely engine response; and
- Ensure start air supply is sufficient and fully charged prior to maneuvering.
