Chances are that when a yacht ties up at a fuel dock, the captain asks how much does the diesel cost per gallon, and is there enough fuel to fill the yacht’s fuel tanks. Although these are logical questions to ask, they are the wrong questions to ask…at first.
There are five vital questions that should be asked whether fueling up at a marina or bunkering from a fuel barge or truck:
When was the last time the marina’s fuel supply tanks were cleaned?
If the marina’s storage tanks are not cleaned at a minimum of twice a year, there is probably a fair amount of water, organic and inorganic contaminants sitting at the bottom of that tank and can be drawn up by the fuel dispensing pump and dumped into the yacht’s fuel tanks. Even if the yacht’s fuel tanks are kept scrupulously clean, adding dirty fuel will soon spread contamination throughout the yacht’s fuel system. It can be likened to adding a cup of sour milk to a gallon of fresh milk, within a short time that whole gallon will be unfit to drink.
When was the last time the marina’s fuel supply tanks were filled by the fuel distributor?
Since having fresh, clean diesel is the goal when fueling up. One would think that if the distributor delivered the fuel just an hour before bunkering, it would be the ideal scenario. Well it’s not. When tanker trucks deliver the fuel to the marina’s storage tank, the process causes turbulence which stirs up any bacteria, mold, water, sand and rust from the bottom and walls of the storage tank. The heavier particulate matter will precipitate out in a relatively short time. But the lighter organic contaminants can stay in suspension in the fuel for up to 48 hours. It is best to wait at least two days after a fuel delivery before topping off at a marina.
What type of additives are being mixed with the diesel by the distributor or marina?
A full spectrum additive package is an important part of diesel fuel maintenance, and if mixed in before it reaches the yacht’s fuel tanks, it can help guarantee cleaner fuel and better operational characteristics of the engines. The types of chemicals that can be mixed in at the refinery or by the distributor include injector cleanliness additives, lubricity additives, smoke suppressants, stabilizers, dispersants, solvents, antioxidants, de-emulsifiers and corrosion inhibitors. However, if a biocide is included as an additive, it can cause problems aboard the yacht. A biocide kills bacteria and fungi, that’s its job. When these organisms die, they fall to the bottom of the yacht’s fuel tank and form a sludge that can clog filters. The only remedy at that point is a complete fuel polishing and tank cleaning.
What size micron filters are used at the fuel dispensing pump?
Primary fuel filters aboard yachts should filter out particles greater than 30 microns (0.0011811 inches) in size, leaving the secondary engine mounted filters to catch the smaller particles before they reach the injection system. At a minimum, the filter on the marina’s fuel dispensing pump should be rated at 30 microns and changed regularly. If it is greater, the yacht’s primary filters will be overworked and get plugged up quickly by larger particles. If it’s less, say 10 microns, then even better, as it will save on primary filter replacement costs.
What is the name and contact information of the fuel distributor?
Should bad fuel get bunkered, chances are the marina won’t admit that the fuel was dirty. This is not because they are being underhanded, but they may truly believe they are pumping clean fuel. If the marina doesn’t want to accept the liability of dispensing dirty fuel, then contact the fuel distributor who delivered that fuel to check their records and the methods they used to keep the fuel clean prior to delivery.
Every captain should exercise due diligence before they agree to buy any diesel fuel, lest the yacht’s fuel system become contaminated. It makes no sense to have a rigorous fuel preventive maintenance program aboard a yacht, and then top off with dirty fuel because five easy questions were not asked.
Capt. Jeff Werner has been in the yachting industry for 25 years, and is the owner of Diesel Doctor (MyDieselDoctor.com). All Triton readers receive a 10 percent discount on online orders. Contact him at Jeff@MyDieselDoctor.com.