Posted : 12/24/12 11:25 AM
Oil has been the fuel of choice for powering ships for over a century now, supplanting coal as a source for running steam boilers just as diesel engines have largely replaced steam engines. The grade used is commonly called bunker fuel and can quite literally be termed bottom of the barrel, since it is the densest form of liquid found in petroleum and tends to sink to the lowest levels during the refining process known as cracking. The term bunker refers to the containers used to store the oil aboard ships. Increasing fuel costs have led to greater attention being given to fuel management systems and advances in technology have permitted greater oversight to be possible. Bunkers are now equipped with sensors that continually monitor fuel use and allow the crew to make decisions on engine speed and course corrections that will impact fuel usage rates. These instruments also allow authorities to closely monitor any spillage that might occur. The system has greatly reduced loss and pollution that used to result from overfilling tanks and has also cut down on pilferage. Ship exhausts constitute a significant source of global totals for emission of both nitrogen oxides and sulfur oxides, two…
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Ship engines are being forced to deliver ever increasing amounts of power as the cargo capacity of vessels continues to increase. There are now ships that carry ten thousand containers, and even larger vessels are in the works. Rising costs for fuel have prompted firms to explore new methods for engine design including gas turbines and a variety of hybrids. For now though, diesel power remains the workhouse of modern maritime engine technology. Other technologies are relegated mainly to combat vessels, where speed is more the issue than cost efficiency. Currently the most powerful diesel is made by the Swiss firm Wartsila Sutzer, which may seem strange given that country’s landlocked geography. Their RTA 96-C motor is a two stroke, turbocharged engine that comes in a variety of configurations ranging from 6 to 14 cylinders. The 14 cylinder model is 88 feet in length and 44 feet tall. The behemoth weighs in at 2300 tons and can produce about 109,000 horsepower operating at 102 rpm’s. Each cylinder head measures 38 inches across with a stroke of 98 inches giving a total displacement of just over 111,000 cubic inches. Each cylinder can produce 7780 horsepower. The thermal efficiency of this monster…
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