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PROPULSION UPDATE Field, Laboratory Tests Of Wartsila Engine Return Good Results Wartsila Diesel recently released accrued test information on the Wartsila 20 engine. The latest in the range of engines designed and manufactured in Finland has gone through an intensive period of testing both in the field and in the Vaasa test laboratory. Altogether, the en- gines have accumulated more than 4,000 run- ning hours in the lab, roughly the same as in the first field installation. The engine maker, to get a wide-ranging, authentic picture of engine performance, imme- diately scheduled an inspection plan when the first Wartsila 20 field installations were started in March 1994. The first inspections were made on three ships — WWKairo, M/VDSR Port Said and MA" City of Tunis (pictured to the right) — each of which have three Wartsila 6L20 auxil- iary engines. The inspection plan included visits to the first ships when the engines had reached 1,000,2,000 and 4,000 operating hours. The plan was to make a complete inspection of all main engine parts on one engine and collect perfor- mance data from the other two engines. The engine room of the M/V City of Tunis. Field Test Results The first visit on the M/V Kairo was made after one of the three auxiliary engines had reached 1,000 operating hours. The vessel is a containership operating in Europe. The field test was de- signed to spot changes in en- gine perfor- mance long be- fore they turn into problems for the owner, and to identify new possibili- ties to continue engine devel- opment. The results of this test confirmed Wartsila's lab tests, the en- gine maker re- ports. All components such as pistons, cylinder liners, valves, connecting rods and bearings were reportedly in excellent condition, showing al- most no wear. Inspections have since been made on five other vessels and the field inspection schedule has been very intensive. A total of 10 visits had been performed by late November. The results from the field inspections have shown very good engine performance, Wartsila reports. An interesting point raised in the field testing, the engine maker found, was regarding low lubricating oil consumption. Low oil consump- tion in itself is not a problem, quite the opposite. The problem, Wartsila points out, is disposing of the used oil, as it is expensive and many harbors have inadequate facilities to handle waste oil. The challenge now lies in developing a lubricator that can meet the needs of low lubrication oil consumption, less than .5 g/kWh, the engine maker believes. Laboratory Test Results Although field testing has increased in impor- tance for Wartsila, lab testing has not decreased in value as it allows the almost continuous opera- tion of the engine. Laboratory testing also allows the ability to test solutions which may not be necessarily safe, but which may have great im- pact on total performance if they succeed. The endurance tests performed in the labora- The M/V City of Tunis has three Wartsila 6L20 auxiliary engines, and data from the engines' performance was used by the manufacturer in field tests of the engine. tory on the Wartsila 20 engine have been at very high loads: up to 20 to 25 percent overload from nominal values and with maximum combustion pressures exceeding 200 bar. A load cycling test from 0 to 120 percent with six-minute cycles has been performed for more than 250 hours and other demanding tests have been performed to stress the engines to their limits — all of which have been passed, according to Wartsila. When the endurance tests have shown that the engine is able to withstand big stresses, the test programs have changed from endurance testing to fuel consumption optimization and emission control. In the laboratory, the test program during 1994 strongly emphasized emis- sion control. Different solutions are being tested and new ideas are being examined and explored daily. Within one year, the NOx emis- sions on the Wartsila engines have been reduced by half and progress is still being made. For more information on Wartsila Diesel Circle 5 on Reader Service Card Pearl Harbor Survivors At Keel-Laying For Avondale's Ship Pearl Harbor Members of the Na- tional Pearl Harbor Survivors Association attended the keel-lay- ing ceremony for LSD- 52 at Avondale's New Orleans shipyard in January. LSD-52, Avondale's latest ship built for the U.S. Navy, will be christenedPearl Harbor at launching ceremonies in 1996, in honor of the naval base on the Hawaiian island of Oahu, and the sol- diers who fought against the surprise Japanese attack on De- cember 7, 1941. For more information on Avondale Circle 93 on Reader Service Card 34 Maritime Reporter/Engineering News
