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that time some shipowners found it advantageous to use interme- diate fuels (IFO) on their auxil- iary engines. Since then the number of en- gines equipped for IFO operation has increased every year, and at the present time about 80 percent of Bergen's annual engine pro- duction is sold for IFO opera- tion. There are today approxi- mately 320 Bergen Diesel engines, totaling 2,700 cylinder units, com- missioned for IFO operation. The majority of the 210 gen- erating engines and a fairly large number of the propulsion engines which are in operation worldwide have to accept the wide variety of fuel qualities available. Experience has shown that, pro- vided Bergen's recommendations for fuel treatment, engine tem- peratures and load levels are met, overhaul times and wear figures generally did not alter signifi- cantly compared to marine diesel fuel operation. Representatives of B&W Diesel, Inc. presented a paper on "The Low-Speed Diesel and the Future Energy Scenario." The authors spoke of the current B&W Diesel engine program which is based on the all-fabricated design which was introduced with their K-GF engines in 1973. Because of the oil crisis in 1973 and the subse- quent demand for increased pro- pulsion efficiency, B&W decided to develop a slower running ver- sion of this series. Due to the uniflow scavenging system of the B&W engine, the slower turning of the propeller could be obtained for the same output by increasing the stroke of the engine. With the introduction of con- stant-pressure turbocharging in 1978 and the improved turbo- charging efficiency, the exhaust- valve timing was modified such that, at the same maximum cyl- inder pressure and at the same mean indicated pressure, a more favorable cylinder process was obtained. An increase in thermal efficiency and a lower thermal load was obtained. This led B&W to the next log- ical step, which was that of fur- ther utilizing the built-in power reserve by increasing the mean effective pressure by 12 percent and the speed by three percent. At the same time, the maximum cylinder pressure was increased by about five percent. B&W two-stroke engines have in principle been designed to burn all commercial grades of heavy fuel, limited by only a few guid- ing parameters, mainly related to the handling of the fuel oils. B&W has systematically inves- tigated for the past three years the effect of such so-called future fuels on a test engine, a two- stroke crosshead uniflow-scav- enged engine and in fact, found indication that such fuels will not cause appreciable difficulties. Hugo Fiedler, Krupp MaK Mas- chinenbau GmbH, spoke on the November 15, 1981 "Prospects of Medium Speed Four-Stroke Diesel Engines in View of Future Fuel Problems." This paper reports on investiga- tions by Krupp MaK in the low- quality fuel field. Prospects for lowering of fuel consumption and possibilities of maintaining low maintenance costs in spite of in- creasing difficulties are discussed. The general feeling has been that high engine speed might re- sult in difficulties in burning heavier and less combustible fuel components on account of less time for combustion. Consequent- ly, Krupp MaK looked for various fuels representing future param- eters as close as possible and in- vestigated the influences on com- bustion and thermodynamics, de- posits on the combustion chamber and neighboring area as well as on the general engine perform- Hugo Fiedler Krupp MaK Diesel Mampaey Makes Your Life Easier! Product Dependability, Priced to Your Advantage; Quick Shipment. Inquiries Answered Immediately. ( A-i. .AL msF^) MAMPAEY J MOORING, TOWING AND CHAIN HANDLING EQUIPMENT MAMPAEY MARINE ENGINEERING B.V. P.O. Box 667 - 3300 AR Dordrecht - Holland Tel. 078-13 53 99 - Telex 29436 MAMPY NL Represented in the U.SA by °BLUE WATER MARINE SUPPLY, INC 1000 Broadway at Channelside • P.O. Box 5457 Houston,Texas 77012 • (713) 928-5951 • Telex: 775-183 New Low Profile Double 100-ton Quick Release Mooring Hook with Explosion-Proof Capstan. Write 137 on Reader Service Card MARINE SALES REPRESENTING
