While it has been proposed that heavy fuel use at sea should be eliminated altogether on emissions grounds this cannot easily be justified and there will be an enormous amount of resistance to this on the grounds of the 40% cost advantage as described above.
6. THE AVAILABILITY OF HFO
HFO is basically a residual fuel and, as such, a waste product. Supply and demand control its price. As the demand for HFO increases because of growing sea traffic the supply of HFO increases as a result of greater use of crude oil for distillate products on land. The HFO cost advantage is therefore likely to remain. For this balance to be upset it will be necessary for the oil companies to remove more valuable products from the crude hence reducing the supply of HFO. This has been done in the past by catalytic crackers and vicebreakers. To take the next step and remove even more products would require a very considerable expenditure on behalf of the oil companies to develop and build new refineries. If this decision were taken today it would take some 8 to 10 years before these new refineries would have a significant effect but there seems to be no certain financial advantage for oil companies to invest these funds at today's prices. If anything the supply of HFO may increase relative to demand as a result of more countries legislating to reduce the use of HFO in land based installations.
7. CONCLUSION
For 40 years the huge price advantage of heavy fuel has given us all a big incentive to overcome the problems which are caused when it is burned in medium speed engines. A combination of an improved understanding of wear and corrosion mechanisms, a better design of components, improved materials and lubricants, better fuel treatment and more efficient components such as turbochargers and fuel injection equipment have meant that these problems have largely been overcome. Certainly the cost of these steps must be considered but the effect on the life cycle cost of a ship of using HFO significantly outweighs the cost of other factors in all but a select few vessels. It is concluded then that the heavy fuel engines of today have clearly maintained their lead by continued development and they will be with us for many years to come. The only remaining threat is the perceived effect of marine engine exhaust emissions on the environment on land. However, this cannot be justified. It will also be a very brave politician who would be a responsible for legislating against the use of HFO at sea and causing an equivalent fuel consumption increase of 40%.
8. ACKNOWLEDGEMENTS
The opinions expressed in this paper are those of the author but he would like to thank the management of AVL and his colleagues for their support.
9. REFERENCES
[1] Lord G.H. and Dexter S.G., "The development of a Highly Rated Medium Speed Trunk Piston Engine for Lubricant Assessment", CIMAC, Oslo, 1985
[2] Guidelines for the Lubrication of Medium Speed Diesel Engines. CIMAC Working Group Report No 13
[3] Borchsenius H.J., "Der Chrom-Keramik-Kolbenring - ein Technologie-Durchbruch", Schiff & Hafen 7/97
[4] Ederer U. and Mergen R, "Development of an aluminum alloy for crankshaft bearings combining high strength and high tin content", CIMAC Congress, Copenhagen, 1998
[5] Brown W.P., Scott M., Warriner J.F., Development of a Bi-metal Bearing Alloy for Medium Speed Diesel Engines, CIMAC 1995 Paper D74
[6] Umstand F., Ritzkopf M., Valve Corrosion in Diesel Engines, MTZ July/Aug. 1975 Vol. 36 No7/8, pp191-195
[7] Lutzen C., Oral presentation, Turbocharging CIMAC Day, Europort, 1999
[9] L16/24 "The First of a New Generation" MAN-B&W Publication
[10] Hall D.E. et al, "A review of recent literature investigating the measurement of automotive particulate; the relationship with environmental aerosol, air quality and health effects", SAE 982602
[11] Dexter S. G., Residual fuels - Combustion, Emissions and Particulates. I. Mech. E. Diesel Fuel Injection Systems Symposium 1989
