While medium speed four-stroke engines and gas turbines have always been recognised on the stationary market, the large two-stroke low speed diesels were almost forgotten by the utilities in the sixties, mainly because fuel oil was plentiful and prices very low. Efficiency was therefore not a very important parameter for plant owners and operators. The oil crisis of the seventies completely changed this situation, and since then there has been a growing interest in the installation of two-stroke low speed diesels for power generation purposes.