4. USER'S REQUEST
Marine fuel oil has some problems in its quality and quality control. From the viewpoint of users, followings are essential for the safety operation.
1) Active control over the degrading of fuel oil and the stabilization of the quality,
2) More reliable engine design and the designation of the fuel oil's quality,
3) Establishment of common standard for pre-treatment system and
4) Introduction of the concept for the safety into ISO 8217 and CIMAC recommendation.
4.1 ACTIVE CONTROL AND STABILIZATION
Fuel oil suppliers are requested to control and maintain the quality of fuel oils at least the current level. Because, there is no effective testing method to know the combustion performance before hand. It means that it is only when the actual engine trouble occurs to know the unfavorable performance of fuel oil. In another words, engines are the only effective testing tools to analyze them.
Also maintaining the uniformity of the quality is another vital issue. And this is more important than control of degrading. According to our analysis, fuel oil quality varies in wide range (10 times difference in a particular item) even the same grade and loading port is the same. This makes it very difficult for users to define the cause of the problem or to improve the engine reliability.
4.2 ENGINE DESIGN
Engine manufacturers are requested to develop trouble free engine and to designate allowable specification for fuel oil.
4.3 PRE-TREATMENT SYSTEM
Nominal performance of the equipment, such as purifiers, filters and so on, are vary with manufactures. There is no common standard to indicate the performance among the manufactures. Therefore, it is desired to establish the common standard. Otherwise, users are often confused when they select suitable equipment.
4.4 ISO 8217 AND CIMAC RECOMMENDATION
Fuel oil is like food for human. We need to avoid unhealthy food in order to maintain our good health. And usually, the acceptable quality or quantity of toxic substance based on good health is pointed out. However, ISO 8217 and CIMAC Recommendation seem to mention only about fatal poisonous food. It is not enough at all. Or they may have nothing to do with safety of engine. (Only "added substance or chemical waste" are mentioned at "note3 of ISO 8217 chapter 4.1")
Therefore when user purchases bunker based on ISO standard, there is no guarantee for safety of engine. The safety concept should be built in ISO 8217 and CIMAC Recommendation and clearly mentioned.
Table 1, which shows the recommendation for fuel oil qualities at engine inlet and bunkering for two stroke low speed engines by Class NK [1], is a good guideline for safety operation of engine.
Table 1 Recommendation for Engine inlet and Bunkering 2 stroke low speed Engine
