Engine designers opt for 100BN cylinder oils

Russian-owned, Hamburg-based Lukoil has been conducting research into high-BN lubricants for more than three years. The objective was for Navigo 100 MCL to be the first – and currently, according to the company, the only – cylinder oil on the market to achieve a base number of 100mg KOH/g. The base number measures the neutralisation capacity of acidic components that are created during the combustion of HFO.

Stefan Claussen, technical and marketing director for Lukoil in Hamburg, said: “In the past few years, the power, consumption and emissions of ship engines have been optimised more and more. This has resulted in engines with an extremely long stroke, which are operated at lower speeds than before.”

In the earlier, common full-load mode, the disadvantages of lubricating oils of 50 to 60 BN did not become apparent. Mr Claussen continued: “In contrast, today’s operating conditions such as slow steaming or new consumption-optimised engine generations require much higher alkalinity of the cylinder lubricating oil than before. This can be achieved either through increased consumption or through increased alkalinity in the cylinder lubricating oil, ideally 100 mg KOH/g,”

In a recent letter from MAN Diesel to its customers, Lukoil says that the 100-series BN oil was immediately recommended as the standard product for the MAN B&W 8.2 series and its successor generations. Therefore, says the company, data in the engine manuals will refer in the future to 100BN oils instead of the current 70BN oils.

Mr Claussen adds: “To ship builders, this means a lubricating rate that is reduced by up to 30% and hence considerable operating cost savings when using the 100-series BN oil. Extensive lab tests as well as on-board practical comparisons, such as with shipping company Norddeutsche Reederei H. Schuldt, have already confirmed to us that cylinder lubricating oil consumption turns out to be considerably lower at a higher base number. In addition, there is increased protection against wear.”