No need to keep different multiple spec lube oils on board any longer say Shell Marine Products as they launched their lube oil, Alexia S4 a few days ago. Their new oil is a ‘one-stop’ solution lube for all climates, all seasons, in a wide range of vessel types with low-speed two-stroke engines, including those steaming at slow and ultra-slow engine speeds. As if that were not enough, Shell also say that the new formulation better protects engines.
VLCC: Photo courtesy of Shell
Fundamentally though, the introduction of this oil for low-speed, two-stroke marine diesels was founded upon a breakthrough in the understanding of oil stress in this type of engine, as will be seen.Lube Oil Stress in Slow-speed Marine DieselsOil stress, the single most important factor that governs the lifetime and performance of an engine lubricant, is the name given to those factors which degrade lubricants, making them less effective. Research on oil stress has been done for many years ... [More]
Oil fuel and lube oil testing proves its worth (let the buyer beware) advises chemical analysis specialist companies Lintec and Intertek, telling a few days ago of their joining hands to provide a service to help guard ship operators world-wide against the perils of using off-specification oils. A case study illustrates their point.
The entire fleet of a Hamburg-based shipowner was placed on Lintec’s chemical screening programme. On one of the ships, on long-term charter, a sample fuel analysis revealed that bunker fuel containing DCPD (Dicyclopentadiene) and Styrene had been taken on board; the charterer being duly informed of the inherent risks to the ship’s engine that might arise from this bunker stem. Soon, operational difficulties, including blocked oil filters, were reported to the extent that the fuel had to be pumped out and replaced at the next port of call. Further lab analysis was done to determine the exact levels of contamination, with results that persuaded ... [More]
"Oil and water don't mix", was oftentimes muttered to explain a certain amount of tension between deck and engine-room personnel in days long past when low-tech ships were manned with far more crew than today. However, the saying is not entirely true as far as lube oil is concerned, since it contains added chemical emulsifiers and detergent, allowing water to mix, or dissolve in this type of oil: only after saturation point is reached will water content indeed finally become separated and then the familiar saying becomes true. These additives to cylinder lube in slow-speed diesel engines are necessary to neutralize acidic products of combustion and also to keep metal surfaces clean.The latest generation of marine diesel engines has higher firing pressures and better combustion characteristics to achieve thermal efficiency, fuel economy and reduced carbon emissions even when burning low-end bunkers, but successful operation depends upon the quality of the lubricant. High moisture ... [More]