Company: Berge Bulk Maritime Pte Ltd
Application: Main engine cylinder oil
Vessel: Bulk carrier
Key Edge: Shell LubeMonitor, Shell Alexia S6
Berge Bulk Maritime Pte Ltd, one of the world’s leading, independent dry bulk carrier owners, operates and manages more than 40 safe and fuel-efficient vessels ranging in size from 34,000 to 388,000 deadweight tonnage.
In 2014, Berge Bulk Maritime informed Shell that there were indications of cold corrosion on the surfaces of the cylinder liners of four of its vessels, which were using a BN 60 cylinder oil in their Wärtsilä RT-Flex 84 TD engines. The company was also keen to reduce the consumption of cylinder oil to lower its operating costs. Shell suggested trialling Shell Alexia S6 (BN 100) cylinder oil on the four vessels, as this engine design is a known to be sensitive to cold corrosion, so a higher base number cylinder oil is recommended to address this issue An average base feed rate (1.05 g/kWh) was determined for the BN 60 cylinder oil for all four vessels in order to validate the outcome of the Shell Alexia S6 trial. This value was deemed as the lowest one that would not compromise engine performance.
The trial showed that cylinder oil consumption had fallen significantly from an average of 520 l/d for the BN 60 cylinder oil to about 370 l/d for Shell Alexia S6 for two of the vessels. The vessels were all able to maintain a feed rate of 0.80–0.85 g/kWh. The piston underside inspections revealed the condition of the cylinder liners was significantly better. The operational benefits included lower cylinder oil consumption and wear rates through better corrosion control.