Cold corrosion halted by a switch to Mobilgard™ 5100 cylinder oil

poseidon general cargo ship

Nanjing Kingship Management was striving to optimise operations and reduce costs in the face of falling freight rates. Severe cold corrosion in four vessels was extremely concerning, as it threatened to trigger engine overhauls and downtime. The Wärtsilä 6RT-Flex 48T engines used fuels with sulphur levels of between 2.8 and 3.2 per cent at an average engine load of 70 per cent. Wärtsilä Pulse Lubricating Systems were operating at a high level – around 1.2-1.3g/KWh.

The technical team at Nanjing Kingship Management worked closely with ExxonMobil engineers and agreed to implement the Mobil Serv℠ Cylinder Condition Monitoring service across all four vessels. This enabled an assessment of the scale of the cold corrosion problem.

The engineers also advocated a switch to Mobilgard™ 5100, a 100 BN cylinder oil, in line with guidance from Wärtsilä. Mobilgard 5100 oil is proven to be a more cost-effective lubricant for engines suffering from cold corrosion than a lower-BN oil at a high feed rate.

Information from the Mobil Serv Cylinder Condition Monitoring service showed that following the switch to Mobilgard 5100 oil, it was possible to end cold corrosion while also achieving a 20 per cent cut in feed rates. The vessel operator additionally reported enhanced engine reliability as a result of putting an end to abnormal wear, and extended overhaul intervals, which helped reduce their operating costs.