Mobilgard™ 5100 helped Kota Sabas to cut lubricant consumption by 36%
By switching to a 100 BN cylinder oil and implementing the Mobil Serv℠ Cylinder Condition Monitoring service, Pacific International Lines (PIL) was able to put a stop to cold corrosion and optimise oil feed rates on the Kota Sabas, a 51,500 ton container vessel. This resulted in improved engine performance and a 36 per cent reduction in lubricant consumption.
The vessel’s Wärtsilä W6X72 engine was the first of its kind and so there was very little performance experience available. Cold corrosion had occurred in similar two-stroke engines produced by other equipment builders so the BN and feed rate were closely monitored. By implementing an onboard Mobil Serv Cylinder Condition Monitoring service, the engineers discovered that cold corrosion was found in the form of black spots on the liners when using a 70 BN oil.
This, along with very low residual BN levels at a feed rate of 1.3 g/kWh, limited their ability to optimise feed rates. In order to overcome these problems, ExxonMobil recommended switching to Mobilgard™ 5100, a 100 BN advanced cylinder oil that helps optimise the performance of engines operating on heavy fuel oil with a sulphur range of up to 3.5 per cent. It has been proven to be a more cost-effective option for engines suffering from cold corrosion versus the use of a lower BN oil at a higher feed rate.
As a result of switching to a 100 BN oil in combination with the Mobil Serv Cylinder Condition Monitoring service, the Kota Sabas’ feed rate was lowered to 0.9 g/kWh with high reserve BN levels averaging at 35. This provided protection against cold corrosion, with no visible signs of phenomenon found on the engine’s liners. Mobil Serv Cylinder Condition Monitoring data also highlighted low iron levels, indicating minimum liner wear, while few deposits were found on the piston rings.