Pure car/truck carrier vessel cuts cylinder oil feed rate by 18.75%

Mobil℠ Cylinder Condition Monitoring helps Hawaiian Highway reduce consumption of Mobilgard™ 5100 cylinder oil

Situation

‘K’ Line’s pure car/truck carrier (PCTC) vessel, Hawaiian Highway, was using Mobilgard™ 5100 cylinder oil in its Japan Engine Corp. 7UEC60LSE-Eco-A2 main engine. The 100 BN lubricant had been selected to combat cold corrosion and its feed rate was being gradually reduced during the engine’s running-in operation. By enhancing the engine monitoring process, ExxonMobil’s Field Engineering Services (FES) team believed that a safe feed rate reduction was also possible without compromising on engine protection.

Recommendation

ExxonMobil’s engineers recommended that the vessel implement Mobil℠ Cylinder Condition Monitoring in tandem with a phased reduction in cylinder oil consumption. By conducting regular scrape down oil analysis, it would be possible to ascertain the optimum feed rate without degrading engine cleanliness or operation.

During this period, the vessel partly operated in Emission Control Areas (ECAs) and as a result switched to a compliant 0.10% fuel in tandem with a low BN cylinder oil, where appropriate.

Impact

The onboard scrape down oil sampling confirmed that the cylinder oil feed rate could be safely reduced to 0.65 g/kWh while retaining sufficient BN to protect the engine liners and piston from cold corrosion. Used oil analysis also confirmed that the cylinder lubricant was continuing to provide outstanding engine cleanliness, potentially extending piston overhaul intervals to more than 20,000 hours.

The Hawaiian Highway safely reduced the consumption of Mobilgard 5100 cylinder oil by 18.75%, which resulted in annual savings of more than 11,880 litres. The test findings indicate that a further feed rate cut to 0.60 g/kWh might be possible.