Passenger ferry boat

Brittany Ferries prolongs medium-speed marine cylinder life using Mobil Serv℠ Lubricant Analysis


Brittany Ferries successfully extended cylinder life and reduced total lubricant consumption on the passenger ferry Mont St Michel with the help of Mobil Serv℠ Lubricant Analysis.

Fuel contamination
Brittany Ferries’ passenger ship, Mont St Michel, operates between France and England, with its engines running at an average load of 80 per cent at a continuous 500 rpm. The ferry’s four 5,400kW MaK 6M43 engines operate under severe conditions and continuous load changes in combination with low oil consumption. This results in high residual fuel contamination and the presence of asphaltenes in the engines’ lubricant. This alters the lubricant’s chemical composition, leading to shorter engine lifespan, spiralling maintenance costs and increased vessel downtime.

Managing asphaltene levels
In the past, Brittany Ferries engineers have relied upon viscosity limit data to schedule partial lubricant replenishments and keep asphaltene levels within the engine manufacturer’s limits. Having switched to using Mobil Serv Lubricant Analysis and its Detecting Asphaltene Contamination (DAC) test, ship engineers have been able to measure asphaltene levels more accurately, optimise scheduled partial replenishments and reduce total lubricant consumption.

Brittany Ferries and ExxonMobil conducted a visual inspection of the main engine during the ferry’s first overhaul at 30,000 hours. According to the engineering service report, the use of Mobilgard™ M440 in combination with partial lubricant replenishments resulted in an engine that was in “perfect overall condition without any noticeable under-crown deposit formation”.

Cost savings
Engineers calculated the accrued savings from the optimised partial replenishments schedule to be an estimated $20,000 annually. This increased to more than $25,000, once Mont St Michel started using low sulphur fuel and switched its lubricant to Mobilgard™ M430 (which is specifically designed for low sulphur levels).

According to Frédéric Pouget, Brittany Ferries’ Technical Director, the DAC test has been essential for complete engine monitoring. “It helps us to quickly identify the source of the residual fuel contamination and protect our critical engine parts from abnormal wear.”

Find out how we can help optimise your vessel’s performance and reliability by contacting an ExxonMobil Marine Fuels & Lubricants representative.

This Proof of Performance is based on the experience of a single customer. Actual results can vary depending upon the type of equipment used and its maintenance, operating conditions and environment, and any prior lubricant used.



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