ExxonMobil Helps Extend Ship’s Piston Ring Life

Athens-based Costamare Shipping has more than tripled the piston ring replacement period to more than 55,000 hours for containership Cosco Yantian, helping the company reduce costs and improve vessel performance.

According to ExxonMobil, the life extension was achieved by switching the container vessel to its Mobilgard 570 cylinder oil in combination with the MobilGard Cylinder Condition Monitoring (CCM) program. 

The expected piston overhaul interval for the Cosco Yantian’s MAN Diesel & Turbo 12K98MC MK7 engine was 16,000 hours of unmonitored operation. Following a consultation with ExxonMobil’s Field Engineers, it was suggested that the vessel operator introduce Mobilgard 570 and the MobilGard CCM program.

As a result of the switch, the piston ring replacement period was extended to more than 55,000 hours while liner wear rates were greatly improved compared with engine builder expectations. Cosco Yantian, which operates globally, had been slow steaming in the 10-40 percent load range, resulting in severe engine operating conditions.

Mobilgard 570 is a cylinder oil that has been designed with antiwear properties to help extend piston ring and liner life, its manufacturer said. MobilGard CCM can help operators identify the most appropriate cylinder oil products, optimize engine feed rates and extend piston overhaul periods through a combination of onboard tests and full laboratory analysis to give real time and comprehensive data on cylinder operating conditions. In combination, the two help operators reduce costs and increase vessel reliability. 

“Cosco Yantian’s piston overhaul intervals were extended by 250 percent, with wear measurements sitting well within acceptable parameters after more than 55,000 hours of operation,” said Iain White, field marketing manager for ExxonMobil Marine Fuels & Lubricants. “By combining Mobilgard 570 with MobilGard CCM, Costamare Shipping was able to realize considerable financial benefits.”