Mobil Serv℠ Cylinder Condition Monitoring helps Danaos Shipping more than double piston overhaul intervals

Mobilgard™ 570 and Cylinder Condition Monitoring (CCM) have helped engineers from Athens-based Danaos Shipping to extend piston overhaul interval by over 250% and reduce cylinder oil feed rates to the minimum setting of 0.6 g/KWhr.

Technical achievement
Danaos achieved these results in the DOOSAN-MAN B&W 12-cylinder K98MC-C engine of the containership MV CSCL Europe, where engineers from Danaos and ExxonMobil systematically monitored the engine with a view to increase the overhaul period.

The achievement was even more significant because the containership has been running under the more strenuous operating conditions of slow steaming since 2009. During this time, the vessel has been averaging 15.6 knots with engine loads as low as 30-40% and also operating with a reduced cylinder oil feed rate.

Since it was built in 2004, MV CSCL Europe has been lubricated with Mobilgard™ 570 , a cylinder oil formulated to reduce piston wear and deposits, and to extend overhaul intervals in two-stroke diesel engines. Danaos has maximised the use of this high-performance lubricant by using the ExxonMobil Cylinder Condition Monitoring programme to detect changes in cylinder condition, allowing engineers to safely reduce Mobilgard 570  feed rates without increasing wear.

Extending overhaul periods

Engineers gradually extended the overhaul period on successive pistons in the vessel’s 12-cylinder engine. Overhauls started at 16,000 hours (the MAN recommended interval) and continued systematically at extended intervals, based on the good condition of the engine’s pistons, rings and liners. In cylinder number 11, the overhaul was done at 42,575 hours, with scavenge air port inspections showing that all monitoring parameters were still within the normal range.

The overhaul revealed that even at 42,575 hours, cylinder number 11 was in remarkably good condition, suggesting that the interval could have been extended much further. Liner wear rate, piston ring wear and the ring groove clearance were all well below the allowable thresholds identified by MAN Diesel & Turbo and no evidence of scuffing was found.

Benefits to Danaos Shipping
Through using Mobilgard™ 570 , Danaos was able to extend piston overhaul interval from 16,000 to 42,575 hours and reduce cylinder oil feed rates to 0.6 g/KWhr, which is the minimum setting recommended by MAN B&W.

“We operate a high-quality fleet of 56 container ships with a reputation for reliability and cost-efficiency,” said Danaos Shipping’s Technical Manager, Dimitrios Vastarouchas. “We have seen that Mobilgard™ 570 can help significantly extend piston overhaul intervals and for us the benefits of this technical achievement are financial and environmental.”

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