Benefits summaryThe MobilGard™ Cylinder Condition Monitoring (CCM) programme enabled Danaos Shipping’s on-board engineers to optimise the performance of two slow-speed Wärtsilä 7RT-flex82C main engines operating in challenging conditions. It was also able to optimise feed rates of the Mobilgard™ 570 cylinder oil used, allowing the engines to operate close to to Wartsila’s recommended minimum feed rate of 0.8 g/kWh.

These changes resulted in improved oil consumption, extended time between overhauls, decreased maintenance costs and reduced environmental impact due to lower amounts of sludge oil disposal*.

SituationShortly after taking delivery of the vessels M/V Hanjin Buenos Aires and M/V Hanjin Versailles it became clear to Danaos Shipping their reduced load operation could cause engine oil-related issues. The company therefore asked ExxonMobil to start a series of scrape down oil analysis from the ships’ main engines using MobilGard CCM, with the objective of optimising the engines’ performance and cylinder oil feed rates.

Case study

On-board and laboratory tests allowed Danaos to determine how the engines, which are both equipped with a pulse lubricating system (PLS) and two active turbochargers, performed on Mobilgard 570, and what could be done to optimise the cylinder lubrication feed rates.

Cylinder condition monitoring, alongside a high-performance cylinder oil, helped reduce feed rates by 5.6 per cent and extend time between piston overhauls, leading to potential cost savings and decreased maintenance.

Customer: Danaos Shipping Company, Ltd

Vessel: M/V Hanjin Versailles and M/V Hanjin Buenos Aires

Product: Mobilgard™ 570 cylinder oil and MobilGard™ Cylinder Condition Monitoring (CCM) programme

Engine: Wärtsilä 7RT-flex82C

Date: August 2015

Feed rates optimised by a switch to Mobilgard™ 570 cylinder oil

Continued overleaf.

ImpactMobilGard CCM’s proprietary on-board test equipment allowed shipboard engineers to quickly detect substantive changes in cylinder condition while the laboratory analysis helped ensure they fully understood the condition of the engines and oil in use.

It enabled Danaos to confirm that Mobilgard 570 provided continued outstanding protection to the engines as feed rates were optimised, enabling the engines to follow Wärtsilä feed rate tables without showing any adverse wear effects.

Based on MobilGard CCM programme’s on-board test readings, which are compared to nearly 100,000 other results in ExxonMobil’s database, a series of incremental cylinder oil feed rate reductions was recommended for both ships. This was based upon Danaos’ continued use of the MobilGard CCM programme to monitor and manage engine performance and cylinder oil feed rates.

* This led to an overall cylinder oil lubricant feed rate reduction of 0.05 g/kWh, from 0.89 to 0.84 g/kWh, operating the engines close to the 0.80 g/kWh minimum Wartsila feed rate, which is a rare feat to achieve. Furthermore, Danaos was able to reduce oil consumption across the two vessels by 5.6 per cent, equating to a saving of 6,700 litres per year.

For more information about Mobilgard 570 and Cylinder Condition Monitoring (CCM)programme, please contact your ExxonMobil Marine Fuels & Lubricants representative or visit www.exxonmobil.com/marine

SolutionMobilgard 570 cylinder oil’s proprietary formulation is designed to optimise the performance of slow-speed two-stroke marine diesel engines operating on heavy fuel oil with a sulphur content of up to 3.5 per cent. It has been proven to help marine operators save costs by extending piston and liner overhaul intervals, optimising feed rates and reducing the amount of waste oil requiring disposal, thus allowing operators to become more environmentally responsible.

MobilGard CCM is a suite of simple-to-use tests that enables on-board and laboratory monitoring of cylinder conditions using scrape down oil samples. This programme analyses the iron content and total base number (TBN) and provides information that can help improve an engine’s reliability, reducing associated maintenance and repair costs.

Scrape down samples were taken from the engines of the M/V Hanjin Versailles and M/V Hanjin Buenos Aires every 300 hours for on-board analysis and every 600 hours for analysis at ExxonMobil’s Signum laboratory in Pernis, Netherlands. This work was undertaken alongside a cylinder oil feed rate optimisation programme.

This case study 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. © 2015 Exxon Mobil Corporation. All trademarks used herein are trademarks or registered trademarks of Exxon Mobil Corporation or one of its subsidiaries. Other trademarks and product names used herein are the property of their respective owners.EMM-DANBR-08-15