Lubrication oil related failure is the most common cause of damage to main engines followed by incorrect maintenance or repairs, finds the Swedish Club.
Between 2010-2014, the Swedish Club found 23 casualties relating the lubrication failure, costing US $663,35. Between 2015-2017, these figures increased to 40 casualties costing $763,320.
VPO Global spoke with Peter Stålberg, senior technical advisor, the Swedish Club, about the issue. He explained that “contamination with water or combustion particles will decrease the lubricating properties of the oil, causing damage to bearings, journals and rotating parts. In this context, crankshaft failure is considered most expensive and severe.”
Mr Stålberg told VPO that many failures on main engines occur shortly after overhaul has been carried out. “A typical, and very costly, failure is the connecting rod assembly. This is a critical and highly stressed joint and as such must be re-assembled exactly in accordance with manufacturer’s instructions with proper tools. All too often the Club sees insufficient understanding of the importance of the procedures and the use of non-calibrated tools leading to very costly engine damages.”
The Swedish Club recommends implementation of robust onboard fuel and lubrication oil management systems to avoid such losses. Mr Stålberg clarified that regular testing using reputable laboratories is essential, and what is even more important is to follow up, find the root cause and take prompt action when test results show that the metal content increases and lubrication oil is deteriorating.
In total, main engine claims account for 28 per cent of all machinery claims, with the majority of these related to lubrication oil. Main engine damage is also the most expensive claim made, with a total cost of 131m USD between 2015-2017, accounting for 34 per cent of all machinery claims.
A poor maintenance routine can cause lubrication failure. In one example, the Swedish Club found that poor maintenance of the rubber membranes between the engine crankcase and the lubrication oil sump tank caused the membranes to lose their resistance to oil. This caused complete failure of the membranes. In other cases, the rubber membranes failed due to natural aging process.
In both cases, excessive quantities of water on the tank top entered the main engine sump tank, and subsequently contaminated the main engine lubricating oil system, resulting in severe damage to the main engine bearings.
According to the Swedish Club, these ‘forgotten’ parts of the machinery can result in serious losses to owners and underwriters and therefore serious enough to promote steps being taken to prevent occurrence.
In a recent case the repair cost alone exceeded USD 3,000,000. This cost does not take into account owners’ deductible, loss of time and other commercial embarrassments connected with the casualty, reports the Club.
Mr Stålberg said that makers and underwriters have sent out several reminders and alerts to operators with a view of including the rubber membrane in the planned maintenance system. This membrane itself cost only a few $ to replace but despite this, poor maintenance is a relatively common cause for water contamination of the lubrication oil.
Reducing damage to main engines
According to MAN, the following can be done to reduce damage to main engines:
- Having the right people with the right knowledge on board. Regular training and clear working processes and guidelines are essential.
- Following required maintenance intervals according to the manufacturer’s requirements and only using OEM spare parts is vital.
- Monitoring fuel, lube oil, and cooling water is necessary to allow an operator to see where any changes in fluid quality lie and react immediately. Remote monitoring technology should also be used where possible to reduce down-time.
Wärtsilä says that the following steps should be taken for problem-free machinery operation:
- Ensure there is a well-designed and specified engine room with superior supervision during construction and commissioning. Wärtsilä reports that poor cleaning of pipes during construction is still one of the main reasons for fuel equipment and bearing problems today.
- Be consistent with engine room manning. Fixing problems as soon as they occur is easier when there is a ‘my ship’ attitude and leads to better condition-based monitoring.
- Do not underestimate prudent engineering practices. Follow manual, bulletings and installation instructions published by the manufacturer.
- Maintain a detailed engine room logbook to identify focus areas where problems have occurred.
The full study can be downloaded here.
Images courtesy of the Swedish Club.