Marine Diesel Engine Lubrication: A critical component to avoid main engine breakdowns

Recently several entered vessels have observed main engine breakdowns brought on by heavily contaminated lubricating essential oil. All of the vessels were relatively recent.

Modern marine diesel motors are technically complex and they are becoming increasingly powerful and effective.

However , newer engines could be less forgiving than old units if not operated, managed and lubricated correctly.

Lubricating Oil

The lubrication associated with moving parts is crucial in order to diesel engine performance as well as longevity.

Lubricating oil decreases friction between components, sets apart opposing surfaces and stops metal-to-metal contact. It also will act as a coolant and minimizes the effect of corrosion. But the condition of the oil has a tendency to deteriorate with use, primarily due to contamination and chemical substance activity.

The manufacturer’s guide for the engine will provide information on the quality and properties regarding lubricating oil required. The actual manual will also include assistance with how the oil should be supervised and maintained while the motor is running to ensure that this remains suitable for use. This kind of advice is generally based on investigation findings, operational experience, continuing analysis and other factors such as technical common sense. The details will even include a margin of mistake to minimise the risk of the actual engine being damaged since the lubricating oil deteriorates, however the extent of this margin is not really known to the user.

Therefore it is impossible for the user to determine along with any degree of confidence if the outcome of exceeding the limits arranged by the engine manufacturer is going to be relatively harmless or possibly disastrous.

Although the engine handbook contains important information about the lubricating oil and specifies crucial requirements and constraints, the essential principles rarely differ:

It is therefore not possible for the user to find out with any degree of self-confidence whether the outcome of exceeding the bounds set by the engine producer will be relatively harmless or even potentially disastrous.

Although the powerplant manual contains important information concerning the lubricating oil and identifies key requirements and limitations, the fundamental principles rarely vary:

•       The viscosity of the lubricating oil must remain inside certain prescribed limits. Usually, oil viscosity increases throughout operation. If it decreases, this might signify an ingress involving low viscosity fuel. Improved or decreased viscosity may result in improper lubrication and energy distortion.

•       The oil should never contain excessive amounts of drinking water or insoluble foreign contaminants as their effects become progressively harmful during operation, leading to poor lubrication and mechanised damage.

•       The oil should be capable of protecting the components from the engine from corrosion due to aggressive chemicals. The ability in the oil to neutralise acid compounds is termed the entire Base Number (TBN) or perhaps, alternatively, the Base Number (BN). The TBN of lubricating oil generally decreases together with use. Acidic corrosion might occur if the TBN drops below the threshold specified through the manufacturer of the lubricating necessary oil, resulting in excessive wear and also reducing the life of the components.

•       The flash point on the lubricating oil should stay within the range set from the manufacturer. A flash stage lower than specified may symbolize the presence of lighter hydrocarbons, perhaps indicating that the oil continues to be affected by diesel fuel.

During operation, the lubricating olive oil normally passes through physical filters to extract strong foreign particles, and centrifugal separators to remove other harmful particles and water. It is essential which both are inspected and taken care of entirely in accordance with manufacturer’s directions.

The viscosity, flash level and TBN of lubricating oil can only be renewed by a full or incomplete oil change.

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