How to Assess Lubricant Choices on Your Vessel
Now that the Vessel General Permit (VGP) standards for environmentally acceptable lubricants (EALs) are well established, it’s worth taking a deeper look to assess the actual performance and value of all lubricants used onboard, including EALs. To begin an evaluation, it helps to place the various lubricants within an assessment framework using four categories:
- Lubricants used above the main deck external to the vessel and lost in use (e.g., wire rope, anchor windlass gears and deck crane open gears).
- Lubricants used above the main deck external to the vessel and captured in use (e.g., hydraulic driven systems).
- Lubricants used with an oil-to-water interface or mechanical equipment intended to be immersed in water.
- Lubricants used below deck inside the vessel.
Because each category involves different functional factors, the framework makes it easy to assess the lubricant. For example:
- For lubricants external to the vessel, above the main deck, lost in use: In the final 2013 VGP, EAL greases or oils are recommended for use in these applications. If choosing an EAL or a standard lubricant, use one that minimizes the amount of lubricant lost to the environment. Consider optimal viscosities, good adhesion qualities, and/or good retention of the base oil in the grease. For this category, sheen characteristics may need to be considered. While the discharge should be below the level of creating a film, discoloration, sludge or emulsion, a visible sheen could still be created.
- For lubricants external to the vessel, above the main deck, captured in use: While the 2013 VGP does not require use of EALs for these applications, there is a risk of accidental discharge into the environment. Consider your organizational values and those of your customers to determine if a lubricant that exceeds regulatory compliance should be used.
- For lubricants used with an oil-to-water interface or mechanical equipment intended to be immersed in water: Choose an EAL grease or oil. Consider lubricants that exceed minimal OEM requirements because a failure of one of these systems could lead to, at best, an unplanned shipyard visit or put the vessel in an unsafe situation.
- For lubricants below deck, internal to the vessel: Because lubricant leakage in these applications should be contained in the bilge of the vessel and not enter the environment, EALs are not strictly necessary. But they may be employed based on organizational or customer policies.
Finally, for all categories, consider the performance characteristics of the lubricant in meeting or exceeding OEM specifications, improving efficiencies, reducing labor, extending the life of the equipment, extending the time between service intervals, improving safety and reducing the amount of lubricants entering the waste stream. A correctly chosen lubricant can improve the overall operation of the vessel.