The Environmental Protection Agency (EPA) first issued the Vessel General Permit (VGP) in 2008 and subsequently reissued it in2013. The VGP provides a permit to the National Pollutant Discharge Elimination System (NPDES), covering incidental discharges into waters of the United States from commercial vessels with a length greater than 24 meters or 79 feet, and ballast water from commercial vessels of all sizes.
The VGP issued in 2008 expired in December 2013 when the new 2013 VGP was issued. The new regulation establishes requirements for 27 specific types of incidental discharges from vessels. All vessels covered under the VGP must use EALs in all oil-to-sea interfaces unless technically infeasible. Oil-to-sea interfaces include any mechanical or other equipment on board a vessel where seals or surfaces may release quantities of oil and are subject to immersion in water. EALs are lubricants that are “biodegradable” and “minimally-toxic” and are “not bio-accumulative” as defined in Appendix A of the 2013 VGP.
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Based on the aforementioned VGP requirements, Brunvoll has developed, tested, and implemented an EAL solution that is technically feasible for most thrusters within our product range. Our EAL solution adopts a split oil system, applying EAL in all direct oil-to-sea interfaces and conventional mineral oil in the gearbox. In our thrusters, oil-to-sea interfaces pertain to the propeller hub with blade seals and the propeller shaft main seal. The gearbox reservoir, containing mineral oil, is sealed with static seals, ensuring at least two barriers between the sea and the mineral oil.
The advantage of this solution lies in its ability to meet VGP requirements and the associated environmental benefits, all while continuing to employ the reliable and well-established mineral oil in the gearbox. EALs, though touted as fully functional gear oils, are relatively new to the market, with limited data on their long-term effects on gears, bearings, and paint. Moreover, there are several limitations to consider when using an EAL as a gear oil, including local temperature and water contamination. By adopting Brunvoll's split lubrication approach, you minimize the technical risk of major breakdowns.
