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www.marinelink.com 51In December 2013, the EPA through its Vessel General Permit (VGP) will introduce the mandatory use of ?Envi-ronmentally Acceptable Lubricants,? or EALs. These products include the lubri- cating oils that are directly used in ap-plications referred to as ?oil to sea inter- faces? where the only thing holding the oil from entering the water is a simple seal or gasket. Understanding what this all means to you is important. The U.S. EPA has determined that four major types of lubricants meet all the neces-sary required criteria to be classiÞ ed as an ?approved EAL? are as follows: ? Vegetable Oils ? Synthetic Esters ? Polyalkykene Glycols PAGs ? Water The Case for PAG?s PAG?s do not sheen the water, are non- toxic and not classiÞ ed as ?oil? by the U.S. Coast Guard and Transport Cana- da. PAG ß uids are approved by the US EPA as acceptable EALs due to both the rate of biodegradability and low aquatic toxicity. Beyond these traits, PAGs demon- strate superior load carrying ability, superior thermal stability (withstand-ing temperatures up to 250 F), material compatibility, are Þ re resistant and are not only heavier than water (speciÞ c gravity of approximately 1.03), but also dissolve readily when mixed with water. Since these products completely dis-solve and dissipate when discharged into water, they do not form an oil slick. The slick itself, regardless of the toxicity or biodegradability of the oil in the event of a spill accounts for much of the initial mortality in marine wildlife in the initial stages of the discharge. One of the reasons the U.S. EPA en- acted the ?Clean Water Act of 1990? and the ?Non-sheening regulation 40 CFR 435? was to try to reduce the en-vironmental impact of any type of free oil ß oating in the surface of the water. If the ß uid is neither a hazardous chemi- cal and is not considered oil, it is exempt from this act as well as OPA 90 oil spill cleanup regulations. This will not only reduce or eliminate Þ nes but can reduce the scope and costs associated with aquatic oil spill cleanup procedures and remediation.PAGs can be designed and tailored achieve certain characteristics or capa-bilities in order to perform very speciÞ c functions or performance requirements to suit the application (?designed,? not reÞ ned).Finally, PAG ß uids are suited to the marine environment. They have very minimal or a negligible reaction to the presence of moisture or water, so corro- sive acids and gums are not produced, as they would be with hydrocarbons and especially vegetable oils and vegetable esters. They can accept up to 1.5% water contamination (15,000ppm) before any performance degradation. There is no saturation point as there is with conven-tional hydrocarbons (maximum satura-tion point of most mineral oils is 200 ppm), but viscosity and lubricity will If your vessel is trading in U.S. wa-ters, you need to be aware of the new oil to sea interface law that comes into effect on Dec. 19, 2013. According to the new U.S. Environment Protection Agency Vessel General Permit (VGP), all vessels built on or after Dec. 19, 2013, must use an environmentally ac-ceptable lubricant (EAL) in all oil to sea interfaces. For all vessels built before this date, unless technically not feasible, ship owners must use an EAL in all oil to sea interfaces. Additional information on the EPA?s VGP can be found at http://cfpub.epa.gov/npdes/vessels/vgpermit.cfm#Þ nal.Most ships use mineral oil to lubri-cate the propeller shaft, and the oil is contained in the stern tube by the aft seal ? which is the oil to sea interface. In most cases, you cannot simply replace the mineral oil with seawater or other oil-based EAL?s. Oil-based EALs need to be compatible with the sealing ma-terials to ensure leakage is controlled ? shipowners will need to check with their seal supplier and it may be necessary to upgrade the sealing rings or upgrade to a new seal. Typically, costs of oil-based EAL?s are 3-5 times more expensive than mineral oils. If you are using an air seal, you are still required to use an oil-based EAL, as it is not possible to guarantee that oil leakage will never occur. Still a concern for ship owners is that oil-based EALs are still considered a pollutant under the Oil Pollution Act of 1990 (OPA 90) and U.S. Clean Water Act (if there is a sheen). Any discharges of oil-based EALs still require reporting of the discharge to the U.S. Coast Guard, as well as having clean-up and remedia-tion costs. Even though biodegradable lubricants may be deemed non-toxic by OECD testing, their presence on the wa-ter surface is a threat to seabirds.For newbuildings, some ship owners are specifying seawater lubricated pro-peller shaft bearing systems, as more than 600 commercial ships are using a seawater-lubricated system that uses no oil ? meaning full compliance with the VGP. (Some shipowners such as Prin- cess Cruises, COSCO, Disney Cruise Lines, U.S. Gypsum Corp., CSL Group, Algoma Corp., Flinter Group, Cono-coPhillips, Carisbrooke Shipping and Staten Island Ferries have chosen to use seawater as the propeller shaft lubricant.) Currently, the U.S. EPA recommends that all newbuild vessel operators en-deavor to use seawater-based systems for their stern tube lubrication to elimi-nate the discharge of oil from these inter- faces to the aquatic environment.Existing ships can be converted to seawater-lubricated propeller shaft sys- tems as these systems typically Þ t in the same space as an oil lubricated system. The oil-to-seawter conversion is accom-plished during a planned drydock where corrosion resistant shaft liners and a water lubricated forward seal were pre-ordered and the shaft and non-metallic bearings were ready for install when the ship drydocked.So when it comes to discharges from a ships propeller shaft system, the ship-owner that trades in U.S. waters has two choices for their existing ships and ships they plan to build: 1) replace mineral oil with an oil-based EAL to lubricate the metal bearings and ensure the seal is compatible with the EAL, or 2) convert or build a ship using a seawater-based system using non-metallic prop shaft bearings. By Craig D. Carter, MBA, Director of Marketing and Customer Service at Thordon Bearings Inc. Don?t Forget: Seawater is a Free EAL Typical netting and rope around rotat- ing shaft damages aft seal.Are PAGS the answer? PAG?s; one and all: DOW?s UCON Trident PAG Hydraulic Lubricant (orange) and American Chemical Technology?s Trident Gear Lubricant (bright green shade yellow). Ron van Wachem, President of Coast Lubricants and Nanaimo Shipyard Group, reasons that PAGS are the best solution to meet the new VGP requirements. MR #11 (50-57).indd 51MR #11 (50-57).indd 5111/13/2013 9:13:06 AM11/13/2013 9:13:06 AM
