Biodegradable Lubricants Under Spotlight
Thordon Bearings has welcomed an industry initiative to evaluate the effect of biodegradable lubricants on sterntube bearings following a reported marked increase in sealed oil lubricated propeller shaft bearing failures.
While many ship operators consider the rise in use of environmentally acceptable lubricants (EAL) a cure-all to meeting environmental regulations, particularly in waters where the US Environmental Protection Agency (EPA) has regulated the use of mineral oils, their performance as a propeller shaft bearing lubricant has come under increasing scrutiny.
It is thought some EALs may impede bearing and seal performance, damaging critical components and compromising oil-tight integrity.
Terry McGowan, President and CEO of Thordon Bearings said: “The initiative to verify EAL performance as a bearing lubricant comes at a critical juncture in the maritime industry. Ship operators are beginning to spurn mineral oil-based lubricants in favour of cleaner, more reliable alternatives, but as yet there is little evidence to indicate that EALs can do what they’re supposed to do without damaging machinery or the environment. There is a lot of confusion.”
Referring to the 1999 large canola oil spill in Vancouver harbour, Canada, which killed thousands of seabirds, Craig Carter, Thordon’s Director of Marketing, raises the environmental issue. “EALs were specifically developed to protect the marine environment from oil-based pollution but just because it says biodegradable on the label doesn’t necessarily mean they are environmentally safe to aquatic life.”
Carter added: “In fact, it is interesting to note that the DNV-GL research will not include the performance of the ‘no cost EAL’ - seawater, but then there has been no reports of ships that have been immobilized using seawater as the propeller shaft lubricant.”
