Simplex BlueRun water-lubricated sterntubes - an eco-friendly solution for cleaner oceans

Approximately 90% of the world’s shipping fleet are equipped with traditional, oil-lubricated sterntubes. However, vessels operating in polar or also US waters must adhere to stricter regulations. The?Polar Code?prohibits any discharge of oil, and under?VGP2013?vessels must use environmentally acceptable lubricants (EALs) at all oil-to-sea interfaces, where technically feasible. Many ship operators therefore opt for sterntubes with a dedicated non-oil-to-sea interface, such as the Simplex Airspace seal?or a completely water-lubricated sterntube.

SKF′s latest development of the Simplex BlueRun water-lubricated sterntube bearings promises to support the shipping industry in complying to these strict environmental regulations while at the same time helping customers to reach their sustainability and financial targets by providing both environmental and operational savings. Water as the lubricant helps to reduce the vessel’s CO2 footprint, as well as the risk of oil spills, and they also eliminate the need for oil storage, handling, and disposal, which can be costly and time-consuming.?

The key innovation of Simplex BlueRun is that it uses water instead of oil as a lubricant in sterntubes, eliminating the need for sterntube oil on board of ships.

SKF chose a specially developed polymer bearing bush for Simplex BlueRun. The selected polyurethane, a formulation developed in-house and tested against more than 100 alternatives, is harder than rubber but softer than composites – ideal for the levels of mechanical wear and tear in a harsh environment below the surface of the sea. This material had to withstand more than 40,000 hours of vigorous testing under real-life circumstances, including emergency runs and low shaft speed conditions, at SKF Marine’s testbed in Hamburg to prove its optimum performance for all water-lubricated applications. During testing the system also showed its high resistance against hydrolysis, as well as minimal swelling which is crucial for water-lubricated bearings.

The Simplex BlueRun bearings and accessories, are complemented by the Simplex water-lubricated sterntube seals, offering a complete package to customers.?Installation and retrofit is easy as the polymer bearing bushes are available in both non-split and split version. The non-split version uses a plain key which is fixed to a carrier bush for anti- twist protection. The split bush version includes a pair of taper keys which provide the tension as well as protection against rotation. There is no need to remove the shaft in order to exchange the bearings. Both variants can be used for all types of water-lubricated sterntube systems: for fresh and sea water as well as for open and closed systems. The solutions are available for shaft diameters up to 650 mm.

The very first Simplex BlueRun installation was installed on a research vessel operating in coastal regions of the North and Baltic Seas.?Since then, a wide range of vessels, including harbour ferries, operating up to 16 hours per day at full steam and stopping in heavy sedimental waters, have been successfully equipped with this solution. Its low noise in operation makes Simplex BlueRun a perfect fit for passenger vessels.

In summary, Simplex BlueRun helps ship owners and operators to further promote their environmental credentials.