UK Ship Owner Opts for Seawater Lubricated Propeller Shaft Bearings
The Vectis Eagle, an 8500 dwt multi-purpose dry cargo vessel, is Carisbrooke Shipping’s latest newbuild and first of their fleet to be fitted with Thordon COMPAC seawater lubricated propeller shaft bearings. The Finnish/Swedish 1A Ice-Class vessel launched in September 2011 and is currently carrying out its maiden voyage through the Panama Canal travelling from China to Haiti and Brazil. Constructed at the Chinese shipyard, Jiangsu Yangzijiang Shipbuilding Ltd., the vessel is the first of four to specify seawater lubrication instead of oil.
“We chose Thordon COMPAC for this vessel because these bearings are environmentally friendly, water lubricated and come with no risk of pollution,” says Simon Merritt, Technical Manager for Carisbrooke Shipping Ltd. “All equipment on board the vessel has been chosen with energy efficiency or with its minimal environmental impact in mind.”
The Vectis Eagle has a single tapered key COMPAC bearing design with a shaft size of 470 mm. The tapered key design allows for removal, inspection and re-insertion of the bearings without shaft withdrawal. Thordon COMPAC seawater lubricated propeller shaft bearings completely eliminate the risk of oil discharges from the stern tube. Seawater is used as lubrication instead of oil and is taken from the sea, pumped through the bearings and returned back to the sea. There is no risk of damage to an aft seal by a fishing net or rope as there is no aft seal. This results in lower in-service maintenance costs and the elimination of storage, sampling and disposal of oil from the stern tube.
The pollution of the world’s oceans and seas has become a matter of increasing international concern for many. As stricter environmental legislation and improved pollution detection methods are becoming the norm in Canada, the United States of America and the European Union, ship owners like Carisbrooke Shipping Ltd. are looking for new ways to reduce all sources of pollution from their ships. Choosing seawater lubricated propeller shaft bearings is just one of the ways ship owners can ensure future compliance with any pending zero discharge legislation.
The Vectis Eagle is characterized by its extremely high bow and versatile single cargo hold making it currently the longest cargo space amongst its vessel class. Carisbrooke expects up to 30% reduction in fuel consumption compared to vessels of equal tonnage due to its large diameter propeller and high efficiency nozzle. The ship’s design below the waterline is hydro-dynamically optimized to further reduce drag and allow better water flow to the propeller. Careful selection of all chemicals used onboard has been made to ensure the least impact to the environment as possible.