ABS awards Approval in Principle to the “sterntube-less ship” concept
Thordon Bearings has today welcomed the announcement by classification society ABS to award Approval in Principle to the “sterntube-less ship” concept developed in cooperation with the Shanghai Merchant Ship Design & Research Institute (SDARI), the National Technical University of Athens (NTUA) and Thordon Bearings Inc., according to Seaborne Communications's release.
The revolutionary design replaces a vessel’s sterntube with an irregular shaped chamber that allows a shorter, water-lubricated propeller shaft to be inspected and maintained while the vessel is afloat, without having to withdraw the shaft in drydock. While the concept completely eliminates the need for oil-lubricated sterntube seals and bearings – a major source of marine pollution – the design is likely to save shipowners hundreds of thousands of dollars in capital and operational expenditure over a vessel’s lifespan.
Craig Carter, Thordon Bearings’ VP Business Development, said: “There are huge savings here. You would never have to withdraw the shaft again, which can cost $100,000 plus in drydocking costs alone. We are not changing the design of the ship or the stern but by moving the engine further aft we free up more space for cargo.”
Dr. Chris Leontopoulos, Director Global Ship Systems Center, ABS Athens, said: “The use of seawater to lubricate the propeller shaft is well-established but the proposed design takes this further by removing the sterntube, decreasing the shaft line length, reducing engine room space and increasing the cargo space. It enables significant efficiencies and cost savings for operators.”
