Axe files: a high seas revolution
IJMUIDEN – The Royal Netherlands Sea Rescue Association has embarked on an ambitious upgrade of its search-and-rescue capabilities by ordering a new generation lifeboat _ a fast 19-m craft with a revolutionary Dutch-designed “semi-axe” bow that will cut “wave slamming” at high speeds. The first NH-1816 _ named for the Noordhollandsche insurance company, a big KNRM donor _ will be delivered by Damen Shipyards in late 2013. Its “semi-axe bow” will increase onboard comfort through a 45% cut in wave pounding and curbing noise to 75 Db. It will have an operating range of 348 nm and a maximum speed of 31 knots. It has a crew of 6 and can transport 120 people. Damen Shipyards _ 7,000 employees, 35 nations _ developed the “axe bow” for fast offshore service vessels such as SAR craft, patrol boats, crew craft, fast suppliers and pilot boats. Developed with Delft University, the bow improves a ship’s sea-keeping abilities in rough seas with no loss of speed and up to 80% less slamming into high waves.
“Never before in the history of the KNRM (founded in 1824) has a new model lifeboat been tested more strenuously,” says KNRM General Manager Roemer Boogaard. His contract with Damen is for 1 NH-1816 lifeboat, with an option for 2 more. Negotiations lasted 3 years. KNRM hopes to buy 10 NH-1816 boats in all and help Damen market the revolutionary SAR craft worldwide. In a paper to the 2010 HISWA yacht design symposium, Jaap Gelling, Damen’s product director for fast work boats, and Lex Keuning, Associate Professor at Delft University’s Ship Hydromechanics Laboratory, saw a bright future for their axe bow saying it guarantees “workable conditions on board” at all speeds. Damen puts an axe bow on all kinds of offshore workboats, including a mega-yacht supply vessel that is almost 70-m long (below).
Since 2007, Damen has sold more than 75 axe bow vessels (it calls them “Sea Axes”) in which, going forward, the keel line slopes down and the deck line slopes up giving the hull an axe blade effect. Together with Damen’s “enlarged ship design,” an earlier design tweak from the co-operation with Delft University, it cuts hull resistance by up to 15% in calm waters, improving fuel efficiency. Damen spokesman Jan-Hein Reeringh says the NH-1816 will actually have a “semi-axe bow because a real axe bow would not be practical given the KNRM’s extreme work, notably in shallow waters.” The NH-1816 comes with retractable rear fins for more course stability and maneuverability. The wheelhouse has state-of-the-art electronics including ship-to-shore data exchange. Crew working conditions have also been enhanced through a host of ergonomic features, such as specialized chairs, improved visibility and reduced vibration and noise levels.
Can an axe bow ever be an option for sailing yachts? Probably not. “One downside of a sailboat is that an axe bow creates more ‘wet surface area’ on the hull than a conventional yacht,” says Reeringh. “And that means more resistance.”
The KNRM is an organization of 1,100 volunteers. In 2011 it collected €10 million in gifts, staged 1,900 missions assisting 3,299 people. The group has been in the high seas lifesaving business for 188 years. Today operates one of the most modern, rugged fleets anywhere out of 44 lifeboat stations. Its area of operations _ the North Sea _ is one of the busiest in the world, recording over 1,000 ship movements in any 24-hr period.