Damen Shipyards develops new hull shape
It’s full steam ahead again for the shipbuilding industry. The Damen Shipyards Group in Gorinchem is making its presence felt on the world’s oceans. Damen Shipyards Singapore recently launched its first axe-bowed vessel.The spiritual father of this invention is Lex Keuning of the Delft University of Technology (TU Delft), who is also a consultant to the Damen Shipyards Group. His research involves different (slimmer) hull shapes for ships, to give improved comfort and greater speed.In 1995, this work gave birth to the Enlarged Ship Concept (ESC). The new patrol boats embodying this concept served to whet customers’ appetites.Damen Shipyards Gorinchem, Delft University of Technology, Marin (Maritime Research Institute Netherlands) Wageningen, the Royal Dutch Navy, the Royal Schelde Group, and the US Coastguard collaborated on a study into a better, faster type of vessel. This was the Axe Bow Concept, a ship with a bow shaped like an axe.
Jaap Gelling, the director of High Speed & Naval Craft at Damen Shipyards Gorinchem, gave an outline description of the innovation process involved. “It is not simply a matter of speed. The major challenge is to design a vessel that is capable of moving at speed without imposing excessive stress either on its structure or its crew. To this end, a sharp, slim bow is very useful. Compared to conventional vessels, longer, slimmer ships are only a couple of percentage points more expensive, yet they have superior handling characteristics in given swell conditions, and they move through the water with less resistance. The ESC came to fruition in 1998, with the truly innovative and successful Stan Patrol 4207 series.''To date, the shipyard has constructed eighteen patrol vessels of this kind for coastguard services throughout the world, and the orders keep on coming. This type of vessel was the basis for the Axe Bow Concept.Jaap Gelling points out that “It is extreme conditions that determine a ship’s ability to operate at sea. When it encounters violent wave impacts, it is forced to slow down. The solution lies in a very deep, and very tall bow shape, that is also as slim as possible. This is the basis of the latest concept, a ship that cleaves the waves while keeping its prow in the water at all times. The study concluded that an axe bow vessel represents a four-fold improvement over conventional vessels. To put it another way, as the prow never leaves the water, an axe bow reduces wave impacts to one quarter of the force experienced by conventional vessels. The axe bow is a breakthrough.''
In theory, bows of this type are only suitable for fast, monohull boats, ranging from thirty to one hundred metres in length, which travel at speeds in excess of twenty knots (37 km/hour). Mr Gelling notes that “Axe bows are ideal for Fast Crew Suppliers (the transport work-horses of the offshore oil industry), and for patrol and inspection vessels.”By last year, axe bow technology had matured to the point at which it could be incorporated into production vessels. Damen Shipyards is currently building five Fast Crew Suppliers which incorporate this new bow structure.Countries throughout the world have expressed considerable interest in ships with an axe-bow. “The fear of terrorism has greatly intensified coastguard activities everywhere.”This is not the only area in which Damen is harnessing innovation to give itself a competitive advantage. When it came to supplying pilot boats for the UK market, the company had previously been unable to get a foot in the door. “What is it going to take to beat the plastic pilot boats manufactured in the UK?” The answer to this question, according to Jaap Gelling, is “Thorough market research!”. “The Stan Pilot 1505 has proven to be a very comfortable vessel, with substantial noise reduction, less vibration, and better sea handling capabilities. The first sale has already been made - a client in Scotland purchased the prototype! The hulls of these vessels are built in Poland, and they are fitted out in Gorinchem.''