Saturday, May 12, 2007

Axebow Part one











Relatively small and fast vessels, such as patrol ships and fast crew suppliers, can have serious problems in heavy seas. The waves push the vessel up with such force that its nose clears the water before dropping back down onto the waves again. This can result in the crew becoming seasick or sustaining injuries and it can also damage the cargo and the structure of the vessel. Dr. LexKeuning of the Delft University of Technology experienced the dangers of these levels of vertical acceleration for himself in the early 1980s when he seriously injured his knee during trials with a high-speed vessel when the vessel fell back into the sea with a huge impact after a gigantic wave had lifted it out of the water. This incident caused him to dedicate a large part of his professional life to improving the sea-keeping behaviour of high-speed vessels. Keuning’s latest solution is the axe bow. A high, straight bow in the shape of the blade of an axe enables the vessel to cut through the waves and it therefore moves much more steadily. This allows the vessel to continue to operate at higher speeds whilst at sea. In February 2007 Keuning took his first trip on a vessel with an axe bow: "Everything’s right. In fact, the axe bow makes the trip even smoother than I had expected. Everyone on the vessel was very impressed. It’s also a relatively simple solution. Other solutions were complicated and therefore too expensive and too prone to problems or simply didn’t work. The Coastguard and offshore operators are very interested in this type of vessel”. The axe bow is primarily intended for relatively small high-speed vessels of between 30 and approximately 100 metres in length. Damen Shipyards Gorinchem has now delivered the first vessels with an axe bow: "Two 33-metre fast crew suppliers have already been delivered in Mexico and we recently also delivered a 35-metre fast crew supplier. Those ships are used for fast transport of crew and goods to drilling platforms," explains Jaap Gelling, who is Product Director High Speed & Naval Craft at Damen Shipyards Gorinchem. Before the ships were first used the fear was that the axe bow would make the ship less manoeuvrable and that it would be more difficult to maintain course: “In practice, however, it is unbelievable how well the ships steer. The trial run with the 35-metre fast crew supplier took place in a period when there were a number of storms. Nevertheless, we were still able to carry out the endurance test (4 hours at the maximum speed of 29 knots) in chaotic seas at force 7 without any problems. The captain was very impressed with the ship and told us that the endurance test would have been completely impossible in such conditions with any other vessel of comparable dimensions and speed


Kort en bondig zou ik het houden , verhaaltje hierboven gaat over de axebow/bijlboeg die gebruikt wordt bij snelle en kleine patrol en crew vessels met een lengte van tussen de 30 en 100 meter zoals die gebouwd worden bij Damen Shipyards Gorinchem met het doel het voorkomen/verminderen van eventuele zeeziekte bij de bemanning en het beschermen van de lading , foto's en informatie komen weer van Mike Lommerde , mijn vliegende reporter . meer/more zie/see label Silni

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