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OWI 01/2016 - Teaser

logistics & operations Photo: dpa would not improve their accuracy – all the more so when long-term forecasting is concerned. Circumventing the inclement weather zone The influence of insurance companies is therefore growing because it is they who have to compensate for any losses incurred. The insurers impose requirements and prescribe a big enough weather window that must be longer than the time the vessel or tow train will take for the journey. To give an example, towing a jack-up vessel from Bremerhaven to Esbjerg will take 18 to 24 hours; a journey for which the insurance company would require a weather window of 36 hours with wind force 4 at a maximum and 1.5 m wave height. The weather window required for a towage over a long distance would be so long that suitable weather conditions virtually never occur. For example, insuring the towage of a jack-up platform from the Denmark’s The North Sea is not a children’s playground: An experience the installation vessel Sea Worker had to make during a towage operation. The Sea Worker has no propulsion of its own and therefore needs to be towed. In order to improve stability, the captain slightly lowered the four hub legs and threw out the drift anchor. When the tow line broke, the vessel started drifting towards a sandbar off Hvide Sande and ran aground. In the process, it was overthrown because of the downward projecting legs and capsized. Fortunately, the crew could evacuate the platform in time; the material damage was however considerable. The incident demonstrates how quickly a mishap can happen, despite a detailed weather forecast that is updated every six hours. More frequent updates of weather predictions would not help either, since this 31


OWI 01/2016 - Teaser
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