Sea anchor safety proven in trials
A trials programme conducted off the far north of Norway has demonstrated how a modern sea anchor could be an important safety aid for high-risk ships.
Oslo based Miko Marine AS has designed a sea anchor that uses modern high strength materials and is capable of being used by the largest vessels. It is intended as a component of the European Ship Arrestor project but Claus-Christian Apneseth, project manager for Miko Marine, believes that a sea anchor should be routinely carried by any ship with a dangerous or potentially polluting cargo. ‘Heavy lift ships and any with a large deck cargo can be in danger if they are lying beam on to the sea following a loss of power, he said. ‘The sea anchor is a simple and well known device that will quickly turn the bow of any ship into the wind. In this way it will ride more safely and its cargo will be less vulnerable. It will also reduce its drift by up to 50% and this could be a vital safety element. Last October a jack-up oil drilling platform was lost from a heavy lift vessel under just these circumstances and is a typical example of the dangers arising from excessive roll when a ship cannot turn into the wind. Similarly, by slowing the movement of a tanker towards land, the use of a sea anchor could provide more valuable time for the ship to be reached by rescue tugs before grounding with disastrous consequences.’
Although it was well known in the age of sailing ships and may still be used by small craft, the sea anchor has fallen into disuse as ships have become bigger and heavier. The Miko Sea Anchor uses modern man made fabrics and lines to create a parachute shaped anchor that is immensely strong yet capable of being stowed in a small container on the foredeck. Calculations based on the recent trials have determined the dimensions of the sea anchors needed for ships of different sizes and have revealed that they need not be as large as might be assumed to be effective.
Trials have confirmed that a parachute anchor with a diameter of 30m is capable of turning and slowing the drift of a ship of up to 100,000 tonnes dwt. Such an anchor can be stored in a small container on the foredeck where it can be kept ready for immediate use. It could be launched over the bow by the crew or installed with an automatic electrical or hydraulic deployment system. Because it can be a self contained unit, the sea anchor could be moved from ship to ship in a fleet to suit the cargo being carried and to meet any instructions from its insurers.
