When it comes to ocean-bound transport, few situations are more hazardous than an oil tanker or other type of cargo ship that has lost power drifting aimlessly toward the coast. Particularly when winds are strong and waves are high, the job of saving the ship and rescuing the crew can be extremely difficult.
To speed and improve rescue operations – and thus save lives, prevent environmental disasters and recover valuable cargo – a European Union (EU) funded research project has developed a unique emergency-response system with vast potential.
Known as ShipArrestor, the system uses a huge, parachute-shaped "sea anchor" to slow down a drifting ship and put it in a better position for rescue and recovery operations. In June 2010 the complete ShipArrestor system was put to the test off of Norway's North Cape, where the Arctic and Atlantic oceans meet. Within 21 minutes, the sea anchor had turned a 120,000-tonne fuel tanker and slowed its drift by 58 percent. ShipArrestor researchers considered the test to be a major success.
When a ship loses power, it will often turn so that wind and waves are striking the vessel perpendicularly – causing it to rock side-to-side. If the weather is harsh, it can become very difficult for rescue and repair crews to board a ship in such an unstable condition.
In a worst-case scenario, a drifting ship can tip over, be driven onto a beach or rocky coast, or slam into an oil rig, lighthouse or other structure.
Supported by an EU grant of €1.1 million, the ShipArrestor team has developed a three-part system to improve rescue operations. First, a helicopter drops a lasso that is fastened to the ship's bow. Next, a 200-metre chain is dropped into the water. At the end of the chain is a 30-metre-wide sea anchor that opens under water like a parachute – both slowing down the drifting ship and turning it 90 degrees. With the wind and waves now in parallel to the ship – instead of hitting the ship from the side – the rolling motion is greatly reduced. This allows the rescue team to board the ship more easily, rescue the crew and make repairs. Finally, a tugboat arrives, picks up a buoy that is connected to the sea anchor, and pulls the ship back to port.
"The system could be used all over the world – anywhere a coast needs to be protected," said Duncan Cunningham of Miko Marine, the project coordinator, adding that the sea anchor can hold up for days, if needed, until help can arrive.
With the research phase of the project wrapped up, the ShipArrestor team is now focusing on placing the system on the market and putting it into practice. Potential customers have been identified in Norway, Sweden, the UK and Germany, and include national maritime agencies, insurers, and salvage companies.