Innovation: Meter on hull cuts risk of oil spills

SPILLAGES at sea will be reduced and the life of tankers extended by a monitoring system now under development, according to Andy Norris, technical director of the marine technology company Kelvin Hughes, writes Nuala Moran.

The system, Ship Hull Integrity Programme, will monitor the condition of a hull. It is being developed by a consortium that includes Kelvin Hughes in a three-year project subsidised by the European Union. Trials of a prototype system begin this month on board a tanker owned by the Hellespont Steamship Corporation of Greece. Structural behaviour will be monitored continuously by stress meters developed by British Maritime Technology Ltd and other sensors attached to the inside of the hull. The data is then fed to displays on the bridge.

Information from the trial will be used to develop a predictive system that will identify normal safety parameters and abnormalities, instantly calculating their significance and advising when it is necessary to take remedial action, such as slowing down. Going at speed, fully laden, in heavy seas can stress a ship to the point of breaking its back.

'We will take each isolated measurement and compare and calculate stresses over time, building up a history of the stresses a vessel has been subjected to,' Dr Norris says. 'Some aspects of stress are cumulative. If you keep bending a thin sheet of metal it won't break the first time but it will the fifth.'

The system will monitor these cumulative structural stresses, as well as corrosion and cracking. It will also identify when abnormal stresses are being experienced because of loss of structural strength.

In addition to providing information on how the vessels should be handled at sea, the system will enable owners to prioritise maintenance.

The data produced by the system can also be used to prove that a vessel is seaworthy and safe, though it may also indicate that some vessels will have to be scrapped earlier than intended.