The first Miko Plaster Polar Kits have been supplied to passenger ship operators sailing in Polar waters.
Polar cruise operators Hurtigruten and National Geographic Lindblad are the first companies to equip ships with the technology.
Using magnetic patches and a special application technique, the kits have been developed to enable ships to effectively repair hull damage caused by Polar ice while still at sea and without using a diver.
This type of damage is a recognised risk, even for Ice Class vessels, and is likely to increase as climate change releases more free-floating ice into open water.
Until now, there has been little possibility of a ship’s crew sealing a hull puncture in sub-zero temperature waters. Interior fittings and the ship’s structure reduce the probability of a hole being repaired from the inside. External repairs can only be performed by divers protected against the freezing waters.
Because few ships carry divers, only pumps can protect the vessels from flooding. If the pumps fail, they will suffer the same consequence as the ‘Explorer’ which sank off Antarctica in 2007 after being holed by ice in calm weather.
The new Miko kit contains magnetic patches that have been used in the maritime industries for over 20 years. Oslo-based Miko Marine has now developed a technique that enables these patches to be applied without a person entering the water.
Since 2017, ships seeking IMO Polar Code approval have been required to demonstrate an effective plan of action for any emergency in Polar waters. This includes the sustaining of ice damage to the hull but until now it has not been possible for the ship’s crew to perform a credible repair, the company said.
Each kit contains magnetic patches – referred to as plasters, due to their instant adhesion to a steel hull. Made from a strong flexible laminate with a powerful magnetic layer, they are widely used by navies and the shipping and salvage industries.
Each Polar kit contains several plasters combined with a number of lines and tackle that are deployed in a unique application technique by two or three crew members in a small boat operating beside the damaged area. Any hole down to 2 m below the water line can now be closed with a plaster without anyone needing to enter the water.
The magnetic adhesion of the patch, combined with the outside water pressure, will keep it securely in place and additional high-power magnets may also be applied to maintain the seal until the ship is safely berthed.
Although warmer seas are opening up Polar waters to more shipping, a new study published by Newcastle University and the Scripps Institute of Oceanography (1) has revealed that the thinning of the Antarctic ice sheet is releasing more ice into the ocean.
This is likely to result in more smaller pieces floating out to sea where some may become an increased hazard to shipping by being difficult to spot by crew and not visible on normal marine radar.
Professor Norvald Kjerstadt of the Norwegian University of Science and Technology, explained; “Ships are usually damaged by ice when they are going too fast in relatively open water or very open drift ice. They tend to go slower when they are in leads or confined spaces which means that there is less risk of damage.”
When ships speed-up in open water where there is now more floating ice they could be at greater risk.
(1): Geophysical Research Letters – Instantaneous Antarctic ice sheet mass loss driven by thinning ice shelves – G Hilmar Gudmundsson, Fernando S Paolo, Susheel Adusumilli, Helen A Fricker – first published 20th November, 2019.