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Marine Electronics


February 2011 Issue

Magnetic Patch Prevents Flooding of Nuclear Fuel Carrier
A magnetic patch made by Miko Marine AS (Oslo, Norway) was successfully used in December to seal a leak in the hull of the nuclear waste freighter Puma. The Danish-flagged ship was in danger of sinking on December 18 after a valve burst in its engine room while sailing along the coast of Norway.

The ship requested help and was allowed to anchor west of the island of Sørøya in the far north of Norway. An inspection by the Norwegian Coastal Administration's KV Farm revealed a burst valve on a pipe supplying seawater to the ship's sanitation system. The crew was unable to stop the flow of water into the engine room until the leak was sealed by a Miko magnetic patch provided by the Farm. The patch immediately stopped the inflow of water and enabled the freighter to be escorted to Hammerfest, Norway, for permanent repair.

Packs of magnetic patches are carried aboard Norwegian Coastal Administration vessels so that they are available to make repairs with minimum delay. By reballasting the Puma, it was possible to trim the ship to bring the leak above the water line. This enabled the patch to be applied without the use of divers and to be reinforced by powerful permanent magnets. After the 30-nautical mile open sea voyage to Hammerfest, the patch was found to have maintained the seal.

Norwegian environmental groups are now accusing the ship of having sailed too close to the coast. Miko Marine said that environmentalists are using the incident to highlight the cost and severity of the disaster that would have occurred if the leak had happened a few days earlier when the magnetic patch might not have been available.

"Our products have been used to save ships and offshore platforms from sinking on numerous occasions," said Nicolai Michelsen, managing director of Miko Marine. "Afterwards, people invariably remark upon the trivial cost of the patch compared with the costs of cleaning up an environmental disaster that might have occurred if it had not been available. It is, however, vital for the patch to be applied quickly and the only way to guarantee this is if the ship has a salvage pack of its own patches on board."

Michelsen said he believes legislation should be passed requiring magnetic patches on certain types of vessels. "Although it is obvious that I would want to encourage more patch sales, we have seen enough incidents to know that the benefits of their use go far beyond our commercial gain." For more information, visit www.miko.no.

Divers Discover USS Revenge Using JW Fishers Metal Detector
Almost 200 years after the USSRevenge ran aground and sank off Rhode Island, a group of Connecticut scuba divers using a JW Fishers (East Taunton, Massachusetts) Pulse 8X metal detector have found what they believe are the ship's remains.

Revenge went down in January 1811 while being captained by Oliver Hazard Perry, who gained notoriety for his bravery during the Battle of Lake Erie in the War of 1812. Perry is also known for his proclamation, "We have met the enemy, and he is ours." At the time of its sinking, Revenge was performing hydrographic survey work in the shallow waters of Long Island Sound. Shrouded in thick fog, the schooner ran aground on a reef near Watch Hill, Rhode Island.

Recreational scuba diver Charles Buffum had always dreamed of finding a shipwreck and eventually read about the Revenge. He partnered with his friend and diving partner, Craig Harger, bringing along Mike Fournier, another friend, to assist in the operation.

This January, after picking up the Pulse 8X, the trio set off for Rhode Island. After two dives, enthusiasm began to decline, but they decided to make one more dive. Sweeping the bottom with the Pulse 8X, they swam through kelp surrounding the shallow reef. Suddenly the detector began to wail. The group had found a small cannon lying on the ocean floor. In subsequent dives the team found another cannon, a large anchor and other metal objects.

The group has contacted the Naval History and Heritage Command, the office that overseas the salvage of Navy ships. They hope to convince the Navy to salvage the remains or to relinquish the rights so they can raise the money needed to do it themselves. For more information, visit www.jwfishers.com.

Saab Inspection ROVs Keep City Water Flowing in Buenos Aires
For the first time, the water authority in Buenos Aires, Argentina, is able to inspect the whole length of its pipeline from the inside. The authority has been sending two Saab Seaeye (Fareham, England) Falcon remotely operated vehicles (ROVs) swimming down its entire 96-kilometer length, around bends and up and down levels, all while 35 meters below ground.

Argentine Water and Sanitation (AYSA) has almost 100 kilometers of large-diameter freshwater pipeline to inspect for potential failure, ranging in diameter from three to six meters. The task has been too dangerous to achieve with divers, so this work has never before been undertaken.

By using the Falcon ROVs, AYSA can work constantly and safely to check for cracks and breaks, according to Saab Seaeye. One of the Falcons is the standard model fitted with a 450-meter umbilical and the other is the deep-rated Falcon DR version fitted with 1,100 meters of umbilical. Each can swim between the inspection hatches dotted along the pipeline.

Inspection must be carried out overnight and only in the winter months when water flow is around one knot. During summer the normal daily rate is five knots.

The two AYSA Falcons are transported as self-contained units on special trucks that are fitted with a powered winch, crane and control cabin. Cameras fitted to each ROV include a Seaeye color video camera with twin lights linked to a tilt-and-pan system and a rear-facing Seaeye monocamera. A fiber optic data and video transmission system is also included in the Falcon DR version.

Fitted on the ROV is a Tritech International (Aberdeen, Scotland) Typhoon video measuring system, a Tritech Super Seaprince profiling sonar and an altimeter. For recovering any unexpected debris found in the tunnels, a single-function three-jaw manipulator was installed on the ROV. For more information, visit www.seaeye.com.


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