April 5 (Bloomberg) -- Houses, cars and tractor-trailers washed out to sea by a 28-foot tsunami are clogging shipping lanes off Japan, posing a bigger challenge to U.S. Navy vessels and commercial lines than radiation from a leaking nuclear plant.
The magnitude-9 earthquake that struck off the northeast coast March 11 launched a wall of seawater that obliterated cities and towns, and left more than 27,600 people dead or missing. More than 206,000 buildings were destroyed, damaged or swept away, the National Police Agency said today.
The debris has prompted Japan’s coast guard to warn ships to stay about 60 nautical miles (110 kilometers) away from Tokyo Electric Power Co.’s crippled nuclear-power plant in Fukushima prefecture, north of the capital. That’s almost four times as far as the 30-kilometer exclusion zone introduced by the government because of concerns about radiation.
“Our forces have seen everything from cars to tractor-trailers to entire, intact homes floating in the ocean,” said Anthony J. Falvo, a spokesman for the U.S. Seventh Fleet, which is helping with recovery efforts. “They have never seen anything like it.”
The Navy said radiation from the Fukushima Dai-Ichi nuclear plant can be scrubbed off vessels with soap and water.
‘Loads of Objects’
Japan’s coast guard posts daily reports about the debris on the Internet, using information gathered from passing vessels. As of April 4, it was recommending that vessels stay up to 90 nautical miles out while passing the zone that suffered the brunt of the destruction from the natural disasters -- a 240 nautical-mile stretch from Ibaraki prefecture near Tokyo to Miyagi prefecture in the northeast.
The tsunami was at least 8.5 meters high, the Japan Meteorological Agency said. Water in some towns rose to as high as 37.9 meters, Jiji Press reported, citing measurements by Yoshinobu Tsuji of the University of Tokyo.
“Usually, there’s only the odd piece of debris,” said Hidefumi Akagi, who is responsible for advising shipping lines on sea routes for Japan’s coast guard. “Currently, we’re getting reports of loads of floating objects.”
Transport Minister Akihiro Ohata said he saw tapes of the floating rubble while meeting with U.S. officials last weekend.
“We have to figure out some way to stop the spread of the debris,” Ohata said today.
The USS Ronald Reagan, which has been delivering food and water to survivors and rescuers in the stricken regions, is keeping farther away from Fukushima than the Japanese government’s 30-kilometer exclusion zone. Some ships have been staying 100 nautical miles out from Fukushima, an area larger than the debris area.
“We’ve surveyed large at-sea debris fields on the surface,” Falvo said. “We’ve also employed side-scan sonar options for under the water.”
Mitsui O.S.K. Lines Ltd., which operates the world’s largest merchant fleet with 889 ships as of Oct. 31, is avoiding the debris area, according to an e-mailed statement from the company.
The tsunami crippled the Tokyo Electric nuclear-power station, which is leaking radioactive water into the sea. A Mitsui O.S.K. vessel was refused permission to offload in China after “abnormal” radiation levels were found.
It resumed operations after the shipping line said an independent check showed the level was “significantly lower” than the Chinese reading.
Nippon Yusen K.K., Asia’s largest shipping line by sales, also said its container ships are taking wider berths around the northeastern region. The Japan Shipowners’ Association monitors the coast guard website daily, said Hatsuho Tanaka, who runs the general affairs division.
“It is a big stumbling block for the ships,” Tanaka said. “Based on this information, ocean-going ships are avoiding the debris.”
Floating debris can damage ship propellers, which can take a week to replace and at a cost of several million yen, said Shuketsu Mizukami, a general manager for the spare-parts supply department at MHI Marine Engineering Ltd. in Nagoya.
‘Scratched or Dented’
“Damage can unbalance the propeller and cause undue vibrations,” Mizukami said. “We have several cases a year where we have to replace the whole propeller.”
Japanese ports handle about 4 percent of the world’s containers, and, prior to the quake, 18 percent of the cargo-box ship fleet by capacity was due to call in the country, according to data from the research unit of Clarkson Plc, the biggest shipbroker.
Nippon Yusen said its car shipments have slumped since the earthquake, which shut down factories operated by Toyota Motor Corp., Nissan Motor Co. and Honda Motor Co.
The Tokyo-based company, which predicted sales of 1.93 trillion yen ($23 billion) for the year ended last month, had a fleet of 820 vessels on March 31, according to estimates from the shipping line.
Nippon Yusen vessels have altered course around the debris field and have not encountered any trouble so far, said Jun Katayama, a spokesman.
“We want to avoid our ships being scratched or dented from debris,” Katayama said. “We’re paying close attention to Japan’s coast guard.”
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