HONOLULU — When the fleet ocean tug USNS Navajo lost more than 8,000 pounds of anchor, chain and heavy rope near Pearl Harbor's entrance during recent Rim of the Pacific war games, the Navy said it was "uncommon" for one of its ships to lose an anchor.
Turns out that isn't exactly the case for the Navajo.
The 226-foot ship also lost a stern anchor last year when heavy anchor line, known as a hawser, snagged on a 101-foot-long shipwreck off Ewa Beach during training and was cut, officials said.
Navy Region Hawaii said in an email that the cost of a new hawser is $40,000.
Military Sealift Command, which operates the Navajo, replaces hawsers on a routine basis due to wear and tear, the Navy said. The hawser that was replaced in 2011 was a regularly scheduled replacement. The hawser damaged this year will not be replaced. The line can be repaired for $600, and the ship will not replace the hawser until it needs to, the Navy said.
"Losing an anchor during marine salvage operations is uncommon, but not unusual," the Navy said. "The Navy takes precautions to conduct all operations safely, and crews are trained to respond appropriately and safely when situations arise."
On April 29, 2011, the Navajo unintentionally severed a hawser as the ship attempted to recover a 6,000-pound stern anchor from a three-point mooring near the 101-foot yard tug, which was sunk in 2010 and is used as a training platform, Navy Region Hawaii said. The wreck is not intended for sport diving use.
The anchor hawser snagged on the wreck, and "it was only a matter of seconds before the line broke away, cut cleanly as the hawser moved across the wreck," the Navy said.
The Navy said the Navajo was training with Mobile Diving and Salvage Unit 1 divers at the time. The fleet ocean tug deploys one to four anchors to stabilize the ship so divers can work below.
Bow anchors are connected by chain to the ship. Stern anchors are connected by chain, wire and/or fiber line that can be as long as 2,000 feet, the Navy said.
The Navajo, currently operating out of Pearl Harbor, lost a stern anchor again on July 28 during RIMPAC when it was also training with the dive team.
The 10-inch-circumference polyester double-braid line was cut due to chafing, the Navy said, sending 546 feet of line, 4,250 pounds of chain and 4,500 pounds of anchor 150 feet to the bottom.
Navy Region Hawaii said it is not known what caused the break in the line.
In both cases, divers with the mobile diving unit helped recover the Navajo anchors. No disciplinary action was taken against the Navajo's operators, the Navy said.
Asked whether any other Navy ships have lost anchors around Hawaii, the Navy said, "We are not aware of any other incidents in the last several years."