Wednesday, July 8, 2009

Drowsy Sailing: Sleep Deprivation & the U.S. Navy Port Royal Accident

The Honolulu Advertiser reports that sleep loss and fatigue may have been factors in the Feb. 5 grounding of the USS Port Royal, a guided-missile cruiser.

The ship’s captain told the Navy Safety Investigation Board that he was tired when the ship got under way. He got less than five hours of sleep in the previous 24 hours; in the three days leading up to the incident he slept for a total of only 15 hours.

The ship ran aground in shallow waters off the coast of Honolulu. The 9,600-ton cruiser remained stuck for days before
efforts to free the ship were successful. The AP reports that the accident caused an estimated $25 million to $40 million in damage to the $1 billion Port Royal.

In April the Sleep Education Blog
reported that the U.S. Navy has been paying attention to sleep. There is concern that sleep deprivation can increase mistakes and accidents.

The National Transportation Safety Board also is concerned about safety on the open seas. For years the NTSB has sought to reduce marine accidents caused by human fatigue.

The NTSB is
advocating for work-hour limits for mariners based on fatigue research and sleep needs. This was added to the NTSB’s “most wanted” list of safety improvements in 1999. But the NTSB reports that the U.S. Coast Guard has not taken action to address this issue.

Sleep deprivation also may have been a factor in the famous grounding of another ship – the
Exxon Valdez. The oil tanker ran aground on March 24, 1989. About 11 million gallons of oil were spilled into Alaska’s Prince William Sound.

The Alaska Oil Spill Commission published a
final report on the incident in 1990. It states that the ship’s third mate failed to maneuver the vessel properly.

The mistake may have been caused by fatigue; testimony suggests that he may have been awake and at work for up to 18 hours before the accident.

“It is conceivable that excessive work hours (sleep deprivation) contributed to an overall impact of fatigue, which in turn contributed to the Exxon Valdez grounding," the report concluded.

Image by the U.S. Navy

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