US Navy orders safety pause for entire submarine force after attack sub ran into underwater mountain in South China Sea

Submarine USS Connecticut with aircraft carrier George Washington
Seawolf-class attack submarine USS Connecticut in the Pacific Ocean with a US Navy HH-60H Sea Hawk helicopter and aircraft carrier USS George Washington and Japanese Maritime Self-Defense Force helicopter destroyer JS Hyuga, November 17, 2009. US Navy/MCS1 John M. Hageman
  • The US Navy has ordered a safety stand-down for the submarine force following an incident last month.
  • Last month, attack sub USS Connecticut ran into an uncharted seamount.
  • An investigation into the incident suggested the accident was preventable.

The US Navy ordered a safety stand-down for the entire submarine force on Wednesday in response to the results of an investigation into an incident last month in the South China Sea.

On October 2, the powerful Seawolf-class nuclear-powered attack submarine USS Connecticut collided with an object, the Navy said in a statement five days after the incident as the damaged $US3 ($AU4) billion submarine limped into port in Guam.

The Navy provided only limited information, revealing only that the submarine was stable, there were no life-threatening injuries, and that the nuclear systems on board were not affected. The sea service did not say where the incident occurred, but officials revealed it happened in the South China Sea.

In early November, the Navy finished its initial investigation into the accident, concluding that the submarine ran into an uncharted seamount. That report has not been publicly released, and the causes that led to the collision and the crew’s responses afterwards remain unknown. 

Days later, Vice Adm. Karl Thomas, the commander of US 7th Fleet, decided to fire the command leadership of the Connecticut.

The commanding officer, Cmdr. Cameron Aljilani, as well as Lt. Cmdr. Patrick Cashin, the executive officer, and Master Chief Sonar Technician Cory Rogers, the chief of boat, were all relieved due to loss of confidence.

After reviewing the investigation, Thomas determined that “sound judgement, prudent decision-making and adherence to required procedures in navigation planning, watch team execution and risk management could have prevented the incident.”

As a further step to make sure this sort of thing does not happen again, Vice Adm. William Houston, commander of Naval Submarine Forces, ordered a force-wide safety stand-down, Breaking Defense first reported Wednesday.

“We will have that and we will go ahead and learn our lessons,” he said at a naval event, according to USNI News. “The safety investigation board is not complete yet, but we know enough right now.”

“We have very rigorous navigation safety procedures and they fell short of what our standard was,” the admiral said.

Naval Submarine Forces spokesman Cmdr. Paul Macapagal told Insider that “the Submarine Force is conducting Force-wide navigational safety training as a result of the incident onboard the Seawolf-class fast-attack submarine USS Connecticut (SSN 22),” 

He said that “submarine crews will be reviewing the lessons learned from USS Connecticut and governing doctrine to reinforce sound navigation practices. Submarine crews will review required procedures in navigation planning, operations, risk management, and best practices as part of this training.”

Navy leadership described this training as a stand-down and that the submarine force continues to operate and deploy.