‘Underwater Mountain’: A Navy Nuclear Attack Submarine Crashed Into the Impossible

What you need to know: In 2005, the USS San Francisco (SSN 711), a U.S. Navy nuclear submarine, collided with an unknown seamount while traveling at high speed near Guam.

-Despite significant damage, the submarine’s inner hull remained intact, allowing the crew to surface and return to port. The accident resulted in one death and injuries to 98 crew members.

-Commander Kevin Mooney, the commanding officer, was relieved of duty following the incident, with several crew members also disciplined for not using up-to-date charts. However, 20 officers and sailors were honored for their actions in the safe recovery of the submarine.

USS San FranciscoThe Miraculous Survival of: How a US Submarine Overcame a Collision with a Seamount

We hear a lot about how well-built and state-of-the-art the U.S. Navy’s submarines are, with many experts telling us they’re the best on the planet.

In 2005, a US Navy attack submarine was put to the test when it crashed into what many would call an “underwater mountain.”

As crazy as it sounds, the submarine did not sink and managed to return to port. Here’s what an expert explained about the incident and his analysis of how the sub got home.

USS San Francisco (SSN 711): a crazy submarine story

Typically, it is fighter and bomber pilots who have to worry about mountains – especially when flying in low visibility conditions. Tragically, it was in January 2022 that a South Korean Air Force pilot was killed after his F-5E fighter jet crashed into a mountain south of Seoul due to poor visibility.

However, it’s not just “riders” who need to be careful in the mountains.

In 2021, a US Navy nuclear-powered submarine collided with an “unknown seamount” – also known as an underwater mountain. The USS Connecticut, a Seawolf-class fast attack submarine, struck the then-unidentified object in international waters in the South China Sea on Oct. 2, 2021, resulting in moderate to minor injuries to 11 crew members.

This incident was the first involving a U.S. Navy submarine since the USS San Francisco (SSN 711) also struck an unknown seamount in 2005, which unfortunately resulted in numerous injuries as well as one death among the crew. Such collisions are uncommon but likely impossible to completely avoid, as researchers believe there are more than 100,000 seamounts that rise more than 1,000 meters (about 3,300 feet) from the sea floor (Source: National Oceanic and Atmospheric Administration (NOAA)).

“New estimates suggest that, together, seamounts cover about 28.8 million square kilometers of the Earth’s surface,” NOAA explained. “That’s bigger than deserts, tundras or any other land-based global habitat on the planet.”

Collisions can be serious

A submarine hitting a mountain isn’t as extreme as a plane flying into it, but it’s still pretty serious. In fact, it is notable that the damage to the USS Connecticut was not greater. Furthermore, it is practically a miracle that the USS San Francisco did not suffer catastrophic damage when it hit the unknown seamount at about 30 miles per hour and at a depth of 525 feet.

This incident occurred on January 8, 2005, about 675 km (364 nautical miles, 420 statute miles) southeast of Guam, while the submarine was traveling at maximum speed. The resulting collision was so severe that the vessel suffered significant damage, and there was a struggle to maintain positive buoyancy to the surface after the forward ballast tanks were ruptured, while the sonar dome was severely damaged. In total, 98 crew members were injured, with broken bones, lacerations and back injuries. Machinist’s Mate 2nd Class Joseph Allen Ashley, 24, of Akron, Ohio, died the next day from head injuries.

Fortunately, the inner hull was not ruptured and, more importantly, there was no damage to the boat’s nuclear reactor. In fact, thanks to the efforts of the command staff and crew, USS San Francisco was able to surface and was escorted back to port under escort by USCGC Galveston Island (WPB 1349), USNS GYSGT Fred W. Stockham (T-AK – 3017) and USNS Kiska (T-AE-35), while MH-60S Knighthawk helicopters and a P-3 Orion provided additional assistance. The submarine, traveling at just 10 miles per hour, took about 52 hours to reach Guam.

Temporary repairs were made in Guam before the ship was sent to Pearl Harbor for a more extensive overhaul. Since the USS Honolulu was scheduled to retire in 2007, while the USS San Francisco was scheduled to remain in service until at least 2017, the U.S. Navy opted to remove the old boat’s nose and give the latter a much-needed “makeover.” . .”

The USS San Francisco finally returned to service in April 2009.

Sailors guilty, others honored

An investigation found that Commander Kevin Mooney, commanding officer (CO) of San Francisco, was to blame for the incident – ​​citing poor judgment that led to the collision. A Navy investigation also found that the boat’s crew was not using the most up-to-date charts to plot its course.

The US Navy relieved Mooney of his command and also issued him a letter of reprimand. However, he was not charged with any crime, nor was he court-martialed. Additionally, six crew members were also found guilty at their own extrajudicial punishment hearings (“Captain’s Mast”) for endangering a ship and dereliction of duty, and were reduced in rank and given punitive letters of reprimand.

Most importantly, for their actions in the crisis, another 20 officers and sailors received awards, including letters of commendation, the Navy and Marine Corps Achievement Medal, the Navy and Marine Corps Commendation Medal, and the Meritorious Service Medal.

“Although the grounding incident compelled me to discipline him and remove him from command, in my opinion it does not negate 19 years of exemplary service,” wrote Vice Adm. Jonathan W. Greenert, commander of the U.S. 7th Fleet, in your report.

“Prior to the grounding incident, the USS San Francisco demonstrated a tendency for continuous improvement and compiled an impressive record of achievement under Mooney’s leadership. Furthermore, the post-landing response of the crew under his direct leadership was commendable and enabled the recovery of the submarine and safe return to port.”

Expert Biography: Peter Suciu, Defense Analyst

Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers and websites with more than 3,000 articles published over a twenty-year career in journalism. He writes regularly about military equipment, firearms history, cybersecurity, and international affairs. Peter is also a contributing writer for Forbes.

All images are Creative Commons.