The Submarine That Hit a Mountain at Full Speed — 98 Injured, 1 Dead

Añadido: 2026-05-26

[00:00:04]On January 8th, 2005 at approximately 11:42 local time, a United States Navy nuclear submarine was traveling at maximum speed through the western Pacific Ocean, 360 mi southeast of Guam.

[00:00:18]She was at a depth of 525 ft. Her crew of 137 men was relaxed. The commanding officer had gone to lunch. The navigation officer, confident in the charts, the submarine to dive deeper and accelerate to flank speed. They were heading to Brisbane, Australia for a port visit. The submarine was USS San Francisco, a Los Angeles class fast attack submarine commissioned in 1981.

[00:00:45]She was 361 ft long, displaced 6,900 tons submerged, and was capable of speeds exceeding 30 knots. At flank speed, she was moving at approximately 35 mph through the black water of the Pacific. At 35 mph, a 6,900 ton submarine has the kinetic energy of a freight train. There are no brakes.

[00:01:09]There are no seat belts. And at 525 ft below the surface, there is no warning of what lies ahead. At 11:42, USS San Francisco hit an underwater mountain at full speed. The impact was instantaneous and catastrophic. Every man aboard was thrown forward with the force of a high-speed car crash. Men flew off their feet. Bodies slammed into bulkheads, consoles, pipes, and equipment.

[00:01:34]The forward section of the submarine crumpled like an aluminum can. The sonar dome was destroyed. The forward ballast tanks were ripped open. Equipment was torn from its mounts throughout the ship. 98 of the 137 crew members were injured. Broken bones, spinal injuries, lacerations, concussions. Men were bleeding on the deck of every compartment, and one sailor, 24-year-old machinist's mate second class Joseph Allen Ashley of Akron, Ohio, suffered a massive head injury that would kill him the following day. This is the story of how a billion-dollar nuclear submarine ran into a mountain because the crew was using the wrong chart, and it is the story of how the submarine survived because of a safety program born from the death of 129 men 42 years earlier.

[00:02:22]This is Naval Depth. To understand how a submarine can hit a mountain, you must first understand what the ocean floor looks like and how little of it we actually know. The surface of the Earth is approximately 70% ocean. The average depth of the world's oceans is roughly 12,000 ft, and despite centuries of exploration, roughly 80% of the ocean floor has never been mapped in detail.

[00:02:46]We have better maps of the surface of Mars than we do of the bottom of the Pacific Ocean. The ocean floor is not flat.

[00:02:54]It is a landscape of mountains, ridges, valleys, and plateaus that in many places rivals the topography of any continent. Underwater mountains called seamounts rise thousands of feet from the ocean floor. Some are well-known and well-charted. Others have never been surveyed. Some are marked on nautical charts as probable or uncertain, meaning their existence is suspected but never confirmed, and some are simply missing from the charts entirely. The western Pacific, where San Francisco was operating, is one of the most geologically active regions on Earth.

[00:03:25]The Caroline Islands mountain chain, a series of seamounts and volcanic ridges stretching across hundreds of miles of open ocean, runs through this area. Many of these seamounts were charted decades ago using primitive surveying methods.

[00:03:38]Some were identified by shipboard sonar during World War II. Others were extrapolated from satellite altimetry data, which can detect subtle variations in the ocean surface caused by the gravitational pull of large underwater features.

[00:03:52]But, satellite altimetry cannot detect smaller seamounts, and the resolution of the data is measured in miles, not feet.

[00:03:59]The charts that San Francisco's navigation team was using on January 8th, 2005, were based on data that was, in some areas, decades old. The primary chart used for voyage planning was a Defense Mapping Agency chart at a scale of 1 to 2 million. At this scale, features smaller than approximately 1 nautical mile would not be visible. The navigation team also had access to a more detailed chart of the specific area at a scale of 1 to 500,000, which showed a seamount in the vicinity of the submarine's planned track. This seamount was marked with a depth of approximately 100 ft, meaning its peak was only 100 ft below the surface.

[00:04:40]The navigation team did not use the more detailed chart. They relied on the large-scale chart, which did not show the seamount.

[00:04:48]The Navy's subsequent investigation found that the navigation team had multiple charts available that depicted the hazard, but failed to use them in planning the voyage.

[00:04:57]This was not a case of bad luck. It was a case of bad navigation. The submarine was transiting from Guam to Brisbane at flank speed. Flank speed for a Los Angeles-class submarine is classified, but generally understood to be in excess of 30 knots. At this speed, the submarine covers approximately 1 nautical mile every 2 minutes. The crew had elected to travel at maximum speed to make up time on the transit to Australia. The commanding officer, Commander Kevin Mooney, had approved the voyage plan and the speed. At flank speed and at a depth of 525 ft, San Francisco was operating in a regime where reaction time to an obstacle was effectively zero. Even if the sonar had detected the seamount, which it did not, the submarine could not have stopped or turned in time to avoid it. The passive sonar array aboard the submarine was running, but passive sonar is designed to detect sound sources like other submarines and ships, not to detect static geological features. Active sonar, which sends out pulses that bounce off objects and return an echo, could potentially have detected the seamount. But submarines almost never use active sonar during transit because the sound pulses reveal the submarine's position to anyone listening.

[00:06:11]San Francisco was running blind at maximum speed through poorly charted waters. It was a combination that had been an accident waiting to happen for years. At 11:42, the submarine's bow struck the seamount.

[00:06:24]The physics of the impact are staggering. A 6,900 ton object moving at 30-plus knots carries an enormous amount of kinetic energy. When that energy is dissipated in a fraction of a second against an immovable object, the deceleration forces inside the submarine are catastrophic. The forward section of the submarine absorbed the initial impact.

[00:06:47]The sonar dome, a large fiberglass structure at the very front of the submarine that houses the bow-mounted sonar array, was completely destroyed.

[00:06:56]Behind the sonar dome, the forward ballast tanks were ruptured. The steel plates of the outer hull were crumpled and torn. Photographs taken later in dry dock showed that the bow of San Francisco looked as though it had been hit by a giant hammer. The entire front end was crushed, compressed, and deformed.

[00:07:15]But the inner hull, the pressure hull that contains the crew and all critical systems, was not breached. This is the critical point. The inner hull held. The reason it held is a program called SUBSAFE. After the loss of USS Thresher in 1963, the Navy created the SUBSAFE program to ensure that every submarine's pressure hull would remain intact in the event of an accident and that every submarine would retain the ability to surface.

[00:07:44]SUBSAFE mandates rigorous quality control of every weld, every pipe joint, every valve, and every fitting that is part of the submarine's pressure boundary.

[00:07:54]It requires redundant systems for surfacing, including multiple independent means of blowing ballast.

[00:08:00]When San Francisco hit the seamount, SUBSAFE was tested in the most violent real-world scenario since the program's creation, and it passed. Inside the submarine, the scene was chaos. Men had been thrown up to 20 ft through the air.

[00:08:14]In the torpedo room, sailors who had been standing were hurled forward into equipment and bulkheads. In the control room, operators were thrown from their seats. In the engine room, men collided with pipes and machinery. Blood was everywhere, broken limbs, cracked ribs, split skulls.

[00:08:30]The submarine's corpsman, the onboard medic, was himself injured, but immediately began treating the wounded.

[00:08:35]Despite the carnage, the crew responded with extraordinary discipline. Within seconds of the impact, before anyone fully understood what had happened, the crew began executing emergency procedures. The first priority was to get the submarine to the surface.

[00:08:49]Someone pulled the emergency blow activator, known among submariners as the chicken switch. This activated the emergency main ballast tank blow, releasing high-pressure compressed air into the main ballast tanks to force out water and give the submarine positive buoyancy. But there was a problem. The forward ballast tanks had been ruptured by the impact. They could not hold air.

[00:09:11]The compressed air that was supposed to fill them was escaping through the torn steel into the ocean. The submarine was supposed to rise immediately after an emergency blow. Instead, there was an agonizing pause. For approximately 30 seconds, the submarine did not move. The crew stood in the bloody, darkened control room waiting, not knowing if the submarine was going to surface or continue sinking. After 30 seconds, the after ballast tanks provided enough buoyancy to begin lifting the submarine.

[00:09:38]Slowly at first, then faster, San Francisco began to rise. At 11:44, approximately 2 minutes after the collision, the submarine broke the surface. The crew immediately began damage assessment. The reactor was intact and operating normally. The nuclear weapons aboard, Mark 48 torpedoes and Tomahawk cruise missiles, were secured and undamaged. The inner pressure hull was intact. The submarine was not flooding.

[00:10:05]She was hurt, but she was alive. But, the crew had 137 men to care for, 98 of whom were injured. The submarine's medical facilities were minimal, designed for one corpsman to treat routine injuries, not mass casualties.

[00:10:21]The crew improvised. They converted the mess hall into a triage center. They used every available first aid kit. They splinted broken bones with whatever rigid materials they could find. They bandaged wounds with torn clothing when the bandages ran out. Joseph Allan Ashley was among the most seriously injured. He had suffered a devastating head wound during the impact. The crew did everything they could for him, but without a hospital and surgical capability, there was nothing that could save him.

[00:10:49]Ashley died the following day, January 9th, 2005. He was 24 years old. San Francisco was now on the surface in the middle of the Pacific Ocean, 360 miles from the nearest port, with a destroyed bow, 98 injured crew members, and one dead. She had to get back to Guam.

[00:11:08]The submarine could not dive. Her forward ballast tanks were destroyed.

[00:11:12]Her sonar was gone. Her bow was crushed.

[00:11:16]But, her reactor was still running. Her propulsion system was intact and her rudder still worked. She could move slowly on the surface. The transit back to Guam took 52 hours. The submarine limped across the Pacific at approximately 10 mph, roughly 1/3 of her normal surface speed. A Coast Guard cutter, USCG Galveston Island, rendezvoused with San Francisco and escorted her back to port. A Navy supply ship, USNS Fred W. Stockham, also joined the escort and provided additional medical supplies and personnel. When San Francisco arrived at Apra Harbor, Guam, on January 10th, the injured were transferred to the naval hospital. The submarine was moved into dry dock for assessment. The photographs taken in dry dock shocked the Navy. The bow of San Francisco was unrecognizable. The sonar dome was gone entirely. The forward ballast tanks were crushed flat. The outer hull plating was torn and buckled over a distance of nearly 40 ft. One Navy official described it as looking like the bow had been ripped off. A temporary repair dome, approximately 20 ft high and 20 ft in diameter, was welded over the damaged bow to restore watertight integrity. The Navy investigation was swift and thorough. A formal investigation found that the commanding officer, Commander Kevin Mooney, bore primary responsibility for the accident.

[00:12:37]The investigation concluded that several critical navigational and voyage planning procedures were not being implemented aboard San Francisco.

[00:12:45]Specifically, the navigation team had failed to use all available charts in planning the voyage. Charts that were aboard the submarine and accessible to the navigation team depicted the seamount that San Francisco struck. The team simply did not consult them.

[00:13:00]Commander Mooney had an otherwise exemplary record. He was described by superiors as one of the best submarine officers in the Pacific Fleet, but the investigation found that his command climate contributed to the relaxed approach to navigation that allowed the accident to happen. Mooney was relieved of command and issued a letter of reprimand. Six crew members received non-judicial punishment for hazarding a vessel and dereliction of duty. They were reduced in rank and given letters of reprimand. The Navy then faced a decision, repair San Francisco or scrap her. The submarine had recently completed a nuclear refueling overhaul in 2002, meaning her reactor had fresh fuel that would last until approximately 2017.

[00:13:43]Scrapping her would waste that investment. Repairing her would be expensive, but would keep the submarine in service for another decade. The Navy chose to repair her. The solution was creative and unprecedented. USS Honolulu, a sister Los Angeles class submarine that was scheduled for decommissioning in 2007, donated her entire bow section.

[00:14:05]Workers at the Puget Sound Naval Shipyard in Bremerton, Washington cut the bow from Honolulu and welded it onto San Francisco. The submarine received a transplant. The bow replacement cost approximately $79 million.

[00:14:19]The work took 3 years. In April 2009, San Francisco returned to operational service with a new bow, a new sonar dome, and new forward ballast tanks. She served for another 7 years before being decommissioned in 2016 and converted to a moored training submarine at the Nuclear Power Training Unit in Charleston, South Carolina. The seamount that San Francisco struck was later surveyed in detail. It was found to be a steep-sided volcanic feature rising to within 100 ft of the surface from a seabed approximately 6,000 ft deep. The seamount was visible on at least one chart that was aboard San Francisco at the time of the collision. The navigation team simply never looked at it. The San Francisco collision reinforced lessons that the submarine force had been learning since the loss of Thresher in 1963.

[00:15:06]The SUBSAFE program saved San Francisco.

[00:15:09]If the pressure hull had been breached at 525 ft, the flooding would have been catastrophic. The submarine would have sunk in water over a mile deep. 137 men would have died instead of one. But SUBSAFE cannot prevent collisions. It can only ensure that the submarine survives them.

[00:15:27]Preventing collisions requires rigorous navigation, thorough voyage planning, and a command culture that treats every transit as potentially dangerous. San Francisco's crew did not treat their transit as dangerous. They were heading to a port visit in Australia. The mood was relaxed. The captain went to lunch.

[00:15:45]The navigation officer authorized maximum depth and maximum speed through poorly charted waters. Nobody checked the detailed charts. Nobody questioned the plan. The ocean does not care about your schedule. It does not care about your port visit. It does not forgive complacency, and it does not announce its mountains. Joseph Allen Ashley is buried in Ohio. He was 24 years old. He joined the Navy to serve his country and see the world. He died because his submarine hit a mountain that was on a chart that nobody bothered to read. The Navy named a conference room at the submarine training facility in his honor.

[00:16:21]Every year on January 8th, the submarine community remembers the collision and the lessons it taught. The most important lesson is the simplest one.

[00:16:29]The ocean is not empty. The charts are not perfect. And when you are driving a 6,900-ton nuclear submarine at 35 mph through the dark, the only thing between you and a mountain is the quality of your navigation. On January 8th, 2005, the quality of that navigation failed, and a 24-year-old sailor from Ohio paid the price. This is Naval Depth.

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