"Minor difficulties" - the death of the nuclear submarine "Thresher"
"The submarine is sinking into the water, look for it in who knows where..."
History This was already so old that even in the USSR, where they did not like to give too much information on foreign fleets, it was possible to learn of the sinking of the American nuclear submarine Thresher. It happened on April 10, 1963, just after 9:00 AM: the last message from the submarine was received at 9:17 AM. American experts, who love absolute precision (even against common sense), put the time of the submarine's death down to the second—09:18:24 AM. However, all 129 witnesses to the submarine's final moments today rest with her at a depth of 2560 meters.
Does everyone know that Americans christen their ships not with champagne, but with Madeira?
The contract for the submarine's construction was awarded to the Portsmouth Naval Shipyard on January 15, 1958. The hull was launched on July 9, 1960, and the submarine was commissioned on August 3, 1961. Thresher's godmother was Mary B. Warder, wife of Captain Frederick Burdett Warder, a celebrated submariner and recipient of numerous top American awards, who served as captain of the World War II submarine USS Seawolf.
Launching the Thresher, view from the stern
It was an innovative ship! The Americans write with justifiable pride that the Thresher was the fastest and quietest nuclear submarine of the 60s. It could reach a submerged speed of 29 knots and dive to depths of up to 400 meters. The Thresher's armament was no less impressive: the submarine was the first to be equipped with launchers for anti-submarine warfare. missiles SUBROC and the most advanced hydroacoustic station at that time.
The design was so successful that the US Navy was able to place an order for 14 similar ships and another 11 similar ones (but with cruise missiles). There was one drawback (from the perspective of the Soviet school of nuclear submarine construction): the submarine was equipped with only one Westinghouse S5W nuclear reactor, which supplied steam to 15 horsepower turbines. Our submarines, just in case, were equipped with two reactors.
Launching the Thresher, view from the bow
In 1961-62, the Thresher underwent lengthy sea trials in the Caribbean. It was lengthy because the submarine was the lead ship of a major series—the largest in the US Navy since World War II. As often happens on lead ships, technical problems arise suddenly and unexpectedly. The Thresher was no exception, although the submarine simply didn't have time for many adventures—she hadn't even sailed under the Stars and Stripes for two years. Nevertheless, she did experience a power outage, accompanied by a completely discharged battery, in November 1961, and the following year, while moored in Florida, she was severely slammed by a harbor tug, denting her ballast tanks.
Lieutenant Commander John Wesley Harvey
The submarine departed on its final patrol on April 9, 1963, under the command of Lieutenant Commander John Wesley Harvey. The Thresher was accompanied by the rescue vessel Skylark, allowing the submarine's demise to be well-timed. That day, it dived to a depth of 400 meters and remained submerged overnight. At 6:30 a.m. on April 10, underwater sound communication with Skylark was restored. Test dives to the maximum depth were scheduled for that day.
The rescue vessel Skylark, formerly a Navajo-class tug
The submarine descended slowly, moving in a circle beneath the rescue vessel, maintaining constant communication. Every 30 meters (100 feet), the dive was interrupted to check the functionality of all systems. When the submarine reached the planned depth, the Skylark received a message that sounded something like: "Minor difficulties, positive ascent, attempting to surface." Roughly, as underwater sound communication produces considerable distortion, especially at great depths. Then came another heavily distorted message, in which only the number 900 could be discerned. No further messages were received from the submarine.
Admiral George Whelan Anderson Jr.
By 3:00 PM, the Atlantic Fleet's submarine command realized they were in trouble. More specifically, oil: the Skylark had spotted a large oil slick on the sea surface. By lunchtime, 15 US Navy ships, including five destroyers, a frigate, and two submarines, had arrived in the dive area. At 6:30 PM, the command began notifying the crew's families that the submarine was missing. Admiral George Whelan Anderson Jr., Chief of Naval Operations, held a press conference at the Pentagon, announcing that the Thresher was missing, along with her entire crew (which included 17 industry representatives).
Bathyscaphe "Trieste"
On the morning of April 11, a search and rescue operation began. The Naval Research Laboratory's research vessel Rockville, equipped with a highly sensitive sonar, was also involved in the search for the missing submarine. The submersible vessels Atlantis II, Robert D. Conrad, and James M. Gillies also participated in the operation. The bathyscaphe Trieste was transported from San Diego to Boston, where it made two dives to the presumed site of the submarine's demise. An old passenger car, the Austin Somerset, was also sunk to study deep currents, which was necessary for the use of towed deep-sea cameras. Several more ships and vessels subsequently joined the search.
The crew of the nuclear submarine "Thresher"
On April 12, President John F. Kennedy declared the submarine lost and ordered national flags across the country to be lowered to half-staff for four days in honor of the fallen submariners. On April 15, a memorial service was held in Portsmouth at the SS-192 conning tower, which has been erected as a monument. A wreath of white chrysanthemums in the shape of the USS Thresher was laid in the ocean at the site of the submarine's demise. Afterward, ships participating in the search and rescue operations passed over the disaster site in a cross formation. The USS Thresher will subsequently be stricken from the US Navy's inventory of warships, but will not be decommissioned. Today, the submarine is considered "on perpetual patrol," a tradition in the US Navy where a combat mission begins with a departure to sea and ends upon returning to base. If a submarine never returns, its mission never ends.
A fragment of the Thresher submarine's anchor on the seabed
The submarine was found on June 27, 1963. Or rather, what remained of it. The destroyed hull of the Thresher lay at a depth of 2600 meters. The submarine had broken into five pieces, scattered over an area of 134,000 square meters. By July 22, most of the wreckage had been photographed. In early August, the bathyscaphe Trieste, crewed by Lieutenant John B. Mooney, Jr., Lieutenant John H. Howland, and Captain Frank Andrews, began diving. After several dives, several pieces of the submarine were recovered by September 1964. During the search, the submarine Seawolf heard strange metallic noises coming from the site of the lost submarine, but it was later officially determined that these could not have been caused by human activity.
Nuclear submarine Abraham Lincoln (SSBN-602)
The question immediately arose: what could have caused the destruction of America's most advanced nuclear submarine? It must be said that there is still no definitive answer to this question, but there are some theories that are considered the most probable. Roughly speaking, the leading theory is an error in strength of materials. On American submarines, the joints of the piping system that supplied seawater to cool the reactor were not welded, but soldered with silver-tin solder. Ultrasound examination revealed approximately 14% of the soldered joints were potentially problematic.
This had led to unpleasant incidents even before the Thresher disaster: on November 30, 1960, the diesel-electric submarine Barbel took on 18 tons of water in three minutes after a similar seal failed. This time, the submarine managed to surface. A few months later, a similar incident occurred with the nuclear-powered missile submarine Abraham Lincoln: during sea trials, the silver-tin seal failed, allowing seawater to enter the submarine. But the Lincoln also managed to surface. So why did the Thresher perish?
Our boat VVD cylinders look something like this (only painted a radical black color)
Engineers reconstructed the disaster as follows. Initially, seawater began leaking from a ruptured pipeline into the hull. This could have caused a short circuit and the collapse of the reactor's emergency protection grilles. Consequently, during the test dive, the submarine became immobile and began to dive uncontrollably. The captain attempted to purge the main ballast tanks with high-pressure air, but... Most likely, the high-pressure air cylinders contained excess moisture, the water froze, and the resulting ice plugs prevented air from entering the ballast tanks. (Here the author raises an eyebrow in surprise: high-pressure air on Russian submarines is stored at 400 atmospheres, and on American ones, it's likely the same. Such pressure, in his opinion, would inevitably force out any ice plugs!).
This situation was subsequently simulated on the Thresher's sister ship, the submarine Tinosa. It appears that ice forming on the filter screens was able to stop the air flow (still doubtful, but that's the opinion of American experts). Since then, all US Navy submarines have had a mandatory air dryer on their high-pressure compressors.
Training of the Thresher submarine crew
Be that as it may, the submarine's hull collapsed during its uncontrolled dive at a depth of 730 meters. However, the SOSUS underwater surveillance system did not detect the acoustic effect that should have accompanied the collapse. An interesting point of view was expressed by one of the few surviving Thresher crew members, Lieutenant Raymond McCool, the "controller" responsible for reactor operation. McCool did not go to sea that time, and his place was taken by trainee Jim Henry. An experienced controller, he said, could have attempted to divert steam from the steam generator to the ballast tanks, but the trainee was unable to do so. Admiral Rickaver, the creator of the American nuclear submarine fleet, noted that such a procedure is not applicable under normal conditions, but could be implemented in the event of a submarine emergency.
It's not as if what happened came as a complete surprise to the American submariners. Before the Thresher's departure, a simulated seawater influx through a ruptured seawater line had been simulated. The watchman needed 20 minutes to fix the leak. But in a real accident, with the reactor shut down, the crew didn't have 20 minutes. Within 10 minutes, the submarine had sunk to a depth of 730 meters, where its pressure hull, designed for a depth of 400 meters, gave way under the pressure and collapsed.
The Thresher disaster generated widespread public outcry. The nuclear reactor, containing unused fuel elements, was found on the seabed. The US Navy conducted regular monitoring of the sunken submarine's reactor using both submersibles and surface vessels. Officially, everything was fine, and the reactor was sealed.
The second measure prompted by the disaster was the establishment of the SUBSAFE program. By the 60s, 14 American submarines had sunk in accidents. Most of the submarine losses were due to navigational issues, but the second most common cause was engineering errors and manufacturing defects. Recover didn't dwell on one sloppy solder joint, but decided to take steps to prevent similar incidents in the future, which involved a complete overhaul of the design and construction of nuclear submarines.
By June 1963 (the investigation into the Thresher's sinking was still ongoing!), the Submarine Safety Program (SUBSAFE) was developed, aimed at improving the strength of submarine hulls, the stability of their structures, and increasing survivability. As part of this program, all existing and under-construction submarine designs were reviewed and re-examined for design flaws and weaknesses. The program established new requirements for submarine design and construction.
The submarine "Squalus" also sank, but not quite...
The third lesson learned from the submarine's loss was the DSRV (deep-submergence rescue vehicle) program. Before the Thresher disaster, there were no specialized ships for rescuing distressed submarines, but on July 17, 1968, the Pigeon (ASR-21) was laid down—the lead ship of its class capable of operating deep-submergence rescue vehicles (DSRVs). She became the first catamaran ship commissioned into the U.S. Navy since 1812 (the year the USS Fulton was built).
The Pigeon could carry a pair of deep-sea submersibles (Mystic and Avalon) on deck, capable of diving to 1,5 kilometers, docking with a stricken submarine, and evacuating its crew to the surface. The ship also carried a McCann diving bell—a design developed back in 1928 and time-tested: it was used for the first time to rescue 33 sailors from the USS Squalus (or "Halibut" in Russian—submariners around the world have a short supply of imagination!), which sank off the coast of New Hampshire on May 23, 1939.
The disaster's impact on the American submarine force is a long one to list. Air dryers on high-pressure compressors, changes in pipeline soldering technology, the design and use of rescue equipment... Even submarine testing procedures were revised: before the Thresher's loss, all submarines were subjected to "explosive shock testing" during testing—real depth charges were detonated near the test submarine, just to see what would happen.
Deep-sea rescue vehicle "Mystic"
Initially, after the disaster, it was decided to build 12 deep-sea rescue vehicles. But after careful consideration, it was decided to limit the number to two: they can only rescue the crews of distressed submarines in the event of an accident at depths shallower than the submarine's maximum diving depth. And 77 percent of the world's oceans are considerably deeper. However, even the Mystic and Avalon submersibles, which were built after the disaster, were never used to rescue the American crew. After Thresher, the Americans took a much more careful approach to nuclear submarine design, and such large-scale disasters involving them simply never occurred again. True, in 2000, they were offered to Russia for the rescue of the Kursk nuclear submarine crew, but our leadership declined the offer (although it was possible to transfer the subs to the Northern Fleet—they can be transported by cargo planes).
This should be music from the 1997 movie "Titanic"
The sinking of the Thresher submarine also inspired the filming of James Cameron's 1997 movie Titanic. Here's what happened: Commander Robert Ballard, who discovered the wreckage of the Titanic, wasn't actually looking for it. More precisely, the search for Titanic became a cover for collecting visual data on the condition of the wrecks of the Thresher and Scorpion submarines. Ballard designed an underwater robot with which he hoped to find the famous liner, but the US Navy only provided funding on the condition that he explore the Thresher wreckage before searching for Titanic.
Submarine wreckage was found on the seabed, the largest of which measured one foot in length. Only after Ballard was assured that the radioactive threat from the sunken submarine reactors was negligible was he given the opportunity to find the Titanic, and the underwater footage obtained during this expedition inspired Cameron to make his classic film. Documents on the submarine's demise began to be declassified in 1998, but in 2012, a decision was made not to publish them. It was only in 2020 that military historian James Bryant sued the US Navy, and the court ordered the US Navy to begin publication in 2020. The phased publication began on September 23, 2020.
A flagpole with the flag flown at half-mast in honor of the crew of the USS Thresher in Kittery, Maine.
Today, there are six monuments to the Thresher submarine in the United States. A memorial chapel is located on the grounds of the Portsmouth Naval Shipyard; a stone with a memorial plaque is also located there, next to the Albacore Museum; a memorial to the Thresher and Scorpion submarines is located outside the main gates of the Seal Beach Naval Base in California; a stone in Eureka, next to the post office on Thresher Drive; a flagpole with a permanently lowered flag in Kittery, Maine; and a memorial at Arlington Cemetery. One can mock the American love of monuments, or one can learn from them. We, too, have lost submarines in peacetime, but we don't deserve so many monuments to their crews...
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