USS Scorpion

The USS Scorpion was an American nuclear-powered submarine which sank on 22 May 1968 with the loss of 99 lives. Many people consider that the sinking has not been fully explained. Between January and March that year, three other military submarines disappeared in suspicious or uncertain circumstances, belonging to the Soviet Union, France, and Israel. This is quite a coincidence, but probably no more than that; however the disappearances of some or all of the submarines have been linked by various conspiracy theories.

Disappearance
Scorpion (SSN-589) was a Skipjack-class attack submarine launched in 1959 and commissioned in 1960. It was designed for fast undersea travel and armed mainly with torpedoes, some of which may have carried nuclear warheads. It was one of the earliest submarines to be powered by the S5W nuclear reactor; this was subsequently a widely-used reactor model with few problems.

The submarine received a rapid overhaul in 1967 and, after training, set sail on 15 Feb 1968 for the Mediterranean Sea. On that mission there were a number of mechanical problems including leaks of freon gas from the refrigeration system, and an electrical fire, although these were not particularly unusual occurrences, and it departed from the Mediterranean on 16 May. There was a last attempted transmission early on 21 May. It was reported "presumed lost" on 5 June. Several search efforts followed, using various advanced techniques including Bayesian search theory, and part of the hull was found in October 1968 by a Naval oceanographic research ship 740 km southwest of the Azores, in 3000 metres of water.

Underwater surveys suggested the submarine's hull had been crushed as it sank far below operating depth, with few other signs of damage. A 1968 court of inquiry sat in secret, its conclusions only released in 1993; it suggested a torpedo malfunction caused an explosion, although it does not appear to have been entirely certain of that. A 1970 study by the Naval Ordnance Laboratory found no evidence of an explosion. There have been calls for another examination of the wreck.

The main theories today are that a torpedo either malfunctioned, was released, and destroyed the submarine from outside; or detonated in a torpedo tube following a fire in the submarine. Fires were a common occurrence due to the presence of large silver-zinc batteries used in the torpedoes. However the lack of evidence of a detonation raises questions about this theory. A malfunction in the trash compaction unit, which crushes and ejects waste underwater, was also suggested as a possible cause, though some experts have claimed this is very unlikely. There are similarities with the loss of the Thresher in 1963, which suffered a burst pipe during a deep dive, causing a reactor shutdown and rapid descent until it was crushed by water pressure. Formal naval officer Paul Boyne suggested the propellor shaft bearings could have failed during a deep dive, leading to sudden flooding and sinking. Hence there are several candidate theories involving mechanical faults, without clear evidence for any.

Other losses
The loss of the submarine was one of four superficially similar submarine disasters in 1968: the others being the Israeli INS Dakar, French Minerve, and Soviet K-129, all lost with no survivors.

Dakar (Israel)
Dakar was a former British diesel-electric boat (HMS Totem) sold to the Israeli Sea Corps, which sunk in January 1968 near Crete, en route from the UK to Israel, with 69 deaths. Weather at the time was stormy. The last communication was received early on 25 January, although a morse code transmission may have been picked up on 27 January. The Israeli navy considered three theories: technical problems or human error causing it to sink without any external agency; a Soviet attack; or collision with another vessel.

Because of Israel's somewhat hostile relationship with its neighbours, theories proliferated. Reportedly the Turkish government prevented Israel searching in Turkish waters. Egyptian media claimed it had been sunk by the Egyptian navy. There were wilder conspiracy theories holding that the submarine's crew were captured and held by the USSR or some middle eastern government, though the discovery of the wreckage in 1999 rendered that less likely.

On the discovery of the wreck, the most likely explanation was considered to be collision with a cargo ship. There is still no evidence of any foreign power's involvement, despite the fall of regimes in eastern Europe and the Middle East.

Minerve (France)
Minerve (S647) was a small diesel powered French submarine of experimental design carrying torpedoes and missiles, with a crew of about 50. It was last heard from on 27 January 1968 near Toulon off the Mediterranean coast of France in very bad weather. The wreckage was only found in 2019, in deep water off Toulon.

K-129 (Soviet Union)
K-129 was a diesel-electric Soviet ballistic missile submarine which disappeared some time around March 1968 in the northern Pacific. It was secretly salvaged by the US government in 1974 with a cover story of suboceanic manganese mining, one of the more notorious tales of cold war secret missions. The US government still keeps very quiet about it, but it is believed they recovered a portion of the submarine and 6 radiation-contaminated corpses. The official Soviet explanation is a crew error or mechanical failure causing flooding of the sub, although a variety of other explanations have inevitably been offered, including a suggestion of a collision with American sub USS Swordfish, which was damaged around the same time (the Americans claim it hit an icepack).

Recovery of K-129 was the capstone of a long CIA effort to develop deep sea submarine recovery capabilities under the cover of Howard Hughes' "ocean mining" enterprise, Global Maritime Corporation (Glomar). The first vessel, the Glomar Challenger, was designed to locate and recover known Soviet submarine wrecks during the early 1960s. It was decided that a larger vessel was required for that task and in 1966 the Challenger project was handed off to the Scripps Oceanographic Institute in La Jolla, California, to be finished as a deep sea drilling research vessel. Challenger went on to a successful career as a research vessel for the starting in 1968, providing the core samples that were used to develop the theory of sea floor spreading at mid-ocean ridges, on which the modern plate tectonic theory of geology is based. So the Cold War wasn't all bad. It kick-started the project that taught us some really fundamental stuff about how the Earth works. Glomar's newer, bigger toy was the Glomar Explorer. After the recovery of K-129 it was decided that the intelligence benefit of recovering deep sea submarine wrecks wasn't worth the cost and Explorer was declared surplus property and offered to the research community. That generated some buzz in the research community about the possibility of reviving to drill into the upper layer of the Earth's mantle, but the prospective benefits of the project were deemed insufficient in light of its great costs. Ocean mining for manganese remained a topic of theoretical interest into the 1980s, but never really penciled in economically.

American-Soviet tit for tat?
There are allegations that the disappearances of the Scorpion and K-129 were linked in some way and the US and Soviet governments agreed to keep quiet about it. It is even claimed that the Scorpion was sunk in revenge for the sinking of the K-129, which the Soviets allegedly blamed on the US Navy (there is no evidence the US Navy was responsible). It's well known that submarines closely shadowed those of opposing navies, with the risk of accidental collision, and all kinds of brinkmanship went on at the bottom of the ocean, including the occasional nudge. It has been reported in books by Ed Offley and Kenneth Sewell that the Scorpion could have been sunk by a Soviet torpedo.

The Cold War wasn't as tense as during the Cuban Missile Crisis but it wasn't an era of detente. had came to power in 1964 and was slightly more repressive than Khrushchev, and the Vietnam War was in full swing, while the was widening, but it was also the era of the Prague Spring (which ended August 1968) and Soviet acceptance of "Goulash Communism" in Hungary, while the economy of the USSR was on an upswing. American naval secrets, including cryptography, had just been betrayed to the Russians by the spy which may have provided the means for a Soviet ambush, although that's largely speculative.

And maybe it sunk somewhere else entirely, on a secret spy mission, caused by the pressure wave from an underwater seaquake, and the wreckage was moved?

Alien submersibles?
Inevitably, the sinking of the Scorpion has also been blamed on Unidentified Submerged Objects, the submarine equivalent of UFOs. The Azores are reportedly a hotbed of USO activity, and the US Navy was reportedly under orders to investigate.

Coincidence?
The loss of 4 submarines in such a short space of time is highly unusual, but it's an intrinsically dangerous pastime combining weapons, flammable batteries, and complex propulsion systems, all crammed in a tiny space and underwater. It's especially worrying when you hear about all the things that happen routinely on submarines that don't result in disasters, such as the mechanical problems on the Scorpion in the months before its loss. The Dakar was also old, the Minerve experimental, and Soviet submarines not especially reliable.

Attempts to link the disappearances must take into account the wide geographical range and the different types of submarine: one of the four was nuclear-propelled while the others were diesel-electric; they were a mix of attack submarines designed to target other boats and missile submarines.

It's hard to tell what happened to a submarine that has been crushed by the ocean and lain underwater for years, and the submarine programs of major powers are even more shrouded in secrecy than other military operations. Plus, everyone on the submarines is dead. So whether it was mechanical problems, accidental collision, enemy action, or something else, we may never know.