The official Soviet Navy hypothesis is that
K-129, while operating in
snorkel mode, slipped below its operating depth. Such an event, combined with a mechanical failure or improper crew reaction, can cause flooding sufficient to sink the boat. This account, however, has not been accepted by many, and alternative theories have been advanced to explain the loss of
K-129: • A
hydrogen explosion in the batteries while charging • A collision with • A missile explosion caused by a leaking missile door seal • Intentional or unintentional scuttle by crew due to
K-129 violating normal operating procedures and/or departing from authorized operating areas Reportedly, as many as 40 of the complement of 98 were new to the submarine for this deployment.
Battery malfunction Lead-acid batteries release explosive hydrogen gas while charging. The hydrogen gas, if not properly vented, could have accumulated into an explosive concentration. John Craven, former chief scientist of the U.S. Navy's Special Projects Office and former head of the
DSSP and
DSRV programs, commented: I have never seen or heard of a submarine disaster that was not accompanied by the notion that the battery blew up and started it all. [...] Naive investigators, examining the damage in salvaged battery compartments, invariably blame the sinking on battery explosions until they learn that any fully charged battery suddenly exposed to seawater will explode. It is an inevitable effect of a sinking and almost never a cause.
Alleged Collision with USS Swordfish Standard practice during the
Cold War was for U.S. Navy attack submarines to trail Soviet missile submarines as they departed their home ports and moved into the North Pacific or the North Atlantic Oceans. The collision hypothesis is the unofficial opinion of many Soviet Navy officers, and is officially denied by the U.S. Navy. According to U.S. Navy sources, put into
Yokosuka, Japan, on 17 March 1968, shortly after the disappearance of
K-129, and received emergency repairs to a bent periscope, reportedly caused by ice impacted during surfacing while conducting classified operations in the
Sea of Japan. The seizure of by the
North Korean government occurred in the Sea of Japan on 23 January 1968, and the U.S. Navy response to this incident included the deployment and maintenance of naval assets in the area off the eastern North Korean coast for some time thereafter. In response to Russian efforts to ascertain whether
K-129 had been lost due to damage resulting from a collision with a U.S. submarine, an official U.S. statement by Ambassador
Malcolm Toon to a Russian delegation during a meeting in the Kremlin in August 1993 related: A news release in 2000 demonstrates that Russian suspicion and sensitivity concerning the collision possibility, and indeed their preference for such an explanation, remains active:
Explosion due to leaking missile hatch On 3 October 1986, the Soviet
Project 667A ballistic-missile submarine , while on combat patrol in the Atlantic, suffered the explosion of a liquid-fueled
R-27 missile in one of its 16 missile tubes. The cause of the explosion was a leaking missile tube hatch seal. The leak allowed sea water to come into contact with residue of the missile's propellants, which caused a spontaneous fire, resulting in an explosion first of the missile booster, then a subsequent explosion of the warhead detonator charge. In the case of the Project 667A, the missiles were located within the pressure hull, and the explosion did not cause damage sufficient to immediately sink the boat. It did, however, cause extensive radioactive contamination throughout, requiring the submarine to surface and the evacuation of the crew to the weather deck, and later to a rescue vessel, which had responded to the emergency. Subsequently,
K-219 sank into the
Hatteras Abyss with the loss of four crewmen, and rests at a depth around . The Soviet Navy later claimed that the leak was caused by a collision with . Some indicators suggest
K-129 suffered a similar explosion in 1968. First, the radioactive contamination by weapons-grade plutonium of both the recovered bow section and the six crewmen of
K-129 indicates the explosion of the warhead detonator charge of one of the missiles,
before the ship reached its
crush depth. The report that the forward section was crushed and that charring in the bow section indicated
dieseling from an implosion (or alternatively from a fire), would indicate that the explosion occurred while
K-129 was submerged and at depth. The report found in
''Blind Man's Bluff that the wreck revealed K-129
with a hole immediately abaft the conning tower would support the theory of an explosion of one of the three missiles in the sail (possibly missile number 3). Since K-129''s missiles were housed in the sail, much less structural mass (compared to the K-219) was available to contain such an explosion, and loss of depth control of the submarine would be instantaneous. A photograph taken by the cameras on the capture vehicle, though, as published in the White and Polmar book, shows extensive sail damage with two missile tubes obliterated, and the target for recovery was the forward 135-ft section of the sail. The wreck was in two major pieces on the ocean bottom.
Patrol deviation According to Craven,
K-129 crossed the
International Date Line at
40°N, which was much farther south of her expected patrol station: Craven does not explain why he eliminated the possibilities that
K-129 was proceeding to a newly assigned and officially approved patrol area, or using a new track to an established patrol area, nor why he concluded that
K-129 was acting in an abnormal or criminal manner for a Soviet strategic missile submarine. According to an internal intelligence memo directed to
Henry A. Kissinger in May 1974,
K-129 recovery site is within the 500 nm transit lane used by a Soviet
Yankee-class submarine on its initial deployment to the East Pacific. Craven also noted: Anatoliy Shtyrov (Анатолий Штыров), a former Soviet Pacific Fleet Deputy Chief of Staff for Intelligence, has said that
K-129 would normally patrol an area off the West Coast of the United States, but it was sent on an unscheduled combat patrol in the eastern Pacific only 1½ months after returning from its regularly scheduled patrol. Vladimir Evdasin, who from June 1960 to March 1961 served aboard
K-129, reported that
K-129 was sent on a secret mission in response to the substantial U.S. naval force build-up off the Korean coast after the
Pueblo incident.
K-129s mission was in support of North Korea, which was an ally of the Soviet Union, and directed against U.S. naval operations, Pacific bases, and U.S. maritime support lines to Southeast Asia. ==Alternative theories==