As already discussed in detail by the document archived on this site under articles by the writer as “Acoustic Detections of the Loss of the (K-129),” the final event in a sequence of event that resulted in the disaster was the firing to fuel exhaustion of two R-21/D4 ballistic missiles still within their closed launch tubes in the sail.

Despite the precise agreement of the firing duration and firing interval of these missiles - derived from acoustic data - with known R-21/D4 system parameters, there are many (all?) within concerned circles in Russia who still maintain the K-129 was lost because of a collision with a US submarine. Their candidate of choice was/is the USS SWORDFISH (SSN 579). All that suspicion despite a photograph that appeared in a Japanese newspaper that showed the SWORDFISH pulling into a Japanese port on about 18 March 1968 with no damage other than a bent periscope sustained by contact with an ice flow in the Sea of Japan, more than 1000 miles from the position of the K-129 wreck.

On the subjective side, there are others reasons for dismissing involvement by SWORDFISH – or any other US platform - with the K-129. First, as pointed out by someone else, how likely is it that none of the 130 or so members of the SWORDFISH crew would have remained silent for 45 years had their ship sunk the K-129, and, be
assured, the long range acoustic data indicates any platform in the immediate vicinity equipped with a passive sonar would have known the K-129 had sunk.

(There also is the issue of who would have repaired the hypothesized damage to the SWORDFISH. How is it possible those shipyard personnel also have been silent for 45 years?)

Second and, I think, even more compelling, is the consideration that had a fatal (for the K-129) collision with a US submarine actually occurred, the last thing the US would have wanted to do would have been to attempt to recover the wreck and possibly expose evidence of a collision to the hundreds of personnel aboard the CIA salvage ship who would see that evidence: the exchange principle. (1) It would appear that imagery available on the K-129 before the salvage attempt was not of high enough quality or of sufficient coverage to establish no such evidence would be apparent upon close inspection of the wreck.

Bottom line: the K-129 was lost because three explosions contained within the pressure-hull allowed a dual launch training event to become the actual firing of two missiles within their closed but subsequently breached launch tubes.

The writer is reminded of the loss of the Russian SSGN KURSK in August 2000. The initial Russian response was collision with a US submarine when, in fact, the cause of the disaster - as later acknowledged by the Russians - was an onboard torpedo fuel fire that triggered explosion of the entire torpedo load, an event seismically detected 3100 statute miles away by an Alaskan sensor (with, as previously discussed, a three Hz bubble-pulse frequency).

End note:

(1) In forensic science, Locard's (exchange) principle holds that the perpetrator of a crime will bring something to the crime scene and leave with something from it.