An intriguing new explanation for the loss of the Russian submarine Kursk has come to light. In the aftermath of the loss, the Russians explained that she had played the attacking unit in an exercise in which the large cruiser Pyotr Velikiy played a defending role. The submarine was about to fire a torpedo when she suffered the first of two explosions, equivalent to about 100 kg of TNT. A retired Russian admiral recently claimed that this was at just the time the cruiser was scheduled to fire a surface-to-surface missile (SS-N-19). He said that at such times radio silence is strictly observed. Unfortunately, it was at just this time that the submarine asked for permission to launch a torpedo as her part of the exercise (she was an hour later than she should have been). In the admiral's view, in some way the submarine's radio transmission caused the missile to lock onto her radio antenna. In his account, the missile seeking the submarine's radio antenna fell into the water and, though unarmed, damaged the submarine (which was at periscope depth) badly enough to flood her fore end. In trouble, the submarine commander tried to power his way to the surface. The admiral claimed that the weight of water in the fore end more than balanced out the effects of the submarine's planes, so that she dove into the bottom. When she struck, the shock caused the fatal mass detonation of her torpedoes' warheads.
This account is suggestive but somewhat implausible. It seems very unlikely that a short radio transmission from the Kursk could have captured a long-range surface-to-surface missile or, indeed, that strict radio silence would be observed during the test of such a weapon. Presumably there would have been considerable telemetry. The submarine might have been observing radio silence simply to avoid confusing attempts to monitor the exercise. It also seems unlikely that the SS-N-19 missile, which is designed to fly only through the air, would have survived crashing into the water at high supersonic speed, or that whatever remained after the crash could fatally damage a submarine.
The account does suggest something much more interesting. The Pyotr Velikiy is armed with a medium-range antisubmarine missile, Vodopod (NATO SS-N-15), similar to the old U.S. Subroc. It carries a short-range torpedo (APR-2E), which it releases into the water near the presumed target position (there is also a nuclear-tipped version, which corresponds more closely to Subroc). Presumably no such weapon was to have been fired during the exercise; instead, a notional firing was intended. Thus the ship's Vodopods all would have retained their warshot torpedoes. The cruiser seems to have been command ship for the exercise. It is easy to imagine a command space full of senior officers, unfamiliar with the details of the ship's combat system. One of them easily might push the wrong button when participating in the exercise—with fatal results. After all, a notional exercise turned into tragedy in much this way in 1992 when the U.S. carrier Saratoga (CV-60) inadvertently fired a Sea Sparrow at the Turkish destroyer Muavenet during a NATO exercise, destroying her bridge and killing several men.
One of the puzzles of the Kursk story is the 100 kg (TNT equivalent) explosion which seems to have initiated the ship's loss. Nothing on board quite corresponds to that amount of explosive. It is possible to envisage a "hot run," in which a torpedo in a tube starts up spontaneously, causes a fire in its battery, and then cooks off the warhead—but full-diameter Russian torpedoes have considerably larger warheads. There are smaller-diameter torpedoes atop antisubmarine missiles (submarines also carry Vodopods), but they would not start up until after the missiles fired. It has been suggested that a Vodopod somehow failed to leave a torpedo tube, and that the torpedo it carried made a circular run—but why would a submarine in an exercise fire a warshot weapon of any kind? There was talk about a new explosive torpedo ejector, but it would have had a much smaller explosive content. Thus it is difficult to identify the source of the supposed internal explosion.
On the other hand, the torpedo carried by a Vodopod has just the right size warhead. It is easy to imagine the cruiser accidentally launching a Vodopod at a target she was tracking with her big bow sonar. Presumably the cruiser's antisubmarine system automatically sets up an attack on any submarine her bow sonar detects and tracks. There would be no way of aborting the shot. If the submarine commander knew he was under inadvertent attack, his natural reaction might well have been to accelerate in hopes of outrunning the missile's short-range weapon. He might also launch decoys—which might have been seen after the loss, and misinterpreted as foreign communications buoys (as the Russian press reported). When it hit, the lightweight torpedo would have torn through both outer and pressure hulls, causing substantial flooding.
The torpedo hit would probably have started a fire in the submarine's torpedo room. Some of the Russian accounts of the disaster stressed that the submarine had a new type of torpedo on board which uses internal combustion instead of expensive silver-zinc batteries (two torpedo propulsion engineers died in the sinking). In recent years, the Russians have stated that they are adopting a U.S.-style monopropellant. Monopropellant means that one chemical contains both oxidant and fuel. Dousing it with water cannot put out a propellant fire, because there is no oxidant to exclude. At least in the U.S. case, monopropellant tends to float on water. One might imagine, then, that the torpedo hit burst at least one of the torpedoes stowed in the Kursk's torpedo room. Fuel from the torpedo would have floated on the water pouring into the torpedo room. Hot fragments from the torpedo hit would have ignited the fuel. As the submarine dove, the blazing fuel would have rushed forward, atop the free surface of the water pouring in, to engulf other torpedoes stowed forward. It would hardly be inconceivable that two minutes of this treatment would have set off the remaining torpedo warheads in a mass detonation—which was the larger of the two explosions heard by NATO ships and seismic stations. This sequence of events seems more convincing than the earlier explanation that simply hitting the bottom caused a mass detonation. Although Russian torpedoes may well be less shockproof than their Western counterparts, the shock of a submarine hitting the bottom at relatively low speed would be less than that of a torpedo hitting a ship. Moreover, the Russians surely have tried to protect their torpedoes against countermining by nearby explosions. Indeed, if they were so easy to shock-detonate, one would imagine that the torpedoes would have gone off because of that initial explosion.
To make matters more interesting, an anonymous Russian officer who claimed he was aboard the Pyotr Velikiy reported that he saw a Vodopod launched and that he saw an underwater explosion soon afterwards. It has been reported widely that the Northern Fleet commander left the cruiser about 15 minutes after the Kursk sank, although in theory he did not know that at the time. If the Vodopod theory is correct, he certainly did know, and presumably he wanted to distance himself from a terrifying human error.
The Vodopod theory would explain the severe external damage, on one side of the Kursk, which some Russians have described. The explanations advanced to date would then be seen as a pair of related attempts to avoid an extremely unpalatable truth. The collision theory had the advantage of appearing to explain the external damage to the Kursk. It is clearly for internal Russian consumption, and it plays to long-standing suspicion of foreigners. Accounts of the supposed collision generally link it to claims that many of the Cold War Soviet submarine casualties, such as the "Golf' and "Yankee"-class missile submarines resulted from collisions with trailing U.S. submarines, which supposedly suffered heavy damage in the process (the absence of proof seems not to be a major drawback).
Some of the Russian news media already have reported that no one within the navy (except perhaps some senior officers) believes in the foreign collision. It does seem remarkable that there has been no announcement of a major new torpedo safety program, which might be imagined as a prerequisite for sending men back to sea after a fatal torpedo accident. Nor has there been any attempt to convince possible foreign customers that Russian torpedoes are still safe.
Recently Boris Spassky, who heads the Rubin Design Bureau which designed the Kursk, has announced that he knows what sank her—but that he is not talking. He certainly has a strong interest in maintaining the integrity of his designs because his bureau was also responsible for the Kilo class which Russia exports. Spassky's rather odd statement might also be read as an indication that he knows the rather unpalatable truth, and thus that it would be wise to keep his bureau well funded.
If the Vodopod theory is correct, it has interesting implications for Western navies. During the Cold War, there was considerable debate as to the value of lightweight torpedoes in the face of huge Soviet submarines like the Kursk. How could they possibly make much of an impression? It was argued that Western navies might have to rely on nuclear depth bombs—with very serious implications for larger strategic policies. Given the Vodopod theory, it seems that a relatively small torpedo could indeed have been quite effective, particularly if it struck toward the fore end of the submarine, causing a down angle. In that case, the momentum of a huge submarine would make recovery extremely difficult. The submarine's broad hull would act as a gigantic plane, pointed down, adding to the difficulty of recovery. Overall, the Kursk incident suggests that Soviet attempts to make large submarines survivable by providing them with double hulls were largely futile. Western navies, which preferred single hulls and accepted a considerable degree of physical vulnerability, seem to have made the right choice.