Many of you may remember that in August 2000 the Russian Oscar-II (NATO reporting name, official designation is Project 949A Antey) class attack submarine K-141 Kursk (Атомная подводная лодка "Курск") suffered an explosion in the torpedo compartment, sinking the ship with the loss of all hands.

Many of you may also remember that at the time the Russians were very reluctant to accept international help, and by the time they did the estimated 24 people trapped alive in the hull had died. There have been a variety of speculations as to why the Russians were so reluctant to seek assistance, ranging from simple explainations such as national pride, to wild and bizzare conspiracy theories.

The exact cause of the explosion is also uncertain, again with simple explainations such as a torpedo misfiring, to more unlikely scenarios involving a collision with a Los-Angeles Class attack submarine, to the extreme consipracy theory suggesting that the American's deliberately sunk her with Mark 48 torpedo's.

The idea of a collision is not as far fetched as you might think, certainly it was not the first nor was it the last time a vessel was lost following a collision with an American submarine. In February 2001, the Los Angeles class attack submarine USS Greeneville (SSN-772) collided with the Japanese fishing trawler "Ehime Maru", sinking her with the loss of 9 crew. Later that year the very same ship ran aground off Saipan, and the following January the same ship again collided with the USS Ogden. Some other navigational blunders made by American submarines include the running aground of the USS San Francisco last year, and the grounding of the USS Hartford in 2003.

Im not going to engage in an in-depth discussion of the idea that teh Kursk was torpedoed by the US, suffice to say that the of US submarines mentioned in the article linked above, one of them is now a test platform for new technologies and has not been combat ready for over a decade, and the other was nowhere near the area at that time.

The idea that an experimental torpedo misfired and sunk the ship is probably the most interesting, there has been a variety of sources suggesting that the Kursk was testing the Russian VA-111 Shkval super-cavitation rocket torpedo. The torpedo is capable of speeds of at least 360km/h, around 7 times faster than the standard NATO Mark 48 torpedo.

The basic principle behind the supercavitating design is that when an object with a suitably shaped nose is traveling underwater and exceeds approximatley 100 miles/hour it begins to deflect the water so powerfully that it flies outward forming a pocket, if the speed is high enough this pocket will extend over the entire body of the object, meaning that the only part of the object in contact with water is the tip of the nose. This substantially reduces friction, the main inhibiting factor in underwater travel.

It is not known for certain whether the origonal VA-111 can actually steer once it has fired, the design reportedly could not but there have been suggestions that newer versions can, it seems that it was initially meant as an evase weapon, forcing the enemy sub to cut the wires on their torpedo and run, giving the Russian submarine a chance to escape

At present only Russian and China are known to definatley have supercavitating torpedoes, (the Chinese purchased them from the Russians), as usual though, Iran can't be left behind and claims to have developed and tested its own design in house, never mind that its performance specifications match that of the Shkval precisley.

Western countries are not far behind though, with Germany currently developing the "Barracuda", which is guided and has been offically stated as being capable of 360Km/h,  but has been rumoured to travel at up to 800km/h. It looks like the Russians have been them to the punch again though, with the Shkval-II already deployed and rumoured of being cable of at least 720km/h whilst also being guided.

Certainly it seems that supercavitation is set to change the face naval warfare in the near future.