Cheonan sinking stirs new interest in coastal submarines

US think-tank Forecast International says last year's torpedoing and sinking of the South Korean corvette Cheonan by a North Korean coastal submarine will prompt a surge of interest in small, low-cost submarines. 

“The corvette was specifically designed for operations in littoral waters and built with full knowledge of the threat spectrum she would face. Yet, she was blown in half by a torpedo she never saw coming. The force multiplier effect was clearly evident here,” the organiation says in a report on the market for submarines. 

“The Cheonan was designed to provide an economical asset for patrolling coastal waters, but the submarine used to sink her cost an order of magnitude less – and that submarine got away with her attack cold,” said warships analyst Stuart Slade, author of the report. “It is quite clear which was the most cost-effective asset in this particular scenario.”

It is likely that the sinking of the Cheonan will cause a surge in the market for small, coastal submarines. These low-cost, quick-to-build and economical-to-operate submarines offer small navies with the means to threaten those who intrude upon their territorial waters. Until recently, the capabilities of such submarines were neglected as attention focused on their ocean-going sisters. With the destruction of the Cheonan, this is likely to change. The question is whether the shipbuilding companies will be able to exploit this altered perception. 

Western submarine builders have attempted to produce small coastal submarines but, with few exceptions, these have never enjoyed any significant success. Russian offerings of small derivatives of their Project 877 and 677 class diesel-electric boats have also met with scant success. The reason is that these boats have tried to package the capability of the larger submarines into a small hull. This is a technological challenge of daunting dimensions and, in solving it, the defining characteristic of the small coastal – its low cost – is lost.

“If the changed perception of the coastal submarine is to be exploited, the requirement is to build a low-cost submarine that makes no pretext of challenging its larger cousins in quality terms but instead requires a minimum investment in resources and personnel to operate,” said Slade. He added that such submarines would exploit a gap in the market but require existing Western submarine teams to break decades of acquired design habits. If they do not do so, Slade said, the coastal submarine market will go to Chinese and possibly Russian producers.