New coastal submarine concepts get ready to break the surface

The modern non-nuclear submarine is acknowledged to be a highly potent sea denial and intelligence gathering asset and, in the right hands, a very challenging adversary for even the best-equipped anti-submarine warfare (ASW) forces.

Even 26 years on, the UK Royal Navy's (RN's) experience in the 1982 Falklands (Malvinas) conflict serves as a salutary reminder of how difficult a prey the conventional submarine can be. Although it deployed a large taskforce equipped with a full range of ASW capabilities, it failed to detect the San Luis, the single Argentine Type 209 conventional submarine deployed in theatre. It is believed that only a faulty fire-control system prevented the submarine from executing a successful attack on an RN frigate operating close inshore.

The US Office of Naval Intelligence points out: "Operating near busy shipping channels or maritime chokepoints, submarines can covertly lay minefields or attack and disrupt commercial shipping. In this way, even a nation having a few relatively unsophisticated submarines can conduct sea denial and exert regional influence.

"Fitted with improved quieting sensors, weapons and propulsion systems readily available in today's market, submarines can operate undetected near a regional adversary's coast, covertly conduct surveillance, engage enemy naval forces and expand their nation's regional impact still further."

Covertness brings another attribute. Operating unseen and unannounced, the submarine can be forward deployed without undue provocation, thereby avoiding crisis escalation or political embarrassment. It can also be employed to support the insertion and extraction of special forces in clandestine missions.

And so for many smaller nations, the conventional submarine remains a prized asset because of the disproportionate impact it can have on military operations in the maritime domain, both above and below the waterline. Its major selling point is as a uniquely cost-effective means of sea denial against far more powerful potential adversaries.

Over the last two decades, the conventional submarine market has been dominated by sales of boats in the 1,400-1,800-ton bracket, typified by German shipbuilder HDW's best-selling Type 209, the successor Type 214 and the rival Scorpene jointly produced by French naval shipbuilding, systems and support group DCNS and Spanish shipbuilder Navantia. Highly capable, and now increasingly adopting air-independent propulsion (AIP) technology to extend submerged endurance and reduce the indiscretion ratio, they afford a powerful and cost-effective deterrent capability.

However, 'cost effective' does not mean cheap and it would be quite wrong to suggest that the acquisition of even a small number of diesel-electric submarines does not in itself constitute a significant capital investment. Furthermore, operating any submarine force in a safe and efficient manner demands the highest levels of design assurance, maintenance, operator and maintainer training and operational control.

As a result, some smaller navies with more limited financial and technical resources - while attracted to the attributes of the submarine - have, to date, shied away from their acquisition. Others, particularly in Latin America, are troubled by the projected costings for the replacement of existing diesel-electric submarines now approaching life expiry.

Acknowledging this fact, four of Europe's leading submarine design houses have now all sought to craft compact, highly automated 'entry-level' submarine concepts specifically engineered to reduce capital cost and support overhead and manning requirements. As well as appealing to navies looking to acquire a submarine capability for the first time, the rival contractors are also eyeing nations that may be looking to recapitalise their existing submarine arms.

Image: DCNS unveiled its double-hull SMX-23 design in 2006. (DCNS) 560 of 3,404 words