Lightweight contenders: torpedoes dive in to meet littoral challenge

Two decades is a long time in the world of underwater weapons. In the mid-1980s it was the Cold War requirement to acquire and prosecute fast, deep-diving nuclear-powered boats that was driving lightweight torpedo design and technology development.

Today, with that period of anti-submarine warfare (ASW) consigned to history, the lightweight torpedo is being honed to take on a quite different threat: the quiet, stopped or slow-moving conventional submarine operating in the shallow - and acoustically poor - waters of the littoral.

This sea change is spurring both upgrades and new developments to counter the challenge posed by reduced target echo strength submarines and sophisticated acoustic countermeasures, set amid the high clutter and reverberation encountered in shallow waters.

With a number of legacy weapons - notably the ubiquitous Mk 46 line - at the limit of their development spiral, the coming years will see a trio of new-generation NATO standard 324 mm lightweight torpedoes vying for orders in the international marketplace. Each has a Cold War heritage, and is claimed to afford superior performance against quiet targets and advanced countermeasures in the shallow-water ASW environments encountered in the littoral, as well as retaining the capability to prosecute blue-water threats.

The Franco-Italian Eurotorp GEIE - an economic interest grouping comprising Whitehead Alenia Sistemi Subacquei (WASS), DCNS and Thales - began production deliveries of the MU90 Impact lightweight torpedo in 2001, concluding a protracted engineering gestation dating back to 1991, when France and Italy merged their respective Murene and A290 torpedo development programmes. Eurotorp was established in 1993 by what was Whitehead (50 per cent), DCN (26 per cent) and Thomson Sintra Activites Sous-Marins (24 per cent).

Under work-share arrangements, French industry - through Thales Underwater Systems and DCNS St Tropez - has taken responsibility for the homing head, warhead and battery, with WASS taking the lead on guidance and propulsion. Development of tactical software has been shared by WASS and DCNS. In addition, WASS has developed the exercise head section, while DCNS is responsible for the practice delivery torpedo.

The consortium, which claims MU90 as the world's only third-generation lightweight torpedo, has received orders for more than 1,000 weapons to date. France and Italy placed a multiyear joint production order through the French D?l?gation G?n?rale pour l'Armement in December 1997.

Worth in excess of USD620 million, the combined procurement covers the delivery of about 300 warshot rounds to each country's navy. The German order was let in early 1998 to the UAW consortium an industrial framework bringing together Atlas Elektronik and Eurotorp. 415 of 4,941 words