VT unveils next generation Trimaran design

19 September 2001

Vosper Thornycroft has taken its family of trimaran warship designs into the next generation with the unveiling of a 116 metre corvette tailored to the export market.

The new design updates the original VT trimaran corvette developed in 1995 and incorporates VTs unique experience in building the RV Triton Trimaran Warship Demonstrator for the UK Defence Evaluation and Research Agency (DERA).

This experience has made VT a world leader in trimaran warship technology and the knowledge has been harnessed in the Cerberus design, which is unveiled for the first time at the DSEI exhibition to be held in Greenwich.

Jon Beadon, VT Export Ship Sales Director, explains: Preliminary results from the trials programme currently being undertaken by RV Triton have supported the initial theory of the advantages of a trimaran hull over a monohull. We remain firmly convinced that trimaran hulls will play a significant role in the design of future warships and Project Cerberus places the latest platform technology within this exciting hull form.

In addition, VT has incorporated some of the advanced features of its Sea Wraith stealth vessel in the new trimaran design, particularly elements that promote a reduced radar cross section. VT has combined these advances with notable trimaran benefits that include savings in propulsion power, improved capability for helicopter operations and better seakeeping. Another innovative approach in warship design is the use of the latest podded propulsion technology.

The result is a fast, stealthy corvette with the capability of a larger destroyer or frigate. The ship is designed to operate in littoral waters and the advantages presented by the trimaran hull form extend further its operating potential, adds Mr Beadon.

The Cerberus design is characterised by a long and slender main hull that produces improved seakeeping and this is augmented by a high bow freeboard complimented by a VT fine form ram bow. The cross deck structure begins some 40 per cent of the ships length aft of the bow and the clearance of its underside from the waterline (sometimes called wet deck clearance) conforms with results obtained from model tests and the full scale RV Triton trials.

The principal structure is of steel whilst composite materials are to be used for the superstructure, masts and the underwater bodies of the side hulls. The latter are constructed in easily replaceable sections to eliminate corrosion and facilitate repair in the event of damage. The sections are also made impermeable to minimise any resulting loss of buoyancy.

Careful shaping of the hulls and reduced clutter of topsides fittings ensures a low RCS. Advances in integrated mast technology have enabled Cerberus to contain radio communications antennae within the main mast or embedded in the structure.

Infra-red sources are reduced by cooling main engine exhausts and directing them to atmosphere under the cross deck between the hulls, while the side hulls also help to mask IR produced by the main engines and generators.

An innovative approach to propulsion has been adopted with the use of Rolls Royce Azipull podded propulsors. These compact units permit the transmission of the required power without excessively long shafting and four units are installed two aft and two amidships each driven by a medium speed diesel engine. Wide separation of propulsion plants significantly increases the vessels survivability in the event of damage to one engine room.

Cerberus is designed to deal with sub-surface, surface and air threats to both itself and vessels in convoy. The helicopter plays a key role in this capability with typical types able to operate from the ship including NH-90 and SH-60 Seahawk. Provision is also included for the operation of UAVs.

The trimaran configuration permits the installation of the latest multi-function radars such as the Empar without comprising stability or performance. This means that Cerberus can exploit the capabilities of the Aster or Evolved Sea Sparrow families of missiles for more effective air defence. Cerberus is designed for the installation of the Mk. 41 Vertical Launch System, which extends the potential mix of weapons to include anti-submarine and anti-ship missiles. An inner layer defence, provided by a mixture of systems including CIWS, a medium calibre gun and two 30mm gun mountings enhances survivability against air and surface attack.

In addition to the helicopter, the anti-submarine warfare equipment fit includes a low frequency towed array sonar and anti-submarine torpedo tubes. Cerebus also carries a comprehensive electronic warfare outfit, including electronic surveillance measures and both active and passive countermeasures.

Trimarans are swiftly gaining credibility as a hull form for the next generation of warships. VT is using its unrivalled trimaran experience to take this theory one step further with a viable design that provides navies with a new alternative for their front-line vessels, adds Mr Beadon.

From: Phil Rood Public Relations Vosper Thornycroft Tel: 023 8042 6000 Fax: 023 8042 6020 E-mail: phil.rood@vosperthornycroft.com