Brits line up Type 45 for AWD

As the Royal Navy begins to address its major requirements for the decade British manufacturers are hoping that their solutions might form the basis of a new generation of surface combatants for the Royal Australian Navy.

Both navies require a new generation of Air Warfare Destroyer(AWD) and the long-awaited Daring class (Type 45) destroyer will be the successor to Britain's Type 42, entering service in November 2007. But it will be a very different vessel even from the latter's Batch 3 ships if only in its displacement of 7,200 tonnes compared with the 4,675 tonnes of the latter (or the 4,618 tonnes of Australia's Perth-class DDGs). The British are seeking a ship with 25-30 years of useful life and in meeting this objective they are willing to accept features which might seem radical.

Naturally, it will incorporate measures to reduce radar, infra-red and acoustic signatures but it will be the first in British service to be built to Lloyd's naval ship rules, which will mean higher accommodation standards as well as generous margins for future upgrading and maintainability.

The most radical element is the propulsion system, for this will be the first electrically-powered destroyer. The decision to adopt an integrated electrical propulsion system has been based upon experience gained by the US Navy at a long-established test site facility, but the Royal Navy's experience with the Duke Class Type 23 frigates may well have been an influence. These ships feature a hybrid CODLAG (Combined Operation Diesel Electric and Gas Turbine) system. The new system retains gas turbines but incorporates the advanced cycle Northrop Grumman/ Rolls Royce WR 21 with two per ship. These 21.5 MW intercooled and recuperated units recycle hot exhaust gases reducing the IR signature and providing more uniform fuel consumption at either high or low power. Similar systems will be offered to the US Navy to meet its DD-21 (21st Century Destroyer) propulsion/power requirements.

The 20 MW alternators for the WR 21s and the remainder of the power/propulsion system will be provided by ALSTHOM Power Conversion and will include two 20 MW advanced induction motors, the commercially-based pulse width modulated converter drive with three five-channel banks and the power system control. The system means there is no need for bulky gears to interface with drive shafts for they feed by electric cable direct to the propellers. But the electrical element itself is bulky, each induction motor weighs 90 tonnes, and requires considerable space amidships.

The other radical feature will be the BAE Systems Sampson multi-function radar, which was offered to the Royal Australian Navy for the now-abandoned Anzac WIP. Sampson is an active array radar but this is not unique, indeed the Signaal (now Thales Nederland) APAR was also offered for ANZAC WIP and apparently regarded as the leading contender for the multi-function radar.

Both radars are surveillance and weapon control sensors but where APAR is based upon four fixed arrays Sampson uses two rotating arrays which are claimed to combine a high data rate with more pulses striking the target to provide greater accuracy and better ECCM performance. The 4.6 tonne mast-head assembly is air cooled and each sensor face has some two thousand five hundred 2-20W gallium arsenide transceivers, each with four 10W channels, providing a peak power of 25kW per face. Sampson features electronic beam steering and its functions will include search, tracking, rapid track confirmation, target classification, midcourse missile guidance and terminal homing.

Like the new German and Dutch AAW frigates equipped with APAR the Type 45 will be fitted with the Thales Nederland SMART dedicated air search radar, although this will be modified by Alenia Marconi Systems to become the S1850M. The first three ships will not have an infra-red alerting system (formerly known as an infra-red search and track or IRST) but this may be added later. It will have a hull-mounted sonar and a towed torpedo detection sonar, with later batches having this integrated with a defence system based upon decoys. A passive electronic warfare suite will be installed, no decisions on this or the hull-mounted sonar being likely until the northern summer, but active defence will consist of the usual decoys and the Siren off-board jammer, a system similar to Nulka.

The main weapon system will be the PAAMS (Principal Anti-Air Missile System) which uses the Eurosam Aster 15/30 missile, regarded as the most advanced capability AAW weapon and the 48-cell DCN International Sylver launcher. However, the Type 45 was designed to accept the United Defense Mk 41 launcher system which is standard in the US Navy. The missiles will be supplemented by an improved version of the 4.5 inch (114mm) Mk 8 gun (later ships might have a 155mm system) and two light gun systems which have yet to be selected. Later ships will have some form of inner-layer defence system but financial restrictions prevent its installation in the first batch ships.

The command system will be based upon the BAE Systems Surface Ship Command System (SSCS) in service with the Duke Class as Outfit DN (1) and with the Republic of Korea's Okpo Class destroyers as KDCom 1 and selected for the KDX-2 destroyers as KDCom 2. The SSCS Ada-language software will include inputs from the Royal Navy's ADAWS (Action Data Automation Weapon Systems) used in both the Type 42 destroyers and Invincible Class aircraft carriers and there will be new flat-panel work stations linked by a Fast Ethernet standard triple redundant fibre-optic cable network.

In both time scale and capability the Type 45 must be of interest to the Royal Australian Navy. It offers a design whose technology is likely to carry it forward well into this century but it is also adaptable with all the basic elements - hull, propulsion/power, sensors, weapons and command system - adaptable to meet Australian requirements. GE for example is reportedly working on an advanced cycle system for its LM 2500 gas turbines used in the RAN's Anzac and Adelaide Class frigates.

Canberra will naturally be concerned that as much US Navy equipment such as the SM-2 Standard missile and the Evolved Sea Sparrow Missile (ESSM) is incorporated in Australia's future AAW destroyer, but BAE Systems is confident that the Type 45 could easily be adapted. The company offered the Sampson Integrated Weapon System with CEA Technologies' CEA-MOUNT illuminators to support both American missiles for the Anzac WIP, KDCom 2 will use the US-supplied WDS-14 weapon direction system with Standard, the Mk 41 launcher can be installed and the S1850M radar could be replaced by the Raytheon AN/SPS-49 for commonality with the Anzac and FFG fleets.

By Ted Hooton, London