Ikara

## Ikara ASW Missile

An Ikara on display

The **Ikara** missile was an Australian ship-launched anti-submarine missile, named after an Australian Aboriginal word for "throwing stick". It launched an acoustic torpedo to a range of 10 nautical miles (19 km), allowing fast-reaction attacks against submarines at ranges that would otherwise require the launching ship to close for attack, placing itself at risk. By flying to a distant target, the engagement time was dramatically shorter than provided by short-range weapons, giving the target less time to respond.

### Design and Development

With the development of nuclear power, submarine performance, especially speed, improved dramatically, as did the threat they posed. Simultaneously, sonar detection capability at long range was also improving significantly, but only short-range weapons were available to surface escort warships. The final British development of the A/S mortar was the Limbo mortar, able to fire in all directions but limited to a maximum range of 914 metres (2,999 ft).

Known initially under the Rainbow Code name **Blue Duck**, the Ikara was a "rocket-thrown weapon" with similarities to the French Malafon. It differed from Malafon in that the torpedo was semi-recessed in the missile body rather than mounted in the nose. Ikara's range at 10 nautical miles (19 km) was double that of ASROC. Ikara was generally considered a superior system to ASROC as it was accurately guided during flight to ensure optimal targeting. A submarine would be aware from sonar contacts that it was about to be attacked and could engage in evasive changes of course. In ASROC's flight time to maximum range of 55 seconds, a submarine travelling at 25 knots (46 km/h) could move 700 metres (2,300 ft) from its position at launch, and a prediction would be made of the submarine's likely position at torpedo splashdown. But during the design of Ikara around 1960 the range of the acoustic seeker of the Mk.44 torpedo was limited to 457 metres (1,499 ft), and consequently its kill probability was low. The range of the acoustic seeker was later improved.

The Turana target drone was designed and built in Australia as a development of the Ikara anti-submarine weapon system. It was a target drone with remote control that was launched from the Ikara launcher for use in naval anti-aircraft target practice.

Ikara was powered by a two-stage in-line solid-fuel *Murawa* rocket engine developed by Bristol Aerojet Ltd in the UK and was guided by radio command link until it reached the vicinity of the submarine, determined by the ship's sonar contact, where it would first jettison the rear ventral fin and torpedo rear covering and then release its 12.7 inch Mark 44 or Mark 46 acoustically-guided anti-submarine torpedo. The torpedo payload would descend by parachute while the missile itself was programmed to splashdown some distance away to avoid interference with the acoustic torpedo's seeker head. The torpedo would then begin a circular search pattern to find and lock onto a submarine contact.

In 1982, work began on an improved version, the Super Ikara. This was to be turbojet-powered to give a maximum range of 100 km (54 nmi; 62 mi), and would be carried in, and launched from a container. While test launches were carried out in 1986, the project was abandoned due to a lack of interest from the UK.