Coast guard

A new unmanned autonomous submarine has been developed to detect explosive mines hidden in shallow coastal waters such as ports and harbours.

BAE Systems introduced the 50kg vessel called Talisman L, which uses high-definition forward and sideways looking sonar and an array of multi-view cameras.

The mini-sub has the ability to zoom through water at a top speed of more than five knots and maintain the manoeuvrability to turn within its own length.

The vessel can operate at depths of 100m for up to 12 hours, but Andy Tonge, head of the underwater unmanned vehicles activity at BAE Systems, said the Talisman L’s real strong point is its capabilities in shallow water.

‘Shallow water presents a lot of very difficult challenges,’ he added. ‘While most people will ask how deep a system will operate at, we’re trying to go the other way and work out just how shallow we can make our systems work. We’re able to operate in the odd one or two metres of water.’

Tonge said those depths are found in ports or harbours near civilian areas that could be prime terrorist targets. He gave an example of a case three years ago when navy officials were alerted to a bomb found in the shallow water of the River Mersey in Liverpool.

The device, which turned out to be an old German bomb from World War II, was moved by navy divers to the Irish Sea where it was detonated.

‘Now that was a legacy weapon from World War II, but it could have been anything,’ Tonge said.

The Talisman L can operate autonomously, using pre-set mission parameters, but operators can assume manual control.

The vessel uses high-resolution sonar to examine suspected mines up close with a resolution that Tonge claimed is better than a centimetre.

‘Then it uses low-light cameras and image enhancement to augment the sonar images with visual data from the camera. That data is compared and correlated with the sonar images,’ he added. ‘So you’re trying to identify something by more than one method.’

If the Talisman L detects a mine, it will communicate the information to officials who then make the decision on how to deal with the threat. The likely method for detonating a mine, Tonge said, is a single-shot mine neutraliser, which is controlled by a military operator.

Talisman L shares common technology with BAE Systems’ range of Talisman autonomous unmanned vehicles. The Talisman L is designed so that it can dock onto the much larger mother ship, the Talisman M unmanned submarine, and become cargo if needed.

Tonge said the Talisman L is the most versatile Talisman vessel developed to date. ‘The technology has moved to keep pace with how threats change,’ he added.

Siobhan Wagner