A Sub-Atlantic Comanche ROV is being used to search for unexploded chemical and conventional munitions near the Nord Stream pipeline route in what is thought to be the most extensive survey of a defined path through the Baltic Sea.

Using the most state-of-the-art equipment available, Swedish company Marin Mätteknik AB (MMT) have been engaged in carrying out a 4,000km survey along the proposed pipeline route to detect munitions dumped during and after World War II - including objects as small as 10cm.

MMT managing director Ola Oskarsson said: “Comanche 03 has been working above our expectations in this very important project. We have equipped it with a 7m wide gradiometer array and can still run effortlessly and accurately along lines on the seafloor.

“We have now run 2,534km and approximately 1,240 hours. Servicing to the Comanche ROV has been very minor. We initially planned for 72 hour maximum dive time between services but have now increased to 120 hour intervals because of its reliability.”

The electrically propelled work class Comanche ROV has been fitted with an Innovatum 'Smartsearch' sensor gradiometer array which allows it to detect and identify any ferrous metals on the seabed. Gradiometer data is processed within a digital terrain model to allow objects to be located for further visual inspection.

Terry Slater, managing director of Innovatum, said: “Smartsearch is an underwater survey system which provides rapid, highly detailed magnetic mapping of small ferrous objects, locating targets unseen by other systems. The low weight, size and power requirements of the Smartsearch system increase the versatility of modern electric vehicles and keep costs down. Installation of Smartsearch on the Sub-Atlantic Comanche showed very low levels of magnetic noise, allowing the full potential of the system to be realised.”

“This customer satisfaction emphasises the reliability of Sub-Atlantic equipment and demonstrates our commitment to ensure our products fulfil the requirements of our customers,” added John Ferguson, general manager of Aberdeen headquartered Sub-Atlantic.

On completion of the gradiometer survey, Comanche 03 will be upgraded with high definition television broadcast cameras and an archeological skid complete with a mini intervention ROV. The ROV will then be used for a TV production for a large TV company.

Further pipeline work in the Baltic, Skagerrak and North Atlantic is also planned for Comanche 03.

Comanche 03