India Rolls Out New Underwater Technology
Union Minister for Science & Technology and Earth Sciences, Shri Kapil Sibal, unveiled devices for underwater sea exploration developed by the Indian Ministry of Earth Sciences, which include: an underwater crawler, an in-situ soil property measurement system and a remotely operated vehicle (ROV). Addressing a press conference in New Delhi, Shri Sibal pointed out that it has put India in the coveted list of other developed countries in the area of deepsea technology.
Development of deepsea technology is a frontier technology area for harnessing non-living resources lying on the seabed. One of the important non-living resources to be harnessed are the potato shaped nodules called Polymetallic Nodules which are available at depths greater than 4000m in the deep sea. These nodules contain Manganese (27-30%), Copper (1-2%), Nickel (1-2%) and Cobalt (0.2-0.3%), apart from traces of other minerals. Copper and Nickel are strategically important elements, as these are not available from terrestrial resources in the Indian sub-continent and hence it is essential that India develop technology to mine these nodules from the deep sea. Deepsea mining is a technologically challenging field as the depth of water and weather conditions are major constraints. The mining system has to collect nodules efficiently from the very soft sea bed. The nodules have to be lifted up to the ship from a depth of 5000m., discharge tailings from the ship with minimum environmental disturbance and then the ship has to have extensive onboard handling facilities.
Ministry of Earth Sciences which includes the Ministry of Ocean Development, through its technical arm – National Institute of Ocean Technology (NIOT), has successfully developed a world class remotely operated vehicle, a deep sea mining machine and a deep sea in-situ soil testing machine which work in extreme conditions. It is comprised of a crawler based machine which can travel on the sea floor, collect nodules to make slurry and pump the material to the sea surface.
The underwater crawler has a manipulator, cutter, slurry pump, instrumentation and control system and has been successfully tested at a depth of 451m. It is an underwater robotic vehicle weighing about 12 tons in air, hydraulically operated. As the seabed is extremely soft at greater depths, it is essential that the seabed property is measured in-situ first to provide undisturbed ground truth. NIOT developed a soil testing machine to measure the soil property in-situ at a depth of 6000m. The instrument is launched using a special underwater cable which carries the weight of the instrument, transmits power and data. Successful trials have been completed at a depth of 5200m in November 2006. A special Remotely Operated Vehicle (ROV) is electrically operated and is equipped with two manipulators and can carry 150kg payload for mounting scientific and mission oriented tools. The ROV is equipped with seven thrusters for maneuvering in manual and automatic mode. In order to navigate and position the ROV accurately with respect to a target, it has a networked hydro acoustic navigation system, Doppler velocity log and photonic inertial navigation system. To measure the underwater environment and seabed at long distance, an imaging sensor is used along with high resolution video cameras for visualization during underwater operations. This equipment has been successfully tested at a depth of 205m in October 2006.
