India sends first remote-operated submersible to ocean bed

The Remotely Operable Vehicle (ROV), developed by the National Institute of Ocean Technology (NIOT) in association with Russia-based Experimental Design Bureau of Oceanological Engineering (EDBOE), will study polymetallic nodules, a rich source of iron and manganese hydroxides, at a water depth of nearly 6000 mts.

According to marine scientists, ROVs are becoming the primary tool for studying the bio-diversity of the deepest oceanic eco-systems and a key technology in Census research. They are linked to a surface support research vessel that controls their underwater activity and transports them to and from the research site.

The Indian ROV is operational at the Poly-Metallic Nodule (PMN) site that has been alloted to the country by the International Sea Bed Authority (ISBA) of United Nations.

"This is a huge feat for India. It means that we are one of the very few nations with this capability apart from United States, France, Japan, Russia and possibly China," NIOT director Atmanand told PTI.

The total resources estimated are of the order of 380 million metric tons and for this, remotely operable vehicles are the key for observations and exploration of mineral wealth, a study by the Chennai-based NIOT indicates.

Polymetallic nodules, also called manganese nodules, are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core.

Data such as temperature, sound velocity, conductivity, density and dissolved oxygen were also collected during the various trials, while numerous photographs were also taken.

"As of now, the ROV has been taking photographs and core samples from the designated area. It would be next made operational in the Krishna-Godavari (KG) basin where gas hydrates exist under the sea bed. However, it will be used in that region after a detailed survey," Atmanand said.

Project Director, Ramadass, said, "In last six months, we have been working on video picture quality enhancement and identifying suitable sensors to make it more useful."|

The ROV is stationed and launched from on-board one of India's key Ocean Research Vessel 'Sagar Nidhi 1', a state-of-the-art research vessel with dynamic positioning capabilities.

Incidentally, in India, the breakthrough in polymetallic nodule discovery was made in 1981 when scientists of the National Institute of Oceanography (NIO) hauled up the first samples from a depth of 4800 mts in the western Indian Ocean and also identified huge deposits in the Central Indian Ocean.

Buoyed by the success of the ROV being operationalised, India is going ahead to build a manned submersible to explore the oceans at 6,000 metres depth.

NIOT is also developing the technology for mining of manganese nodules. An underwater crawler was tested for operation at a depth of about 500m in the recent years and more tests are in the offing.