Crushed 6.2 miles underwater: Robo-sub lost at crazy depths

Chris Davies - May 12, 2014
Crushed 6.2 miles underwater: Robo-sub lost at crazy depths

A moment of silence for a fallen explorer: one of the few submarines capable of exploring depths greater than six miles has been destroyed in action, with the unmanned Nereus sub believed to have imploded under the vast pressures of the Kermadec Trench. Neureus, built by the Deep Submergence Lab at the Woods Hole Oceanographic Institution (WHOI), had already navigated the deepest point in the ocean, Challenger Deep in the Mariana Trench, spending ten hours at depths as great as 35,768 feet.

The dive this weekend – day thirty into a forty day mission – should have been less intensive, with the WHOI declaring that the submarine had been lost at just short of 33k feet.


Researchers have blamed the astonishing pressures that deep underwater for the damage, with the submarine squeezed by as much as 16,000 pounds per square inch. The team on the Thomas G. Thompson research vessel first lost contact with Nereus on Saturday afternoon, then later observed debris floating to the surface.

That wreckage was collected, and will be analyzed in the hope of figuring out exactly what happened. Nereus was capable both of being remotely operated, using a slender 25-mile-long fiber-optic tether to the surface, or set loose on its own, autonomously swimming around the depths.


Construction of the submarine was completed in 2008, packed with around 2,000 li-ion batteries and constructed with a hull made up of ceramic spheres each intended to withstand incredible pressure. A hydraulic arm could be used to collect samples, and the top speed was 3 knots (3.45mph).

Nereus will now miss its second visit to the Mariana Trench, which had been scheduled for November 2014. The team had hoped to recover even more animal specimens as well as sediment samples.

SOURCE Woods Hole Oceanographic Institution

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