Boat-cleaning robots for a greener ocean?

Tom Marcinko @ 24-08-2009

autonomousunBarnacles, oysters, algae, and other sea-life can slow a ship by 10% and increase fuel consumption by as much as 40%. The U.S. Office of Naval Research is testing a Roomba-like autonomous hull-cleaning robot to cut the drag.

The robot incorporates the use of a detector that utilizes modified fluorometer technology to enable the robot to detect the difference between the clean and unclean surfaces on the hull of a ship. Used to groom ships in port, the Hull BUG [Bio-inspired Underwater Grooming tool] removes the marine biofilm and other marine organisms before they get solidly attached. This is especially important because Navy ships spend more than 50 percent of their service life in port, giving barnacles and marine life ample time to become settled and, if allowed, to further colonize and grow on the ship’s hull.

Underscoring the benefits of combining the Hull BUG with newly developed environmentally benign antifouling hull coatings, [ONR Program Officer Steve] McElvany estimates that “the Navy will save millions of dollars per year in fuel. Using less fuel also means less carbon dioxide in the atmosphere.”

[Photo: U.S. Navy]


The perpetual aircraft carrier: turning seawater into jet fuel

Paul Raven @ 20-08-2009

aircraft carrierIf you’re getting twitchy about the uptick in petrol prices, spare a thought for the US Navy: fighter jets don’t just fuel themselves while parked on those aircraft carriers, y’know. But what if those same aircraft carriers could suck up seawater and catalyse it into aviation fuel?

Navy chemists have processed seawater into unsaturated short-chain hydrocarbons that with further refining could be made into kerosene-based jet fuel. But they will have to find a clean energy source to power the reactions if the end product is to be carbon neutral.

Nuclear-powered carrier? Sorted. So how does it work?

The process involves extracting carbon dioxide dissolved in the water and combining it with hydrogen – obtained by splitting water molecules using electricity – to make a hydrocarbon fuel.

[…]

In the conventional Fischer-Tropsch process, carbon monoxide and hydrogen are heated in the presence of a catalyst to initiate a complex chain of reactions that produce a mixture of methane, waxes and liquid fuel compounds.

Dorner and colleagues found that using the usual cobalt-based catalyst on seawater-derived CO2 produced almost entirely methane gas. Switching to an iron catalyst resulted in only 30 per cent methane being produced, with the remainder short-chain hydrocarbons that could be refined into jet fuel.

Heather Willauer, the navy chemist leading the project, says the efficiency needs to be much improved, perhaps by finding a different catalyst.

There you go – once those niggling little details are out of the way, you’ve got yourself an aircraft carrier that doesn’t need to pick up fuel for itself or its complement of aircraft, and hence doesn’t need to return to base for years (provided they can scrounge up food for the sailors and pilots in whatever theatre of operations they’re in at the time, natch).

But now imagine that it goes rogue… or someone manages to hijack it, Somali pirate style, only with no intention of ransoming it – why get rid of your own private strike-force-equipped floating nation-statelet, after all? [image by Serendigity]

Regular readers may note I’m becoming vaguely obsessed with the intersection of the oceans, geopolitics and sustainable technologies. I’m no Bruce Sterling, but I’m still confident in my assertion that plenty of weird stuff will be happening on the high seas in our not-so-distant future.


Blowing things up from far away

Jeremy Eades @ 03-12-2007

rail-guns-navy Everyone knows spaceships will have laser guns that go “pew, pew” and kill the fat guy in the x-wing.  But until then, we’ll have to make do with blowing the crap out of stuff at 220 miles with the most powerful rail gun ever.  The 32-megajoule Electric Laboratory Rail Gun (a name only a military bureaucrat could love) is four times more powerful than the previously-most-powerful rail gun, capable of accelerating steel slugs to Mach 7.

The scary thing is, this model is only half as powerful as the specifications given by the Navy – they want a 64 megajoule weapon.  BAE’s got a ways to go, the current model only lasts a few shots before blowing itself out of alignment.

(story and image via DailyTech)