Meet the Nadeshiko Maru, an electric-powered ... oil tanker?
The Nadeshiko Maru, a Super Eco-Ship, was launched in Sasebo, Nagasaki Prefecture today, Sept. 11. It uses two electric motors to drive the contra-rotating propulsion system, which supposedly improves efficiency and reduces CO2 emissions by 10 percent. What am I forgetting... oh, yeah; It's a 749-ton oil tanker. How ironic is that?Related:
[Source: Kyodo News]
Reader Comments (Page 1 of 1)
Tim 8:30PM (9/11/2007)
Hey, they have to buy the oil too. Anyway, if diesel-electric is economical for the cruise ships, and trains, and Volt...
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Galls 9:13PM (9/11/2007)
All large prop ships use electric motors, the diesel engine is only used to generate the power.
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rcousine 11:31AM (9/12/2007)
Well, this is neither universal nor unique. Lots of ships (and trains) use diesel-electric drivetrains, where the electric motors effectively act as a transmission for the always-running diesel motor.
That said, you would normally expect a tanker application like this one to have a direct-drive of some sort (engine coupled directly to prop shaft, maybe with a clutch or a reduction gear in the middle; the simplest designs do away with even the clutch or the reduction gear, and run in reverse by running the engine in reverse).
Interesting that they're claiming efficiency gains for this setup.
I found a good primer on marine propulsion systems. Note that cruise ships are mostly diesel-electric "hybrids," but there it gives them advantages like a quiet, compact drive (they often use turbines instead of piston engines), and the ability to use pod-thrusters, which help these dock-once-a-day ships be very maneuverable.
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rcousine 11:33AM (9/12/2007)
Aw crap. I screwed up my last comment. The primer on marine drivetrains is here:
http://www.dieselduck.net/machinery_page/propulsion_layout/propulsion_layout.htm
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