Killer ships

Discussion in 'Boat Design' started by JonathanCole, Apr 24, 2009.

  1. JonathanCole
    Joined: May 2005
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    Location: Hawaii

    JonathanCole imagineer

  2. Fanie
    Joined: Oct 2007
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    Location: Colonial "Sick Africa"

    Fanie Fanie

    He he... maybe switch back to slaves and the rowers....

    Time for more neuclear props.
  3. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    the Guardian has never been known for incisive reporting....

    True, when cracking low sulphur fuels, the sulphur gets left in the heavy residuals which LSD's burn offshore. Also, to prevent fouling, they run a little hot so that also forces up the NOx's. But, when some governments (lets call them the EU nanny states) dictated Low Sulphur shoreside fuels (50 ppm), they also allowed shipboard fuels to go up to 1.5% sulphur (15000 ppm) in certian areas with maximum sulphur for bunker is 4.5% (45000 ppm) (see MARPOL Annex VI).

    But something doesn't add up. So using the data from the referenced article, 750M cars that go 100 km/hr for 15,000 km/yr on 100 kw delivered, then cars generate a low balled number of 23x10^6 units of SOx. 15 ships at 100,000 kw underway 280 days a year generate a high-balled 19x10^6 units of SOx. Also, SFC of LSD is lower than automotive engines by about 10%, so I see the number overstated by 20% or more depending on the owners choice of bunkering.
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  4. Guillermo
    Joined: Mar 2005
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    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    Putting things in perspective:

    5.2-7.8 SOx megatonnes/year from ships in 1996

    Total anthropogenic Sulphurs emissions: 79 megatonnes/year [Bates et al., 1992; Spiro et al., 1992; Andreae, 1990].

    Annually, international shipping utilizes only between 2% and 4% of the world’s fossil fuels. It accounts for around 5% of the global sulfur emissions from human activity [Corbett and Koehler, 2003; Corbett and Koehler, 2004].

    And also:
    "The global annual average net cloud forcings due to shipping (year 2012) are in the range of −0.27 to −0.58 W/m2 with regional cooling occurring most over the remote oceans."

    From: "Assessment of Near-Future Policy Instruments for Oceangoing Shipping: Impact on Atmospheric Aerosol Burdens and the Earth’s Radiation Budget" Axel Lauer, Veronika Eyring, James J. Corbett, Chengfeng Wang and James J. Winebrake . Environ. Sci. Technol., 2009, 43 (15), pp 5592–5598

    3 people like this.
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