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Pollution from ships vs cars

In a recent article (E&T Feb - Hybrid Ships - https://eandt.theiet.org/content/articles/2019/01/hybrid-ships-take-to-the-high-seas/) it is stated that "According to figures originally published in the Guardian in 2009, one giant container ship can emit almost the same amount of cancer- and asthma-causing chemicals as 50 million cars, and around 50,000 premature deaths in Europe have been attributed to international shipping".  This seems a bit much to me, since there are only about 30 million cars in the whole of the UK. Can one container ship with say two diesel engines of 40,000 hp each produce the equivalent pollutants of the exhausts of 50 million cars with a combined engine power of perhaps around 2.5 billion hp? (Note that I am ignoring issues such as the 15,000-20,000 lorries kept off the road). As this information was originally published in the Guardian, does anyone know how the journalists gather and, more importantly, validate their statements?

Alasdair
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  • Former Community Member
    0 Former Community Member
    Greetings from Southampton, a container port,  “the home of ocean cruising”, a city with an air pollution problem.

    I suspect the stats are to do with the fuel chemistry just as much as the raw arithmetic.

    Outside of territorial waters, ships can burn bunker fuel, it’s cheap and keeps the share holders happy.  I guess there is probably more to the exhaust than Co2, Nox and sulphur.
    At the last economic downturn, the conveyor belt of ships from China slowed down a couple of knots in order to keep the shipping capacity fully loaded. The reduced speed also saved about £250k per trip in fuel costs. Even cheap fuel is expensive.

    In uk regulated waters and when docked, ships must use “high quality” low sulphur fuel.  I’m guessing it’s probably not as clean as car diesel, i dont know ?

    “When docked” is part of the UK problem. Elsewhere, ships can plug into the quayside for eco power. In the UK they can’t and have to keep their engines running to generate the power.
    Probably not so bad for the container vessels, with a skeleton crew and all the hard work being done by the container terminal cranes but for the cruise ships, it’s a different story.
    The cruise ships generate enough power for a small town to provide facilities for passengers & crew [= 8000 people], kitchens, swimming pools, theatres etc......
    For perspective, here is the latest arrival...
    https://www.theguardian.com/travel/gallery/2016/may/17/harmony-of-the-seas-cruise-ship-southampton-in-pictures

    https://en.wikipedia.org/wiki/Harmony_of_the_Seas

    check out the flume tube !



     
    Installed power:



    • 2 × 19,200 kW (25,700 hp) Wärtsilä 16V46F[2]


    Propulsion:




    • 4 × 5.5 MW (7,400 hp) Wärtsilä CT3500

    •       bow thrusters[2]





Reply
  • Former Community Member
    0 Former Community Member
    Greetings from Southampton, a container port,  “the home of ocean cruising”, a city with an air pollution problem.

    I suspect the stats are to do with the fuel chemistry just as much as the raw arithmetic.

    Outside of territorial waters, ships can burn bunker fuel, it’s cheap and keeps the share holders happy.  I guess there is probably more to the exhaust than Co2, Nox and sulphur.
    At the last economic downturn, the conveyor belt of ships from China slowed down a couple of knots in order to keep the shipping capacity fully loaded. The reduced speed also saved about £250k per trip in fuel costs. Even cheap fuel is expensive.

    In uk regulated waters and when docked, ships must use “high quality” low sulphur fuel.  I’m guessing it’s probably not as clean as car diesel, i dont know ?

    “When docked” is part of the UK problem. Elsewhere, ships can plug into the quayside for eco power. In the UK they can’t and have to keep their engines running to generate the power.
    Probably not so bad for the container vessels, with a skeleton crew and all the hard work being done by the container terminal cranes but for the cruise ships, it’s a different story.
    The cruise ships generate enough power for a small town to provide facilities for passengers & crew [= 8000 people], kitchens, swimming pools, theatres etc......
    For perspective, here is the latest arrival...
    https://www.theguardian.com/travel/gallery/2016/may/17/harmony-of-the-seas-cruise-ship-southampton-in-pictures

    https://en.wikipedia.org/wiki/Harmony_of_the_Seas

    check out the flume tube !



     
    Installed power:



    • 2 × 19,200 kW (25,700 hp) Wärtsilä 16V46F[2]


    Propulsion:




    • 4 × 5.5 MW (7,400 hp) Wärtsilä CT3500

    •       bow thrusters[2]





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