7 ms·

1 ship producing the same pollution as 50 million cars? I find this very, very difficult to believe. Let's look at some numbers: The biggest ship engine in the

by SeanDav 11y ago

1 ship producing the same pollution as 50 million cars? I find this very, very difficult to believe. Let's look at some numbers: The biggest ship engine in the world has around 25,000 litres displacement, weighs 2,300,000 kg, produces 109,000 hp and has a fuel efficiency of 0.26 lbs/hp/hour. Using very conservative equivalent estimates for a car of 1 litre, 100 kg, 75 hp and 0.6 - 50 million cars would displace 50 million litres (2000 times more than ship engine), weigh around 2175 times as much, produce 34,000 times as much power and use 79,000 times as much fuel. Keeping in mind the ships engine is very fuel and thermal efficient, 1 ship producing equivalent pollution to 50 million cars just does not seem plausible, in the slightest.

hmate9 11y ago
It sounds a little hard to believe too, but I think it takes into consideration that most of the time cars are idle while big ships are utilized nearly 100%.
willvarfar 11y ago
They don't burn the 'clean' fuels that your car does. This is described in the article.
cperciva 11y ago
1. Ships have a much higher duty cycle than cars. 2. This measure of "pollution" is sulfur oxides, which are extremely low in automobiles since sulfur is almost completely removed from their fuel.
ranman 11y ago
^ agreed. They should show the math.
michaelwww 11y ago
The article addresses this in the paragraph containing the line "...these powerplants are some of the most fuel efficient units in the world. The real issue lies with the heavy fuel oil...lack of regulations applied to the giant exhaust stacks" Have you ever been stuck behind a car with a broken exhaust system? The amount of pollution coming out of such a car is surprising, and that's with relatively clean gasoline. "But, unlike power stations or cars, they can burn the cheapest, filthiest, high-sulphur fuel: the thick residues left behind in refineries after the lighter liquids have been taken. The stuff nobody on land is allowed to use." [http://www.dailymail.co.uk/sciencetech/article-1229857/How-16-ships-create-pollution-cars-world.html http://www.dailymail.co.uk/sciencetech/article-1229857/How-1...] I'm not saying you're wrong. 50 million does seem high, but there are other factors. A a former Navy nuke technician, I'm wondering why these ships aren't nuclear powered. I suppose it is the cost.
- wolfgke 11y ago
  > A a former Navy nuke technician, I'm wondering why these ships aren't nuclear powered. I suppose it is the cost. I rather assume the risk of terrorism.
  - michaelwww 11y ago
    Yes, that's probably it. Cargo ships could be a good use case for thorium reactors. http://blogs.discovermagazine.com/crux/2015/01/16/thorium-future-nuclear-energy http://blogs.discovermagazine.com/crux/2015/01/16/thorium-fu...
  - XorNot 11y ago
    This is not a serious risk. You could easily armor the reactor module to resist any amount of pirate weaponry, and rig it so when damaged it just drops to the bottom of the ocean intact. Getting into it isn't a threat either: terrorists aren't going to be plasma torching into a reactor and surviving long enough to do anything.
    - scrumper 11y ago
      Incomplete thinking. What about land-based fuel handling - creation, storage, transport, delivery? What about waste processing? The attack surface isn't just the ship.
      - wolfgke 11y ago
        Exactly what I meant.
  - deleted 11y ago
    [deleted]
- radiorental 11y ago
  "I'm wondering why these ships aren't nuclear powered." A combination of cost and environmental concerns; 'The ship that totally failed to change the world" http://www.bbc.com/news/magazine-28439159 http://www.bbc.com/news/magazine-28439159
tim333 11y ago
Reading the Guardian article the thing's based on, the 50 mil figure refers to 'sulphur oxide gases' which could be possible because modern car fuel is pretty low sulphur. The industrytap article is pretty misleading.
arbuge 11y ago
Perhaps you missed this part: "109,000-horsepower engines that endlessly spin away 24 hours a day, 280 days a year." Most cars, in comparison, are idle for over 95% of their lifetime. My car for example sits in a driveway or parking lot approximately 23 hours a day. Brings another factor of 20 into play. Now 1 ship only needs to produce pollution equivalent to 2.5m cars. (Claim in the article still seems dubious considering that an average car has a 100 - 200 hp engine these days).
drvortex 11y ago
They are probably comparing amount of pollution per km travelled, per tonne of vehicle. I agree, the article is so imprecise as to be completely worthless in terms of information content.
rco8786 11y ago
Also keep in mind that the ships are effectively in use and engines running 100% of the time. While car engines spend most of their lives turned off
seanhunter 11y ago
Ships' engines are amazing, but heavy fuel oil is really really gross stuff. It's basically all the bits of the barrel that are left after distillation. Ie what they've dug out of the ground but can't sell off for more money as aviation fuel, gasoline, diesel etc. Therefore it has really high sulphur content and very long/complex hydrocarbon chains that burn much less efficiently than gasoline or diesel.

by SeanDav 11y ago

hmate9 11y ago

It sounds a little hard to believe too, but I think it takes into consideration that most of the time cars are idle while big ships are utilized nearly 100%.

willvarfar 11y ago

They don't burn the 'clean' fuels that your car does. This is described in the article.

cperciva 11y ago

1. Ships have a much higher duty cycle than cars. 2. This measure of "pollution" is sulfur oxides, which are extremely low in automobiles since sulfur is almost completely removed from their fuel.

ranman 11y ago

^ agreed. They should show the math.

michaelwww 11y ago

The article addresses this in the paragraph containing the line "...these powerplants are some of the most fuel efficient units in the world. The real issue lies with the heavy fuel oil...lack of regulations applied to the giant exhaust stacks" Have you ever been stuck behind a car with a broken exhaust system? The amount of pollution coming out of such a car is surprising, and that's with relatively clean gasoline. "But, unlike power stations or cars, they can burn the cheapest, filthiest, high-sulphur fuel: the thick residues left behind in refineries after the lighter liquids have been taken. The stuff nobody on land is allowed to use." [http://www.dailymail.co.uk/sciencetech/article-1229857/How-16-ships-create-pollution-cars-world.html http://www.dailymail.co.uk/sciencetech/article-1229857/How-1...] I'm not saying you're wrong. 50 million does seem high, but there are other factors. A a former Navy nuke technician, I'm wondering why these ships aren't nuclear powered. I suppose it is the cost.

wolfgke 11y ago
> A a former Navy nuke technician, I'm wondering why these ships aren't nuclear powered. I suppose it is the cost. I rather assume the risk of terrorism.
- michaelwww 11y ago
  Yes, that's probably it. Cargo ships could be a good use case for thorium reactors. http://blogs.discovermagazine.com/crux/2015/01/16/thorium-future-nuclear-energy http://blogs.discovermagazine.com/crux/2015/01/16/thorium-fu...
- XorNot 11y ago
  This is not a serious risk. You could easily armor the reactor module to resist any amount of pirate weaponry, and rig it so when damaged it just drops to the bottom of the ocean intact. Getting into it isn't a threat either: terrorists aren't going to be plasma torching into a reactor and surviving long enough to do anything.
  - scrumper 11y ago
    Incomplete thinking. What about land-based fuel handling - creation, storage, transport, delivery? What about waste processing? The attack surface isn't just the ship.
    - wolfgke 11y ago
      Exactly what I meant.
- deleted 11y ago
  [deleted]
radiorental 11y ago
"I'm wondering why these ships aren't nuclear powered." A combination of cost and environmental concerns; 'The ship that totally failed to change the world" http://www.bbc.com/news/magazine-28439159 http://www.bbc.com/news/magazine-28439159

tim333 11y ago

Reading the Guardian article the thing's based on, the 50 mil figure refers to 'sulphur oxide gases' which could be possible because modern car fuel is pretty low sulphur. The industrytap article is pretty misleading.

arbuge 11y ago

Perhaps you missed this part: "109,000-horsepower engines that endlessly spin away 24 hours a day, 280 days a year." Most cars, in comparison, are idle for over 95% of their lifetime. My car for example sits in a driveway or parking lot approximately 23 hours a day. Brings another factor of 20 into play. Now 1 ship only needs to produce pollution equivalent to 2.5m cars. (Claim in the article still seems dubious considering that an average car has a 100 - 200 hp engine these days).

drvortex 11y ago

They are probably comparing amount of pollution per km travelled, per tonne of vehicle. I agree, the article is so imprecise as to be completely worthless in terms of information content.

rco8786 11y ago

Also keep in mind that the ships are effectively in use and engines running 100% of the time. While car engines spend most of their lives turned off

seanhunter 11y ago

Ships' engines are amazing, but heavy fuel oil is really really gross stuff. It's basically all the bits of the barrel that are left after distillation. Ie what they've dug out of the ground but can't sell off for more money as aviation fuel, gasoline, diesel etc. Therefore it has really high sulphur content and very long/complex hydrocarbon chains that burn much less efficiently than gasoline or diesel.