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One Giant Cargo Ship Pollutes As Much As 50M Cars
thecarchik writes "One giant container ship pollutes the air as much as 50 million cars. Which means that just 15 of the huge ships emit as much as today's entire global 'car park' of roughly 750 million vehicles. Among the bad stuff: sulfur, soot, and other particulate matter that embeds itself in human lungs to cause a variety of cardiopulmonary illnesses. Since the mid-1970s, developed countries have imposed increasingly stringent regulations on auto emissions. In three decades, precise electronic engine controls, new high-pressure injectors, and sophisticated catalytic converters have cut emissions of nitrous oxides, carbon dioxides, and hydrocarbons by more than 98 percent. New regulations will further reduce these already minute limits. But ships today are where cars were in 1965: utterly uncontrolled, free to emit whatever they like." According to Wikipedia, 57 giant container ships (rated from 9,200 to 15,200 twenty-foot equivalent units) are plying the world's oceans.
I suspect the resistance to using a nuclear cargo vessel has less to do with anti-nuclear fears and more to do with the cost of operating them.
This has come up before, and I'll say it again for good measure: naval nuclear reactors are expensive. If they weren't, you can be sure the military would use them on cruisers and destroyers. As it stands the only vessels that use a nuke plant are carriers and subs, both expensive as hell, and the latter only use nuke plants because they don't need to surface for oxygen (on a pure operating cost basis diesel-electric subs win out).
Plans for nuclear surface ships below carrier weight have been put forward, and axed repeatedly, almost always on the basis of cost alone. And if the American navy says something is too expensive, believe me, it's too expensive.
Now, what I wonder is, would a cargo vessel be less polluting if it used a multi-hull design to reduce drag and was fitted with more advanced filtration system to mitigate the worst of its exhaust? That's a lot more achievable than the nuclear option, and wouldn't sacrifice cargo capacity, unlike the sail option put forward earlier in the thread.
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One big ship or lots of smaller ships? Is it time to lose "the fear" and go nuclear on cargo vessels?
Fear has nothing to do with it. Expense does. We've built nuclear merchant vessels before. They're just too expensive to operate. We built a fast, beautiful nuclear merchant ship (the NS Savannah) as a technology demonstrator, and when companies looked at the costs involved, they simply didn't see the point. Only a handful of nuke cargo ships were ever built, and only the Russians used them for any length of time.
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Exactly. The "50 million times more" thing is about sulfur oxides emissions, and honestly this number doesn't seem extraordinary to me. Diesel oil and gasoline have virtually no sulfur in them, while the Heavy Fuel Oil (HFO) that powers most ships is about 2% sulfur.
HFO is what's left when all the "good stuff" is extracted from crude oil. This "good stuff" is mostly shorter hydrocarbons such as methane, ethane, propane and butane (gases with 1 to 4 carbon atoms in them), gasoline (roughly 5 to 7 carbon atoms) and diesel oil (8 to maximum 21 carbon atoms).
What's left is an incredibly dirty, viscous, and nearly useless goo (asphalt is one other use, there aren't a whole lot). It still has a high energy density which makes it a decent fuel, but it's so viscous (because it consists mostly of very long hydrocarbon molecules) that you have to heat it up to around 80 degrees centigrade (176F) to even pump it into an engine. It also has high amounts of pollutants, because all the "clean" stuff has been taken out and you're left with all the dirty stuff. It is technically possible to remove most of the sulfur from this goo, but that means refineries would end up with giant piles of sulfur that nobody wants, and they'd have to dispose of it somehow. That's a cost refineries aren't willing to pay, so they just leave it all in to be burned up.
Legislation is being made to reduce HFO use in some heavy traffic areas (such as the North Sea in Europe), forcing ships to switch to clean diesel fuel in those areas. Of course, shipowners are against this because diesel is about 3 times as expensive as HFO. If all the ships in the busiest sea in the world suddenly start burning diesel fuel, you can expect the price to go up for everyone. Which is why we keep on burning the bad stuff.
I'd rather you rationally disagree than irrationally agree.
Small nitpick, wooden shipbuilding techniques before ~1800 required long pieces of wood for the strakes, and specifically curved pieces of wood for the scantlings. Shorter pieces worked too much at sea, making the ships hog and sag, and creating leaks. A typical third rate 72 gun ship of the line required over 5,000 old growth oak trees to build. Finally, thirty years was the service life discounting rebuilds, which could extend the life of a ship to double that, or more.
I have heard the theory that Britain wanted American wood for ships in other places before this. We have a type of oak, White Oak, that is particularly suited to shipbuilding due to its strength and resistance to splintering.
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Nope, he was pretty close. Your figure is way out - there's no way a gallon of fuel put into a cargo ship would move 1 ton 500 miles (or the inverse)....Fuel consumption is listed as 3.80 litres per second, or 1 gallon per second (3600 gallons/hour). That's a hell of a lot of fuel, and far off your 1 gallon = 1 ton moved 500 miles.
So, 3600 gallons/hour. The engine you mentioned is on the Emma Mærsk. Say it cruises at about 20 mph (speed is given as 29, but let's be conservative). That's 180 gallons/mile.
Now, to get 500 ton-miles/gallon you need to be carrying 500*180 = 90,000 tons. The Emma Mærsk can actually carry 154,000 tons. That works out at 856 ton-miles/gallon.
So, he may have been wrong, but in the opposite direction to the one you thought. Cargo ships do use an insane amount of fuel, but they also carry an insane amount of cargo.
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