Modern cargo ships slow to the speed of the sailing clippers

[MineGoesTo11]

Modern cargo ships slow to the speed of the sailing clippers | Environment | The Observer

The world's largest cargo ships are travelling at lower speeds today than sailing clippers such as the Cutty Sark did more than 130 years ago.

A combination of the recession and growing awareness in the shipping industry about climate change emissions encouraged many ship owners to adopt "slow steaming" to save fuel two years ago. This lowered speeds from the standard 25 knots to 20 knots, but many major companies have now taken this a stage further by adopting "super-slow steaming" at speeds of 12 knots (about 14mph).

Travel times between the US and China, or between Australia and Europe, are now comparable to those of the great age of sail in the 19th century. American clippers reached 14 to 17 knots in the 1850s, with the fastest recording speeds of 22 knots or more.

Maersk, the world's largest shipping line, with more than 600 ships, has adapted its giant marine diesel engines to travel at super-slow speeds without suffering damage. This reduces fuel consumption and greenhouse gas emissions by 30%. It is believed that the company has saved more than £65m on fuel since it began its go-slow.

Ship engines are traditionally profligate and polluting. Designed to run at high speeds, they burn the cheapest "bunker" oil and are not subject to the same air quality rules as cars. In the boom before 2007, the Emma Maersk, one of the world's largest container ships, would burn around 300 tonnes of fuel a day, emitting as much as 1,000 tonnes of CO2 a day – roughly as much as the 30 lowest emitting countries in the world.

Maersk spokesman Bo Cerup-Simonsen said: "The cost benefits are clear. When speed is reduced by 20%, fuel consumption is reduced by 40% per nautical mile. Slow steaming is here to stay. Its introduction has been the most important factor in reducing our CO2 emissions in recent years, and we have not yet realised the full potential. Our goal is to reducing CO2 emissions by 25%."

The Royal Navy and BP, meanwhile, are among those adopting different ways to reduce fuel use and cut carbon emissions. The Ark Royal light aircraft carrier, the new Queen Mary 2 cruise liner and 350 other large commercial ships have had their hulls coated with special anti-fouling paint. This has been shown to cut around 9% from CO2 emissions by keeping their bottoms free from barnacles and other sea life.

Some ships have been fitted with kite-like "skysails", or systems that force compressed air out of hulls to allow them to "ride" on a cushion of bubbles. These measures can cut fuel consumption by up to 20%.

Environmentalists say that a reduction in speeds makes sense but warn that there is no guarantee that ships would not revert back to full throttle once economic conditions improve.

WWF International's marine manager, Simon Walmsley, said: "It's a no-brainer. Slower speeds reduce pollution but what the industry needs to do is to address its whole supply chain."

John Sauven, head of Greenpeace, said: "The simplest thing you can do to reduce emissions is reduce speed, but this must now be backed by regulation to make this the norm."

That's why I said I'd like to sail cargo in a schooner...

 

[ext1jdh]

one of the world's largest container ships, would burn around 300 tonnes of fuel a day, emitting as much as 1,000 tonnes of CO2 a day

Can anyone explain how 300 tons of fuel can produce 1000 tons of CO2? That doesn't logically make sense, but there's got to be a reason in it somewhere...

 

[Rich]

If they're using engines to travel slower than sailing ships, perhaps they ought to attach big freakin' sails to the things instead.

 

[MineGoesTo11]

If they're using engines to travel slower than sailing ships, perhaps they ought to attach big freakin' sails to the things instead.

It may come to that, although the scale of the ships may be smaller.

 

[River]

You're into this stuff, aren't you OP? Me too.

I'm sure wind will be playing a much larger factor in propelling oceangoing vessels in the years to come. But it still blows in the wrong direction much of the time.

I'm enthralled by the days of the Clippers, and have built three models of the Cutty Sark and one of the Thermopylae.

 

[MineGoesTo11]

You're into this stuff, aren't you OP? Me too.

I'm sure wind will be playing a much larger factor in propelling oceangoing vessels in the years to come. But it still blows in the wrong direction much of the time.

I'm enthralled by the days of the Clippers, and have built three models of the Cutty Sark and one of the Thermopylae.

I learned sailing at a young age. My grandparents had a boat and in the summer, they paid for us kids to do the sailing programs on smaller boats. I've never been on one of the big ships though. Haven't had much opportunity since then to get on a boat.

It's in me blood!

 

[River]

I learned sailing at a young age. My grandparents had a boat and in the summer, they paid for us kids to do the sailing programs on smaller boats. I've never been on one of the big ships though. Haven't had much opportunity since then to get on a boat.

It's in me blood!

Me too. I've chartered in the BVI a few times, and need to do that again before I get too old. I've almost got Riverette talked into trying a Windjammer cruise.

 

[spitfire]

Can anyone explain how 300 tons of fuel can produce 1000 tons of CO2? That doesn't logically make sense, but there's got to be a reason in it somewhere...

I’m not a chemist, but I think the reason is the oxygen (the O2 part of C02) of course comes from the air when the fuel is burned and is not in the fuel. The fuel is made up of hydrocarbons (carbon and hydrogen) and therefore the carbon is the majority of the weight of the fuel. Carbon is much heavier than hydrogen.

But when burned, 1 carbon atom (atomic weight 12) combines with two oxygen molecules (atomic weight 16). So the carbon accounts for 12/44 (between ¼ and 1/3rd the weight) of the weight of the CO2.

Bottom line is the most of the weight of the original fuel ends up in the CO2, but this represents less than 1/3 rd the weight of the CO2. Thus more CO2 by weight than original fuel.

 

[Wilko]

If they're using engines to travel slower than sailing ships, perhaps they ought to attach big freakin' sails to the things instead.

From the article: "Some ships have been fitted with kite-like "skysails"..."

 

[MineGoesTo11]

Watched a doc on PBS Online about the Essex whaling ship tragedy... grim stuff. I didn't know that it had served as the inspiration for Moby Dick.

 

[ext1jdh]

So the oxygen is combining with the carbon as the hydrogen is released. Okay that makes sense.

 

[spitfire]

So the oxygen is combining with the carbon as the hydrogen is released. Okay that makes sense.

Yes, when the fuel burns, the oxygen in the air combines with the carbon. The hydrogen that was in the fuel also combines with the oxygen to make H2O (water). Of course, depending on what the fuel is, you’ll get other combinations of things like CO (carbon monoxide) and I’m sure a host of other things.

I think a lot of what you end up with depends on the variables of the burning such as temperatures and such. Things like fuel air mixture ratios. Though I think CO2 and H2O are generally the main byproduct of burning fossil fuels. But I’m beginning to talk over my pay grade. So I’ll leave it to others to correct me if I’m wrong and elaborate.

 

[McLovin]

for shorter trips and smaller cargos sailing ships have already started a comeback: Tall ships make a comeback as oil price hits exports - Times Online

 

[Sin Nombre]

That's why I said I'd like to sail cargo in a schooner...

Come to Maine and spend a week on a schooner:

Maine Coast Windjammer Sailing Vacations - Maine Windjammer Association

Me too. I've chartered in the BVI a few times, and need to do that again before I get too old. I've almost got Riverette talked into trying a Windjammer cruise.

We've chartered in the BVI three times but never will again.Too many of the New York/Boston crowd that charters there in the winter these days has lost any concept of nautical rules, courtesy or common sense. They will have six or eight people powering full speed on auto pilot on a giant catamaran with apparently no one actually in charge. We had to take evasive action to avoid being rammed twice winter before last. The Grenadines, Mediterranean and Baja have continued to be great for chartering however.

And yeah, gotta do it while you still can, I can't put off doing this stuff either.

 

[River]

Watched a doc on PBS Online about the Essex whaling ship tragedy... grim stuff. I didn't know that it had served as the inspiration for Moby Dick.

This is an extremely well-written account. I highly recommend it.

<snip>And yeah, gotta do it while you still can, I can't put off doing this stuff either.

Thanks for the warning about the BVI. I should've seen that coming.

 

[cynic79]

Now if they can just stop crashing the damn things into whales...

 

[Mike's_LP]

That story sounds great, it really does. Huge corporations valuing common sense over profit, but that reminds me of the old axiom: Time = Money. I guess as long as the shippers & receivers don't mind the delay, it'll work!

 

[Sin Nombre]

This is an extremely well-written account. I highly recommend it.

Great book. I read a good review of this one in the Economist and gave it to my father in law but haven't read it myself yet.

 

[MineGoesTo11]

That story sounds great, it really does. Huge corporations valuing common sense over profit, but that reminds me of the old axiom: Time = Money. I guess as long as the shippers & receivers don't mind the delay, it'll work!

I'm sure the main motivation is the cost savings in fuel.. but less carbon emissions is a plus.

 

[Sven]

I still question the "tons of CO2" figures. We have to remember that not all of the carbon is released as CO2. Large portions are also CO (carbon monoxide). Also significant portions remain unburned and/or are emitted as smoke and soot.

The whole thing reeks of those phony "statistics" that are used to punish, torture, enslave, and abuse people.