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Modern Cargo Ships Slow To The Speed Of The Sailing Clippers

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http://www.guardian.co.uk/environment/2010/jul/25/slow-ships-cut-greenhouse-emissions

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%."

I'm surprised they haven't developed new sailing ships. The wind is free and if they are travelling at the same speed as the clippers why not just build sailing ships.

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http://www.guardian.co.uk/environment/2010/jul/25/slow-ships-cut-greenhouse-emissions

I'm surprised they haven't developed new sailing ships. The wind is free and if they are travelling at the same speed as the clippers why not just build sailing ships.

I did read somewhere they ships have small sails off the bows now... problem is wind isn't exactly reliable and a war frigate made of wood requires somewhat more energy to move than a 600,000 ton monster cargo ship.

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I'm surprised they haven't developed new sailing ships. The wind is free and if they are travelling at the same speed as the clippers why not just build sailing ships.

About 15 years ago, I saw one of those Swedish cruise ships that had sails for when the wind was in the right direction, with engines for when it wasn't. Ideal.

On a practical point, all the sails and mast needed to propel a big boat take up a hell of a lot of room and weight on a ship, as well as the maintenance etc. When one outweighs the other is debatable.

Valid point though. Age of austerity. Remake The Onedin Line.

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http://www.guardian....house-emissions

I'm surprised they haven't developed new sailing ships. The wind is free and if they are travelling at the same speed as the clippers why not just build sailing ships.

Something wrong with the maths in that article clip. Ships run in displacement mode. Consumption roughly halves for every two knots of speed decrease. I reckon they meant "to 30% of consumption" rather than reduced by 30%.

The engine damage happens because at the low cylinder pressures, the bores glaze, and then the lubrication fails - the engine burns the lube instead of it's own fuel.

There is a neat invention called a tow kite, which is exactly what it's name suggests. Far more efficient and cheap than sail, and oil-powered ships can use one as a supplement.

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Something wrong with the maths in that article clip. Ships run in displacement mode. Consumption roughly halves for every two knots of speed decrease. I reckon they meant "to 30% of consumption" rather than reduced by 30%.

The engine damage happens because at the low cylinder pressures, the bores glaze, and then the lubrication fails - the engine burns the lube instead of it's own fuel.

There is a neat invention called a tow kite, which is exactly what it's name suggests. Far more efficient and cheap than sail, and oil-powered ships can use one as a supplement.

Erm I'm pretty sure gigantic ship engines are two stroke, therefore the fuel is the lubricant.

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http://www.guardian.co.uk/environment/2010/jul/25/slow-ships-cut-greenhouse-emissions

I'm surprised they haven't developed new sailing ships. The wind is free and if they are travelling at the same speed as the clippers why not just build sailing ships.

Slow steaming also saves a lot in berthing charges as the alternative is to idle the ships in harbour whilst paying crews retainers whilst on shore leave.

Good news for carbon emissions, bad news for Rotterdam hookers

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There is a neat invention called a tow kite, which is exactly what it's name suggests. Far more efficient and cheap than sail, and oil-powered ships can use one as a supplement.

That wouldn't work, they always get tangled up in trees and on power lines.

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...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...

How can burning 300 tonnes of fuel a day lead to CO2 emissions of up to 1,000 tonnes per day?

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How can burning 300 tonnes of fuel a day lead to CO2 emissions of up to 1,000 tonnes per day?

Carbon combines with 2 oxygen to make carbon dioxide.

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Guardian: "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."

That's not what the horse's mouth told me. It's all down to overcapacity, not recession or awareness. Between 2005 and 2007, they ordered and built a load of ships that were never going to be needed in even the most optimistic economic growth scenario and they had to do it because everyone else was.

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  • 145 Brexit, House prices and Summer 2020

    1. 1. Including the effects Brexit, where do you think average UK house prices will be relative to now in June 2020?


      • down 5% +
      • down 2.5%
      • Even
      • up 2.5%
      • up 5%



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