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Ldz

(1)

Hi,

When you're calculating the energy consumption of the plane and boat, you've omitted mention of the duration of each journey. Watts aren't a measure of energy, but power. Using fewer watts for a long period can be more expensive than using many for a short duration - ask anyone who's accidentally left their car headlights on for too long about that!

Using the above figures:
- For the boat voyage, 34kW per person over the 84 hour trip gives a total consumption of 2846kWh for each passenger.
- For the flown voyage, 130kW per person over the an 8 hour flight produces a total consumption of 1104kWh for each passenger.

Thus, excluding engine efficiencies and other external factors, the trip by plane currently seems to be less energy intensive.

Harry

(2)

I think your representation of the energy involved in Atlantic crossings is misleading: "Thus, to transport one passenger across the Atlantic, a plane needs 4 times more engine power than a ship".

Your units kW are power, and you seem not to have factored in the time component of travel, as they are different for a plane versus a boat. While the plane does indeed require more power than a boat, it uses less energy per person because, as you said, the plane trip is 10 times shorter. A 747 requires 580 kJ versus the QM 2800 kJ per passenger per kilometer (according to http://www.batteryuniversity.com/parttwo-53.htm). As the Atlantic crossing distances are roughly constant (though the routes do vary) the energy required per person in the 747 is considerably lower than the energy required for the QM.

Chris Gemignani

(3)

The biggest problem with your analysis is you're not taking into account the relative speed of a 747 compared to the Queen Mary 2. The QM2 may be four times more efficient per hour of travel, but the 747 travels 20 times faster. Energy efficiency per passenger kilometer traveled would be a more appropriate measure.

I'm also perversely curious about the amount of human waste generated by 30,000 people over 4 days.

Kris De Decker

(4)

You are all right, of course.

This means that the 2,620 passengers on the Queen Mary 2 consume 2,856 kilowatt-hours, versus 1,040 kilowatt-hours per passenger for the plane. The ship scores 2.7 times worse than the plane.

If the Queen Mary 2 would transport 500,000 people, this comes down to 15 kilowatt-hours per passenger, versus 1,040 per passenger on the plane. The ship scores 70 times better than the plane.

If the Queen Mary 2 would transport 30,000 people, this comes down to 252 kilowatt-hours per passenger, versus 1,040 per passenger on the plane. The ship scores 4 times better than the plane.

These are still serious energy savings, but then ocean liners need engines that are as "clean'" and efficient as the engines of planes, otherwise switching from planes to ocean liners would not make sense.

On the other hand, replacing planes by ships would definitely lower the demand for long-distance travel, because of the duration of the trip. So in the end, the savings would be greater than that.

And we could still try to squeeze 500,000 passengers in the Queen Mary2 of course...

Nick

(5)

Just a thought: why not use the human waste generated by 30,000 people over 4 days to power the ship?

anonymous

(6)

Since shipping freight by ship is by far the most energy efficient way to move goods (even over rail), you would expect the same to hold for ship vs. airplane.

Of course 3 days and some hours is incredibly fast for a transatlantic journey by ship. Wonder if that takes advantage of seasonal winds or currents or something, and the return trip would be longer.

Kris De Decker

(7)

3 days, 12 hours and 12 minutes is a standing record held by the SS United States. She captured it in 1952 on the westbound trajectory (Cornwall, UK to New York). She lost her record in the other direction (3 days, 10 hours, 40 minutes) to a fast catamaran in 1990. These are record times, so actual travel times may vary according to weather, current and so on.

http://en.wikipedia.org/wiki/Blue_Riband
http://en.wikipedia.org/wiki/Hoverspeed_Great_Britain

Robert Firth

(8)

I note that the Hindenburg in 1937 could transport passengers across the Atlantic in 2.5 to 3 days. Its four engines delivered a total of 3600 kW for 72 passengers, or 50 kW per passenger. With a little less luxury she could easily have carried 100 passengers, for 36 kW per passenger.

Sixty years later, we could surely do better. A lot better. Buoyant flight is the answer.

Kris De Decker

(9)

Robert, I am a big fan of airships, too. I still hope they will make a comeback, but there seems to be a problem: we are running out of helium.

http://www.scientificblogging.com/news_releases/next_on_the_endangered_list_helium http://www.sciencedaily.com/releases/2008/01/080102093943.htm

Maybe we could use something else, like hydrogen, but helium is definitely the better choice since it is not flammable and much easier to handle. Another problem of airships is heavy weather. A storm is no problem for a very large ship, the Queen Mary once survived a rogue wave of 28 meters when transporting 15,000 people (see link below). Of course, being a passenger on a ship in a storm is not very comfortable, but the ship can sail out. On the other hand, if there is a bit too much wind, your airship stays grounded.

I don’t know if buoyant flight is the answer, but I agree that it deserves serious research.

http://en.wikipedia.org/wiki/Rogue_wave_(oceanography)#Reported_encounters
http://www.lowtechmagazine.com/2007/06/green-slow-air.html

S.P. Gass

(10)

Very interesting. I'd like to see transatlantic ocean travel make a comeback. There is a group trying to "save" the S.S. United States, if interested: http://ssunitedstatesconservancy.org/SSUS/Home.html

Jay

(11)

Dorothy Gambrell of Cat and Girl went around the world on boats and trains.
http://www.catandgirl.com/
http://www.verysmallarray.com/?p=36

ecoangel

(12)

Who on earth would want to be treated like walk on freight for 84 hours! The reason ships have bars and restraunts is to make economically viable. Do you know the cost of a transatlantic journey by ship? It is about 8 times more expensive than an Airline ticket.

Basic human rights would decree washrooms for these 30,000 people - all additional weight and hence KWH and CO2 per journey.

An A380 for 8 hours seems like heaven by comparision.

You should really be promoting the return of the EKRANOPLAN / Wing in Ground Effect Craft - a way of reducing Trailing Vortex /Lift Induced Drag to ZERO. All the advantages of Aircraft speed without the need for cabin pressurisation.

EAL

(13)

Not sure how practical this is, but perhaps use incineraters to generate energy from waste produced onboard to fuel the ship. With proper cleaning techniques (scrubbers, filters, etc.) they can be quite clean. Ash can be reused later.

davidpaterson

(14)

can any 1 tell me the cost of flying a boeing 747 from london to new york in £s, as i thought it must have been a misprint, when i read last year that it was around £60,000 to fuel 1 for a flight to canada, from london, just wouldnt be viable, this being the time of the big fuel increases a few months ago now

regards
dp

Sam F.

(15)

An additional point: If the Queen Mary 2 were carrying 500,000 passengers, the resulting power required would be many times more than the power required to move 2,620 people.

Not only are you increasing the people weight of the cargo by 200 times, but also all those people need fresh drinking water, food etc.

Finally, of course you cannot pack people in like sardines for a three-day trip like you can for an 8-hour trip. Also, your gross tonnage figure fails to account for the size of the engine and other large space requirements in a ship. So using a more modest figure of, say, 15,000 people, this only gets you a savings of 2 times above what a plane gets. And that's before we factor in the increase in power required to move 15,000 people.

Finally, of course, consider the energy and materials required to build these ships.

Dawn

(16)

This is very late, but in light of the newest TSA rules (basically flying as a prisoner with no access to bathrooms during the last hour -- or more and full-body scans), I think I'd LOVE to go by oceanliner. I think air travel's time has come and gone. It's not sustainable, wastes precious oil reserves, and produces so much waste, not to mention that you check your civil rights at the airport. My next few trips will be cruises, but I'm hoping for a resurgence of these beautiful ocean liners. (And I have motion sickness! lol)

Shane Carr

(17)

What no one has mentioned, given the recent transatlantic terrorist activity, is safety. I am sure that if the chance to go UK to the USA (on business or otherwise) by passenger ship were available on a regular (say weekly) basis then lots more people would take up the service. This would make it cheaper. I always travel on business in Europe by train now. Its less stressful and because of the laptop and internet I get more work done than when I used to fly. You must also compare a boat trip with Business Class on a plane for fairness when comparing prices.

Mercury

(18)

I've crossed the Atlantic twice on the old great liners- once on the SS United States and once on the Cristoforo Columbo of Italian lines.
Why not a middle approach?. Outfit 4 or so 45' containers with bunks and minimal accomodations- and send them over on a scheduled large containership( 7 days transit). Today the maritime laws are strict- more than 12 passengers requires a doctor aboard- perhaps that can be loosened creatively? In the early 80's a line serving south america did carry more than 12 passengers- but this was a dodge to get priority berthing in crowded, delay prone ports. It was a failure-

Kris De Decker

(19)

Great idea. And why not use these shipping containers: http://www.lowtechmagazine.com/2006/06/lego-for-big-bo.html

Stephen

(20)

The energy comparisons clearly need to be done carefully.

I, for one, though, would much rather cross the ocean on a ship than in a plane, which I've done quite a few times.

I would be willing to travel by ship second or even third class, where I had a bunk, and space for my luggage, and could buy food a la carte at cafeterias. No need for expensive restaurants and 'fine' food. So I hope travel by ship does make a comeback before I croak (I'm 65). Probably not too likely that it will, though.

Michelle

(21)

The problem with using ships as transport is more societal than anything else. Most folk can afford a quick dash in a plane to get somewhere, but taking days to do so means either their employer or their family gets that much less of their time - in this day and age of limited time off, using most of it to merely get somewhere isn't an option.

Of course combining on-liner business meetings with travel could mean an entire committee arrives on the other side in consensus.. or making internet access freely available could add that bit of "quiet time" (remote office!) to accomplish things that many of us modern rushers crave.

Josh Allen

(22)

Personally, I would love to be able to take transatlantic and transpacific ferries at a low cost comparable to an airline ticket.

However, there are three things that will always keep this from happening: Fuel costs, Maintenance costs, and crew costs.

The average cargo ship holds over $1 million in diesel and burns about $100,000 per day when fully loaded.

Oceangoing vessels are usually scheduled to go into extensive drydock periods every 7-10 years. Sometimes less. This is to check for weakness in the hull and to repair, repaint and recoat the hull with a protective layer that reduces the amount of damage done by the sea water.

Then you have the full time crew. Unlike an airline crew, these men and women have to live and work onboard. Engineers, navigators, boatswains, cooks, doctors. It all costs money. Unlike a flight where the crew flies somewhere and takes a different flight later for minimal pay, these men and women are always on the clock and getting paid well for their time. I used to get paid $220/day and that was low on the scale.

systemBuilder

(23)

I was going to suggest you correct the article's figures to quote everything in Kwh. You can still make a point that ocean lines COULD be more efficient, but you'll have to work much harder to get your conclusions.

The size of a typical cruise-ship cabin berth (I think) is much larger than the cabin berth of a typical train. If we were to build ships with train-sized cabin berths, I think we could double or triple the number of passengers per voyage.

Hugh

(24)

I believe the future might be in ocean liners with an hybrid propulsion (wind/clean diesel, or wind/solar). When gas price will finally reach 200 $ a barrel, it might be the only solution

VonMagnum

(25)

Ecoangel said the cost of traveling across the ocean by ship is 8x higher than an airline ticket. Unfortunately, this is a complete fabrication. I'm looking at a trip to visit England right now and the TRUTH is I can get an inside room on the Queen Mary II for 7 nights (which includes food and obviously a room/board) from New York to Southampton for $899 (or a balcony cabin for around $1300) in April or May of 2013. An airline ticket to return from England, on the other hand will cost me between $1200-1400+ for a coach ticket to Ohio (I would have to pay around $115 for a one-way ticket to New York, so add that to the cruise price) and it's STILL $200-400+ less to take the Queen Mary 2 and that's with a leisurely cruise with plenty of leg room and relaxation, not STUFFED into a tiny airline seat for over 10 hours with my legs feeling like jelly by the time I get off the plane and the horrible grumpy mood that comes with such MISERY.

A vacation is NOT about speed. A cruise can be as much fun as visiting the target country itself. The only problems are how much vacation time one can get and whether a return ship is available at the proper time (in this case, I can get 3 weeks no problem and about one week in England would be IDEAL, but unfortunately, there is NO return run on the Queen Mary until the following week, which means I'd need to take a full 4 weeks off to do the trip and spend 2 weeks in England (which adds to the overall expense of the trip since staying in England isn't cheap and I'd have to use my entire 4 weeks of vacation time for the year to do it). In short, if there were more ships like the Queen Mary 2 that make that trip in 7 days, I could make this trip work for less money without ever spending more than an hour and 15 minutes on a cramped, miserable airplane.

Thuin

(26)

For a cruise to be fun, the energy efficiency is lost. And that's assuming that current tech will offset current safety, security, environmental, and comfort requirements - a big "if."

Scott Wells

(27)

What was the "this is uncomfortable" photo referring to? The link is down.

drs

(28)

"Since shipping freight by ship is by far the most energy efficient way to move goods (even over rail), you would expect the same to hold for ship vs. airplane."

Ocean freight is an amazingly efficient way of transporting mass, and thus freight. The catch with passenger travel is that the longer the trip takes, the more mass per passenger you need, for room, water, food, bathrooms, crew, etc. 1 hour needs a chair, 3 hours needs a bathroom, 9 hours needs food and would like a bed, 27 hours really needs walking space and would really like a bed.

So, as shown in the article, if you go slowly enough in a self-contained vehicle then you start losing the putative efficiency of being slow.

Then there's economics: a faster vehicle carries more passengers over a fixed distance than a slower one, spreading the capital cost of the vehicle over more people (and tickets.) If an airship costs as much as an airplane but is 1/6 as fast, capital cost per ticket will be 6x higher. Plus of course the opportunity cost to the passenger of spending more time in travel, though that would lead to willingness to pay more for speed, not planes being cheaper.

Basically if energy costs are overwhelming then you want to go slow, but if capital and overhead costs are significant the optimal speed goes up, to increase turnover and reduce overhead.

Aenn

(29)

Even if a trip took a whole week, going in a comfy ship cabin and getting real food and sea air more than makes up for it. Consider that there are no practical luggage weight limits (an issue for anyone who has to transport heavy equipment), and it all looks like a bliss. Internet access and, of course, onboard electricity makes everything that much nicer. Make translantic ship trips cheaper (33% cheaper, say) than airplane fares, and there will be crowds queueing up for the rides.

Viktor

(30)

As someone who worked on cruise ships, the logistics is huge! Serving 15000 pax is physically impossible. Let's take the Caribbean Princess(T'was my last ship) which carries about 3600pax and 1500crew at full capacity.
Now if you want to convert her to be a commercial liner(hence downgrading services) you could free up about 3 decks(theatre, gallery, shops, most of the restaurants, spa)for additional pax cabins which would about double the capacity. The number of crew would be about the same, since you need more cooks, stateroom stuards, and all the waiters would be transferred to an enormous buffet, and the additional room service bases. To keep the pax "occupied" the rooms should be fixed up with game consoles, and other entertainment stuff. Still it's a 3-4 days journey, and the cost of feeding and housing 7000+1500 people is enormous(also, the crew is not working for marbles -but the wage of many of them are really close), so I don't think the price of tickets could be compatible to jets... maybe with no or really minimal profit.
...Or you could put a fridge in every single cabin, and stuff it with 3 days worth of microwave food, instant drinks and sodas to eliminate the galley department and much of the restaurant department, then have about 8000 TV-zombies disembark every 3 days on each side of the Atlantic :D. If i had a couple billion bucks to burn, i might build a ship for this project just for the sake of fun and social experiment...
Note: you might find that a 4 days getaway on a ship costs the fracture of a transatlantic flight(say, with Lufthanza). That's because the ticket for the ship "just keeps it afloat" the wages, cost of consumer goods and the profit are all generated from on-board sales and charges, but since in this example we have eliminated everything that could generate income, we have to cover everything on the tickets.

321

(31)

Half a million people aboard the Queen Mary, packed like people are in a jet. Sure, energy efficient. But nobody would buy a ticket. Ever. Transatlantic trip time is about a week, man. A week. Sitting in an airline seat. A WEEK SITTING IN AN AIRLINE SEAT. Shared bathroom, no shower, no changing clothes, no shave, no brushing teeth, nothing. Sitting next to screaming babies and annoying people. A week of this. Sorry, man, but nobody would do that. Nobody SANE, at any rate.

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