back to article Greenbird sail-car wafts in as future of zero-emission motoring?

So how's this for emissions-free motoring? Greenbird Greenbird: record breaker Called Greenbird, the hi-tech land yacht is the brainchild of British engineer Richard Jenkins and last week it snapped up the word land-speed record for a wind-powered vehicle at Ivanpah dry lake in Nevada with a top speed of 126.1mph (202.9kph …

COMMENTS

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  1. Anonymous Coward
    Anonymous Coward

    Call me dense but . . .

    . . . can someone explain how it can go faster than the wind that is pushing it?

  2. Michael
    Happy

    Where..

    ... are the parking wardens going to put the ticket?

  3. melt
    Go

    cor

    That's a very pretty bit of kit.

    Wonder how much the paint weighs?

  4. ben
    Coat

    Emissions free?

    Made entirely of carbon fibre composites... polyester resins are well known for their green credentials; their low toxicity and completely non petrochemical basis are particular highlights of their characteristics.

    Mine is the one with eco-pedant on the back...

  5. Ian McNee
    Stop

    Never mind bridges...

    ...have they tried parking that thing at Sainsbury's? And even if you could find three consecutive spaces you can bet some chav will drive his Nova over your wheel strut!

  6. Lionel Baden
    Happy

    well im oinly guessing

    but its gonna be a bitch to park

    and i can just see people tacking up the m25 LOL

  7. Frank

    Neat Idea

    I think I understand how this works. Has anyone tried using a vertical wing on a boat?

  8. Steven Jones

    A thing of beauty

    It may be completely useless as a form of transport, but if we are to take the form follow function rule as defining beauty, then this is just what this is. It is, asthetically speaking, gorgeous.

    Well maybe I'm a bit harsh when I say it's useless as a form of transport, possibly ships might use rigid wings as a means of reducing fuel consumption (I think some companies were experimenting with the idea).

  9. Steve

    "Only if you live somewhere without bridges."

    ..... and there's a plentiful supply of constant wind,

    and the wind is always blowing from the right direction,

    and there are no buildings to block the wind or create turbulence,

    and there are 10 meter wide carriageways,

    and you don't need power for heating, indicators, lights

    and you don't need to carry goods!

  10. Steve

    "Only if you live somewhere without bridges."

    ... and there's a plentiful supply of constant wind,

    and the wind is always blowing from the right direction (for all drivers),

    and there are no buildings to block the wind or create turbulence,

    and there are 10 meter wide carriageways,

    and you don't need power for heating, indicators, lights

    and you don't need to carry goods!

  11. Luis Ogando
    Paris Hilton

    Cool

    This looks well cool, but there only appears to be an out-rigger on the right-hand side of the craft. This would make a fast right turns through the streets of Old London very precarious..

    Paris, 'cos her emissions are far from zero (probably)

  12. Anonymous Coward
    Anonymous Coward

    CyberSub

    "that moves of skates rather than wheels"

    It probably moves ON skates, but I know nothing about wind powered journalism.

  13. QrazyQat

    explaining

    "can someone explain how it can go faster than the wind that is pushing it?"

    Google "Greenbird" go to their site and click on "How it works". BTW, there was a post and comments on this wind-powered "faster than the wind" on Good Math, Bad Math a while back (http://scienceblogs.com/goodmath/2008/12/the_real_bozo_attempts_to_aton.php) where MarkCC, to his credit, apologised for calling the guys who demonstrated such a "faster than the wind" device bozos when he himself just didn't understand how it worked. The subsequent comment thread (and the threads in his previous posts on the subject) do a lot of explaining about how this works, including the math if you're into the nitty gritty.

  14. Steven Jones

    re: Call me dense but . . .

    If the machine had been "sailing" with the wind directly behind it, then it could, indeed travel no faster than the wind speed. Paradoxically as it might seem, the highest speeds are attained with the wind arriving approximating to 90 degrees from the direction of travel. The aerofoil shape generates "lift" which provides a force that propels the vehicle (or boat) forwards.

  15. Anonymous Coward
    Stop

    Future of motoring?!?

    I believe only being able to move when the wind is coming from your left would seriously limit the number of destinations you could reach with this. And of course, you couldn't make it back home until the wind reversed direction!

  16. ian

    Isn't that impossible?

    Doesn't the theory of relativity explicitly rule out travelling faster than the wind? Eh? Oh, sorry.

    Well, then! Perhaps if we went sideways to the light we could exceed "c".

  17. Jon Minhinnick
    Boffin

    Faster than the wind

    It doesn't go directly downwind but at an angle to it. The apparent wind then becomes the vector sum of the craft's motion plus the wind's. This new vector can have a scalar velocity greater than the original wind itself. Since the craft is propelled by the apparent wind, it effectively generates its own wind and sails in that.

    If you observe (say) America's Cup racing you'll see that the boats are always sailing about 45 deg to the wind, both upwind and downwind. This is the most efficient angle. To understand it fully, do a google for Polar Curves and Velocity Made Good. Some good stuff at Sailplanner.net.

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