Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Aerospace Caspian Sea Monster vs Conventional Airlift

  1. Sep 4, 2010 #1
    http://www.youtube.com/watch?v=V8Nu94khHoo&feature=related", but let's now entertain realistic discussion:

    Claim one: "It's capable of carrying 50% more weight while using half the fuel of a conventional cargo airplane.

    With a it's cargo carrying capacity, I'm wondering why FedEx isn't there?
    Last edited by a moderator: Apr 25, 2017
  2. jcsd
  3. Sep 4, 2010 #2
    Last edited by a moderator: Apr 25, 2017
  4. Sep 4, 2010 #3
    Oh, wow! http://www.youtube.com/watch?v=-wmyrlZttHU&feature=related"!

    No, I am not a russian spy - I was born in New Mexico.

    Hey! Pay attention to the video! Tons of huge and very serious issues for cargo transportation!

    I think the point is that this technology is very, very far from being "dead."
    Last edited by a moderator: Apr 25, 2017
  5. Sep 5, 2010 #4


    User Avatar
    Science Advisor
    Gold Member

    The thing is, with these sorts of "planes", you only get the beneficial effects close to the ground. They don't even work higher up, and in order to make them work, you would have to redesign the airfoils to likely make them stop working in their normal mode directly above the ground. They also only work over a body of water apparently. I suppose you could make it work over the ground, but avoiding trees, buildings and other obstacles would be nearly impossible.
  6. Sep 6, 2010 #5
    I'm going to build one 400 feet long. It will be the biggest ship made to date, and to honor its glorious size I will name it the Titanic.
  7. Sep 6, 2010 #6
    The original Titanic was about 883ft long and DWT 46,328t. Today, the largest in service ship, in length, is the containership Emma Maersk with 1302ft and DWT 156,907t. But the record is held by the tanker Seawise Giant with 1504ft and DWT 564,763t, unfortunately already scrapped.
  8. Sep 6, 2010 #7
    In that case, I will make it 2000 feet long! and call it the SPITEANIC :D
  9. Sep 7, 2010 #8
    That's sort of the idea behind ground-effect machines...

    They're not made to work higher up, but that's one behind their design. Although the longer the wingspan, the greater the height of the ground effect (typically half the wingspan for modern aircraft). Large wingpans, however, aren't suitable for most areas, given the maneuvering and obstacle avoidance requirements.

    Even so, http://en.wikipedia.org/wiki/Boeing_Pelican" [Broken]ignores or avoids this consideration and sports a 500-ft wingspan, so it has a considerable altitude capability (20,000 ft).

    FAA regulations prohibit flight below 1,500' AGL above populated areas (cities), so above "buildings" isn't going to happen. Flight above trees isn't going to happen either, as efficiency is best the closer to ground one goes, and above trees... That's just not going to happen (birds, rough terrain, cell phone towers...)

    Trains are nearly an order of magnitude more efficient than props or jets, but the latter are significantly faster (4 to 8 times faster).

    The niche for the WIG craft is that they are significantly more efficient than jets/hydrofoils/props/hovercraft, and faster than ships/trucks/trains, but they can operate without either runways or railways, both of which are quite expensive, particularly for developing areas.

    The principle objection and reason for earlier program cancellations in the 50s-70s was the lack of confidence in their ability to navigate waterways at high speed. Today, however, high-resolution surface radar and inexpensive GPS/INS-coupled systems combined with computerized coastal terrain/object mapping render these earlier objections all but moot.

    Or you can call it the Boeing Pelican ULTRA. It's designed useful load was 1,400 tons (2.8 million pounds). Makes the Spruce Goose look like a tadpole.
    Last edited by a moderator: May 4, 2017
  10. Sep 7, 2010 #9


    User Avatar
    Science Advisor
    Gold Member

    mugaliens, I think you are missing my point.

    I am well aware of the fact that a ground-effect vehicle is only designed to work close to the ground. The reason I brought that up is because in an earlier post, you said something about them being more efficient than comparably sized regular aircraft. The thing is, that generally isn't true if you compare comparably sized aircraft in their designed mode of flight to a GEV. The advantage effectively vanishes at that point.

    As for the Pelican, it is a concept plane. Whether or not it actually performs to those specs is unknown. Factor in that a 500 foot wingspan doesn't really leave much room for maneuverability. The Pelican doesn't really avoid the consideration. Rather, it tries to incorporate the best of both worlds. It has airfoils that are designed to work near the ground while still being capable of flight at altitude, albeit at 60% the efficiency. Still, it is a concept plane for a reason. Whether or not it could ever live up to its 10,000 nm range is unknown, and whether or not it would even actually be flyable is also unknown. The XB-70 looked good on paper, too.

    But then, that is precisely my point now isn't it? Without the ability to go to altitude, They are physically capable of operating on land but you just could not practically do so. They are effectively confined to water operations. The Pelican ULTRA claims to take off from a runway, but good luck finding a runway that is large enough to accommodate it. It seems like you would need JATO to get it off the ground and a 6 mile runway to land it because it is so large.

    Fair enough, but with a wingspan of 500 ft, the Pelican still would not be able to navigate any waterway except the ocean.

    The only realistic use for these sorts of vehicles seems to be transoceanic shipping duty, so your comment about FedEx seems to be right on.
  11. Sep 7, 2010 #10
    I've always thought that Russian WIG craft was pretty cool. However one of the downsides to the practicality of such craft is you need a pretty flat stable surface for them to work well. Imagine that thing trying to cross the North Atlantic in a storm with 30-50 ft swells!


    [PLAIN]http://media.oceaninspire.com/2010/09/waves.41.jpg [Broken]

    [PLAIN]http://media.oceaninspire.com/2010/09/deadliest-catch11.jpg [Broken]

    I'm with Cyrus - I'd probably call that craft the Titanic for good reason! :biggrin:
    Last edited by a moderator: May 4, 2017
  12. Sep 13, 2010 #11
    They are.

    You are incorrect. There are two reasons as to why conventional aircraft rule: speed and corrosion. Flying anywhere near the surface of the ocean causes huge corrosion problems for aircraft, a fact as to why the US Navy has aircraft washing stations for its P-3 Orion's at nearly all bases where P-3s are stationed. They taxi through the wash stations ever landing.

    As for speed, why would a pax travel at 250 kts if they can travel at 500 kts? GEVs are well-suited for cargo missions, though.

    I'm willing to bet the engineers at Boeing are fairly adept at aircraft design... (rolls eyes).

    You're correct. It's pretty much a straight and level flier. Back when I flew B-52s, we were limited to 20 deg of bank while flying low-level, 30 deg in the pattern, though we could easily bank it up to 60 deg at altitude if needed. The most I'd ever seen in a B-52 was 110 degrees of bank, but that was at the hands of the rule-breaking pilot at Fairchild who wound up killing two of my friends, along with himself, in 1994. It was the fall of 1991, and he was hot-dogging in the pattern with the vice wing commander.

    Your skepticism is unfounded. Boeing engineers aren't stupid, even at the concept phase.


    If you have any information (calculations) to support your assertions, which 20 years of flying large aircraft tells me are groundless, now's the time to pony up.

    Exactly. You weren't thinking it'd be flying anywhere else, were you?


    dtango, cool pics of some serious sea states in the North Atlantic! Fortunately, the oceans host hundreds of bouys which monitor, among other things, sea states. Flying around such troubled areas is easy.
  13. Sep 13, 2010 #12


    User Avatar
    Science Advisor
    Gold Member

    To be fair, I didn't do any calculations. I merely factored in that a 747 needs a 10,000 foot runway to operate, all while using presumably more powerful engines and being a fraction of the size. Unless Boeing planned to come up with 4 turboprops that put out more thrust than four CF6's or four RB211's. At this point in time, I am unaware of a turboprop that can put out that kind of power.

    False. There is a third reason: versatility. A conventional aircraft can fly to a lot more meaningful places than a GEV. Sure, 75% of the earth is water, but 60% of the world's population doesn't live within 100 km of a coast. It seems to me that GEV's are more of a supplement to the shipping lines than they are to aircraft, since they have about the same useful areas they cover.
  14. Sep 17, 2010 #13
    mugaliens - on a tangent, wow sorry you were friends with some of those onboard the B-52 that crashed at Fairchild. I've read "Darker Shades of Blue". The crash was made that much more senseless and tragic. I can't imagine how hard it was for Col Robert Wolff's family he waited for him on the field for his fini-flight.
  15. Sep 22, 2010 #14
    Actually, I've seen one put down athttp://www.airnav.com/airport/KPOB", and take off again. Pope's primary runway is 7,501 feet long.

    Actually, this isn't at all unusual, as Evergreen's (and other carriers') 747's landed there all the time, primarily as TRANSCOM-contracted air cargo transport for various units in the 18th Airborne Corps out of Ft. Bragg, NC (adjacent to Pope).

    What was unusual about this particular flight is that it was the http://en.wikipedia.org/wiki/Shuttle_Carrier_Aircraft" [Broken], and with the Space Shuttle on top of it, no less! It sat for about two days on yellow ramp, then departed in the wee hours.

    The SCA 747s both use 4× P&W JT9D-7J turbofans, 50,000 lbf (222 kN) each.

    No doubt. Neither do I. It's certainly conceivable they could be designed and built, however, and in that slower flight regime (250 kts) a turboprop, even very large, multi-bladed ones, would be more efficient than a high-bypass turbofan.

    You're correct, and GEV's are not the panacea of air transport, that's for sure. They're best for long, overwater hauls, although they've also proven their worth in island-hopping air taxi service, as well, as they are indeed cheaper to operate than traditional floatplanes, and can pull up to pretty much any dock (which are many). Airfields are less common. For that matter, they can also be used as diving platforms, and can simply be beached at remote locations.

    I agree, as we're primarily talking about coastal ports. However, because Boeing's concept aircraft included flight up to 20,000 ft and conventional landing gear, it's likely the designers intended to fly it well inland, possibly over mountainous terrain (transition altitude in CONUS is 18,000 ft).
    Last edited by a moderator: May 4, 2017
  16. Nov 4, 2010 #15
    Bud Holland. I drive past that memorial marker on Fairchild AFB all the time.
  17. Nov 4, 2010 #16
    Go over the pole, a nice region of flat smooth sea/ice that's otherwise rather tricky to sail through - but is conveniently between canada/europe and S.E asia.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook