The Future of the Tank

[Gibsonm]

And you'd get short skirts too.

[dejawolf]

what is the limitations of doing double-decker cargo lift airplanes?

[Homer]

Size -> drag -> less aerodynamic efficiency -> less range -> etc.

Like the need to balance firepower, protection, and speed for AFVs, the three basic things that govern aircraft design are lift, thrust, and drag.

[Hedgehog]

And you'd get short skirts too.

Where do I sign up?

[GH_Lieste]

Whoa... not something we want to see.. Hedgehog in a short skirt :cul:

[FletchRDG]

Ive worked it out and it works out to only half that of a chinook in terms of lift power. So rotory is a theory thrown out but theres still other known opportunities. We could look at delta wing design or like deja said rigid airships.

[Tacbat]

Whoa... not something we want to see.. Hedgehog in a short skirt :cul:

I think he calls it a "kilt".

[Gibsonm]

I think he calls it a "kilt".

No obviously I was being too cryptic.

The initial reference to USS Enterprise and "beaming" made me comment about "short skirts" as in the ones you'd see in the show, I was not implying some sort of cross dressing / Scots requirement.

Although some seem to have willingly embarked on such a course of action.

[Tacbat]

The initial reference to USS Enterprise and "beaming" made me comment about "short skirts" as in the ones you'd see in the show, I was not implying some sort of cross dressing / Scots requirement.

Thanks Tips.

[Hedgehog]

I think me in a short skirt would be well, just. Wrong.

And too much I think even for this esteemed Forum to handle.

No, I was commenting on the Female Crew members aboard said ship with their short skirts. :biggrin:

And I'm not scottish, I'm about as far from Scotland as its possible to get without leaving England. (More or Less, Okay theres the West Country and the Channel Islands which are further south than Sussex.)

(Just to clarify)

And with regard to the other matters of VTOL Tank carrying Aircraft.

If it was feasible and economically viable, don't you think we'd have seen a Prototype by now?

[FletchRDG]

And with regard to the other matters of VTOL Tank carrying Aircraft.If it was feasible and economically viable, don't you think we'd have seen a Prototype by now?

http://www.damninteresting.com/buoyancy-bounces-back

[Homer]

We could look at delta wing design or like deja said rigid airships.

These are not ideal solutions either. Delta wings are better suited for high speed aircraft like jet fighters. They have issues at low speeds, like higher landing speeds. Airships are too fair weather dependent and slow.

[Hunt3r]

It would be an interesting transport aircraft, but it'd have to actually be able to get somewhere reasonably fast... that just looks like a lot of parasitic drag.

[Gibsonm]

They have issues at low speeds, like higher landing speeds.

And high angles of attack, hence Concorde's "jointed" nose so the pilots could see where they were going on approach.

[Sabot_Up]

The only aircraft that I could see lifting four Abrams would either be an airship or a ground-effect aircraft like the Russian Ekranoplans or the Boeing Pelican. http://en.wikipedia.org/wiki/Boeing_Pelican

Such an airship would have to be really, really huge. It takes a cubic meter of hydrogen to lift 1.2 kg of weight, so just lifting four abrams would take a hydrogen-filled airship with the same volume as the 800-foot-long Hindenburg. Then you'd need even more hydrogen to lift the structure, engines, etc.

There are two major problems with a jet-powered VTOL of that size. The first is that it will require an absurd amount of fuel for takeoff and landing. The second is what you will take off and land on - the much smaller Harrier can't take off and land immediately from the same patch of runway due to heat, and the Navy has had to reinforce their ship's decks to deal with the heat of the Osprey's engines.

For VTOLs I think one IFV or light tank is the limit. Even the C-130 size Mil Mi-26 can only carry 20 tons, and nobody else has ever bothered to make a real operational helicopter (ie not the V-12) anywhere near that size.

[dejawolf]

for an airship, its volume and lift capacity increases more rapidly than its weight, so the larger an airship is, the more efficient it becomes.

[Ssnake]

Yeah, but that's just one side of the coin. Maneuverability, robustness, and system complexities are primarily a problem of large airships. Pretty much 99% of all large airships were lost due to some sort of disaster (I know of none that was actually retired after an extensive career). Recent attempts to build modern airships burned three-digit millions of shareholder and taxpayer Euros, yielding the world's largest in-door pool but no flying airship. The complexities were massively underestimated.

Small blimps, on the other hand, have been in the air successfully for decades.

[Ssnake]

I mean, one would think that a loss rate near 100% would give people a clue about the validity of the whole concept (unless you can keep the whole structure above the troposphere); even if you discount the hydrogen disasters, all the large helium-inflated airships were still lost in storms as well.

But nooo, some ideas simply won't die, I guess, like urinating on electric fences or powerlines - no matter the past record.

[Hedgehog]

I mean, one would think that a loss rate near 100% would give people a clue about the validity of the whole concept (unless you can keep the whole structure above the troposphere); even if you discount the hydrogen disasters, all the large helium-inflated airships were still lost in storms as well.

But nooo, some ideas simply won't die, I guess, like urinating on electric fences or powerlines - no matter the past record.

A dirigible (Sorry, I really like that word for some reason) does make a good advertising feature.

How about comissioning a small one for next year's ITEC?

[FletchRDG]

yeh, it works out as follows (in Newton-meters):

Atlas = Rolls Royce Trent XWB-93 x 4 = 2,017,457.12N.m

Atlas = Rolls Royce 1000-K x 4 = 1,601,349.68N.m

C-17 = Pratt & Whitney PW2040 x 4 = 911,109.68N.m

Chinook = Lycoming T55-GA-712 x 2 = 5,592,749N.m

there isnt enough lift to counter act the weight. So this is an apology, Im learning still. I just didnt go far enough when I worked it out.

[Hedgehog]

As an outlandish hypothetical scenario:

I've just thought of the ultimate QRF.

What about Pre Positioning Equipment in Orbit?

You can deploy a tank anywhere on the surface of the Earth with 120mins.

Mind you the crew would need a seperate Dropship.

Think about it: Rocket engines are far more powerful than Jet engines.

Just an idea, Which you may now pick apart with glee.

[GH_Lieste]

No, you might be onto something... drop a 70 ton lump of metal fast enough and goodbye target area...

Anyone know what the terminal velocity of an M1A1(HA) would be - you could probably improve it somewhat by adding a ballistic cap, and stabalising fins...

Orbital insertion FSMBTBC.

[MAJ_Fubar]

As an outlandish hypothetical scenario:

That it is...just too expensive to loft the damn things. Now if we built them up there to begin with...:sonic:

[Ssnake]

Recommended reading: The Moon Is A Harsh Mistress by Robert A. Heinlein.

A lecture in the power of dropping rocks from very high above.

Pinpoint precision and minimal collateral damage however were not part of his considerations.

[MAJ_Fubar]

Orbital bombardment is never subtle.