Building the Better Airship

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Sareth
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Building the Better Airship

Post by Sareth »

So, I got a wild hair this morning and started thinking hard about steampunky airships. You know, airship pirates, swashbuckling in the skies, that sort of thing. (I blame the fact I drank my body weight in beer last night.) Well, this did lead me to working on armoring the gasbag of an airship against enemy fire and the conclusion I reached was "can't be done."

But why? Why must it be that way? Impy delighted my black and shriveled little heart by challenging my assumption on twitter (seriously, I was thrilled to see her contradicting me.) So I thought that those of us with creative bents, too much time on our hands, and a complete lack of fear when it comes to mixing fantasy and physics might have a little fun exploring. So here's the deal.

Design an airship for a pirate or naval officer and rationalize it. It can be in one of three catagories: Real World (meaning it has to be doable within the laws of physics as we know them); Steampunk (meaning you have to use a lifting gas of some sort but you can use some sort of applied phlebotenum to lighten materials, exaggerate the lifting power of a lifting gas, or harden materials); and High Fantasy (meaning the use of magics and/or fantasy creatures to get the job done.) Then we all can get our panties in a bunch arguing about how the idea would never work, following which we don top hats, monocles, and go get a pint at the closest public house.

Ready? Go!

:catgirl:

(A few useful bits of information:

Volume of a sphere: V=(4/3)πr^3 Surface area of a sphere: A=4πr^2
Volume of a cylinder: V=πr^2h Surface area of a cylinder: (end piece) A=πr^2 (side) A=2πrh
Volume of an ellipsoid : V=(4/3)πabc Surface area of an ellipsoid (approximate): 4π((a^pb^p+a^pc^p+b^pc^p)/3)^(1/p)
Where r=radius; a, b, c; equal each cardinal radii on an ellipsoid; and p=1.6075.

For comparison purposes, the Hindenburg had a volume of 7,062,000 cu. ft. and used hydrogen to achieve a lift of 510,000 lb and weighed 470,000 lb without gas. The U.S.S. Acron had a volume of 6,500,000 cu ft and used helium to achieve a lift of 400,000 lb.

This gives us a basic 16 lbs per 1000 cu ft. using hydrogen and 13 lbs per 1000 cu. ft. using helium.

Feel free to correct me on these.)
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Graybeard
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Re: Building the Better Airship

Post by Graybeard »

Now that I'm back from Death Valley, I'll play. For starters, anybody got good specs on the density of Kevlar armor? Chobham?
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Sareth
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Re: Building the Better Airship

Post by Sareth »

According to Wikipedia, the relative density of Kevlar is 1.44 (in comparison to water, I assume), and according to Ameriwiki (I have no idea who they really are, so BIG grain of salt here) Chobham armor has a density of 2.22 g/cm3
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Labrat
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Re: Building the Better Airship

Post by Labrat »

Well, if we are going to go into the magnificent realm of phlebotnium (made from the processed corpses of untold millions of slaughtered phlebots) then the only sane lifting gas is no gas at all. If you make a sufficiently strong, rigid 'balloon' then you can forcibly pump the air out the same way you might with a light bulb.The resulting dirigible would have the best lifting capacity possible for any lighter-than-air craft that doesn't use magical floating god-testicles™ as a drive system and would have a 92% lower chance of attracting divine wrath.

Of course this would, more or less, require bulk-produced fullerine compounds or Ringworld scrith/floor material... which would have pants-soiling levels of crazy if jammed into a Steampunk universe's literary cornhole by a wandering narrative redneck. Not that we couldn't do with some brain-sphincter widening these days. Jam it in! Jam it in hard enough for me to feel it in my frontal lobe!

But I digress. Let me think about a more realistic historical airship.

Military vessels will be more concerned with profile, the amount they expose themselves to the enemy, and the ability of exposed parts to be hit or even disabled without outright downing the entire vessel. Something of a 'circus tent' of lightly armored cloth that envelops the lift-bags without actually touching them would prevent the enemy from taking pot-shots at them from a distance or trying to detonate a shrapnel bomb over the airship. This would also probably be lighter than attempting to armor every lift-bag individually... which is good because there will be precious little metal on an airship besides the weapons and engines. As you are most likely to take fire while facing the enemy, zeppelin dogfights being rare to the extreme, you would want a long, narrow ship with angled sides on the front. There should be one primary long range cannon facing forward and an armed crow's nest above.

Hm. I'll have to think about the exact build.
Sareth wrote:I'm actually going to rule that this is definitely a case of coitus interuptus prematurus gawdammiticus.
BonnieBrilane
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Re: Building the Better Airship

Post by BonnieBrilane »

maintains its buoyancy with a series of gas-filled bladders. And unlike hybrid airships, the Aeroscraft doesn't require forward momentum to generate lift via a set of wings. It's all helium power.
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