Monday, June 29, 2009


Sail to Steam
Wood to Ironclads
Dreadnaughts to Carriers

Carriers to ?????

Consider the magic of Carbon. Building a ship or aircraft out of carbon results in more structural strength than the metals of the past. Building an aircraft or ship out of carbon gives it a natural "sink" that absorbs electromagnetic radiation; making the aircraft or ship more "stealthy" than before. Shaping a carbon constructed ship or aircraft can cause it to reflect radar away from the emitter; again, more stealthy than before. This is, after all, much of the premise behind the B-2 Bomber, or Sea Shadow ship.

Now, enlarge the vision. Hearken back to the giant dirigibles of the 1930's...constructed then out of aluminum and canvas. Substitute Carbon for those materials. As carbon is almost half the weight of aluminum, and several times stronger than steel of the same weight, it would be possible to re-create those giant airships of the past, in exact dimensions as before, but using the new carbon materials; end up with craft that weighed almost half; thereby increasing their payload by that much; and, making them stronger as well.

Consider a new type of Navy; one that can take full advantage of the "Aerial Ocean".; one comprised of flying ships. From small craft carrying a dozen crew members, or giant flying aircraft carriers carrying new UCAV aircraft.

Ships that can fly overland; without worrying about "draft" or shorelines, or ice. Ships that simply float in the air; that can hover, or land and take off straight up and down like a helicopter.
Ships that can land in the water, or land on any unprepareed empty field.

Ships without range limits, or re-fueling needs. As airships are by their nature, very large, they can carry large arrays of solar cells. Coupling these with other forms of power generation such as fuel cells or similar technologies; it is possible to create ships that fly without need of any fuel

Airships can carry immense payloads; these can be configured in almost any form of defensive or offensive manner wanted.

An "Aerial Ocean" Navy, more versatile than the longer limited to the water.


Scott B. said...

Campbell said : "Coupling these with other forms of power generation such as fuel cells or AIP"

Why would an Airship need AIP (Air Independent Propulsion) ?

Just askin'...

campbell said...

Hello! Finally found this on 2 July.
No......airships certainly wouldn't need Air Independent Propulsion. I had written that in another place; writing to quickly and posting the comment before giving it a proof-read.

my bad! (good catch though!)

Tugboat said...

In the spirit of being openminded (on my part) about airships... as a design exercise, what would expect capability and design-wise from the airship equivalent of a destroyer? In the sense that a destroyer is one of the smaller vessels that receives independent tasking, and can both attack other ships or shore targets, and defend itself? Something good for showing the flag, and not likely to be destroyed in the first 5 minutes of a shooting match? Being that power systems are my background, I'll ante up: Solar panels are nice, but we're several generations of solar panels away form making them light enough for practical use on a combat airship; I know one of the strengths is lifting power to burn, but in a small capable combatant I wouldn't want to waste weight allowance unneccesarily. I posit that radioactive thermal decay generators are crying out to fill the power supply niche. They have proven themselves as power supplies in deep space probes; we're talking 5-8MW each, no moving parts, totally scalable without redesigning the basic unit. Shielding would be an issue, but for the power-to weight ratio, one could bury the TDGs deep in the ship surrounded by the He cells, with some lead right around the TDGs for attenuation.
The kind of power those would deliver (without needing refuelling for years) would allow the ship to operate muh like nuclear subs; range limited only by food and spare parts. Power for sensors? Check! Power to run DEWs for point defense? Check!

Sorry for the long post :) Got into theory today when I should have been working...

I know that you are referred to as Campbell on Information Dissemination; do you prefer Darrell, or Campbell here at your home?

Darrell Campbell said...

Hello Tugboat! thank you for dropping in. Darrell is fine here, or Campbell. Whatever makes a guest comfortable.

Hmmmmm....a destroyer sort of airship? I'm going to suggest something along the idea of 300' long x 180' wide x 75' deep. A little over 2Million cu. ft; or, a total lift capacity of approx. 60 tons. That should be large enough to carry something like VLS for offense, sufficient self defense sensor and missiles, (large enough for radar array similar to Ageis?) maybe. Power is the question.
Thin Film solar cells can do the job; but used as low speed/long linger time propulsion only. for high speeds, a back-up, diesel fueled JET propulsion would be good.
We then move on to such things as fuel cells and small nuclear plants, as you suggest. Yes, these would be excellent. Some political ramifications of using them, plus the mentioned dangers of losing control of the airship somehow....

your comments, nicely considered. thank you again. Darrell

tugboat said...

While I am still sceptical of the overall military usefulness of airships, if I don't approach it with an open mind, then I'm not helping anyone. And as I pointed out to someone on ID, no one started out putting guns on helos, and when they started arming helos, no one dreamed of the AH-64...
I started my thinking in SAE, but went metric for the ease of mental math (being 1m^3 of He can lift 1kg)... I started playing with the math a bit; the Graf Zepplin carried about 105,000 m^3 of H, and had a useful load of 60,000kg, which at first glance means that about 40% of the total lift was absorbed by structure, engines, hotel load, etc. Staying conservative on the design side, say one could get the sum total of those loads to 30% for a given gas volume. A ship with 85,000m^3 of He would yield just shy of 60 metric tons of useful load. The problem as I see it is that a Tomahawk weighs 1,311kg (source:Raytheon), so I would see these being limited in number aboard. Say maybe a 10-cell VLS, which is good enough for the 688I submarines. That's about 15 tons, if we fudge for launcher weight. If we're willing to accept the 'bomb-bay drop-launch' method of deploying the TLAMs, it might be a bit lighter, and the structural requirements aren't so high (no need to resist launch forces). That gives us about 45 tons for defense and hotel loads, although crewing would be pretty minimal by naval standards.

I type too much... I'll take a break :)

Darrell Campbell said...

Thank you for your continued considerations. I'd quickly agree, bearing in mind my very limited knowledge of missile weights, etc.

As you point out, development of airships for the military will and should be, a gradual step-by-step upwards in scale and capabilities. Whether commercial, or military, I've seen more than a dozen other would-be airship programs go down because they tried to bit off to much, to soon. (DARPA Walrus and CargoLifter as examples).

Start small, test, learn, build larger. Seems to be fairly obvious, but tends to get lost in the giant airship dreams of many.

tugboat said...

I'm going to have to do some math research... figure out how much power is req'd to resist wind or do a certain speed for a given aero profile. The smaller the airship gets, the less favorable the power equation is with solar cells, but the bigger it gets, the worse the wind resistance is. Must be a critical point where the cells win out, somewhere.

Darrell Campbell said...

Hello. I'll look forward to reading what you come up with. Just as you write, drag is an increasing problem with size; and size determines solar gain. However, there are some other things to factor in re: Turtle.
First, the use of a lifting body shape gives added aerodynamic lift that a typical "blimp" shape does not; and so offsets the drag in some measure. Not much, but needs to be considered.
While the faceted hull of the Turtle does increase drag, at the same time, that serves to break up a boundary layer. how much, or how that effects flight is unknown just yet.
One of the reasons why the Turtle uses dual propulsion is to allow it to generate thrust that the electric motors will not reach; so, high speeds (overcome drag) is largely a task of the jet engines; not the solar.

Too....when DARPA first began the Walrus airship program, it was supposed to use an ion drive. this would have been able to reduce drag on the hull by up to 30%; doesn't mean that we'll be using it on commercial airships...but military use might happen eventually.

Anonymous said...

How much volume does such a ship need to carry the equivalent of an LPD or an LHA for example?

Does such an airship have a chance to escape optic detection?

Thanks a lot for the answers.

Darrell Campbell said...

I do not have enough knowledge about the weights of cargos/equipment/personnel CARRIED by either of these craft.

Although it is feasible to build airships of greater size and capability; we deliberately choose to keep them "smaller", meaning no greater than 600 feet in length.

As a Turtle Airship always measures the same ratio of length/width/height of
(5):(3):(1.25)....this makes it 600 feet long, 360 feet wide, 150 feet high. about half the lengh/height of a marine aircraft carrier. how visible this might be is comparable as well; except that the airship would present a lower and cleaner profile than the carrier.

in practice, we propose that such airships fly only a few meters above the sea surface under most mission parameters.

this 600' x 360' x 150' would have a volume of approximatly 16 Million cubic feet (Hindenburg was 7 million).

total lift would be just more than 500 tons. if we allow one third of this weight as an allowance for the deadweight of the airship, this would give us an approximate 340 ton payload capacity.

how much cargo/equipment/personnel this 340 tons would unknown.

as ever, just making the airship larger increases payload considerably. the geometric volumetric constant says that if we DOUBLE the dimensions of an airship (to 1,200' x 720' x 300'), we could increase the payload by EIGHT 2,700 tons.