An airship design question

Could we see floating air-ports built, where massive airships transports/cargo haulers dock and unload, and never have to come into the turbulent air near the ground, as passengers and freight ascend and descend within the massive tethers?
:eek::eek::eek:Except, I don't see why it couldn't be done.

I don't think it would be. First, how do you tether it? What with? Where do you put it? (Over a city would seem to be the most logical place, but what happens if the tethers break?:eek::eek:) And there's the issue of delivering freight & passengers to it. I imagine a funicular up the tether(s), but is that cheaper than landing the airships at a conventional (more/less) airport? And how resistant to storms/high wind is it? Or is it winched down if really inclement weather threatens?
the only limit would be on available structural materials for the frame and envelope.
And that is the key question I started by asking... Only everybody's gotten sidetracked by cool applications.:rolleyes: (Not immune, myself, I know.)
 
Back to your original question then, Here is a link to the Hindenburg of OTL, with the question of it's weight. Frame weight is not the same as total weight, of course, so we need to know what portion of the 242 tons were taken up by the frame, and then, using your numbers from the OP, find out how much lift we would be talking about.

Hindenburg-Class airship

Wiki says it held 200,000 cubic metres (7,062,000 cu ft) of gas in 16 bags or cells with a useful lift of approximately 232 t (511,000 lb). This provided a margin above the 215 t (474,000 lb) average gross weight of the ship with fuel, equipment, 10,000 kg (22,000 lb) of mail and cargo, about 90 passengers and crew and their luggage.
This still doesn't give us the value we need/want, but it does give us some useful information. What % of the total tonnage should we guess is the actual weight of the frame? Once we have this, and using your "Just as strong, but only 10% of the weight" from the OP, we can begin to guesstimate how much additional lift capacity would be usable for cargo/passengers.

It's your thread, so give us your best guess.
 
Could we see floating air-ports built, where massive airships transports/cargo haulers dock and unload, and never have to come into the turbulent air near the ground, as passengers and freight ascend and descend within the massive tethers?
:eek::eek::eek:Except, I don't see why it couldn't be done.

I don't think it would be. First, how do you tether it? What with? Where do you put it? (Over a city would seem to be the most logical place, but what happens if the tethers break?:eek::eek:) And there's the issue of delivering freight & passengers to it. I imagine a funicular up the tether(s), but is that cheaper than landing the airships at a conventional (more/less) airport? And how resistant to storms/high wind is it? Or is it winched down if really inclement weather threatens?
For something like OTL airships, I don't see them going much beyond ocean liner size/panamax freighters.
I'm not seeing why not. Hindenburg was already that length (almost), & only carrying a maximum 72 passengers.

Postulate a craft 6000' long & 1000' diameter, or a volume about 55x Hindenburg's. What would her freight lift be? Is there a market for moving that much cargo at around 200mph as cheaply (almost) as a freighter? I think there is. Airports will have to be redesigned to handle that much freight at one time...given the "flying airport" isn't in place & able to.

So, too, if they're to cope with 2000-4000 passengers per airship.:eek:
the only limit would be on available structural materials for the frame and envelope.
And that is the key question I started by asking... Only everybody's gotten sidetracked by cool applications.:rolleyes: (Not immune, myself, I know.)
 
Back to your original question then, Here is a link to the Hindenburg of OTL, with the question of it's weight. Frame weight is not the same as total weight, of course, so we need to know what portion of the 242 tons were taken up by the frame, and then, using your numbers from the OP, find out how much lift we would be talking about.

Hindenburg-Class airship

This still doesn't give us the value we need/want, but it does give us some useful information. What % of the total tonnage should we guess is the actual weight of the frame? Once we have this, and using your "Just as strong, but only 10% of the weight" from the OP, we can begin to guesstimate how much additional lift capacity would be usable for cargo/passengers.

It's your thread, so give us your best guess.
[OT]
Anyone have a copy of GURPS Vehicles?
 
I don't think it would be. First, how do you tether it? What with? Where do you put it? (Over a city would seem to be the most logical place, but what happens if the tethers break?:eek::eek:)

{first} We would need a tether that includes multiple freight/passenger elevators, the elevators must be designed to remain upright, while ascending/descending within a non-vertical (the tether will not be perfectly straight, ever), moving (it will not be perfectly still, ever; re moving air masses, at different altitudes/speeds/directions) hollow tube. This sounds more complicated than it probably is, but then too, we would need to know how such a tether moves in various wind conditions, to get an idea of how long any given section of a tether can be between platforms. Say for instance, a tether is good in any normal wind conditions, with acceptable tolerances in vibration/swaying motions, for a length of 1km. If such were the case, then a platform riding at 10km would need to have 10 small 'platforms' for firming up the stability of the tether all the way up to the main construct. You'll have to find someone with the proper engineering/science background to answer the second part. I wouldn't put these above inland cities for the most part, but rather offshore. One thing that ground based ports/air ports have in common, is the cost of the land that they take up, but not so with these. If the tether breaks? Something like what happens when a huge skyscraper falls, I would imagine, IE, was the engineering insufficient, or was the disaster caused by some other force? In either case, would we see changes made, and newer and better constructs built, or the end of the concept?

And there's the issue of delivering freight & passengers to it. I imagine a funicular up the tether(s), but is that cheaper than landing the airships at a conventional (more/less) airport?
I would think that getting to and from would be very cheap, fast, and cost effective, assuming that the whole tether system can be built in the first place, that is. If we lack the material sciences to built something light and strong enough, then the idea is stillborn, but considering our lift capacity, I doubt the weight factor will matter at all.

Postulate a craft 6000' long & 1000' diameter, or a volume about 55x Hindenburg's. What would her freight lift be? Is there a market for moving that much cargo at around 200mph as cheaply (almost) as a freighter? I think there is. Airports will have to be redesigned to handle that much freight at one time...given the "flying airport" isn't in place & able to. So, too, if they're to cope with 2000-4000 passengers per airship.:eek:
Oh, I agree that freight that can be moved 10 times faster than by the fastest merchant shipping, and can ignore geographical restrictions regular ships cannot, is likely to be a huge market, but...Using your own figures, you now have lighter than air airships coming into an airport that needs to eat up far more costly land than what we now have, and this doesn't address any of the OTL problems with surface winds common to all airships, with or without better lift capacity from improved material sciences.

And how resistant to storms/high wind is it? Or is it winched down if really inclement weather threatens?
I was rather thinking in term of the platform being above the weather, not in the weather.

I have not gotten your best guess yet, so I don't know what ball park is within your thinking, but...

Say that the OTL hindenburg's 215 tons weight, is 160 tons of frame. I don't have any clue, so this is just a number off the top of my head, but going with that...

So, our OTL Hindenburg's weight now has it's frame weighing in at a mere 16 tons (As per you OP), so 215-160=55 tons weight not reduced by better frame construction materials. We now add: 55+16=71 tons weight, and arrive at the ATL Hindenburg's weight, and this subtracted from the lift capacity of ~232 tons, gives us 144 tons usable lift capacity, while retaining the original 17 tons safety margin. These numbers, if my groggy mind is doing the math right, are based upon your premise, and my USWAG (Un Scientific Wild Ass Guess), so feel free to swap these numbers out with your own.

In other words, the OTL Hindenburg could haul ~11 tons cargo and about 90 people & all the junk they needed, whereas your ATL Hindenburg could haul ~144 tons. As these are just very rough guesstimates, lets just simplify it to say 110 tons, or ten times more. Thus, the Giants you mentioned up thread, would be able to handle ~6,000 tons.
 
Last edited:
{first} We would need a tether that includes multiple freight/passenger elevators, the elevators must be designed to remain upright, while ascending/descending within a non-vertical (the tether will not be perfectly straight, ever), moving (it will not be perfectly still, ever; re moving air masses, at different altitudes/speeds/directions) hollow tube. This sounds more complicated than it probably is, but then too, we would need to know how such a tether moves in various wind conditions, to get an idea of how long any given section of a tether can be between platforms. Say for instance, a tether is good in any normal wind conditions, with acceptable tolerances in vibration/swaying motions, for a length of 1km. If such were the case, then a platform riding at 10km would need to have 10 small 'platforms' for firming up the stability of the tether all the way up to the main construct. You'll have to find someone with the proper engineering/science background to answer the second part. I wouldn't put these above inland cities for the most part, but rather offshore. One thing that ground based ports/air ports have in common, is the cost of the land that they take up, but not so with these. If the tether breaks? Something like what happens when a huge skyscraper falls, I would imagine, IE, was the engineering insufficient, or was the disaster caused by some other force? In either case, would we see changes made, and newer and better constructs built, or the end of the concept?

I would think that getting to and from would be very cheap, fast, and cost effective, assuming that the whole tether system can be built in the first place, that is. If we lack the material sciences to built something light and strong enough, then the idea is stillborn, but considering our lift capacity, I doubt the weight factor will matter at all.
That sounds right. It also sounds like we're beyond the limits of known materials. Even something like Kevlar +P, maybe 10x stronger, seems overmatched, here.

Second thing, tho, is a big one: putting these only offshore seems to contradict the usefulness of giant airships in the first place. If you can't (effectively) use them over CONUS, except as flyovers...
Oh, I agree that freight that can be moved 10 times faster than by the fastest merchant shipping, and can ignore geographical restrictions regular ships cannot, is likely to be a huge market, but...Using your own figures, you now have lighter than air airships coming into an airport that needs to eat up far more costly land than what we now have, and this doesn't address any of the OTL problems with surface winds common to all airships, with or without better lift capacity from improved material sciences.
Okay, fair point. OTOH, usefulness, as noted, means you swap to heavier-than-air from the "ports", or go to trains or truck--& that creates an enormous bottleneck.
I was rather thinking in term of the platform being above the weather, not in the weather.
Maybe we're disagreeing on the definition of "weather", here, but I'm thinking, any storm system going through is going to produce effects on the "port", unless they're tethered extremely high--& even moderately high is pushing the boundaries on tether material strength.
I have not gotten your best guess yet, so I don't know what ball park is within your thinking, but...

Say that the OTL hindenburg's 215 tons weight, is 160 tons of frame. I don't have any clue, so this is just a number off the top of my head, but going with that...

So, our OTL Hindenburg's weight now has it's frame weighing in at a mere 16 tons (As per you OP), so 215-160=55 tons weight not reduced by better frame construction materials. We now add: 55+16=71 tons weight, and arrive at the ATL Hindenburg's weight, and this subtracted from the lift capacity of ~232 tons, gives us 144 tons usable lift capacity, while retaining the original 17 tons safety margin. These numbers, if my groggy mind is doing the math right, are based upon your premise, and my USWAG (Un Scientific Wild Ass Guess), so feel free to swap these numbers out with your own.

In other words, the OTL Hindenburg could haul ~11 tons cargo and about 90 people & all the junk they needed, whereas your ATL Hindenburg could haul ~144 tons. As these are just very rough guesstimates, lets just simplify it to say 110 tons, or ten times more. Thus, the Giants you mentioned up thread, would be able to handle ~6,000 tons.
I found numbers for Los Angeles, so let's use that: loa 200.7m, diameter 27.6m, empty weight 35.3 tonnes, max lift (100% hydrogen) 81.3 tonnes (useful, 46 tonnes). So, if the structure is 9x stronger, empty weight is around 3.5-4 tonnes, useful lift is around 77 tonnes; at 6000x1000', that's just over 100x more volume, so... Call it 7000 tonnes. (Which is a lot less than I guessed it would be...)

And I'm back at the question of maximum size. A 6000'-long:eek: flying machine sounds insane, but...is that actually an upper limit? is there a real engineering reason an airship can't be bigger? Or do we start getting into practical reasons they wouldn't be, per the "skyport" idea?

One other thing I should mention: given over 100yr development, I'm presuming many of the issues of ground handling in the face of surface winds have been solved by use of hull-mounted, swivelling thrusters. That being so, it might be possible to bring even big airships into existing airports.
 
LCZMywt.jpg



Those wacky Soviets had a plan for a nuclear-powered airship. 300 meters long, helipad, contained aircraft...
But notice, there's no room left for LIFTING gas.!!!!
 
Top