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Cargo Airships Are Happening

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Re: Cargo Airships Are Happening

#11

Post by jordanb »

00N8 wrote: post #5

One challenge I've heard of is: If you carry 100 tons of cargo from point A to point B in an airship, for the airship to return to point A, it needs to take on another 100 tons of new cargo (or ballast), or it needs to vent (or compress) lifting gas, in order to maintain the correct buoyancy. I wonder what the best approach is here, & how it affects the economics? Is water ballast safe & cheap enough, or is there a b…

Yeah although typically they used water ballast, which is cheap and easy to find.

One thing worth considering is going back to hydrogen as a lifting gas. Not only is it a better lifting gas than helium and much cheaper, it could be used as fuel.

An airship that burned its own lifting gas would have the curious property of getting heavier the further it traveled. This could be countered by dual-fueling it and also have engines that burned heavier-than-air fuel like kerosene or propane. The hydrogen engines could burn the lifting gas at the same rate as the kerosene engines burn the ballast-fuel.

Re: Cargo Airships Are Happening

#12

Post by Invictus0 »

dpflan wrote: post #10

What is the current target use-case for this company's airships, the use-case that will get them a consistent business that will allow them to grow? What is the target operating speed considering cargo weight? How much cargo can such an airship carry at its target operating speed such that this is more efficient than air-freight and land-freight?

Read the article dude

Re: Cargo Airships Are Happening

#13

Post by jordanb »

metalman wrote: post #4

Cargo airships will not happen,in any land based area where wind happens,ie :anywhere this has been hammered flat on numerous aviation engineering forums the only way around the guaranteed ground handling debaucle is to engineer mega structur masts for anchoring,which will need to have a circular pad underneath,where the cargo would have to follow the LTA,as it pivots in the wind so back to a debaucle,with lots of sm…

Modern airships are semi-rigid. They have a keel and a rigid structure to support the empennage. The rest of the structure can be deflated and collapsed just like a non-rigid blimp.

Re: Cargo Airships Are Happening

#14

Post by dpflan »

Invictus0 wrote: post #12
dpflan wrote: post #10

What is the current target use-case for this company's airships, the use-case that will get them a consistent business that will allow them to grow? What is the target operating speed considering cargo weight? How much cargo can such an airship carry at its target operating speed such that this is more efficient than air-freight and land-freight?

Read the article dude

Yes, this seems like the best paragraph from the article related to those questions:

Airship Industries is designing its vehicle to dominate transoceanic air freight. It checks all the right boxes. It shortens end-to-end freight delivery time. It lowers freight handling costs, delays, and breakage. It’s highly profitable on a unit basis. It lowers fuel burn and carbon emissions by 75 percent without any sustainable fuel breakthroughs.

How many shipping container can a single airship carry?

Re: Cargo Airships Are Happening

#15

Post by peterashford »

frickinLasers wrote: post #7
metalman wrote: post #4

Cargo airships will not happen,in any land based area where wind happens,ie :anywhere this has been hammered flat on numerous aviation engineering forums the only way around the guaranteed ground handling debaucle is to engineer mega structur masts for anchoring,which will need to have a circular pad underneath,where the cargo would have to follow the LTA,as it pivots in the wind so back to a debaucle,with lots of sm…

I'd bet a bunch of former SpaceX engineers will figure out a solution.

Yeah, dude was head of Hyperloop. Nailed that one

Re: Cargo Airships Are Happening

#16

Post by aaron695 »

labcomputer wrote: post #8
xnyan wrote: post #6

The (biggest) problem that keeps airships from practical use is that they are huge sails. Big sails mean even small amounts of wind can be powerful forces acting on the airship. In the air a big push from the wind might be safely managed, but if you're near anything solid such as the ground, you can get smashed to bits. To safely operate a suitably efficient (large) airship, we'd need both huge specialized docks with…

> There are other challenges too (what do you do when you drop off your cargo and the airship wants to shoot up into the air? Vent gas? Rapidly compress your gas?) Not to detract from your overall point, but you do the same thing you do when burning fuel while cruising: Add ballast. Yes, but how do you add ballast to an airship while it is underway? Simple: condense water out of the exhaust like the zeppelins did.

[dead]

Re: Cargo Airships Are Happening

#17

Post by jodrellblank »

jordanb wrote: post #11
00N8 wrote: post #5

One challenge I've heard of is: If you carry 100 tons of cargo from point A to point B in an airship, for the airship to return to point A, it needs to take on another 100 tons of new cargo (or ballast), or it needs to vent (or compress) lifting gas, in order to maintain the correct buoyancy. I wonder what the best approach is here, & how it affects the economics? Is water ballast safe & cheap enough, or is there a b…

Yeah although typically they used water ballast, which is cheap and easy to find. One thing worth considering is going back to hydrogen as a lifting gas. Not only is it a better lifting gas than helium and much cheaper, it could be used as fuel. An airship that burned its own lifting gas would have the curious property of getting heavier the further it traveled. This could be countered by dual-fueling it and also hav…

The Graf Zeppelin burnt Blaugas[1] because it's about the same density as air, so as the fuel tanks emptied the buoyancy didn't change. See [2] for other things the Zeppelins did, which says "The LZ 127 Graf Zeppelin had bi-fuel engines, and could use gasoline and Blau gas as a propellant. Twelve of the vessel's gas cells were filled with a propellant gas instead of lifting gas with a total volume of 30,000 cubic metres, enough for approximately 100 flight hours. The fuel tank had a gasoline volume of 67 flight hours. Using both gasoline and Blau gas, one could achieve 118 hours of cruise time."

That article mentions that the Zeppelins experimented with burning Hydrogen lift gas as fuel "without much success" but doesn't add detail.

[1] https://en.wikipedia.org/wiki/Blau_gas

[2] https://en.wikipedia.org/wiki/Buoyancy_compensator_(aviation...

Re: Cargo Airships Are Happening

#18

Post by jodrellblank »

cookiengineer wrote: post #9

I think this has actually great potential for fruit transports. Many countries export and import fruits from neighboring countries, because goods like fruits need a riping process and time, and storage space locally is more expensive than transporting them via container ship. For example, almost the same fruits that are exported from Hawaii are simultaneously imported from Chile, and vice versa. Both nations grow tho…

> "if they could invent a storage space .. offshore above the water"

like, a boat?

Re: Cargo Airships Are Happening

#19

Post by zabzonk »

labcomputer wrote: post #8
xnyan wrote: post #6

The (biggest) problem that keeps airships from practical use is that they are huge sails. Big sails mean even small amounts of wind can be powerful forces acting on the airship. In the air a big push from the wind might be safely managed, but if you're near anything solid such as the ground, you can get smashed to bits. To safely operate a suitably efficient (large) airship, we'd need both huge specialized docks with…

> There are other challenges too (what do you do when you drop off your cargo and the airship wants to shoot up into the air? Vent gas? Rapidly compress your gas?) Not to detract from your overall point, but you do the same thing you do when burning fuel while cruising: Add ballast. Yes, but how do you add ballast to an airship while it is underway? Simple: condense water out of the exhaust like the zeppelins did.

> Simple: condense water out of the exhaust like the zeppelins did.

Citation? Would not the condenser need to burn fuel, thus lightening the ship?

Re: Cargo Airships Are Happening

#20

Post by jordanb »

jodrellblank wrote: post #17
jordanb wrote: post #11

Earlier quoted context omitted.

Yeah although typically they used water ballast, which is cheap and easy to find. One thing worth considering is going back to hydrogen as a lifting gas. Not only is it a better lifting gas than helium and much cheaper, it could be used as fuel. An airship that burned its own lifting gas would have the curious property of getting heavier the further it traveled. This could be countered by dual-fueling it and also hav…

The Graf Zeppelin burnt Blaugas[1] because it's about the same density as air, so as the fuel tanks emptied the buoyancy didn't change. See [2] for other things the Zeppelins did, which says " The LZ 127 Graf Zeppelin had bi-fuel engines, and could use gasoline and Blau gas as a propellant. Twelve of the vessel's gas cells were filled with a propellant gas instead of lifting gas with a total volume of 30,000 cubic me…

My understanding was blau-gass was unpressurized propane, which is a little more dense than air. But I guess according to that article it's slightly less.

I'd expect that, like a lot of problems zeppelins had in the 1920s, burning hydrogen would be more feasible with modern technology.

I'd also point out that the thing that made hydrogen dangerous in those airships was that the skin was two layers. The inner skin was the gas bags, which were very fragile, and then the rigid structure and the outer skin to protect the fragile bags. This was a problem because hydrogen could accumulate and mix with air between the inner and outer skins. The outer skin also was quite flammable. Nowadays, we can make materials that are both strong enough to serve as an outer skin and impervious enough to serve as a gas bag for lifting gas, so modern airships have only one skin and nowhere for the lifting gas to mix with air inside the structure.

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