For example an airship-hoist can be more useful than a helicopter. 

it's a kind of balloon in the drawing.

What do you think about a useful h2-aircraft in the future?

 

14 minutes ago, harlock said:

 

For example an airship-hoist can be more useful than a helicopter. 

it's a kind of balloon in the drawing.

What do you think about a useful h2-aircraft in the future?

 

Doubtful as a hoist, since the volume required to lift any significant weight is so large. 

38 minutes ago, harlock said:

For example an airship-hoist can be more useful than a helicopter. 

In what situations?

44 minutes ago, swansont said:

In what situations?

Where there is no space to land while a 'balloon' can be on top tied to the ground with a rope

1 hour ago, exchemist said:

Doubtful as a hoist, since the volume required to lift any significant weight is so large. 

Air weighs ~ 1.225 kg/m3 while h2 ~ 0.09 kg/m3, so 1 m3 H2 
gives an upward thrust of approximately 1.225-0.09(~1 with 2 bar H2) kg/m3 without considering the

airship weight.. therefore the upward thrust'd be 1 ton per 1000 m3 of H2.

Maybe it isn't a wrong volume. 

 

If there’s no place to land, how do you deploy your ~12.5m diameter balloon? 

(roughly the same size as a Bell 407, which can lift more weight and is maneuverable)

1 hour ago, harlock said:

Where there is no space to land while a 'balloon' can be on top tied to the ground with a rope

Air weighs ~ 1.225 kg/m3 while h2 ~ 0.09 kg/m3, so 1 m3 H2 
gives an upward thrust of approximately 1.225-0.09(~1 with 2 bar H2) kg/m3 without considering the

airship weight.. therefore the upward thrust'd be 1 ton per 1000 m3 of H2.

Maybe it isn't a wrong volume. 

 

Yes so 12.6m diameter ballon, if it is approx.spherical, per tonne of lift. (The lifting gear and gondola itself may weigh half that, before you start.) So it’s going to be very big.

Also, unlikely any regulatory body would sign off on hydrogen as the lifting gas, which would mean helium.  Which there's a shortage of, so it's getting expensive.  I've seen estimates that we will run out in 100-200 years unless some other sources are found or ways to reduce loss.  

3 minutes ago, TheVat said:

Also, unlikely any regulatory body would sign off on hydrogen as the lifting gas, which would mean helium. 

C'mon. They want to use liquid Hydrogen inside of regular cars. I have here buses which run on liquid Hydrogen ATM...

 

18 minutes ago, TheVat said:

Which there's a shortage of, so it's getting expensive.  I've seen estimates that we will run out in 100-200 years unless some other sources are found or ways to reduce loss.  

There are smarter ways to use this precious helium than balloons and airships.

 

6 minutes ago, Sensei said:

C'mon. They want to use liquid Hydrogen inside of regular cars. I have here buses which run on liquid Hydrogen ATM...

Liquid hydrogen made from coal tars or gasoline? Are they using fuel cells to power the buses? They tried that here under Bush II, with cells that used petroleum for the hydrogen. It was about as efficient as our burning ethanol from corn to fuel our cars. Have they come up with a way to make H fuels not so dirty? Iirc, it used more gasoline than just burning gasoline.

9 minutes ago, Sensei said:

C'mon. They want to use liquid Hydrogen inside of regular cars. I have here buses which run on liquid Hydrogen ATM...

 

The way hydrogen is contained in a fuel cell or IC system has far less flammability problems than a giant bubble of gaseous hydrogen.  There's a reason blimps are required to use helium rather than Hindenburg gas.  

 

12 minutes ago, Sensei said:

There are smarter ways to use this precious helium than balloons and airships.

Yes.  My point exactly.

4 minutes ago, Phi for All said:

Have they come up with a way to make H fuels not so dirty? Iirc, it used more gasoline than just burning gasoline.

Well, the presumption of the green energy economy is that H fuels will be made cracking water using windmills or other clean sources.  That is the hope for future big rig trucks, where a battery system looks less practical.

Not exactly a hydrogen-powered vehicle accident, but a CNG-powered bus. It starts at the 47-second mark if you don't want to listen to the short introduction:

 

I think the vulnerability of airships to bad weather is their greatest weakness and that isn't different by using hydrogen  - there are uses for them but they are limited.

I am still a bit surprised there haven't been serious efforts to use hydrogen by improving ways to do so safely; I am sure it could be done a lot safer than a century ago. And most zeppelins back then never caught fire. Dramatic examples of things going wrong don't necessarily mean they are very likely or cannot be avoided

 

1 hour ago, Ken Fabian said:

I think the vulnerability of airships to bad weather is their greatest weakness and that isn't different by using hydrogen  - there are uses for them but they are limited.

I am still a bit surprised there haven't been serious efforts to use hydrogen by improving ways to do so safely; I am sure it could be done a lot safer than a century ago. And most zeppelins back then never caught fire. Dramatic examples of things going wrong don't necessarily mean they are very likely or cannot be avoided

 

I wonder what happened to the Flying Bum: https://www.businessinsider.com/photos-see-the-flying-bum-airlander-10-2021-9?op=1

It looked quite an interesting idea and had an emissions profile similar to trains.