[Professor Mega-Mind (OP)]

       Heavier than air Airships
 Are these a good idea ?  It is hereby put forth that they are .  Slightly heavier than air , lifting-body airships could be extremely fuel efficient , extremely quiet & comfortable , extremely controll-able , extremely safe , and extremely convenient as well .  The very-low thrust requirement means that extremely efficient , alternative fuel drivetrains can be used . Traveling directly from city-core to city-core would become entirely practical , as would close-up , directly over-head eco-tourism .  Both mech-anical malfunction , and terror-strike , would be greatly reduced in terms of the danger they posed to the passengers & crew of these craft .  Their physical performance , and avionics , would be good enough to keep them well away from any bad weather that might head their way .  Travel times would be comparable to those for general aviation , or helicopters . 
Overall , modern technology ensures that these airships would realize the potential that their 20th century predecessors evidenced so long ago .
The preposition here is that changing societal needs call for changing technological archi-tectures and paradigms .  HTA. airships could fulfill many 21st century needs beautifully . 
That's all for now , folks !...P.M.

[Kryptid]

You're not the only one who thinks they are a good idea: https://inhabitat.com/the-dynalifter-could-transport-160-tons-of-freight-using-less-fuel-and-money-than-a-jet/

[Professor Mega-Mind (OP)]

                       Airships
Riddle me this:Would a flying-wing version , with a more airplane-like construction and performance , be a worthy idea also ?.....P.M.

[syhprum]

The Hindenburg was a success comparable to the Concord creaming off wealthy customers who wanted more speed and comfort than the liners would provide.
Unfortunately the use of Hydrogen as Helium was not available turned what may well have been a relatively minor incident into a spectacular fire (although half the passengers survived) that led to its successors being scrapped at the start of WWII. 

[Professor Mega-Mind (OP)]

 You are one right syprum-dude !
What would you rather be on when the Mad-Bomber strikes ?  Me , I'd rather sink back to Earth , than auger in !.....P.M.

[alancalverd]

Analysis of the Hindenburg fire shows the problem was more the fault of the aluminum-impregnated fabric than the hydrogen fill.

The "Flying Bottom" is a regular sight around here, though it spent more time on the ground than in the air recently. Definitely has potential.

[Professor Mega-Mind (OP)]

 Kind of resembles NASA's recent
" Double Bubble " design , eh ?
 Interesting that when the Akron & Macon went down , the initial crashes were non-fatal .......P.

[Supervolant]

I hope so...

I would love to see them again. I especially like the heavier-than-air approach making them less prone to wind sheer as these flying giants were really dependent on good weather. These airships filled with a lighter then air gas would be really expensive tough.. Hydrogen is a huge Nono... no matter then safety precautions no-one does wan't so see something flying again what essentially is a flying bomb. Helium is good enough and offers just marginal less lift. But one has to count in that Helium is a very finite resource dependent on radio active alpha decay which needs millions over millions of years to be created in useful ammounts! Our Helium is about to come to an end and we need it more for clinical and industrial use cases then we do so for something flying. (tough I love everything flying). Tough I do believe that helium asteroid / moon mining becomes a thing before we run out of it.

Let's put the scarcity of Helium aside for a moment. Let's see the lifting power of a 100 meter diameter spherical balloon.

Sphere Volume = 4/3 x Pi x r3

= 4/3 x Pi x 50m3

= 4/3 x Pi x 125000

Sphere Volume = 523.598,78 m3

1m3 of Helium Lifts about 1,11 kg

523.598,78 m3 x 1,11kg = 581.194,64 kg

This quick calculation shows a 100m diameter spherical balloon can lift 581 tons. Thats the very extreme dry weight of course! One has to subtract any weight used for construction.  To comparison: A Containership usually carries around 1000 containers filled with 15.000 - 18.000 tons. The largest ones are able to carry up to 25.000 tons!

Even tough our Airship would only be able to carry a very marginal amount of something in comparison to our naval brothers the Airship would be about +3 times faster and can overfly water and land. Directly leave cargo where it's needed, a huge logistical win!

For cargo a good Idea? I actually believe yes! We could even build way larger Airships making them even more commercial. And such a large Airship delivers more then enough space for solar cells. Flying over the clouds with near maximum sun irradiation one would be completely self sustaining!

Also a good Idea for people? Not so much.. Way too slow. One can easily travel by plane and is +20 times faster then one inside an Airship no matter how innovative the propulsion system. A huge Airship has literally tons of drag one has to overcome in the first place.

But for the super rich? Well multi billion dollar yachts are a thing, so why not flying ones? I would certainly buy a flying mansion if I would have the money. A wonder none have been made yet. I have to do some other stuff beforehand but in some years from now I will take this challenge on for sure! (actually the reason why I answer on this topic, as this is cargo and yacht airship topic is of extreme interest to me)
Imagine a flying mansion with your private rooftop VTOL Aircraft Landing place... one would be a true citizen of the world!

Modify:

Now to your heavier-than-air approach. Just realized something. I wan't to give you credit for "solving" a huge problem in airship design. Counter balancing is the keyword. Whenever a passenger steps inside an airship it usually drops blast in the shape of water being thrown out. This counter balancing makes airships extremely unhandy... But when one builds an airship so it's perfectly balanced with and without payload the airship would rely solely on it's propulsion system and way less on it's lifting gas. I put "solving" in quotes because the problem has just been stated, now one has to come up with a technical solution in order to really solve it. Takes some time for me but I will find it.... Thank you.

[Bored chemist]

If the wind is in the wrong direction they become hugely inefficient because they present a massive cross section.

[Professor Mega-Mind (OP)]

To : Supervolant
Glad you see the advantages of a heavier-than-air airship .  I figure steerable , contra-rotating , ducted , turboprop engines , combined with a streamlined lifting-body shape , would allow for jet-class altitudes with turboprop-class speeds .  No need to vent , compress , or dump anything .  Just have enough thrust for VTOL capability at max. TOW .

[Bored chemist]

Just have enough thrust for VTOL capability at max. TOW .

That'll; be fun when it's windy.

[Supervolant]

Just have enough thrust for VTOL capability at max. TOW .

That'll; be fun when it's windy.

@Bored chemist I believe what Professor Mega-Mind is talking about are rigid body - rigid shell airships, thats why the term heavier then air in contrast to lighter then air airship comes up. These airships in comparison to soft body - soft shell "blimps" can be designed to be structurally sound while giving sheer winds less aerodynamic resistance then current and old age airship designs. I believe a saucer shape to be one good design since it would have ist major surface area up and down. VTOL - Tech can balance up and down moving air streams but most of the weather comes from the side where the overall surface area of a saucer shape would give the wind less surface area to attack on. Making the ride in fact fun.

People inside the Hindenburg were capable of balancing a pen horizontal for hours (in standard weather conditions). Airships are incredibly stable and vibration free.

_

@Professor Mega-Mind I am all in for revolutionary technologies setting new benchmarks for whole industries. Do you have made any construction plans or at least sketches? Would love to see them.

[Professor Mega-Mind (OP)]

I have had them on my internal blackboard for several years , however , there are several lifting-body designs out their that would approximate these .  Try sizing up the later flying-wing designs .  Also the various Airfish , and even Flying Flapjack designs are good starting points .  In the end , form follows function .
......... P.M.

[Bored chemist]

The point of the gas bag bit is to reduce TOW.
So, if that works properly TOW will be small (in principle, you can have it negative with the engines holding the ship down when you need to land)
And if you then say "Just have enough thrust for VTOL capability at max. TOW ."
you have specified that you want very little thrust.

With the best possible profile- and saucer shaped might be a good choice- you still have a craft with a large drag.
So, in all but the lightest wind, the thing will go whichever way the wind blows.

Essentially Professor Mega-Mind hasn't realised that TOW isn't the thing you use when you want to establish the thrust you need.

[Professor Mega-Mind (OP)]

Think flying saucer , as in the Jupiter 2 .  Cross-wind have minimal effect .  The is at 30% weight with helium at sea-level .  Vectored thrust is strong enough , but not gas-guzzling .  Exhaust velocity is surprisingly high , as is fuel economy .  Safety is incredible , as is mission flexibility .
Of course the parameters are fully adjustable .
.....P.M.

[Bored chemist]

Think flying saucer , as in the Jupiter 2

Were you expecting to be taken seriously?

[Professor Mega-Mind (OP)]

Hey , flying-saucers have their strong points !
......P.

[alancalverd]

The fuel efficiency of airships is partly due to their low speed, since drag increases with the square of indicated airspeed. If the only competition is a ship, then the airship in general has an advantage with an airspeed of up to 100 kt over long distances, but a headwind will directly reduce groundspeed whilst a large surface ship can proceed at 20 kt under almost any conditions and can thus provide a more reliable scheduled service.

Matters are slightly complicated by passenger comfort considerations. 100 kt from surface to cloud base can be very rough, but once you get above cloud the wind speed increases significantly and you can be flying backwards at 15,000ft in the UK. Climbing and descending through active cloud requires a certain determination in any machine, and nerves of steel if the beast is only marginally denser than air.

However if you are looking for adventure, want to loiter over a target, or need to deliver something to the middle of nowhere and beyond the range of a helicopter, the HTA airship has a lot going for it.

[Professor Mega-Mind (OP)]

............Boeing X-48C  BWB
Take this concept craft , enlarge it to 300' by 300' .  Thicken it significantly , install permanent helium chambers to reduce MTOW to 200 klbs.  Have 4 rotatable contra-rotating hi-perf. ducted turboprop disk assemblies w/internal gas turbines , and external free turbine drives , providing 300 klbs. of static thrust , mounted quadrilaterally about the aircraft .  Make the craft's surface completely rigid-shell , and designed for 400+ mph at altitude .  Include tie-down capability for extreme weather .  Such an aircraft would provide the capabilities of both airplanes & helicopters , while having the fuel efficiency of an airship .  This craft would be highly resistant to bomb or missile , and extremely unlikely to actually crash .
Overall , the combination of HTA & Rigid Shell design would add new abilities , and safety factors , to an increasingly challenged aeronautical industry .
..........P.M.

[Bored chemist]

OK let's do a  "back of an envelope" calculation.
It's roughly 100m by 100m; that's 10,000 square metres*
And you are talking about 300,000 Lbs of thrust
That's about 150 tonnes or 1.5MN
About 150N/ m^2

And, according to this
https://www.engineeringtoolbox.com/wind-load-d_1775.html
that's the wind loading at about 16 m/s which is about 35mph.

If you have a headwind of more than 35 mph your invention goes backwards.

Did you not believe me earlier?

* yes, I know- but if you make balloons that aren't fairly near spherical, they have too much area (and thus weight) for their volume, and they don't fly