Physics ruins all our Fun: Luxury airship edition

This “concept airship” by Dassault keeps showing up on the interwebs, so I did some quick math to calculate the weight of the water in that swimming pool.

Nonsense Luxury Airship Concept from Dassault

Based on the size of the human figures (assuming the people are 6 feet tall), and assuming the pool is 6 feet deep, a very rough estimate of the water in that pool would be 30,240 cubic feet, or 226,210 gallons, or 1,886,591 pounds.

Just to lift the water in the pool alone would require 31.4 million cubic feet of helium at 60 lb lift per 1000 cu. ft.

 That’s 4-1/2 Hindenburgs.

Of course, the airship would need to lift more than just the pool: Engines, anyone? Fuel? How about that hard carapace of a shell?

This “airship” has as much chance of floating in the air as Hugo Eckener after a meal of sauerbraten and kaiserschmarrn.

Which is good, because placing two million pounds of water above the lifting gas would cause this thing to capsize and dump all those people onto the pretty mountains.

And at that altitude, high above those mountains peaks, the helium would expand so much the airship would have to be vastly larger than in that illustration.

And the water in the pool would likely freeze into a block of ice without some rather effective — and heavy! — heating system.

But when some people think about airships, they forget about physics.

Bless their hearts. 🙂

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Skystare
Skystare

A pool on top threatens to be dull anyway – might as well be on a cruise ship. For real vertiginous thrills hang it underneath, with a transparent bottom. At a reasonable size, say 24 x 8 x 4 feet deep, the water would weigh 23 tons; within the capabilities of the big rigids, especially as it could double as ballast.

Skystare
Skystare

And why have a pool on top anyway? Ordinary, even dull – might as well be on a cruise ship. A pool underneath, with a transparent bottom would be far more vertiginously amazing. It could even be actually done, if kept to smallish proportions. An 8′ x 12′ pool 4′ deep would weigh a mere 11 tonnes. Might as well get two uses out of the water ballast!

Alastair Reid
Alastair Reid

The greatest problem lies in dealing with expectation. One modern airship designer, Roger Munk, (whose company was responsible for the Skyship 500, 600 and 1000) noted: “People either think that airships can do nothing or everything. Very few people realize what their true capabilities are.”

Tayo
Tayo

In terms of heat, I see a huge greenhouse on top of that ship. Cooling, rather than heating, will be their primary concern. Fortunately, with so much available surface area, solar is implemented.

Tayo
Tayo

What about the fact that this ship is not lighter-than-air? Looks more like a lifting-body dirigible, with wings. Those wings are at least as long as a 747’s, but with longer chord lines. At almost 1,000,000 lbs, a 747 can remain straight and level at 120kias. That has to affect the math.

The Hindenburger
The Hindenburger

Very Intresting, but if the pool were to be removed, and at a lower altitude it would be a cool consept with solar panels running electric motors.

Michael Grace
Michael Grace

The up in the air “pool problem” reminded me of the little engine that couldn’t make it. The Denver and Rio Grande RR commissioned the Prospector. The overnight train between Salt Lake City and Denver via Grande Junction offering coach and Pullman accommodations. There was an observation dining area. The train was inaugurated November 17, 1941. Budd Company-built diesel multiple unit trains numbered M-1 and M-2 built for the ordered streamlined train. But the trainsets had significant reliability problems. The steep terrain, with a full load, make it impossible for the train to get over “the mountain” and the train… Read more »

Alvaro Bellon
Alvaro Bellon

And you can add using airships for fighting forest fires. You would only have capacity for a”few buckets” of water to drop and would have to contend with the severe up and downdrafts caused by the intense heat below.

These ideas are not practical and are usually developed by “visionaries” who do not understand the physics (and constraints) of buoyant flight.

Kalab
Kalab

Isn’t it the visionaries that create the playground for the physicist to do their math. Combine those minds and things happen.

Michael Hopp
Michael Hopp

Rather reminds me of the old 50s era atomic airship that left no room for lifting gas…