A 'safe' version of a hydrogen airship

Working with Gemini,  I postulated an airship with a double layer gasbag. The inner gasbag would contain hydrogen. This would provide lift and act as a store of fuel for fuel cells powering electrically driven propellers. The outer gasbag would contain helium which provides fire risk insulation from the hydrogen. I asked Gemini if such a design was feasible.

Gemini: You've proposed a very interesting and conceptually sound design for a safer hydrogen airship! The idea of a double-layered gasbag with hydrogen inside and helium outside offers a significant safety advantage. Let's analyze its feasibility and discuss a possible cross-section design.

Feasibility: The concept is definitely feasible from a technical standpoint. The main challenges would revolve around engineering and material science rather than fundamental physics.

Material Selection: Choosing appropriate materials for both the inner and outer gasbags is crucial. The inner bag needs to be highly impermeable to hydrogen, while the outer bag needs to be strong and relatively impermeable to both helium and air. Modern materials like multilayer laminates with specialized coatings could meet these requirements.

Weight: Adding a second gasbag increases the overall weight of the airship, which reduces its payload capacity. Set against this is the increased lifting ability of  hydrogen. This is a key trade-off. Careful material selection and design optimization are essential to minimize this weight penalty.

Complexity: Manufacturing and maintaining a double-layered gasbag system is more complex than a single-layered one. This would increase production and operational costs.

Pressure Management: Maintaining the correct pressure differential between the inner and outer gasbags is important to prevent stress on the materials and ensure optimal performance.

Cross-Section Design: Here's a simplified cross-section concept based on the 1930s British R105 airship. I've shown an Airbus 380 fuselage for size comparison:

     Structural Framework (e.g., lightweight beams)

Key Features of the Design:

Outer Envelope: Provides the primary aerodynamic shape and protection from the elements. It also contains the helium.

Helium Layer: Acts as a buffer zone, preventing any potential ignition source from reaching the hydrogen. It also contributes to overall lift, though less than the hydrogen.

Inner Envelope: Contains the hydrogen fuel. This layer must be exceptionally good at preventing hydrogen leakage.

Structural Framework: Provides structural support for the gasbags and connects them to the airship's gondola and other components. This would likely be a lightweight frame made of aluminum or composite materials.

Advantages:

Enhanced Safety: The helium layer significantly reduces the risk of hydrogen ignition.

Redundancy: If the outer gasbag is breached, the inner gasbag still contains the hydrogen.

Disadvantages:

Increased Weight and Complexity: The double-layered design adds weight and manufacturing complexity.

Cost: The use of specialized materials and more complex construction will increase costs.

Conclusion:

The double-layered gasbag concept is a very promising approach to improving the safety of hydrogen airships. While there are engineering challenges to overcome, it is technically feasible and offers a significant safety advantage over single-layer designs. The trade-offs between weight, complexity, and cost need to be carefully evaluated in any practical implementation.

OK industrialists, you have the concept. Feel free to develop and make use of it but remember - I proposed it and you owe me for that.

If I were 'Jaydax Almighty' I would...

[Revisited December 2024. Originally posted 2009]

...re-educate laptop manufacturers who continue to design laptops that can't easily be used on your lap! Your personal laptop would redesign itself so that everything, keyboard, sockets and screen was all on the front edge of the laptop.
Let me give you a hint guys - buttons, optical drives and headphone sockets should NEVER be placed on the front edge of a laptop because they cause problems when it is used on your lap or - heaven forbid - in bed.
My Dell Inspiron 1720 is an example. If it's used on raised knees (in bed) then the front edge presses into you and several buttons are pressed which plays havoc with the sound system and for some reason stops some of the keyboard from working. The buttons Dell tells me are positioned there so I can play sound files with the laptop lid closed. Hey guys, if I want to listen to music I use an mp3 player or my mobile phone. I don't lug a laptop around!
HP Pavillion laptops have headphone sockets on the front edge which mean a jack plug sticks into you and which can give you a mild stinging shock if they touch bare skin.
Front opening optical drives? You have to move the laptop before you can change a disk. While I'm on the subject of computer design i WOULD CONSIGN TO AN ASSYLUM THE IDIOT WHO FIRST PUT 'cAPS lOCK' NEXT TO 'sHIFT'

[Update - For some reason laptop manufacturers seem to think smaller, thinner and lighter equals most desirable. I want a power laptop with bigger screen/s. Make me a 17" one with multiple folding screens and a detachable tablet which acts as a control surface/numeric keypad/extra screen. Those who produce tiny screens would be condemned to a laptop with a five inch screen for eternity.]

...Spray paint silver those who design paint on laptop palmrests. Don't worry about the paint on you guys - it will wear off just as it does when you use a laptop enough. It wears away even faster if you use a mouse on the palmrest. On my Dell the plastic under the paint is grey so it just looks scruffy when the silver paint covering it wears away but my HP has black plastic under it's silver paint scheme and looks awful after just a year's heavy use.


...give a permanent thirst and only £1.00 to soft drink manufacturers who think its OK to charge £1.65 ($2.67) for a bottle of Coca-Cola! You must be kidding. I stop buying the stuff at my local supermarket when its price goes above £1.00 per 2 litre bottle and that price I consider too high considering I can buy 'Cola' for less than 40p. How about a 1 litre bottle of water for 90p ($1.46)? I have a tap at home and water from it which has stood in the fridge overnight tastes just as good.
[Update - Those 2 litre bottles of Coke are long gone. Now we pay £2.49 for a 1.75 litre bottle! I would consign those soft drink manufacturers who think shrinkflation and exorbitant prices to Hell with a perpetual thirst and 50ml bottle of salt flavoured liquid.]

...fill the cars of people who litter roads with 100 times the amount of rubbish they dump. I live in the country on a main road which passes through a beautiful area of Northumberland. Each day I clean up rubbish thrown out of cars. Plastic bottles, fast food wrappers, beer cans, newspapers, plastic bags, used nappies (diapers) and cigarette packets all get dumped outside my house. Oh how 'Jaydax Almighty' would enjoy watching them try to dump their rubbish a second time.

...consign those who shrink wrap their products to an environment where everything was shrink wrapped and there wasn't a sharp object or fingernail in sight. I'm sick of plastic wrapping around DVDs. The stuff you spend ten minutes trying to get into. There already is a better alternative to preventing people removing the disks, those red tabs which are removed at the checkout.

[Update - Yes I know - who buys DVD/Blue ray now? It's all in the cloud now which really sucks if you have a slow Internet connection so I'll consign those convinced everyone has a lightning fast connection to 28 Kb/s dialup. (Microsoft please note)]

... at night I would enter the houses of supermarket managers and move everything in the house to a different location while they slept in revenge for them moving everything in the stores to a new location. I know why they do it - it's so that you have to look for it and hopefully you will see something else to buy as you do so ...but it's SO annoying! Lets see how they would like hunting for their car keys relocated to the bottom of the freezer, a shoe in the oven, the alarm clock in the garage and all their clothes in/on the front porch.

… consign all those politicians who talk about democracy to an eternity of watching party political broadcasts by their opposition. We in the UK and US do NOT live in a democracy where the majority rule. Our government is a minority government elected by a minority of the electorate. Currently in 2024 the UK's Labour government was chosen by 9,704,655 out of the 48,214,128 electorate. That's 20.13%. In the US in 2025 Trump and the Republicans got 74,983,555 votes but since the US electorate appears to be 209,240,895 that means he represents 36.92% of the electorate. 

… consign the person who came up with the idea of captured bottle tops to an eternity of trying to open an unopenable bottle or carton where the grip around the top is made of razor blades. I've lost skin on these things and the top gets in the way of pouring the contents out cleanly. In some cases the entire top of a carton twists off leaving a carton which can't be re-sealed. Fine, keep the captured tops on single serving bottles, that's being environmentally sensible, but there's no need for these on multi-serving containers.