[IW] Zeppelins mean Alternate Timelines. So, how are they made feasible?

[Stormcrow]

Doctor Who played with this theme a couple of years ago. The TARDIS lands in an alternate universe, and they know this because of the airships flying around.

No explanation was given for this; it was just there so you—and the characters—knew it was an alternative universe. It certainly wasn't due to a lack of technological expertise.

[Erik_Nielsen]

It may be worth mentioning that at least one RL commercial company is trying to repopularize airships (aka blimps or Zeppelins):

Airship Ventures

You can take an hour-long tour of the San Francisco Bay Area from Oakland airport for $495.

To recap what others have suggested, the difference between timelines where dirigibles became popular than in our own timeline might be nothing more than better weather on May 6, 1937.

[Ulzgoroth]

Originally Posted by Erik_Nielsen

To recap what others have suggested, the difference between timelines where dirigibles became popular than in our own timeline might be nothing more than better weather on May 6, 1937.

I doubt that's sufficient. If WWII is still in the cards, the Hindenburg not going down isn't going to prevent a huge wave of advancement in heavier-than-air craft. It might be theoretically possible to field an airship that wouldn't be utterly vulnerable to fighters of the era, but Germany didn't have the Helium and nobody else had much experience in the field. So airships would still get sidelined, and by the end of the war fixed wing planes have the range and lifting power to compete with them in a great many roles. Airships might see more use than they do, but they would lose a lot of ground when large, safe, fast, powerful intercontinental heavier-than-air craft are available.

On the other hand, a British failure to develop effective incendiary bullets in 1915-1916, or some viable countermeasure, might go a long way.

Oh, if you've got really vast tracts of generally low-value land, airships can potentially serve a useful role as aircraft carriers. That was proved workable historically, but is a bit harder to justify in a world dominated by sea when non-air ships can also carry aircraft. On a plain too vast or inhospitable to set up lots of ground bases, a flying airbase might be viable.

[vitruvian]

Originally Posted by Ulzgoroth

I doubt that's sufficient. If WWII is still in the cards, the Hindenburg not going down isn't going to prevent a huge wave of advancement in heavier-than-air craft. It might be theoretically possible to field an airship that wouldn't be utterly vulnerable to fighters of the era, but Germany didn't have the Helium and nobody else had much experience in the field. So airships would still get sidelined, and by the end of the war fixed wing planes have the range and lifting power to compete with them in a great many roles. Airships might see more use than they do, but they would lose a lot of ground when large, safe, fast, powerful intercontinental heavier-than-air craft are available.

On the other hand, a British failure to develop effective incendiary bullets in 1915-1916, or some viable countermeasure, might go a long way.

Oh, if you've got really vast tracts of generally low-value land, airships can potentially serve a useful role as aircraft carriers. That was proved workable historically, but is a bit harder to justify in a world dominated by sea when non-air ships can also carry aircraft. On a plain too vast or inhospitable to set up lots of ground bases, a flying airbase might be viable.

A less flammable doping material on the envelope might be quite sufficient to make things different, though. The thing about vulnerability to fighters only really matters for military aircraft, and heavier-than-air craft certainly advance but may never have either the freight load or range capabilities of large airships. They're being seriously looked at again not just for tourism and luxury travel, but also for bulk freight transport. I don't necessarily see a path for massively increased military uses, but for civilian purposes, it's not at all implausible, just counterfactual to history as it happened.

[Anthony]

The basic problem with dirigibles is that they simply don't have the performance to compete with either ships or aircraft. A dirigible with basically equivalent performance to a 747 (same takeoff weight, same fuel consumption) would be about 1500' long with a cruise speed of less than 150 mph. The 747 is 231' long with a cruise speed of close to 600 mph.

Something that results in smaller dirigibles is the most useful option. Denser atmosphere would do the trick.

[Ulzgoroth]

Originally Posted by vitruvian

A less flammable doping material on the envelope might be quite sufficient to make things different, though. The thing about vulnerability to fighters only really matters for military aircraft, and heavier-than-air craft certainly advance but may never have either the freight load or range capabilities of large airships. They're being seriously looked at again not just for tourism and luxury travel, but also for bulk freight transport. I don't necessarily see a path for massively increased military uses, but for civilian purposes, it's not at all implausible, just counterfactual to history as it happened.

The problem on the bulk freight side is that the CL160, which didn't actually manage to get built, would have lifted slightly more mass than the soon-to-be released 747-8F...and cruised at one-tenth the speed. It was supposed to be able to operate with little infrastructure, but moving at modest highway speeds is a significant drawback.

I'd love for heavy-lift airships to work out, but I'm not convinced they can beat the existing technology. So I'm looking for ways they could have preempted that technology's being developed in the first place.

[gjc8]

Originally Posted by Ulzgoroth

It might be theoretically possible to field an airship that wouldn't be utterly vulnerable to fighters of the era, but Germany didn't have the Helium and nobody else had much experience in the field.

So a greater (and more evenly spread) global helium reserves is another thing for alternate universes featuring airships?

[quarkstomper]

Originally Posted by Molokh

Regarding 'no airplains', what about Gernsback?

Ah, but Gernsbeck is based entirely on the Rule of Cool; therefore heavier-than-air and Lighter-than-air craft can co-exist, along with rocket packs and contragrav.

[Woodman]

Something that would really cripple Airplanes is the lack of engines with a high power density like internal combustion and jet engines, for a zeppelin the low power density of a sterling engine doenst matter as much because the lifting capacity is independent from the actual engine. Where normal aircraft depend on more powerfull engines for lift (or really big wings). The other thing that lighter-then-air crafts are better at, is the time they can stay in the air, without fuel aircraft will come down while zeppelins just drift in the wind if the engines are stopped, this might make them much more energy efficient and cheaper to operate.
With the last points i think that lighter-then-air crafts could make a comeback for cargo where speed isnt as much of an issue as cost. My vison would be a body made of extra light but tough synthetic or compound materials, the top beeing covered with solar-cells, modern electrical motors that can be powered by the solar-cells, fuel-cells and depending on the actual scenario a multifuel-engine with a generator as backup.

[Mysterious Dark Lord v3.2]

Lighter-Than-Air vehicles lost popularity because they were seen as unsafe compared to heavier-than-air vehicles. Every LTA craft operated by the US military was destroyed in a crash. All that would be needed is more cautious pilots and better publicity.

If you want perfectly safe airships, the closest you'll get is vacuum dirigibles - using vacuum instead of lifting gas, which would be more efficient than even helium and would not explode. But for that you would need rigid material as light as cloth with the tensile strength of inch-thick steel. And the ramifications of a material like that would alter civilization and technology almost beyond comprehension.