Why Dirigibles?

[sn0wball]

I am just back from a family trip to the Tropical Islands resort/theme park, located south of Berlin, Germany. It is built inside what has become the CargoLifter production hangar in another timeline, branching of somewhen around 2000. The hangar is 360m long, 106m high (granting it a claim to the biggest hall in the world and making it quite a sight to behold!). It should have allowed the simultaneous production of two CL160, rigid cargo airships, 260m in length, with a cargo payload of 160 tons. While the kids had much fun, I felt always accompanied by the ghosts of all the Zeppelins not being built, with the company going bankupt in 2002 without ever completing one. The economic feasibility of the craft has been disputed all along, although it must have been plausible enough to collect about 100 million Euro from investors.

[maximara]

Originally Posted by khorboth

I see a lot of "how" but not much "why"

What if in the 1760's, the British Empire decided that the colonies should have more rail lines?

Very unlikely. There wasn't much in the way of rail transportation in the 1760s. Never mind that the rail lines of that era were designed to transport coal for fuel and material to make steel.

This is all ignoring one of the points of a colony was to make money for the mother country.

Finally there is the little matter of taking what you mine across the ocean.

There would be no incentive to build rail lines in the colonies in 1760's.

[Crystalline_Entity]

Originally Posted by khorboth

I see a lot of "how" but not much "why"

What if in the 1760's, the British Empire decided that the colonies should have more rail lines?

I agree with maximara, I find this very unlikely. The first public passenger-carrying railway was in England in 1825, and I can't see an economic benefit to developing one in the colonies in the 1760s, even if the technology had existed. Railway development in Britain was normally done by private companies, rather than by the government (which led to lots of competing lines), so I don't think that there'd be any centrallised planning of colonial railway lines you could blame on an imperial government. The primary aim of the empire was to make money, at least in that era!

For airships to be viable you need to come up with a plausible way of hobbling heavier-than-air travel. Maybe aluminimum is classed as a strategic resource, and not available for commerical use, so aeroplanes have a very limited niche? Transoceanic civilian travel is then done by airship.

[tanksoldier]

. There would be no incentive to build rail lines in the colonies in 1760's.

We need to keep in mind that in the past things weren’t just done randomly.

There were sound reasons for doing or not doing something, decisions made by the best minds of the time. Yes, there are always mistakes and missed opportunities but nobody looked at the situation and said for example “more rail transport would make more money... let’s not do it”.

The only real exceptions are where public opinion made an otherwise economically sound decision impossible.

Something has to change to change the decision making process.

For airships to be viable you need to come up with a plausible way of hobbling heavier-than-air travel.

Especially since jets airliners have ended the use of trains and ships. Oh, wait...

If airships had developed in parallel with heavier than air craft, they would be equally advanced.

Airships would fill a cargo and tourist travel role.

[johndallman]

Originally Posted by Crystalline_Entity

Maybe aluminimum is classed as a strategic resource, and not available for commerical use, so aeroplanes have a very limited niche? Transoceanic civilian travel is then done by airship.

Without aluminium, airships have much heavier frames and much worse lifting capacity.

One advantage they have is that they can hover without burning fuel anywhere near as fast as a helicopter. Can we make something of that?

[Phoenix_Dragon]

Originally Posted by tanksoldier

Especially since jets airliners have ended the use of trains and ships.

Jet airliners serve a different niche than trains and ships: high-speed transport of small cargos.

There have been a good number of attempts to create modern lighter-than-air craft, pretty much continuously since they fell out of use. The problem is, they're out-competed in every role. The largest airships might compete with heavy-lift cargo airplanes for how much they can carry, but they do it much more slowly and are harder to load and unload, so they're not good for express cargo. They're faster than trains or ships, but carry a tiny fraction of the cargo, and are more expensive to operate per ton/mile, so they're not good for bulk cargo.

They even require specialized facilities for proper operation (At the very least you need some way of mooring them in place while you lift cargo up to it), which makes them less useful in poorly developed areas than, say, cargo helicopters that can load and unload in a bare field, while also being poorer at precise station keeping (They are slower to react to changes in wind direction than a helicopter).

Tourist sight-seeing is about the best you can hope for, and they're already doing that. It's just that there isn't much of a market for it, and it's in competition with airplane and helicopter tours.

So yes, for dirigibles to become useful, you have to hobble its competition. The only nitpick I'd give is that it doesn't have to be the heavier-than-air travel that gets hobbled, it's just that that's the one that makes the most sense. Hobbling trains and/or ships might give you a niche, too. But something has to give.

[AlexanderHowl]

Hydrogen dirigibles might make sense on a newly colonized world. Even though they are less useful that ships, they can go places where ships cannot, and it will probably take a century to develop sufficient infrastructure for hydrogen dirigibles to become uneconomical. Paradoxically, worlds with higher levels of tectonic activity and volcanism would have more use for them, as it would take longer to develop the appropriate infrastructure.

[RogerBW]

My Victorian Atoms setting has useful airships in the 1880s, before internal combustion… powered by the Blackwood Atomic Boiler, driving the new Parsons steam turbines. You really can't scale those down very well.

(It's not intended to be strictly rigorous, but it stands up to at least mild prodding.)

[gruundehn]

One problem that I do not see addressed here is that dirigibles could not keep a schedule tighter than a day. Dirigibles were affected by the weather too much and would have to delay mooring while waiting for the weather to calm down enough. Also, headwinds or sidewinds affected them much more than heavier-than-air aircraft so a course from point A to point B would vary in time too much. If you had to be in New York by Wednesday, you flew in a passenger plane or took the train. Or, if coming from Europe, a steamship. A dirigible might get you to New York Wednesday morning, Wednesday afternoon or Thursday. Better forecasting could reduce the variability of flight times, but even today the weather surprises forecasters a lot. The people taking a dirigible would have to be the ones with no time pressures and the cargo would have to be the same. And cargo would have a problem with loading and unloading since all the evidence I have seen is that a dirigible, when "landed" was a higher distance from the ground than an airplane.

[Mr_Sandman]

Originally Posted by Fred Brackin

The problem is that we already have solar-powered planes (drones mostly but sometimes fairly large ones) and they work pretty well even without the virtually weightless solar cells you'd need fpr dirigible skins.

The solar powered planes I know about are made with cutting-edge materials, and are slow, single-seaters. A solar dirigible might have significantly worse cargo and passenger capabilities than fossil fuel versions, because of the weight of solar cells and batteries. (Although they wouldn't have to carry fuel.) But I don't think they would be out-competed by solar planes in the 20th century.