What is the earliest an Airship could be built?

[Unalist]

Saw a few threads containing this, for and against.

Starting as point of departure hot air balloons in early civilization (after the Nasca design) with a few hundred years for material and design improvement could Airships of been developed in say the Bronze Age?

[carlton_bach]

No. Hot air balloons theoretically yes, but to build an airship you need lifting gas. Hot air can exert great political lift, but physically, it's limited. To produce hydrogen (your most likely candidate for lifting gas) as well as to hold it, you need a lot better technology than your average bronze-age civilisation can provide. Of course if you wanted, you could posit a civilisation of bronze-age silkweaving dwellers in bamboo forests tangled with rubber vines on the seashore that go whaling (for goldbeaters' skin) and live near an area of volcanicv activity where meteoric iron abounds and sulphuric acid is produced naturally. But seriously.

[Elfwine]

I'd say, for Europe, anything faster than a century or so than OTL would require an unrecognizable world. And even that would mean a very different Europe.

You also need working engines to have an airship and not just a hydrogen balloon, after all.

[Dathi THorfinnsson]

Originally Posted by Elfwine

I'd say, for Europe, anything faster than a century or so than OTL would require an unrecognizable world. And even that would mean a very different Europe.

You also need working engines to have an airship and not just a hydrogen balloon, after all.

Exactly. An airship requires engines, and decent ones at that. You're not going to get that before the technological equivalent of 1800 OTL, more likely 1850. Should be doable by then, but wouldn't be much help, as it would still require calm air, massive gangs of handlers at each end and the weight of the steam engine would mean the useful payload wasn't that great.

Also, given the sparks that come from a railroad steam engine, combining one of those with highly inflammable gas in the envelop would be ... tricky.

So maybe oil fired and closer to 1900?

[jotabe1789]

Carlton mentioned a great alternative idea: gliders. Again a glider has a very limited control and you need to start from a great height. What else could be used to power the flight that wasn't an engine? Something that is technologically available much earlier? Gunpowder.

A civilization where both gliders and fireworks were independently used, eventually might have some guy with a death wish that would put both things together. The first explosive trials would provide improvements on the placement of the rocket so it wouldn't consume the glider. Further tests could improve the speed gain with different combustibles. Eventually they would find something powerful enough they can lift off without needing to start from a height.

For such glider, i'm assuming you'd need at least a steel frame. I'm not sure if silk has the mechanical properties to withstand the air speed without ripping. Maybe only synthetic fabrics can.

If this is at all possible, eventually the glider frame would include a capsule to protect the pilot, and not long after, the glider itself would be changed into actual wings.

If this works, reaction-powered flight could appear much earlier than engine-powered one.

[dgharis]

Originally Posted by jotabe1789

Carlton mentioned a great alternative idea: gliders. Again a glider has a very limited control and you need to start from a great height. What else could be used to power the flight that wasn't an engine? Something that is technologically available much earlier? Gunpowder.

A civilization where both gliders and fireworks were independently used, eventually might have some guy with a death wish that would put both things together. The first explosive trials would provide improvements on the placement of the rocket so it wouldn't consume the glider. Further tests could improve the speed gain with different combustibles. Eventually they would find something powerful enough they can lift off without needing to start from a height.

For such glider, i'm assuming you'd need at least a steel frame. I'm not sure if silk has the mechanical properties to withstand the air speed without ripping. Maybe only synthetic fabrics can.

If this is at all possible, eventually the glider frame would include a capsule to protect the pilot, and not long after, the glider itself would be changed into actual wings.

If this works, reaction-powered flight could appear much earlier than engine-powered one.

GURPS Alternate Earths did something similar, with a surviving Roman Empire using rocket-launched gliders (jactovolantes, to use their term) for scouting and message delivery. Being such a glider pilot would definitely be a high-risk occupation.

[jotabe1789]

Originally Posted by dgharis

GURPS Alternate Earths did something similar, with a surviving Roman Empire using rocket-launched gliders (jactovolantes, to use their term) for scouting and message delivery. Being such a glider pilot would definitely be a high-risk occupation.

Haha it certainly would be I guess they would try to make the jactovolantes as cheap as possible, so as to make them disposable, and invent the parachute as main landing method.

Jactovolante... i like that name!

[Unalist]

Originally Posted by carlton_bach

No. Hot air balloons theoretically yes, but to build an airship you need lifting gas. Hot air can exert great political lift, but physically, it's limited. To produce hydrogen (your most likely candidate for lifting gas) as well as to hold it, you need a lot better technology than your average bronze-age civilisation can provide. Of course if you wanted, you could posit a civilisation of bronze-age silkweaving dwellers in bamboo forests tangled with rubber vines on the seashore that go whaling (for goldbeaters' skin) and live near an area of volcanicv activity where meteoric iron abounds and sulphuric acid is produced naturally. But seriously.

You’ve managed a hydrogen balloon but are far from a powered one. I agree even if all those things were in the same place I don't see someone putting them together.

But, instead of naturally occurring iron and sulfuric acid you might as well use a Baghdad Battery (yes assuming it is a battery) to separate hydrogen from water. I do like the goldbeaters' skin, I guess it would be easier than dissolving rubber and varnishing silk for the gas bag.

I was holding on to the possibility of a pedal powered propeller driven hot air Blimp but after digging in the historic record I’m not finding any compelling support. There are hot air airships and human powered blimps but both are very recent and I haven’t found a hot air human powered airship yet. I’ll leaven the Heronic steam engine power plant in ASB.


Thank you and I’ll get in my OOPArt Airship and set course for Atlantis.

[sloreck]

You can use bamboo or other strong but lightweight wood for a frame. You can get steam engines using coal gas rather than coal to save weight for power. For all this using more or less OTL tech means 1850 or a little before...

[Derek Jackson]

I saw a tv show which seemed to suggest that a human powered airship might work sort of

[Elfwine]

Originally Posted by sloreck

You can use bamboo or other strong but lightweight wood for a frame. You can get steam engines using coal gas rather than coal to save weight for power. For all this using more or less OTL tech means 1850 or a little before...

Except that the coal is not the problem - its the engine itself and the water that are the heavy parts.

[wietze]

how about compressed air for propulsion.
Bit like this idea: http://en.wikipedia.org/wiki/Fireless_locomotive

[Elfwine]

Originally Posted by wietze

how about compressed air for propulsion.
Bit like this idea: http://en.wikipedia.org/wiki/Fireless_locomotive

How powerful are those?

From what little I know, fireless locomotives were only used in limited circumstances - no one tried using them in situations where the issues with fire weren't an issue.

But I'm open to being enlightened.

[wietze]

can't find reference to how powerful they were, but they are able to work several hours on one charge. power probably comparable to same size shunting locs.

[Fiver]

You also need large quantities of aluminum for an airship. This wasn't possible until 1886 in OTL and requires large amounts of electrical power.

[pieman97405]

What about a stirling engine?

[Elfwine]

Originally Posted by wietze

can't find reference to how powerful they were, but they are able to work several hours on one charge. power probably comparable to same size shunting locs.

Sounds reasonable. Just trying to get a sense if you could make a larger engine work as well, or if something keeps it limited to that scale.

It's something worth exploring, although I don't know if you could do it particularly early (as much of what you need for a steam engine in the conventional sense is still relevant, tech-wise).

Fiver: Why aluminum? Or is it just that no other material is "light but strong' enough?

[hairysamarian]

The thread seems to be running along a line of the expected, so to speak. No one has considered sail-powered airships, which are at least theoretically possible. Imagine a very bright group of early engineers with access to lots of bamboo, give them the realization that they need to drag some sort of keel-like object for steerage, and you have a situation worthy at least of consideration.

[Daztur]

What would be the earliest that simple hot air balloons would be possible? I can imagine pre-modern aristocrats travelling in hot air balloons that are tethered to ox carts while they float slowly along above the sink and sounds of the world below. If you use an ox card to draw them along they wouldn't be useful as much besides an extravagance but they could be a fun cultural quirk. Imagine the wealthy travelling in a hot air balloon from the top of one tower to the next without even setting foot on the ground, sort of a palanquin taken to the next level.

[Elfwine]

Originally Posted by hairysamarian

The thread seems to be running along a line of the expected, so to speak. No one has considered sail-powered airships, which are at least theoretically possible. Imagine a very bright group of early engineers with access to lots of bamboo, give them the realization that they need to drag some sort of keel-like object for steerage, and you have a situation worthy at least of consideration.

That looks rather less like an airship and more like how draped in a fishing net is "neither clothed or naked" for traveling over the water.

And is bamboo strong enough?