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

[Ulzgoroth]

In principle extreme scaling does favor LTA craft, though. Their lifting capability scales with the cube of dimension, same as mass. I'm fairly sure that airplanes have a less-desirable scaling law.

[Fred Brackin]

Originally Posted by Ulzgoroth

In principle extreme scaling does favor LTA craft, though. Their lifting capability scales with the cube of dimension, same as mass. I'm fairly sure that airplanes have a less-desirable scaling law.

Not that I've ever seen evidence of.

[Anthony]

Originally Posted by malloyd

Some. For finite length wings aerodynamic lift generates induced drag - raising the drag for the airplane above what it would be simply for its area. But it's not enormously big compared to other drag terms.

Actually, at an airframe's most efficient speed, induced drag is 50% of total drag (induced drag scales as K/V^2, parasitic drag scales as K*V^2, so you get minimum net drag when the two terms are identical). That's still a lot lower than airship drag, however, though it's generally about 5x higher than rolling resistance on roads and up to 50x higher than rail.

[Ulzgoroth]

Originally Posted by Fred Brackin

Not that I've ever seen evidence of.

...are you saying you think fixed wing aircraft lift scales with the cube of dimension? I'd very much like some explanation of that.

[David Johnston2]

In the end the essential element of ensuring Zeppelin as a method of transportation is putting in a reason why nobody built a heavier than air flying machine larger than a Cessna. You could just put a kink in aerodynamics so that wings larger than a certain size won't work, have them never have invented fixed wings at all, avert the invention of internal combustion engines but have steam engines good enough for Zeppelin propulsion but not for HTA propulsion, use magic wind propulsion or just stick the current time at point where they just haven't refined HTA much

[vicky_molokh]

Originally Posted by David Johnston2

In the end the essential element of ensuring Zeppelin as a method of transportation is putting in a reason why nobody built a heavier than air flying machine larger than a Cessna. You could just put a kink in aerodynamics so that wings larger than a certain size won't work, have them never have invented fixed wings at all, avert the invention of internal combustion engines but have steam engines good enough for Zeppelin propulsion but not for HTA propulsion, use magic wind propulsion or just stick the current time at point where they just haven't refined HTA much

Well, that's probably not fitting for explaining how [IW]Gernsback[/IW] works.

[David Johnston2]

What if moving too fast makes it impossible to use beamed power? That would eliminate a lot of the commercial advantage from aeroplanes.

[Joseph Paul]

Originally Posted by Molokh

And why wouldn't this advancement be used on HTA craft?

It could but I am not sure that they would want to. Aircraft would be limited to airscrews with that technology and I am not sure just how bad that would be compared to jets. With just airscrews how big can a plane get? [Googles] AN-22 size apparently with a payload of 90 tons and max take off weight of 275 tons. It uses turboprops which aren't quite jets.

One of the problems with the economics for the LTAs that has been brought up is payload fraction. It looks like fuel took up 60% of the Hindenburg's excess lift. I suspect that electric motors (at some tech levels) would have less mass than diesels and that the nuclear generator + turbine weighs less than the normal fuel load. I also suspect that the nuclear source would be able to deliver enough energy for the LTAs to be made very large 300-500 tons of payload.

If large prop planes are limited to ~300 MPH by this technology their operating costs go up but the payload fraction of the LTA's does also. I have not had the time to piece together a spreadsheet for this yet. Anyone got a gut reaction on it?

[Groslon]

I'll admit, I mostly just skimmed the thread, so tell me if it's been mentioned before. What if we kept LTA craft around for the same reason that we aren't switching over to electric cars?

If the infrastructure to support LTA craft became very widespread before the creation of large fixed wing aircraft then that could go a long way towards explaining a lack of planes. If nobody wants to use huge parcels of land for runways, and deal with the transportation and storage of jet fuel then that would be a decent reason not to move on to fixed wing aircraft, even if they were noticeably more efficient. It's an important factor in why we've stuck with the internal combustion engine this long.

If the zeppelins had a longer period of use before highly efficient planes were discovered, then society would have adapted to their use. Things like loading docks, and modular freight containers would all be engineered to work with dirigibles, and switching over an entire industry would be massively expensive and labor intensive. If your factory yards are already built to accept their incoming shipments on the drop pad built into the roof, how much fun is it going to be redesign and rebuild that factory to accept the new fleet of trucks that will have to carry your freight from the airfield because the new-fangled planes can't land anywhere near your factory?

[Joseph Paul]

That is a cogent thought Groslon.

On the matter of keeping certain technologies out of other industries how does monopoly and spite work? If Gernsbeck has zeppelins with a compact efficient drive and the HTA aircraft do not is it plausible that the drive is kept off the market to intentionally stifle the development of HTA and preserve the edge for LTA manufacturers and users? How about if we throw in the development of the EULA as a significant business development? Zeppelin Gmbh will *not* sell you a dirigible but will lease you one. For an extra price you can have your very own mechanic on board to help with any problems that may crop up. You may not copy, disassemble, modify, or reverse-engineer the critical components of the dirigible. Doing so will bring the full wrath of Zeppelin Gmbh down on you.

Short sighted on the part of business owners? Perhaps but if their position is that they are in the business of making and selling Zeppelins and not marketing alternative uses for the drive they are not going to diversify into other areas.