Thinking on aircraft a bit. Here are some starting assumptions:
1) The physics of aircraft remain valid. There's no magic anti-aircraft decree across the world.
2) The new world has access to historical data about Doolittle, Taranto, Midway, etc, just as it does about Jutland, Bismarck, and Iowa.
3) The new world's cities are coastal or at sea; they are compact, with minimal land to spare for large airfields. The area around an airfield would be city, with dire consequences if planes crash into them.
4) The biosphere may have an airborne predator that is somewhat dangerous to slow, non-metal aircraft: canvas and wood biplanes, airships, maybe helicopters.
5) There may be an honor code that discourages strategic bombing of cities.
Thus:
-We expect that militaries will seek to use aircraft.
-They will also have defences against them - deck armor, dual-purpose guns, etc.
-Their aircraft will almost exclusively be ship-based or floatplanes. Land-based aircraft may be possible - if somebody's willing to carve out the airstrips and endure the higher attrition rates caused by the local biota.
-Since it's easier to put a bunch of AA guns on ships than to build aircraft carriers, we'll probably find that, for a while, attackers can't generate a critical mass of aircraft necessary to overwhelm enemy AA defences. For a while, we may see aircraft primarily used in scouting and ASW roles, with attack as a distinctly secondary function.
-Other than flying boats, we may not see development of multi-engined aircraft, with the implied loss of transport/attack capability implied. Strategic air power may be a non-starter.
Thoughts?
Quote from: The Rock Doctor on November 30, 2011, 08:07:31 AM
4) The biosphere may have an airborne predator that is somewhat dangerous to slow, non-metal aircraft: canvas and wood biplanes, airships, maybe helicopters.
I also thought of that. My conclusion was somewhat different though:
Airspace is dangerous (because of predators for example), so even when early light aircraft are build noone would dare to use them ,because they would be attacked almost immediately and most likely killed. But without previous examples/test, how would they ever get to sleek, fast all metal aircrafts? Certainly not impossible, but a really long way to go.
It'd be possible to run a development program in some places. Land-based air might be developed on isolated, sanitized islands (~Midway Island), or float-based air might be developed in marine areas with relatively calm waters.
Training air crew would be a challenge. You would essentially be starting from scratch, with no existing pool of civilian aviators or outside infrastructure to make use of. The graduated air crew would be pretty special - not something to throw away against hard targets with heavy AA defences...
Hmmm...
I like this idea.
We would see a lot of aircraft cruisers, but not a lot of aircraft carriers... at least, not for 20+ years.
Lets run with it.
Unless you've got these little islands to work with, I suspect it'd be easier to develop a training program for floatplanes than for wheeled planes. After all, you only need a tender for a floatplane, whereas you need an aircraft carrier for the wheeled plane.
On that basis, you might see Tone-style cruisers used as scouting vessels, and your main strike platform might be a Commodore Teste-style seaplane carrier. One might also find other large ships carrying a handful of seaplane-fighters for self-defence. The Ise/Hyuga style hybrids might make sense, God help us all.
Of course, wheeled aircraft from proper carriers will still chew them up once fielded...
Speaking just for myself, I'd prefer to keep airships viable - solely out of cool factor, I admit.
Even that aside, I suspect that our interfering bird-analog is less of a roc or one of Alpha Shade's flyers, and more of a kind of sky piranha - aircraft don't get plucked out of the sky, they get mobbed. An airship can deal with this, by shutting the windows and using tough enough fabric for the outer envelope and so forth. Maybe ducted fans protected by screens. Airplanes... well, I think you probably could design one to cope, but it'd be tricky.
How the technologies would work out, I don't know. That's what the game's for, to find out!
Uhm... there would be no fabric durable enough.
That's not how fabric works.
Kevlar can stop bullets... but not knives.
As the creatures would be focusing the cutting action of the bite on a point rather than an area, they would penetrate easier than a bullet. The metal in aircraft would be more suited to resisting the bites. Also, the higher speed of fixed-wing aircraft would make them more likely to be able to flee a natural predator which probably couldn't fly more than 100 m.p.h.
Additionally, in a place where land is at a premium, airships take more area than aircraft.
Claws and predatory beaks aren't knives, I note, but piercing weapons. 'Hard'-skinned airships are perfectly possible. And so on; the technical details aren't the substantive part of my previous post.
The thing that makes a swarm of killer songbirds dangerous to an aircraft, in my mind, isn't their attacks - it's the 'flew through a flock of geese' problem.
The amount of cleared area required for an air station, whether serving airships or airplanes, is not, IMHO, significant. It's not small, sure, but what makes farming difficult is the amount of territory required to feed a major population - You could only feed about seven thousand people off of O'Hare's area, for instance. This is big in human terms, but relative to the requirements of a nation of millions, it's peanuts.
Quote from: Valles on November 30, 2011, 10:45:41 AMClaws and predatory beaks aren't knives, I note, but piercing weapons. 'Hard'-skinned airships are perfectly possible. And so on; the technical details aren't the substantive part of my previous post.
A knife, V, is a piercing weapon.
A slash doesn't go through kevlar easily (though it does cut it) but a stab will go through fairly easily.
A 'hard skinned' airship is not possible simply because of weight- airships depend upon lift from the envelope to get off the ground- make the envelope thick enough that it can withstand what you suggest and you have an envelope that is too heavy to fly!
Quote from: Valles on November 30, 2011, 10:45:41 AMThe thing that makes a swarm of killer songbirds dangerous to an aircraft, in my mind, isn't their attacks - it's the 'flew through a flock of geese' problem.
OK- now we are getting somewhere!
If you make the airship sturdy enough that the aircraft 'deflects' impacts from this mass of medium-sized songbirds, you are going to get dramatically heavy rather quickly. Birds routinely dent cars and crack/shatter windshields. IF the envelope is flexible, they can kind of 'bounce off' and damage would be limited; if the envelope is stiff, then impact damage is magnified and starts to beat things against each other-leading to a larger chance of breakage. Now, if the bird can dent a car at 55 mph or shatter a windshield at 65 mph... what can a swarm of them do to an aircraft-thickness piece of aluminum at 110 mph? As you suggest- they would beat the ever-living shit out of it. Ducting the propellers wouldn't accomplish a thing, as the birds would still be getting chopped up, and the prop would still be getting damaged... because if you close the ducts, you are gonna loose control of your ship.
Quote from: Valles on November 30, 2011, 10:45:41 AMThe amount of cleared area required for an air station, whether serving airships or airplanes, is not, IMHO, significant. It's not small, sure, but what makes farming difficult is the amount of territory required to feed a major population - You could only feed about seven thousand people off of O'Hare's area, for instance. This is big in human terms, but relative to the requirements of a nation of millions, it's peanuts.
Yes- but every time you build that structure, you remove the possibility to support another small city or large factory. That makes it very non-trivial in the grand scheme of things:
"Do I build an airfield and give up the food for a cruiser squadron for a year?"
Quote from: Carthaginian on November 30, 2011, 11:11:19 AM
A knife, V, is a piercing weapon.
A slash doesn't go through kevlar easily (though it does cut it) but a stab will go through fairly easily.
Ah, yes. *facepalm* I think about swords too much.
Quote from: Carthaginian on November 30, 2011, 11:11:19 AMA 'hard skinned' airship is not possible simply because of weight- airships depend upon lift from the envelope to get off the ground- make the envelope thick enough that it can withstand what you suggest and you have an envelope that is too heavy to fly!
So this is a hoax, then? (http://en.wikipedia.org/wiki/ZMC-2)
I've looked into the design of the thing a bit, and it looks to me like the envelope actually was of significant thickness - enough to take having a sparrow fly into it, at least, even if not with its own speed added.
Quote from: Carthaginian on November 30, 2011, 11:11:19 AM
OK- now we are getting somewhere!
If you make the airship sturdy enough that the aircraft 'deflects' impacts from this mass of medium-sized songbirds, you are going to get dramatically heavy rather quickly. Birds routinely dent cars and crack/shatter windshields. IF the envelope is flexible, they can kind of 'bounce off' and damage would be limited; if the envelope is stiff, then impact damage is magnified and starts to beat things against each other-leading to a larger chance of breakage. Now, if the bird can dent a car at 55 mph or shatter a windshield at 65 mph... what can a swarm of them do to an aircraft-thickness piece of aluminum at 110 mph? As you suggest- they would beat the ever-living shit out of it. Ducting the propellers wouldn't accomplish a thing, as the birds would still be getting chopped up, and the prop would still be getting damaged... because if you close the ducts, you are gonna loose control of your ship.
...Or you could just seal the ducts with mesh grilles finer than the size of your attackers, just like house fans. This would cut down on aerodynamic efficiency, but should protect the props.
Some quick googling turns up this site (http://nationalzoo.si.edu/scbi/MigratoryBirds/Fact_Sheets/default.cfm?fxsht=9), whose immediately relevant datum is the suggestion that small birds are unlikely to bother going higher than a couple of thousand feet. Obviously it's possible that they'd continue an attack above that altitude, but IMHO it'd be unlikely for such a small organism to bother, instead just counting the intruder as 'driven off' and calling it good.
Airships, after all, don't
have to remain constantly in forward motion - they can launch perfectly well by just casting loose and venting ballast until they drift up out of the danger zone, and maneuver at a walking pace if need be to land again.
Assuming that the call is made to have our killbirds perceive airships as 'intruders' rather than 'objects', the way they do airplanes. Sheer size might very well mean that they didn't. This'd be a GM call based on the desirability of having airships be common in the setting.
Personally, I'd be in favor - aside from the alternate-history cool factor, an airship is unlikely to make a successful air-attack platform against any target smaller than a city, and having them filling the 'airborne scouting' niche would further delay the development of the airplane and accordingly prolong the battleship era.
Quote from: Carthaginian on November 30, 2011, 11:11:19 AMYes- but every time you build that structure, you remove the possibility to support another small city or large factory. That makes it very non-trivial in the grand scheme of things: "Do I build an airfield and give up the food for a cruiser squadron for a year?"
Of course it's a serious question! But it's not an absolute game-breaker the way you seemed to be implying.
Alright, so that's something to mull over. Let's park that issue for the moment...
Lets imagine some nasty flying animals here*. To be a threat to aircrafts they would have to be (at least some of them) the size of small aircrafts. But how would people in the cities on the ground be safe? Maybe they just don't like confined spaces like streets? Fields could be covered by wire nets.
Airships or Zeppelins, they are HUGE. Maybe just big enough to be attacked by those nasty bird?
About the metal/hard skip airship: it's hull has had a maximun thickness of only 0.24 mm (0.0095"). Not really going to stop anything. It would also loose its shape should the internal pressure drop.
Oh and isn't it time to move the "air" stuff in it's own section as well?
*)trying very hard not to think of dragons... although there should be enough big birds, flying Dinosaurs and meter-sized fireflies etc.
Quote from: Valles on November 30, 2011, 12:11:09 PM
Quote from: Carthaginian on November 30, 2011, 11:11:19 AM
A knife, V, is a piercing weapon.
A slash doesn't go through kevlar easily (though it does cut it) but a stab will go through fairly easily.
Ah, yes. *facepalm* I think about swords too much.
Nothing wrong with that!
Quote from: Valles on November 30, 2011, 12:11:09 PM
Quote from: Carthaginian on November 30, 2011, 11:11:19 AMYes- but every time you build that structure, you remove the possibility to support another small city or large factory. That makes it very non-trivial in the grand scheme of things: "Do I build an airfield and give up the food for a cruiser squadron for a year?"
Of course it's a serious question! But it's not an absolute game-breaker the way you seemed to be implying.
Meh- I just looked at it as it was... the choice between having an airbase of planes likely to get eat, or the chance to field a bakers dozen
Tone class aircraft cruisers. It's not really a game breaker by any means; it was just something to think about in-character.
I don't think I have the ability to move the air stuff into a new thread - maybe Mike could do that?
Quote from: Nobody on November 30, 2011, 12:24:04 PM
Lets imagine some nasty flying animals here*. To be a threat to aircrafts they would have to be (at least some of them) the size of small aircrafts. But how would people in the cities on the ground be safe? Maybe they just don't like confined spaces like streets? Fields could be covered by wire nets.
Airships or Zeppelins, they are HUGE. Maybe just big enough to be attacked by those nasty bird?
About the metal/hard skip airship: it's hull has had a maximun thickness of only 0.24 mm (0.0095"). Not really going to stop anything. It would also loose its shape should the internal pressure drop.
Oh and isn't it time to move the "air" stuff in it's own section as well?
*)trying very hard not to think of dragons... although there should be enough big birds, flying Dinosaurs and meter-sized fireflies etc.
Suddenly, I'm flashing back... (http://www.alpha-shade.com/0Comics/pages.php?AS_page=76)
I'd read the description of the method of construction as implying multiple layers of the hull-metal, actually. Could be wrong on that.
Any case, although the flyers are awesome, I don't think that a species that large is really plausible - hence my suggestion of the hazard's being more by way of a 'willing birdstrike' issue than actual hunting.
http://en.wikipedia.org/wiki/Argentavis
Why not- this fellow was 23 feet wingtip-to-wingtip and 11.5 feet long, weighing in at 170 pounds.
The wingspan is the same as a WWI Nieuport 11!!!
http://en.wikipedia.org/wiki/Azhdarchidae
These guys were even more colossal, with wingspans on the order of 40 feet!
This is more like a modern fighter plane's wingspan.
I could easily see these kinds of creatures existing on NewWorld... after all, if there are badass land animals running around, then the birds have to be equally badass to be able to feed on them!
Wow..... we wont go into why humans would not be going outside with things like this flying around. Nor would explain why we didnt use Artillary on the nesting grounds every nesting season for several decades at the earliest opportunity.
Remember Folks Happiness is achieving the Top of the Food Chain. The fact that humans have forgotten to remind the Lions, Tigers, and Bears of our dominance more often seems to be a problem that is leading many Bears, Lions, and Tigers into making mistakes like thinking we are back in the early period of Fire where man was still trying to fight his way off the Lunch Menu....
Quote from: ctwaterman on December 01, 2011, 09:22:35 PM
Wow..... we wont go into why humans would not be going outside with things like this flying around. Nor would explain why we didnt use Artillary on the nesting grounds every nesting season for several decades at the earliest opportunity.
Well, I think the point is that the land is so dangerous that we cant
reach the nesting grounds. ;)
As far as just going outside... well, local defense can handle flying things around settlements- so no problems there.
Quote from: ctwaterman on December 01, 2011, 09:22:35 PM
Remember Folks Happiness is achieving the Top of the Food Chain. The fact that humans have forgotten to remind the Lions, Tigers, and Bears of our dominance more often seems to be a problem that is leading many Bears, Lions, and Tigers into making mistakes like thinking we are back in the early period of Fire where man was still trying to fight his way off the Lunch Menu....
Meh- this is good for Man's constitution.
If we stop fighting, we get soft... and too many people are willing to stop fighting and rest on their laurels at this point. The Lions, Tigers and Bears are doing us a favor by reminding us that if you stop fighting to stay on top, someone is gonna pull you back down.
The birds of prey on Earth only attack small birds that eat insects. I do not think that birds have ever tried to attack a flying machine (as opposed to be run into or sucked into a prop or turbine), and they would likely be scared off by the noise generated by the engine and the size of the machine.
Birds would probably avoid airships because they are so large that the bird would likely view them as objects (animals generally avoid running into visible objects, notice how birds will fly into windows but not more visible objects) and avoid airplanes because they are noisy and are hard targets due to their speed and turbulence. We also have to take into account that biology and the requirements of flight limit birds. If the atmosphere has similar oxygen content to Earth animals will reach a certain maximum size, but if levels are higher animals can be larger because energy is easier to acquire. With birds they have to be light enough to fly (hollow bones and light structure), so even lots of oxygen still produces a reasonable upper boundry. The birds would still be birds, so no matter how big and scary they might be, they would not pose a threat to people armed with a 7.62mm service/hunting rifle. I also do not see them carry off people to drop from the air, at worst they might crack someone on the head with something or try to peck or claw them (like a crow).
While I agree that something like Argentavis wouldn't be a particular threat to humans, I was thinking of crows' habit of mobbing any raptor they catch sight of - that is, that this species or cluster of species would recognize 'large flying thing!' and immediately classify it as, well, a megaraptor like Argentavis, and thus an ENEMY and THREAT TO CHICKS and try and drive it away.
It's not that any of them would be individually dangerous to a human on the ground, so much as the crosswired problem of small birds actively trying to dive bomb an intruder that falls out of the air if it eats a bird in the wrong place.
Quote from: Delta Force on December 03, 2011, 02:24:02 AM
The birds of prey on Earth only attack small birds that eat insects. I do not think that birds have ever tried to attack a flying machine (as opposed to be run into or sucked into a prop or turbine), and they would likely be scared off by the noise generated by the engine and the size of the machine.
Spoken like a man that's never seen a bird of prey attack an animal.
D.F., for years I had a nesting pair of Redtail Hawks living in my backyard; they remain to the same eyrie year after year, and remain mated for life. This gave me ample time to observe them. Over the years, we lost several kittens, a few puppies, dozens of chickens, a couple of ducks and a kid goat to these magnificent creatures or their offspring. I also saw them take countless squirrels, rabbits and mice.
Truthfully, the only real 'bird hunter' I can think of in the Southeast is the Peregrine Falcon; they are more what you are thinking of here, and are actually fairly unique in their choice of prey.
Perhaps you need to watch some documentaries on raptors... you have a lot to learn.
The vast majority prefer land animals or fish as they take less energy than birds to hunt/kill, and almost all of them will scavenge if given the opportunity... in nature, a meal that doesn't move is free energy. A few of the Redtails I mentioned above got so accustomed to our habit of dumping scraps for our pets that they would wait in the trees nearby and swoop in to take any meat we poured out.
Quote from: Delta Force on December 03, 2011, 02:24:02 AMBirds would probably avoid airships because they are so large that the bird would likely view them as objects (animals generally avoid running into visible objects, notice how birds will fly into windows but not more visible objects) and avoid airplanes because they are noisy and are hard targets due to their speed and turbulence. We also have to take into account that biology and the requirements of flight limit birds. If the atmosphere has similar oxygen content to Earth animals will reach a certain maximum size, but if levels are higher animals can be larger because energy is easier to acquire. With birds they have to be light enough to fly (hollow bones and light structure), so even lots of oxygen still produces a reasonable upper boundry. The birds would still be birds, so no matter how big and scary they might be, they would not pose a threat to people armed with a 7.62mm service/hunting rifle. I also do not see them carry off people to drop from the air, at worst they might crack someone on the head with something or try to peck or claw them (like a crow).
Did you notice the links I posted?
While there might have been some variances in oxygen concentrations during the period with the pterosaurs, the actual
birds that I linked were present on an Earth largely identical to our own. The basic climate bands that we recognize as 'normal' were laid out, deserts where deserts should be, forests where forests should be, and seas where seas should be (with the exception of the poles, which had not yet suffered such great ice buildup).
Argentavis would really only be a threat to a lone man or a group of unprepared people. A nesting pair could cause trouble for a small group of intruders even if they are prepared (ever had mockingbirds come after you? Mean bastards, ain't they?).
This is why I think about a single large predictor at the top, and also like Valles' idea of a mobbing 'small bird' as well- both have their place.
Let me add that I find a world with a primarily avian-based biome very interesting- prehistoric South America on a large scale!
I know birds of prey attack land and sea animals. I didn't know they would attack goats though.
Quote from: Delta Force on December 03, 2011, 03:26:46 AM
I know birds of prey attack land and sea animals. I didn't know they would attack goats though.
Yes. The goat was days old- just past the wobbly-legged stage- but still small enough to look tasty.
If a bird is big enough, then any animal it perceives as weak enough or young enough becomes a prey animal.
(http://www.shahrogersphotography.com/gallery/Vultures/AS0948.jpg)
Here is a bonafied scavenger chasing down a gazelle that weighs more than it does.
Animals kill when hungry... hungry enough, they can do some pretty crazy things.
My - totally uncalled for - thoughts on how to make aircrafts less plausible.
There is plenty of coal available. Liquid fuels, however, has to be made from crops - alcohols and vegetable oils. While it is theoretically possible to make liquid fuels economically from indigenous plants, they are big technological hurdles to solve. The same is valid about coal liquefaction technologies - the colonists arrived with nice, clean and feel-good-PC solar arrays in mind, not nasty, dirty fossil fuels. In other words, biofuel production would compete with foodstuff. If you postulate lower yields due to somewhat hostile biosphere, food becomes expensive. As in, either you have that 100 liters of alcohol for a single flight, or enough food to feed one more person a year.
The coal incidentally is necessary to make steel in industrial amounts.
To get those large avians of prey, reduce gravity a bit, a'la Pandora.
No need to diddle with gravity... Earth had her own monsters. Unwieldy on the ground, but then again, we aren't really able to touch their nesting areas easily to kill them there.
I don't believe that aircraft should be non-starters; just that they should take longer to get.
Besides, for one type of carbon-based fuel to exist in the absence of any other... that's a bit of a stretch.
Revising gravity would sprock our-the-players' calculations and calculators for ballistic performance and so forth but hard. I'd prefer to avoid that; such things are complicated enough to work out in the first place.
Chemically speaking, coal liquification is not complicated; certainly it's easier than a lot of the physical and industrial problems already implicit in the City structure! Doing it 'en masse' might require a facility slot, but would, IMHO, be fairly straightforward for anyone willing to dedicate same.
Returning to the birds, there've been two real proposals levied: First, the simple presence of sufficiently large predators given to hunting on the wing, and second, 'mobbing' behavior by flocks of smaller birds. The former is more visually impressive and does a better job of carrying through the 'deathworld' feel, but requires physical strength, flight speed, and sheer size to all meet or exceed known maxima for flying animals. The latter requires only the jump of applying a known behavior from otherwise unexceptional species to aircraft rather than just other birds, but has the downside of seeming kind of trivial until you really think about it.
My next piece of smartassness is to reduce the air pressure (less N2), but that would also play hell with ballistics.
BTW I am aware of the deceptively simple chemistry behind coal gasification. But getting it economical would again take some time.
Of course it would. But such a technology is hardly limited in use to military applications - if our own history is any indication at all, I think it would've been worked out and put into practice long before the reintroduction of the standing army.
My question is why can't we, say, change the air pressure? You say because it would play hell with ballistics calculations but why can't we pretend that it doesn't effect them at all? Would it really harm the game?
We could, yes.
But even the 'giant killer roc' approach would be less of a logical strain. Given two or three options to get the same mechanical effect, I'd prefer to go with the one that breaks from reality the least.
You do not want to go down the road of changing gravity. If you do that you end up changing the atmosphere's composition, which changes weather, which changes agricultural and native species, etc. Obviously it changes ballistics and how motorized vehicles function as well (the vehicles they are moving weighing more).