In an attempt to create semi-believable pre-dreadnought gunnery duels fought in the air instead of the sea for a story of mine, I ask you all a question: how do flying battleships work?
Do know that I am not an expert in naval or aerial matters or in physics so feel free to correct anything I say.
I will narrow done possibilities with the following parameters, but you are free to discuss or answer the question without taking them into account or point out why they are not believable. Who knows, I may just use your ideas instead .
Parameters:
Steel-hulled ships are able to achieve lighter-than-air capability by use of an unobtainium called “pairelite”. Its processed and refined form is capable of permanent lift. It is sealed in ballast tanks evenly spread out on a ship and can change altitude if heated or cooled.
The hulls of the ships take the form of naval vessels. While this is probably not optimal for flight I like the aesthetic so meh. You are free to put any other part of the ship anywhere you see fit. It is currently the age of the pre-dreadnought and naval experimentation (and arms races).
The cutting edge form of naval propulsion are steam engines. If coal powered engines are not believable enough to move the ships, I may have to make another unobtainium and throw steam turbines into the mix to achieve the necessary force for propulsion.
My current problems with suspension of disbelief are with propulsion and fire control. There may other problems which I haven’t considered like the effect the unobtainiums may have on other areas rather than flight.
Right off the bat the flight dynamics are going to be a problem. Steam engines are still used to drive a piston. What is the piston turning that is going to give you forward and reverse propulsion?
Also how are you turning the airship? Turning only work on airplanes because the aerodynamics of the craft allow it to bank and move forward through the air by climbing at an angle. That requires wings with ailerons and forward propulsion at a fairly fast clip. Rudders only allow it to “slide” right or left it doesn’t change the heading.
Next a ship is long and flat on its sides. It is going to be very susceptible to shearing winds which will push it off course unless it has a means to correct.
As to heating and cooling the unobtainium steam from the coal plant could heat but how will you cool? This current model is also going to require a great deal of water.
Primitive heat-sinks maybe, though you do need either a mechanism to reliably replace those in-flight, or you have to accept them as a (severe) limit on the operational range and duration of your vessels. If you use ones with fluid, the fluid might be a second unobtainium
At higher altitudes, you can also cool somewhat by using the relatively cold outside air.
If you have magic in your world, I suppose mages with frost-spells, or an industrial application of magic could do the trick as well.
Using naval vessel hulls for aircraft automatically removes all plausibility from the scenario. Naval hulls are designed to interact with water. That’s their sole purpose. The only reason the aesthetic is pleasing is because it is reminiscent of naval ships that actually existed. Here’s the thing. Naval combat is two dimensional. Air combat is three dimensional. That alone completely changes everything.
That said, the best example I can think of for semi plausible steampunk airship/battleship hybrids is Last Exile. https://www.youtube.com/watch?v=_3lXas9dzjY One important thing about that particular universe is that the culture is very Pre-WW1 in terms of their view on combat. Combat is about rich guys sending poor people to die gloriously for honor, and the poor should damn well appreciate the honor. Of course… not all of them exactly do…
And restrictions to the ascetic of 1900 battleships
Basicly take a battleship cut it off at the waterline and mirror it. Push out the side walls to round it out and give the armor the ability to better deflect munitions and the wind. I see Basicly a hexagonal shape. Struts with belts or chains inside to power propellers for basic manuvers. I also see wings with tanks on the end for dual purpose of cooling water and changing the ships gradient. Allowing a somewhat responsive pitch and yaw by pumping the water from one side of the ship to the other or keeping the tanks level.
For forward thrust you could use steam through pressure nozzles but that likely wouldn’t produce much thrust. But really if your talking coal and steam desiel fuel could supper heat the steam to provide the thrust. Air compressors have been in use since 1850ish. The front of the ship could be one big air intake. Compressing and supper heating the air adding steam and you’d have a steam rocket. Not efficient by today’s standards but.
There is actually one great advantage to building aerial warships on a wet-navy warship’s hull.
In the early days of aviation, before paved runways and landing strips were common, a lot of heavier aircraft, especially passenger and cargo craft, maintained boat-shaped hulls. These “flying boats” had the ability to land anywhere there was water, as opposed to only on runways. Up until the eve of WW2, flying boats were the best, and often the only choices for the transport of large numbers of passengers or cargo. Pan-Am and Imperial Airways made their names running long-range flying boat routes, and many long-distance flights, including the first trans-atlantic air voyage were done by flying boat.
When you scale this up to warships, the reasons for having “flying ship” hulls become an order of magnitude more pressing. It took nearly a quarter of a century for a network of airports to reach the point where commercial land-based commercial aircraft became feasible. Now, imagine that instead of 8-tonne airliners, you needed airfields to maintain 20 000 tonne flying warships. The costs to construct and maintain a single facility capable of serving as a landing facility for such craft would be astronomical. The only real practical solution, I think, would be to use open water as landing strips, and port quays as hangars, hence the need for a naval hull.
That kinda limits their practical use since you would need to land to restock the coal, ammunition, food and water for the crew. I guess you could have supply ships for inland expeditions. Since in this case the unobtainium just needs to be heated to lift the ship then an areodome with gantries and external cuplings for precisely heated water would work just as well, probably better than trying to service a ship at sea.
I’m really not seeing the practical advantages of having a land-based aerial warship, especially if we’re talking ships with 5000 km+ ranges on a setting that’s got as much open water as Earth does.
Not only would whatever’s keeping the ship airbourne be effectively irreplaceable (which is a bit of an issue if it needs constant power to stay up), it would also require considerably more complex facilities, especially to do major maintenance and refits on the superstructure and armament. More importantly, such a vessel would only be able to be resupplied by such a facility. A water-capable hull would be able to set down anywhere and rendezvous with conventional colliers or tankers
There’d also be the problem that any ship that lost its lift capacity would effectively be a total loss, while an air-battleship with a naval hull could just land if a boiler burst, or the like, and effect repairs so long as the hull was repairable.
You are right to a certain extent. You would probably need both given the limited range of coal powered engines due to a comparatively low mass to entertain conversion ratio, especially if you are just burning it the old fashioned way.
It’s not like a port facility that can service several warships at once is super affordable either.
Suppose you could use inland lakes and even man made ones in this situation. Not sure if a man made inland lake port facility in Saudi Arabia would be any less expensive than an areodome.
@cascat07
To be fair, a port facility that can service several warships can also be used as a civilian port. Unless flying hulls are cheap enough to be used as commercial freight haulers, I doubt the same could be said of land-based facilities.
That is an advantage, but it comes at the cost of crippling the ship in it’s primary function as a combat vessel. Having a giant flat watertight bottom means you have a giant flat soon to be not very watertight blind spot on the most important side of the ship. The side that keeps everything inside the ship. Before World War 2 combat aircraft weren’t really used all that extensively. It was during that war in which air combat really came into it’s own. And of course, these are not airplanes. They’re more like heavily armored yet more agile zeppelins. They don’t need a runway, just a flat space or a tower. They don’t necessarily even need to touch the ground.
@Shoelip
The difference is that Zeppelins are by nature, slower, larger aircraft, as opposed to warships in the sky. Warships would need the ability to stay a given area of operation for long periods of time, which would naturally mean refuelling, repairing, or even refitting “in the field”. Warships need to be strategically versatile in the places they can operate and the places they can move, and a warship that needs specialised facilities to refuel or rearm, and one which risks catastrophic loss every time something goes wrong with its engine is not one I would be comfortable spending millions of [currency unit] of taxpayer money on.
As for blind spots, I don’t think they’re as big as you might think. Assuming that the only craft capable of puncturing a hole in an armoured warship’s hull is other warships, then observation blisters along a ship’s tumblehome, or even extended from the ship’s main deck on spars will give you the observation angles needed.
Even with gaping blind spots, I could imagine that the tactical solutions (fleet manoeuvres to manage the high altitude advantage of greater visibility and possible dive-speed advantage vs the low-altitude advantage of an optimum angle of attack) to be more feasible than the logistical and technical ones.
The two main advantages of air ships versus ocean ships are that 1) They can move in three dimensions, and 2) They aren’t limited to being over water.
The boat hull makes the ship fair less capable of coping with people making use of the first advantage. And is only a benefit to safety if the vessel is completely ignoring the second advantage, and doesn’t fall fast enough when it malfunctions that it sinks just from the impact anyway.
Putting weapons out on spars would mitigate the first issue somewhat, but that presents a whole new list of problems. Like, can you actually put guns large enough to do serious damage to a floating battleship out on spars jutting off from the edge of the ship?
The largest strategic advantage to flying battleships would be the negation of the traditional use of forts and fortress. Much in the same way tanks did in WW2.
Provided the unubtanium works the way discribed there would be a natural floor in which room temperature pairelite would sit and you would simply have to pack enough to keep it that way. Of course battle damage could sink the ship.
Resupply isn’t a huge issue in most cases. A long hose and a pump can take care of the water issue. And built in cranes can lift the rest. Repairing battle damage would be problematic but assuming the pairelite doesn’t work at relitive altitude but absolute altitude you could build your shipyard on a convenient mountain. And resupply could be assisted by towers at lower altitudes.
Also with a discovery like pairelite would actually slow the development of what we view as aircraft. Gliders would be present but not much else. What use is a 100 pound aircraft that has a range less then one of these airships and one that could not carry the ordinance to breach the hull of one? Perhaps not even the hull of a civilian one?
Why would slow the development of aircraft? You would just develop small airplanes that relied on pairelite for lift. That would solve a bunch of the challenges of early aircraft makers irl and they would be the perfect counter to who ever has the air navy advantage.
Your right but then they wouldn’t use aerodynamics for lift. They would be small 2 ton steam jetties. Or tugs. They would be small airships v aircraft.
Simply because they would never had to solve that problem of making a plane go fast enough to generate lift. You need it to fly? Add pairelite and fly
Assuming it has to be a ship, as that’s a huge bloody target all on it’s own, your propulsion might be achieved through turbines turned by the piston, using steam vents is hardly an option when you only have a limited space for water on the ship.
Essentially your ship is a hot air balloon with combat capabilities, any weapons you can fit onto it to pierce other hulls will likely cause thrust sufficient to push your ships off-course. If your ships are mostly made of steel I doubt you’ll have problems with fire, you don’t exactly have flammables on the ship.
I have questions.
What would the specific heat capacity of your pairelite be?
How quickly does it lose heat?
Wouldn’t it be unrealistic to both need to heat your pairelite and the water for thrust?
What kind of weapons are you outfitting these ships?
How are you going to deal with the winds? Your ship is likely to have a huge area to be pushed by winds.
How high are we talking? Thin and frigid air could be a problem.
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