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Amarynceus — Daily Draw 0146
#dieselpunk #skyship #airship #corvette #cruiser #warship #dailydrawingchallenge #1000daysofdoodles
Published: 2016-08-24 02:37:55 +0000 UTC; Views: 3151; Favourites: 65; Downloads: 0
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Description
Isometric layout sketch using the dimension's of yesterday's design. This stage always reveals flaws; several I anticipated when I was doing the rough draught yesterday, but there were many other problems that came to light that I didn't anticipate. Probably 3-4 hours of doodling and calculating; I'm trying to do some of the weight group calculations at an earlier stage, especially easy ones like armour plating. It helps in avoiding situations like I encountered when working on some older ships, when I had to reduce a lot of protection to keep the ships at design weight.
Anyway I think it's a promising design, simple and relatively cheap to produce. Reasonably pleased. A little more hull length and longer nacelles would probably make it more handsome.
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Copyright 2016 Avatar Z Brown
Corel Painter, Cintiq 22HD
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Comments: 17
I`m most interested in your ship speed calculations. Do you think that 16 knots is really good enough to make way in a headwind? I'd imagine that you'd want more Zeppelin like speeds, which shouldn't take much in the way in horsepower. After all the Hindenburg cruised at 76 mph with less than 4000 horsepower.
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26 knots, actually - but that's not the main point. I don't plan on explaining all the details on the lift systems just yet, but one of their standard-physics-breaking side-effects is that they violate the laws of inertia, and not in a good way. They will stay in motion relative to the sphere of reference of the planet only when force is actively applied, and the faster they are moved the more they 'want to stay still' so to speak; that is, they generate an 'intertial drag' proportional to the square of the velocity times the mass suspended and then some.
Thus large vessels require massive thrust to maintain any sort of speed. The Silverfish, for example, would move at over 220 knots if the only factor were aero drag; as it is, each engine produces 9.5x105 Newtons to achieve a mere 24 knots at full trot. Obviously ships avoid top speed unless absolutely necessary; besides the noise and fuel consumption, having some parts of your ship want to stay in place while the rest of it wants to move forward means substantial material stresses. It's part of why I've had to re-engineer everything over the past few years.
The combination of massive weight and bizarre physics mean most skyships are barely affected by wind.
There's a second lift system in use for small craft that plays more nicely with physics, but it's unsuitable for large warships and a topic for another day.
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And so the sky ships will behave like surface ships! I'm still tinkering with my liftwood ships (I've got a better idea of their shape and sail-plan, and I've finally figured out how lift works (It's inversely proportional to altitude) and have managed to find a map that really fits the world I'm trying to imagine), but it seems that every time you go into more detail about your lift system that I find you've already taken all the good ideas. My liftwood also has a drag component- it requires one so that the sailers can tack upwind- though I will admit I haven't thought about it in as much detail as you- I haven't really been thinking about the drag's use as a method for station-keeping, though I suppose that if it can allow a skyship to tack it probably will slow them down quite a bit. Even so, the engine tech in my world is not capable of producing the kinds of force that your ships require- I'm counting on them requiring far less horsepower (and so a much smaller engine) than a similarly size surface ship would need, which would free up boiler and engine space for the water-tanks and air-cooled condensers that my ships will need- so drag better be a lot less than for your lift system!
I swear that I've not taken the idea of drag from your ideas- I've taken it from THIS guys ideas:
EDIT: deviantart won't let me post the link to his page
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My first thought for your systems is to make the drag exactly analogous to that of water, for example if the liftwood reacts against some sort of ætheric medium (I always forget how it works). Then you can just apply the standard methods of sailing ships more or less directly, with the added bonus that you could use moving liftwood panels to steer the ship very effectively. One could make the æther flow around the planet too, so you have the added influence of currents to throw into the mix.
I doubt I've thought of anything original, and besides I've never posted anything about the lift system's drag before that I remember. My drag factor is ridiculous in its strength, really, but I can't get rid of it without redesigning every single ship. 
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Eh, I've moved away from the 'aethic medium' stuff, at least for this particular world (I've got several on the go- one of them is a Space 1889 conventional-Victorian-physicists-were-right sort of thing- but this one, Sky Ships of Siphonia (title subject to change: Siphonia is one of series of alternate Earths created by a California artist, though the sky ships and, well, the human element are all me. The artist creates slightly different Earths- Earths with different axial tilts, Earths with inverted land and sea, Earths with too much or too little water, etc., and lets the reader imagine the rest- he doesn't really get into how people would live on these geographic models, apart from a few suggestions about good trade routes. Siphonia itself is just a series of topographic and climatic maps showing what Earth would look like with less water- exposing that much ocean floor does a lot of interesting things to our world) just takes the concept of a biological no-energy-input contragravity system and runs with it.
Liftwood here is just repelled to by the Earth's magnetic field, allowing it to float like the big rocks in Avatar. Resistance to magnetic fields is what causes the drag on the liftwood, and thus the ship its attached to. I have considered making it's drag equal to that of water, which does fix the the whole tacking thing. The problem is that I've not quite settled on how fast I want my ships to be able to move at. Do I want them to move at watercraft speeds, or at something more like airship speed (nothing too spectacular, say in the range of 30-50 knots)? Whichever I choose will have big repercussions for how my world works. If I go with water drag, than only watercraft speeds make sense, obviously. Lesser drag makes airship speeds practical, but screws up the whole sky-sailing thing. The tech level of my world (which is rather all over the place, since it's set in a successor civilisation to ours) won't really allow for merchant ships to rely on engines-(It's a bit like the American Civil War era- sure, the Navies have all sorts of steam driven vessels, but the merchantmen are all still in sail). The rules I've created for governing lift means that a low-altitude heavy frieghter could have a total lift of 20,000 tons of more, but of course if it has to be sail driven in water-level drag I don't think it'll go anywhere. Hence my dilemma.
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I promise that this is the last one, but I've actual figured out a work around. Downward facing panels of liftwood resist the Earth's magnetic field and buoy it up, so panels facing fore, aft, starboard and port would resist movement in those directions. Obviously they could be rotated to on/off positions like the lifting panels, but these 'resistor panels' could stop unwanted movement. If the forward facing panel was 'off' and the ship heading forwards, then there would be comparatively little drag and you would not require a ridiculous engine to move the ship at airship speeds. If a headwind tries to push the skyship back, the aft facing resistor panel would resist movement in this direction and 'push back'- providing water level drag, if not completely cancelling out the force of the wind and allowing the skyship to move forward at it's original speed. This would let skyships tack- the starboard and port panels would resist the winds attempts to push the skyship sideways, while still allowing it to sail upwind.
Also, since the lifting panels are turned 'off' by rotating their active surfaces so that they are perpendicular to the keel, they would provide additional port and starboard resistance. Obviously, the fore facing resistor panel would only be set on when the ship is backing into a berth, or when there is a dangerously strong tailwind. In any case, this should allow the skyships to act as if they are in water, without requiring the same amount of power a watercraft would require.
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That all makes good sense to me, right on.
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Oh, good. I'm glad it makes sense outside of my head. As is probably obvious, I have not thought out the physics as well as you have (indeed, my knowledge of physics is certainly far more basic than yours). I hope that whatever I come up with doesn't have any unintended side effects. I am trying to improve, though!
As a final thought, it strikes me that even with water-analogue resistance on a skyship, it will probably be affect much less than an equivalent surface ship- does wave action apply more force than a crosswind? I need to start reading sailing manuals....
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Off the top of my head I can recommend reading the 'Elements of Practical Seamanship' in Darcy Lever's A Young Sea Officer's Sheet Anchor as well as the section on Seamanship in Steel's Elements and Practices of Rigging and Seamanship, Vol II. The former is available in PDF form through the google books project (probably openlibrary.org) and the latter I have found online at the Historic Naval Ships Association site: www.hnsa.org/resources/manuals… . Print versions would be preferable due to the many diagrams involved, but I have been too poor to enrich my library of late -- at least there are many free and legitimate resources unavailable not too many years ago.
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thanks! I'll look into them
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This looks super cool, but from an engineering perspective, I have some issues. Why not use double turrets? Change the front two and rear turrets to dual turrets, and you would be able to delete all of the wing turrets, as well as the amidships centerline turret. This would improve stability by focusing more weight along the centerline, allow you to save weight, and maintain a 6 gun broadside. Second, it might be a good idea to shorten and widen the mess area and move the forward turrets farther aft. You could move the magazines further aft as well, and concentrate the armor around a smaller area, and save more weight. Finally, if you are going to downgrade the firepower, why not go with 127mm guns? Add a torpedo launcher or two and you might have a really nice Destroyer.
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All valid points, and almost all of which I considered whilst sketching and rejected, for quite valid resons.
Double turrets are not yet in wide usage in calibres below 200mm by any fleet, and the 140mms on this craft are pedestal mounts. I don't think three decks is enough depth of hull for between-deck mountings, though it would be easy enough to raise the sides and make the hull flush from stem to stern. Turrets would be much heavier and more expensive than shielded pedestals. Economy dictates a lot of these decisions, and this is definitely a 'budget class' of ships. The age-old debate between quantity and quality is different for every case, but for light craft in a significant navy, it almost always tips towards quantity.
What that configuration would be useful for would be the equivalent of the small coastal defence battleship, but that's not a corvette.
Regarding concentrating the firepower: it comes at the price of heavy damage when a hit is landed. This is especially so with open mounts, but true of fully armoured barbettes and turrets as well. I've already gone down that design road years ago, and with every redesign I end up increasing the spacing between mounts wherever possible. Also, the lift units need to be spaced reasonably evenly for structural reasons, so most of the hull needs to be armoured anyway....
Finally, regarding gun size, that's an author's decision from ages: the Torvan forces employ no intermediate sizes between 180, 140, and 100mm, preferring to standardize fleet weaponry as much as possible and limit the profusion of calibres frequently found in other forces. Aerial torpedoes have not been invented yet (fixed-wing flight has lagged due to having great big flying things) so the 'destroyer' does not yet exist in the skies of Tethys.
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I was making a guess on gun caliber, 152mm is a common historically used one, so that's why I suggested it. Standardizing on a few calibers makes sense, although you would probably end up with a profusion of different guns in those particular calibers. The Italians ended up with 18 different 120mm naval guns for example.
I would like to hear more about tactical doctrine in your universe. With no torpedoes and limited strike craft, it seems like big capital ships would absolutely dominate the battlefield. It makes me wonder how smaller nations would respond to the larger ones. What sort of asymmetrical responses are there? I take it there are no flying submarines...or just submarines?
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For this particular navy I've enforced standardized guns and eliminated variations in each size, having written in a DNO (Director of Naval Ordnance) obsessed with fire control both on the fleet and ship level, but most forces follow the bad practices of real-world navies.
Tactical doctrine is still evolving a little; the fixed-wing aeroplane hasn't gotten off the ground yet, and rocketry is still a little touch-and-go, so the primary asymmetrical response to capital ships comes in the form of Gunboats or Gunships, which are pretty much just a large-bore gun with a bit of flying ship bolted on the back. They can be dangerous in packs and are quite cheap, but as current lift systems are very averse to inclination out of the horizontal plane, not as dangerous as they could be if they could attack from below. Small craft armed with batteries of howitzers to attack the thinner underside can be useful as well, but easily countered by just flying low and are mainly an ambush weapon.
At the start of the current setting, smaller nations are either being swallowed up or forging themselves into larger bodies to resist the larger powers. Obviously, having flying warships changes the face of ground warfare, and fleet actions will probably be far more decisive than in our world. It's a topic I've thought a lot on and would like to expound on in the future.
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Haha, oh, c'mon, give yourself a bit of credit. This looks awesome
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Thanks kindly! Those are certainly some of my inspirations, but I've still got a long ways to go. Lots of room to grow, though!
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Yay! Yea, of course, but it's alright to feel good about yourself every once in a while xD Seriously though, keep up the good work
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