Part of my point was that 4 tons per dton was on the low side and a 100 dTon scout was one of the smallest ship's commonly encountered. . .
A bit on the low side, but not terribly. TNE gives the weight of a fully loaded scout as 698 metric tons, very comparable to the 575 tons of the A380.
Let's try again with your Airbus 380 tires (575 tons/22 wheels = 26 tons per wheel) and an 800 dTon Freighter loaded with freight at 10 tons per dTon.
800 dTon ship = 8000 metric tons / 26 tons per tire = 308 tires.
Is that what you imagine when drawing the deckplans?
Three landing struts at 100+ tires each?
Five landing struts at 60+ tires each?
Even at my light 4 tons per dTon and your 26 tons per A380 Tire, the 800 dTon (3200 ton) Freighter still needs 123 tires ... three landing struts at 40+ tires each.
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Your math is way off. This is why the A380 doesn't need 200+ tires. As the weight increases you use larger tires. As the size of a tire increases the amount of area in contact with the ground and containing pressure both square. A tire that is twice as tall and twice as wide actually provides the same support as 4 tires. This is why the A380 is able to support so much more weight than a fully loaded truck with only 4 more tires. Using the A380 tires on a ship that is almost an entire order of magnitude larger is like saying that a Smart car must have 40 wheels because a skateboard typically supports 100 kg.
Also, remember, the tires on the A380 are TL-8 tires. The tires on your starship are probably at least TL-11. Will that really make a difference? Absolutely. Compare a modern (late TL-8) tire against a tire produced early in the 20th century (early TL-8). Modern tires are tubeless, often self sealing, with steel belts. You can shoot them and they will only leak air slowly. Most of our images of a tire hitting a nail and blowing out immediately stem from the old inner tube tires of the early 20th century.
TL-11+ tires are probably belted in things like high density long chain polyethylenes arranged in patterns that reduce separation between the chains and constructed so that the tire is supported by something other than atmospheric pressure (since worlds will have very different pressures).
We had a change of over 1 order of magnitude going from truck tires to actual airplane tires. You don't think we might not see another order of magnitude as we gain at least 3 tech levels with tires that are the appropriate size for the larger ship? Now your 8000 kton ship needs 30 tires. Is that a lot of tires? Sure, but it is 'do-able'.
Setting aside the visual impracticality of the mental image of a starship with all those tires ...
I think we can do that since there's plenty of possibilities to reduce the count of those tires to much more reasonable numbers.
Large aircraft (like a 500 ton A380) require special runways that are extra strong (to support the weight) and extra long (to give room to accelerate to takeoff speed). A 3200 to 8000 ton starship will need a staggeringly strong runway that will be constructed at an equally staggering cost. Beyond that, an A380 has really large wings designed to provide lift at low speeds. Starships (at least the designs that I have seen) do not. Even the most 'aerodynamic' have rather stubby wings that will provide lift more like a flying brick than an airfoil. I will leave it to someone better versed in aerodynamics (since they clearly exist) to estimate the take-off speed of 'flying brick' ... and from there, to estimate the runway length needed to accommodate that craft.
My opinion, is that will be a very long runway, built at staggering cost to accommodate craft that look very different than what has traditionally been imagined.
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None of this is to say that it is 'impossible'. It is just very different than the craft and starports presented in the OTU or the Traveller splat books. To create such an ATU will require more than just slapping some wheels on a Type S and Type A and calling it done [without a large dose of 'handwavium'].
That was my only point.
Yes, these ships would require very long run ways. Given that there is only a few starports per world as opposed to the hundreds airports in the real world that service large aircraft I don't see that as a real problem.
The aerodynamics is a completely separate issue. As I said in an earlier post it either requires the handwaving of some sort of 'airshaping' technology in order to make the existing deckplans work or you need to redo the plans (or decide to introduce some other technology that allows vertical landing). That's got little to do with me 'wanting' airplane style takeoffs, however. Even if you go to a tail lander solution the deck plans need to be redrawn because they make no real sense for a tail lander. The fact is that those plans are drawn with the assumption of some kind of vertical takeoff ability that does not require pointing your main engine directly at the ground.
To be completely honest I would assume that ships in such a universe would come in one of 3 basic designs.
The first and simplest would be ships that simply don't land. The largest ships would probably fit into this category because it is in many ways the simplest design. You can build a ship that transports cargo between star systems that doesn't require a massive maneuvering drive and you don't have to worry about aerodynamics. Since the thrust is low your structural engineering is also much more simplified. Parts that would snap off if exposed to 1G will be able to handle a constant .1G with no problems (yes, I realize Traveller doesn't have drives that produce that low an amount of thrust but we are already stepping out of the OTU).
The second would be 'tail landers'. This would include both tall tower shapes and 'flying saucer' shapes. They would have to have engines capable of producing at least 2Gs for a reasonable length of time and honestly are probably far more common than the type 3 design.
The last design would be ships that have drives that are stronger than the type 1 ships but not as strong as the type 2. They are built along lines similar to modern airplanes and they take off and land in a manner similar to what I've been talking about. Ones capable of using land based runways probably top out at around 400-600 dtons. Any larger than that and they probably resort to water landings, partially so they can simplify the ever increasing problem of wheels (the problem does continue to get worse and you can't just solve it with ever bigger tires because of something known as the cube/square problem, but I think you could probably get by with up to about 600 dtons before it becomes too great) but largely because such massive vessels require longer and longer runs to bleed off (and pick up) energy in a safe manner.
I'll be completely honest, type 3 designs would probably be in the minority in a true 'hard sci-fi' Traveller setting. They're just not as efficient as the type 2 or type 1 designs. However, most deckplans can be updated to type 3 designs with a lot less work. Their advantage is that they don't require engines capable of directly overcoming gravity, but since in Traveller an engine capable of producing 2G only requires a few percent of your ship that's something of a non-issue.
