I stand corrected. After reading your response I looked into this and you are correct. Naval tonnage represents the water displaced, which is the actual weight of the ship. Thank you for making me a little smarter tonight.Glad to be of service. :)
Also modern ships are again built with armour in mind...the previous mistake was corrected after the falklands war when the discovered that a missile hit does not spell the doom of the ship but having the ship catch fire due to the aluminum structure igniting does. Modern ships are also slower than WW2 ships stupidly enough, but I suspect that is more because you compare a modern DD to a WW2 DD and you should more reasonably compare it to a WW2 CA or CL.Hmm, conflicting information. When I tried to find data on not only the ships above, but also further other destroyers and frigates, I could never find any information about any armor, despite for the WW2 battleships, and of course the Nimitz. I thought that was due to that they indeed do not care about armor anymore. You don't happen to know any source for ship data that goes beyond wikis and the ~top 20 google results where I drew from?
I'm thinking that it's probably due to automation leading to denser more efficient use of space, as well as a conscious design effort to reduce cross section which improves top speed and fuel efficiency.
I love the effort that went to the chart and the diagram is excellent for getting such a simple concept across for a casual like myself.
Edit: wait, I had that backwards, modern ships are less dense so I'll completely ignore how wrong I was and instead suggest modern ships are built significantly more cheaply, lighter grade metal across the board, more plastics and composites etc. Even ignoring the actual hull most individual components that goes into a ship would be significantly lighter now than it was back in the 40's.
Just keep in mind that a naval ship must float. This means it must have a final density that is less than water. A spacecraft does not need to float, but (obviously not in aurora) needs to consider that the acceleration it can achieve (which determines its velocity) is limited by being the Force applied divided by the mass of the ship...where mass is volume*density.Thanks to trans-dimensional Cthulhu magic, Aurora ships don't accelerate though. :) However, needing not to care about mass at all when it comes to "acceleration" makes the other point about space ships being able to afford to be more dense even more prominent. This would indeed mean that (Aurora) space ships could be smaller than the naval drawn average V/M ratio would suggest, but I think first that it only appears to some degree, as modern ships are still already mostly made out of metals, so the amount you can add to that shouldn't be too groundbreaking unless you start to intentionally include lead for randomness' sake. Then secondly I would argue that the direct comparison of Aurora and Naval ships stands very strongly, as it seems to come up with the same data on given ships masses, namely for example the crew count, which after further lookups turned out to be pretty much parallel. Since a more dense ship should be smaller, this would normally result in Aurora ships then having lesser crews on same sizes, but they actually even got a bit more. This strongly suggests similar built.
As a first guess Aurora ships size is determined primarily by the volume needed for the crew space. Work stations, maintenance spaces, walk ways, mess halls, kitchens, medical facilities, sleeping areas and toilets probably define the volume of most of the ship. Missile magazines, cargo, fuel, hangers spaces probably are the other major volume components. These are also the "low density" components of the ship being largely air. After that you have the various plants and things like beam weapons which are mass intensive but volumetrically small.I don't quite know what you mean with "Aurora ship sizes suggest volume needed for crew space". The only thing that determines crew are exactly the components that require them, so a mere tanker for example has very little of that, as tanks run without technicians, and complex war ships with military grade engines need a relatively high ratio.
Also a cargo ship might be just a spar with a small-ish crew volume and mostly just empty space one attached containers to.I am pretty sure it is legal to assume the cargo ships as being as big as if those cargo bays were full, because at some point they are, and this space will be needed. If anything, I would argue in the opposite direction, that cargo ships might even be bigger, because cargo space here is not given in volume, like it should be on a space ship, so you could fill that available space with super heavy neutronium that would weight way more than a standard cargo container assumes to make place for.
To determine an average size of an aurora ship you first need to know the approximate density of any particular component and that defines the volume it occupies if you accept the mass as a given. Or you need to know its approximate volume (if you figure that is correct) and then knowing the density you find the ships final mass.Again, since the naval comparison fits so tight with Aurora as it does, I think it is reasonable to at least consider this average ratio to be a good guide. A grand average through all components is just good enough then, so even if it was possible, I think calculation per component wouldn't really improve much on that.
Hmm, conflicting information. When I tried to find data on not only the ships above, but also further other destroyers and frigates, I could never find any information about any armor, despite for the WW2 battleships, and of course the Nimitz. I thought that was due to that they indeed do not care about armor anymore.
2) Armor. In WWII, entire external hull was heavily armored. Post-WWII, that changed to internal armor (some of it Kevlar) on critical compartments, e.g. magazines and/or engines.With the internal armor, do you mean just the practice of building in a bulkhead compartment scheme? I read that became modern relatively late in western war ships, despite chinese ships employing this with wood since ancient times. In that case this shouldn't change too much, because it is more about floodgates and structural integrity other than actually stopping blasts.
With the internal armor, do you mean just the practice of building in a bulkhead compartment scheme? I read that became modern relatively late in western war ships, despite chinese ships employing this with wood since ancient times. In that case this shouldn't change too much, because it is more about floodgates and structural integrity other than actually stopping blasts.
If not, and there ware serious walls of armor internally, then how much are we speaking about? Is it comparable to the former outside armor just being scrapped and re-erected inside?
You need a central corridor of some sort from bow to stern to allow movement of the crew. On a surface ship that is called the top deck and it is not enclosed so it isn't an issue.
Can't they just use the Jeffries tubes?
Jefferies tube (Memory Alpha spelling)
Interesting thread. I just want to point out that Carriers also have huge internal hangar bays that distort their density.It doesn't matter for the values that have been determined, as the volume and consequent calculation of density already span over those internal hangars. It might be a point that it could be unfair to include carriers into the calculation of the average V/M, as ships with such large empty internal areas might water down this ratio. Yet, as baffling as it is, these carriers turned out to even have greater density than the other ships for some reason. ...Maybe because their volume calculation was more tricky and a lot more eye-judgement based. I took them out of the calculation though to test how it would impact the average V/M, and the difference is negligible. Might as well keep them enlisted. :)
For example, the USS Harry S Truman has 3 internal hangar bays, here's a picture of one of them.
No not just addition of bulkheads. On thickness, my understanding is that the walls are thicker around sensitive compartments, but not e.g. 18 inches of steel.130 tons sounds reasonable, especially for Kevlar. Would that have been steel, we would already deal with nearly 800 tons. Well, I guess I will scrap that idea with the armor weight correction. Of course this will still impact as soon as multiple layers are added, but the starting point seems now equal in weight to me.
I googled for "naval Kevlar armor" and picked up an excerpt from "The Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet" by Normal Polmar talking about Arleigh Burke class DDGs. He says they're the first pos-WWII US destroyers with steel superstructures (due to Belknap and NOT due to Sheffield's loss in Falklands) and that they have "130 tons of Kevlar armor plating to protect vital spaces".
My recollection is that it's to help protect against fragmentation damage after a bomb's exploded (outside the compartment), rather than trying to keep a bomb from entering a compartment altogether.
When I say that the crew spaces define the volume I mean just that. People take space, much more space then wiring or solid engines. You need a central corridor of some sort from bow to stern to allow movement of the crew. On a surface ship that is called the top deck and it is not enclosed so it isn't an issue. In a space ship you need to enclose it...that means a 2.5 m high, 2.5 m wide and x m long square corridor. Each person needs a bunk, space to eat, space to void by products of eating, life support systems to keep them alive and all the rest. If you look a modern submarine you see that a lot of the internal space is occupied by "space" for crews. If my memory of the Polaris class submarine I built as a teen ager is accurate about 20-30% of the internal volume was space for people to live or work. And a space craft has a lot more need for things like food storage, air storage, air processing and water processing facilities to keep its crew alive. This is volume intensive (but not particularily mass intensive) so probably in my view defines the volume of the ship. This has nothing to do with the rules, which are just some numbers Steve threw together from whatever.Those are good reasons, and they pull in both directions. 1. Spaceships should be more dense because there is no reason to have extra empty halls for floating purposes. And 2., Spaceships should be less dense, because extended requirements of survival support is far greater in space, hence inflating "crew quarter".
My comment on mass in a surface ship is simple. Surface ships are designed on the basis of fairly complex hydronamic factors determined by the speed you wish to achieve and the overall mass of the ship in question plus a host of other considerations. Warships are built around their turrets in WW2 terms as well. These in general defines beam, speed desired defines length compared to beam etc BUT the ship has to float that means a density of less than 1. So the trick is to expand the volume occupied by things to reduce the density. So a turbine power plant which is massive is set into a large mostly empty room. In a space ship the large massive engine is set into a room that is just big enough to support maintenance and has no requirement to be big enough to reduce the density of the ship to something that is accepable from a "not floating like a brick" point of view. Surface ships are limited by that constraint in terms of their mass...space ships are not. This means the density of a space ship will tend to be high in most cases where the density of a surface ship has to be low or else the damn thing plays brick. It is not really believable that a space ship would have a density of 1 or less. If you want to use a ship to compare to...use a submarine as they are closer to a space ship in terms of constraints then a surface ship. Also they are largely just a cylinder so you get better their dimensions with simple mathematics.
First and foremost ships in Aurora are made in large part (or even in majority) of TN elements, which can be as dense as you please. As such you can easily use this to justify whether volume to mass ratio you want.Hmm, "large parts" is definitely stretching it.
Second, both mass and size impacts how a ship maneuvers. Also the larger the ship the more armor you need. Ergo it would stand to reason that ships would be made as small as possible.We had that before. Simply said: No, mass does in Aurora not affect maneuvering at all. The ancient TN magic excavated from sunken R'lyeh ensures that any ship or fighter can in a mere 5 second interval turn 180° and reach astonishing full velocities of up to 99.66..%c. Either you say that is because in the new TN age, it is not a matter of moving through space, but move space itself (or maybe through some in comparison really slippery bulk plane loophole instead), or acceleration is now just so easily available, that heaviness of equipment really does literally account for nothing anymore.
And last but not least, in real life mass is a very important consideration when launching stuff into space. In addition Aurora takes place in the future (usually) where very strong but light materials may be available, like carbon nanotubes for example. Those may completely replace current materials used, making ships strong but light.It is very vague what a shipyard in Aurora actually is. It could be ground based, and needing to care about launch fuel, but it could also be orbital. I would argue it is more likely orbital, as shipyards can be destroyed by weaponry that usually wouldn't pierce the atmosphere of any planet. Even if not however, who says that all the old expensive launching methods still apply? This is TN age, where either space moves itself without concern for gravitational potential bonds pretty much. Or otherwise extreme acceleration can be generated and release of equivalently gigantic energy is a minor task.