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munch
05-14-2012, 12:35 AM
Hey guys might not be the right place for this but how do you work out how big a space ship needs to be I ask this because I have been working on a scfi world for several years now and have written a number of wiki style articles detailing the military capacity’s and crew compliments of most ships in the military of this universe however I find it very hard to work out how big they are I know off course this largely depends on how much of a ship is needed for engines

But assuming engines and the like only make say a 1/3 of the mass how would I go about creating a formula that will tell me the rough size of a ship with say 30 or 500 or 2000 crew?

once done found deck plans for there 40 odd ship types will not be far off

atpollard
05-14-2012, 09:19 AM
For 'Space Opera' universes with 'magic' drives (like Traveller, Star Wars and Star Trek), the answer is 'whatever the plot requires'.

However, for answers dealing with hard science, this is the single best source of data that I know of:
http://www.projectrho.com/rocket/index.php

[The problem with 'realistic', is that 'realistic' ships are slow (months to the next planet and hundreds of years to the next star) and 90% reaction mass ... that's a lot of 'nothing' for a deck plan of a ship.]

For just the 'cargo' portion of the ship (including human cargo, but ignoring drives, fuel and reaction mass) this is a good source of data on how much room is needed for living space and food production:
http://www.nss.org/settlement/library.html

Hope that helps and Good Luck.

[PS. If you just want some quick and dirty answers, Traveller (the RPG) requires:
1. about 2000 cubic feet of living space (200 square feet of floor area) per person ... which includes all common areas, life support, living quarters, food storage etc.
2. about One crew member per 50,000 cubic feet of total ship.
3. about 15% of the ship dedicated to 'Engineering' (drives, power plant and fuel) per unit of speed ... which in traveller are gees of acceleration for normal travel and parsecs per week for faster than light travel.
4. each 2000 cubic feet of unused space can hold 1 passenger worth of accomodations or 1 TEU standard cargo container. ]

Jaxilon
05-14-2012, 10:24 PM
I ran across this cool poster online while I was looking up what a blueprint should look like on my latest lite challenge entry. It might be of some help since it compares pretty much all the well known sci-fi spaceships.

It's a cool chart: Sci-Fi Space ship Comparison chart (http://conservationreport.files.wordpress.com/2009/01/spaceship-size-comparison-chart.gif)

arsheesh
05-14-2012, 10:34 PM
Hey nice find Jax, this could come in really handy.

Cheers,
-Arsheesh

Hai-Etlik
05-15-2012, 12:31 AM
It's intended for use in Roleplaying Games, but GURPS Spaceships would probably do a decent job of providing consistency of starship size without too much difficulty. GURPS books are pretty well researched so you can be reasonably confident that they aren't just making up numbers. The biggest downside is the use of US Customary units.

munch
05-16-2012, 02:16 PM
Yeah having now considered this question even more I think its more complex this for a space oprah thank you for that chart jaxlon right now I only have drawings of the style of each ship and the relative sizes of each ships and rough estimates of crew sizes im thinking the engines and like do not take up a huge part of the ship as you know it’s the future and all so I’m more inclined compare it to a Morden air craft carrier then anything else

What I might do when I get to the holidays is look at a whole lot of different ships from modern and historical naves looking at diagrams there engine rooms take up barely anything so I’m thinking I will try to work out what size of ship you need for what size crew then forming a spread sheet where you tell it what ratio of the ship is engine and what is crew space then tell it what level of luxury they can have on a scale form 10 a cruise ship to 1 a modern sub or a warship from the age of sail

And then you put whether the ship is military or cargo and its crew size and it will try to calculate a rough size for you

That said everything I just said is words right now lets see if I can find sources to give me the figures I need and get my head around the maths to do it all

Jaxlon if your chart says anything it is that there is no agreed size in scfi which I found stunning I somehow assumed they were all working of the same figures in working out how to build there models but very cool find none the less

While I’m doing this to try to make floor plans of some of the smaller ships the maps are really all in aid of a novel I have been writing

bartmoss
05-21-2012, 05:36 AM
Realistic spaceships have large engines and huge fuel tanks because they need to carry (and accelerate) loads of reaction mass. There are plenty of design studies and examples out there, but the basic point is you'll end up with a huge percentage of fuel to propel even a tiny payload...

If you are going for space opera, then ships are any size you want. Most SF authors probably just make stuff up as they go along, some may have rough guidelines and I am guessing very few actually have set "rules" on ship design.

I've looked at ship sizes myself some time ago, mostly trying to figure out what a "tramp freighter" would be like, and I've based my comparison on Traveller, H. Beam Piper, and some real world stuff:

http://enderra.com/2011/10/14/starsship-sizes/

MadCartographer
06-01-2012, 12:03 AM
Here is a great site for ship size comparisons:

http://www.merzo.net/

Jeff Russells Star Ship Dimentions.

taro222
05-27-2013, 12:44 PM
Wow that's a cool and nice build ship which is totally amazing for me that i have no idea about to make the ship but these information is very informative for me..Nice work on it..Send me the complete pic of the ship?What update?

Scot Harvest
05-27-2013, 05:56 PM
Technology folks!

The answer lies in what level tech you have chosen.

Remember when watches, TV and phones where HUGE! Now the only reason they are the size they are is because of our ability to interact with it.

I purpose that with high enough technology the only limiting factor will be .... us! Thats is our size and limited 5 senses. Include a 6th sense (PSI) and it takes on another twist.

So if you have chosen low tech space travel, make engines and support crew large and clumsy,
but if you chose high tech make them small and elegant.

2 cent given

munch
05-29-2013, 03:49 AM
Yeah you guys really dint read the question but thanks for making the effort I understand that the amount of room things like engines and such take up is about tech level but things like bedrooms and showers and kitchens take up pretty much the same room everywhere I am saying leeavining out the tec stuff how much room would you need just for the living space for a crew then I am going to decide that for every x amount of living space you need x amount of non living space


Tho you guys have made me think a few things like how much cargo would be needed my thinking is in this world trips of a year are about the longest with out being resupplied

rdanhenry
06-01-2013, 01:22 AM
That varies culturally and also technologically. People will adapt to very cramped spaces by most of our standards if they have to. OTOH, if your tech supports the equivalent of a nice hotel suite per person instead of submarine quarters, you'll likely do that. Do you have a kitchen and dining space, or can a 'replicator' the size of a microwave oven provide food on demand in most rooms? Theoretically, if the tech is advanced enough and psychological effects aren't a problem, you could keep a man in a 3' x 3' x 7' space quite easily. For long voyages, passengers in suspended animation (including most crew, since their jobs would be intermittent at best during most of the trip as the ship holds course under steady acceleration) might well have such a space (plus probably a bit more for sustaining machinery, of course). At the far end from that, you have the TARDIS, with a potentially infinite interior. In other words, there is no fixed answer.

Scot Harvest
06-03-2013, 09:44 PM
I agree whole heartedly.

If you have a concept in mind i.e. Submarine quarters, find some sub reference on line.

Otherwise you might have to just "make something up" from your imagination.

Also, what is the consequences of making an error in this endeavor. It might be something done simply for aesthetic value rather than a usable craft.

Make it FUN not real.... or not :)



That varies culturally and also technologically. People will adapt to very cramped spaces by most of our standards if they have to. OTOH, if your tech supports the equivalent of a nice hotel suite per person instead of submarine quarters, you'll likely do that. Do you have a kitchen and dining space, or can a 'replicator' the size of a microwave oven provide food on demand in most rooms? Theoretically, if the tech is advanced enough and psychological effects aren't a problem, you could keep a man in a 3' x 3' x 7' space quite easily. For long voyages, passengers in suspended animation (including most crew, since their jobs would be intermittent at best during most of the trip as the ship holds course under steady acceleration) might well have such a space (plus probably a bit more for sustaining machinery, of course). At the far end from that, you have the TARDIS, with a potentially infinite interior. In other words, there is no fixed answer.

s0meguy
06-29-2013, 09:19 PM
Yeah having now considered this question even more I think its more complex this for a space oprah thank you for that chart jaxlon right now I only have drawings of the style of each ship and the relative sizes of each ships and rough estimates of crew sizes im thinking the engines and like do not take up a huge part of the ship as you know itís the future and all so Iím more inclined compare it to a Morden air craft carrier then anything else

Sorry I just had to comment on this, I love how you write space opera as space oprah from the talk show host.

Anyway, this can be pretty flexible. I'd imagine military ships to focus purely on functionality and the crew wouldn't have much space. But on private ships a lot more space would probably be dedicated to leisure. If it is a ship where most of its inhabitants are in cryogenic stasis or whatever, then you can probably go with only 2 to 3 cubic meter per person. It depends highly on the priorities of the person building the ship.

Erik Tiber
06-30-2013, 12:42 AM
For 'Space Opera' universes with 'magic' drives (like Traveller, Star Wars and Star Trek), the answer is 'whatever the plot requires'.

However, for answers dealing with hard science, this is the single best source of data that I know of:
Atomic Rockets (http://www.projectrho.com/rocket/index.php)

[The problem with 'realistic', is that 'realistic' ships are slow (months to the next planet and hundreds of years to the next star) and 90% reaction mass ... that's a lot of 'nothing' for a deck plan of a ship.]
No, not really. The trip would be reduced to mere days with the use of a nuclear fusion space drive, also known as a fusion torch.

For most missions you'd just have one half to two thirds of the ship's mass be reaction mass, nowhere near 90%. You'll only see something like that for long-range missions to the outer solar system or something. Since this setting has FTL, you'll likely just have the reaction mass for normal interplanetary missions.


Yeah you guys really dint read the question but thanks for making the effort I understand that the amount of room things like engines and such take up is about tech level but things like bedrooms and showers and kitchens take up pretty much the same room everywhere I am saying leeavining out the tec stuff how much room would you need just for the living space for a crew then I am going to decide that for every x amount of living space you need x amount of non living space
That ratio will vary wildly depending upon the role of the ship as well as the delta v (change in velocity, because there is no friction in space so speed remains constant) it will need to reach its destination.

The last one will depend on how much maneuvering the ship will do in combat and how often it will use a slower-than-light drive.

As for the size of the crew, that can be anything, really. Computers should be able to do almost all of the work on the ship, so you could have a Nimitz-sized space ship with a crew of, say, ten, and it would be realistic.

This is space opera so obviously you would have a larger number of people than would be realistic, so it can be anything you want. I would just advise that you make the size of the crew less than half that of a real world naval ship of the same size, in order to avoid straining suspension of disbelief too much.

Look at submarines if you want to see a naval equivalent of a space ship. Submarines go without resupply for longer, the crew is isolated in cramped conditions for long periods of time, and any holes in the ship will be extremely problematic.


Tho you guys have made me think a few things like how much cargo would be needed my thinking is in this world trips of a year are about the longest with out being resupplied
If a ship is going a year without resupply, it would need its own manufacturing capacity, it would need hydroponics to make food, and it would need a large number of things in order to be self-sufficient. In real life, naval warships are resupplied far more regularly. Because, in space, you will want to minimize mass as much as possible, you will not want to take anything with you if it is not necessary to the mission.