Starship Shape

[Elliot]

OK so i'm not a gearhead so I need an explanation.

Traveller ships look cool. However, it seems totally illogical to me to have anything above 800-1000 tons streamlined and airframed. That's what a cutter is for.

So here's the question:

What are the disadvantages in 'reality' and in the rules of closed or open framed ships that have no streamlined shape. I say this because even dreadnoughts have nice cylinder or wedge like shapes.

Also why are there no sphere or saucer shaped ships outside of K'Kree space in canon? (Expect to be correct if wrong)

 

[jfwking]

Aside from the fact that the ships look a lot nicer on the recruiting posters and evening news casts you mean

Partial streamlining allows for fuel skimming off a gas giant, fuel shuttles able to handle quick refueling of the bigger ships take up space or require dedicated support vessels. Warships that can gas giant refuel are strategicly more usefull.

Defence against meson weapons can also be a factor. Best combo of fueling and defence is the needle then the cone. Dispersed structure is best meson defence but cannot be streamlined so cannot skim refuel.

Also with contragrav just because a ship is over 1000 tons doesn't mean it will never be in an atmosphere.


Opens window, looks at Tigress hovering over city

Surenders..............

 

[aramis]

10 KTd isn't THAT big. A 3:1 cylinder is 105.5m diameter, and 316.5 m long. about the size of a large aircraft carrier.

Even a 500KTd in the same 3:1 cylinder is only 1431.5m diameter! 4294.5m long. That's battleship sized.

if you bullet-nose the ends, you can add another 1/2 the diameter to the length, as a rough figure, per end bullet nosed.

A 5km ship, yeah, I don't see it landing. But I can see 100KTd Fuel Skimmer using an airframe... for safety while skimming.

And lets just ignore TNE/T4 technobabble for the moment. These ships are stressed to withstand 6+ G's. Landing on a 1 G world is NOT likely to be an issue, provided the axis of thrust is kept on target.
Now, I'd hate to see the runway needed by cyl/af battleship....(30-40 km?)

 

[mike wightman]

You missed out GT and MT in your technobabble statement. Both of these systems allow for gravitic drive VTOL

,but your point about their ability to withstand multi G stresses is well made.
If you are willing to accept G compensation fields and reactionless thrusters what's the problem with contra-grav, either included in the maneuver drive or as a separate component like the CT grav module?

 

[Pwyll]

heya Elliot

if you consider the full cost of ship-born support craft (displacement, personnel, and $) you might be surprised at how attractive streamlining the hull instead becomes.

also consider that many starports are likely to provide (and perhaps insist upon) tugs or repulsor/tractor beams to aid in large vessel landings.

there are economical, tactical and strategical (is that a word?) advantages to being able to refuel ships quickly and in a variety of circumstances, for which streamlining allows.

 

[Richard Saunders]

Originally posted by Aramis:
[QB] 10 KTd isn't THAT big. A 3:1 cylinder is 105.5m diameter, and 316.5 m long. about the size of a large aircraft carrier.

Even a 500KTd in the same 3:1 cylinder is only 1431.5m diameter! 4294.5m long. That's battleship sized.

--------------------------------------------
Hello.
Who built a Battleship 4.25 Kilometers Long.
I could believe 425Meters long but 4.25Kilometers is a bit hard to swallow, I dont think a blind geriatric pilot could miss a target that big with a bomb.

.
Bye.

 

[far-trader]

Originally posted by Elliot:
Also why are there no sphere or saucer shaped ships outside of K'Kree space in canon? (Expect to be correct if wrong)

Actually a few come to mind.

The 400dT Free Trader from the CT Alien book Solomani. It's a saucer, in the picture at least. Or at least that's what I always saw.

And of course the 800dT CT Mercenary Cruiser is a sphere but I imagine you just forgot about it, and the bigger Happy Fun Ball, the Tigress

And likewise the 200dT CT Safari ship is a kind of saucer/flying wing.

 

[marginaleye]

I have a slightly different question: Why is "partial" streamlining good enough for screaming through a gas giant's atmosphere at hypersonic speeds, but not good enough for a rather leisurely antigrav-buoyed flight through the atmosphere of a terrestrial planet?

A heretical idea re. starship hull shape:
Suppose that all "jump bubbles" were absolutely spherical, and centered on the starship's center-of-mass. The obvious temptation would be to build spherical starships, to stuff as much ship as possible into a jump bubble of a given size. Merchant ships (governed primarily by cost considerations) probably would be spherical. Warships, however, might not be, since (a) spherical starships lack surface area for big radiators, sensors, and weapons, (b) spherical starships are "meson-gun bait," and (c) it's easier to build a needle- or cone-shaped ship around a big spinal-mount weapon.
Just an idea.

A sort of spooky thought...
Externally, everybody's starships -- Solomani, Vilani, Aslan, K'kree, and so on -- would all look alike (apart from minor details and the paint), just as fish, icthyosaurs, penguins, and whales all look a lot alike.

 

[mike wightman]

Sounds just like the Adamist starships in Peter Hamiltons Night's Dawn Trilogy. Spherical ships that sprou radiator fins, sensor clusters and weapon pods when in normal space and retract them all for jump.
I liked the ship combat in those books too.

 

[savage]

Why would I be tempted to do spherical ships? Just design the bubble based on the most distant parts of the hull.

I suppose the negative I'd bring up is deckplans. Your reducing yourself to only using versions of the happy fun ball.

Savage

 

[marginaleye]

Why would I be tempted to do spherical ships? Just design the bubble based on the most distant parts of the hull.

Because the volume of the jump drive itself, and the amount of fuel it requires, would depend upon the volume of the jump-bubble that it generates, not that of the actual ship enclosed. In other words, if your ship isn't spherical (and just big enough to fill up the jump-bubble) you'll be going to a vast amount of trouble to transport that unused empty space through jump-space. A compelling argument for freighters, perhaps slightly less so for warships.

I agree the deck-plans would be less aesthetically appealing -- you're quite right about every jump-capable starship looking like a variation on the infamous Happy Fun Ball. For extra constraining fun, I envisioned the jump drive mechanism itself being located right at the ship's center-of-mass, or perhaps the geometric center of the spherical jump-bubble.

On the other hand, is that really such a big deal? If, for instance, one were to draw up deck plans for all the seagoing craft of the 18th and early 19th centuries, they would all be shockingly similar. That didn't, however, present a problem for Forrester or O'Brian.


Ooh...
Here's a nifty idea:
Installing really long spinal mounts would be difficult on jump-capable starships (only really obscenely large ones would have the necessary diameter to fit them in). On the other hand, relatively dinky non-spherical system defense "boats" (well, cruiser-sized ones, anyway) could boast disproportionately large spinal mounts. I'm envisioning ding-dong battles between cruiser-sized system defense "boats" armed with spinal mounts, and jump-capable warships armed with, say, vast numbers of missles. Circular (equatorial) "spinal" mounts might be possible for jump-capable warships, but they'd be very, very fragile in battle (lose one set of magnets, and that's the end of your primary weapon).

 

[mike wightman]

Wouldn't you also reduce the jump "fuel" requirements for your spherical ships?
After all, you aren't going to have all that empty space to fill with hydrogen.

This varient of yours makes a lot of sense in a way. Jump drives and maneuver drives have always been volume rated so it is logical to consider the shape of that volume.

 

[aramis]

Originally posted by Sigg Oddra:
Wouldn't you also reduce the jump "fuel" requirements for your spherical ships?
After all, you aren't going to have all that empty space to fill with hydrogen.

This varient of yours makes a lot of sense in a way. Jump drives and maneuver drives have always been volume rated so it is logical to consider the shape of that volume.

Minimum surface area for a given volume is a sphere.

Now, adding in the TNE/T4 technobabble and technical issues, on many large designs, the problem is NOT volume, but a lack of surface area for radiators!

Now, aside from frontier refuelling, surface area serves as radiator space, turret mounting space, antenna mounting space, and access space. Soooo.... the Tigress and other LARGE (500KTd) battleships in the OTU don't have nearly enough, nd needs something like vented sodium gas to maintain combat power levels more than a few minutes! (Or need massively reduced weaponry.) At least when converted into TNE/T4.

Now, there are 2 500KTd designs for battleships. 7 000 000 kiloliters (rememering a kiloliter and a cubic meter are, in fact, the same thing). That's a 191 meter cube. I think on the above I messud up... I accidentally use the wrong bank of stored formulae on my HP... those are SA calcs... OOPS. (first nummber is SA in Square meters... Oh, what a major blunder... Maybe I should have waited til I was awake...)

So for some correct numbers
V=Pi*R*R*2AR
V/Pi=(R^2)*2AR
V/Pi=3R^3
V/(2APi)=R^3
(V/(2APi))^(1/3)=R
V = Volume
A= Aspect Ratio
R = Radius
Pi = Pi

Or, in HP:
<< -> V A << V 2 A * / 3.1415 / DUP DUP 2 * SWAP 2 A * * >> >>

Returning R, D, and L.

500 KTd = 143.75m diameter, 0.431 km long

500 KTd 10:1 Cylinder: 96.2x 962.3 (or roughly 1km)

By the way, modern "widdebody" airplanes are typically 10:1 or longer...

10 KTd 3:1 Cyl: 39x117m
10 KTd 10:1 Cyl: 26.1x261m


BTW, if one can't laugh at one's own mistakes... Rest of that post looks right.

Now, assuming a "Quantized effect", ie, if Sf <1 effect is nil, and if Sf >=1 effect occurs at 100%, we have two modes for theory. Either has been supported in canon: The central coil Jump Drive (Some TNE references, and some CT deck plans) and the surface grid field (lanthanum grid) (MT, some CT, some TNE, T4, plenty of art). THe lanthanum grid should have a volume based upon the surface area, which scales roughly as Cv^(2/3), and the central coil which scales to the same... but is limited to sphereoids or multiple nodes of field generation.

The grid makes more sense, in that it allows for nearly any hull shape, but the grid should take a fraction of SA, rather than straight % of volume. Say 1L/m^2 or so... but that rapidly makes larger ships have toruble with volume, and rapidly increases their surface area issues, too! (the above assumes fairly small lanthanum grids, and not scaling them with hull size.

But this makes the rest of the configuration either smaller as the driven ship size increases, OR, increases drive effective size at higher sizes.

In short, it breaks the extant ship design systems to account for field strengths, etc.