[0.23.5] Spherical and Toroidal Tank Pack (Updated 05/02/14) (New download link)

[Talisar]

I think he'll be ok, otherwise his kerbals would look much more worried. All 3 are having a ball, apparently

[Wyseman76]

Nope, there wasn't any. Somebody is just a little aggressively defensive, it seems.

"Ugh I don't like the new textures at all", was your reply. You where short and unapologetic about your disliking them, I was short and unapologetic in return. Your follow up statement was far more appropriate.

[RoboRay]

"Ugh I don't like the new textures at all", was your reply. You where short and unapologetic about your disliking them, I was short and unapologetic in return.

Really?

I don't see any reason to apologize merely for not liking something. You are overly sensitive.

I don't like it. And that's ok. Somebody will dislike everything you ever do. Get over it.

I didn't say it was awful. (It's not.) I didn't say you are a horrible artist. (You aren't.) I indicated that I, personally, liked the old version better. (I do.) I didn't insult you in any way.

Your response of "you could have refrained from acting like my kid about it" is far beyond "unapologetic." The insulting intent is crystal clear.

If you must continue this, please direct any further responses to a more appropriate place. I doubt anyone else cares to see it even as little as I do.

Regardless, thank you for you contribution to a great mod.

Edited May 28, 2013 by RoboRay

[taniwha]

Talisar: beautiful tanks (and I like the newer textures, though I might check out the older ones too).

Just one thing: your tank masses (dry weight) are out by quite a bit. Going naively (ie, just using surface area to calculate dry mass, and using the Rockomax Jumbo-64 (orange tank) as the basis, the large sphere should have a dry mass of around 10.29t give or take a bit:

Jumbo surface area = 7.5 * 2 * pi * 1.25 + 2 * pi * 1.25**2 = 68.72

Large sphere SA = 4 * pi * 3.75 ** 2 = 176.71

The ratio is 2.5714, thus 10.29t. Lets say 10t as a nice round figure (a sphere can be slightly lighter due to more even stresses)

From there, the radii of your smaller tanks are 1/2 and 1/3 the large tank's radius, so their surface areas and thus masses should be 1/4 and 1/9 the areas/masses of the large tank, thus 2.5t and 1.111t

The fuel quantities/masses seem to be fine.

[taniwha]

PS: on thinking about it, 9t, 2.25t and 1t would also work well (not too light (still in the right ballpark), but nice round numbers).

[RoboRay]

your tank masses (dry weight) are out by quite a bit. Going naively (ie, just using surface area to calculate dry mass,

I don't think a direct correlation between dry mass of a cylindrical tank and dry mass of a spherical tank based purely on surface area would be correct... the sphere should have a slightly lower dry mass for the same surface area, I would think, because the cylinder would require additional reinforcement for the weaker areas where the end caps attach to the cylinder walls.

How much of a difference, though, I don't know. Probably not much. Your follow-on suggestion of 9 tons for the big one is probably close enough.

Edited May 28, 2013 by RoboRay

[Mihara]

How much of a difference, though, I don't know. Probably not much. Your follow-on suggestion of 9 tons for the big one is probably close enough.

Quite significant, actually, otherwise spheres hidden inside cylinders would not be such a common feature in rocket design.

[Talisar]

Those are pretty close to the numbers I had been looking at as well. I'll change them in the next update. Speaking of updates, I've made half-spherical versions of the small and medium tanks and I've also made a version of the large tank with an expanded centerline ring at someone's request(It kind of looks like a UFO). I don't have pics available until I get home, unfortunately, but would anyone be interested in these? And if so, should I add them to the existing pack, or make a separate pack for them?

[taniwha]

Spheres hidden in spheres (probably for anti-slosh baffles) would make the dry mass even higher (unless your point is that the reduced strength requirements allows the inner spheres without excessive mass penalties). Even with my suggestion the mass ratio of the large tank is still a whoppig 22.23 (compared to all stock tanks' 9). Even a mainsail gets 8.4km/s delta-v (just mainsail and tank).

Spheres can be thinner (and thus less mass per square meter) than cylinders (a cylinder with too much internal pressure will tend towards spherical (the optimum shape)), but they would have nasty slosh characteristics, so extra mass would have to be added to act as baffles, but the baffles probably don't need anywhere near the strength of the main walls.

[Mihara]

Spheres can be thinner (and thus less mass per square meter) than cylinders (a cylinder with too much internal pressure will tend towards spherical (the optimum shape)), but they would have nasty slosh characteristics, so extra mass would have to be added to act as baffles, but the baffles probably don't need anywhere near the strength of the main walls.

Slosh? What slosh? Fuel has no inertia in Kerbal universe, otherwise asparagus wouldn't work.

[FlexGunship]

I don't usually suggest things in these forums, but I would LOVE to be able to delivery these tanks to a ship in orbit for refueling. My method of choice would be a decoupler in the shape of a ring around the center of the tank. Doesn't have to do anything really, just allow for radial attachment, hit "decouple" and it let's go. I've been using radial decouplers, but I always end up having two tugs afterwards, one for each side.

[FlexGunship]

[double post]

Edited May 30, 2013 by FlexGunship

[Talisar]

I don't usually suggest things in these forums, but I would LOVE to be able to deliver these tanks to a ship in orbit for refueling. My method of choice would be a decoupler in the shape of a ring around the center of the tank. Doesn't have to do anything really, just allow for radial attachment, hit "decouple" and it lets go. I've been using radial decouplers, but I always end up having two tugs afterwards, one for each side.

I've been working on some custom clamps for these tanks that would serve this purpose, but haven't come up with anything that works well yet. Another thing I've been considering is a type of mount that the large tank would sit inside which would have places to mount other items on radially.... Kind of like a big version of the existing quadcouplers but with a bowl-shaped frame on the top for the tank to sit in.

[loppnessmonsta]

So... I've been playing around with the cfgs for these (just for myself) and I decided to make xenon versions. I suck at maths, so I tried to use a ratio that other tanks seemed to use. The lowest ratio of monopropellant-xenon I could find was 12.5, which, even rounding down to the nearest thousandth (or ten-thousandth), still gives me a 350,000 capacity for the large tank and "only" 13,000 for the small tank. Is that anywhere close to right!? That sounds like way too much.

[RoboRay]

The first crew for the new orbital HÄÂlau Depot arrives, aboard a Malihini Orbiter spacecraft.

(Yes, I've tired of Greek mythology names for my craft and am switching to Hawaiian.)

LKO's new fuel station is open for business.

Edited May 29, 2013 by RoboRay

[Scotius]

Was it full at the launch, or did you filled it in orbit? How many tankers it took?

[RoboRay]

Full at launch. The launch vehicle was a single Jumbo tank and Mainsail under the sphere for the third stage; a ring of six more Jumbos and Mainsails for the second stage, crossfeeding fuel to S3; and a ring of 12 more Jumbos with Skippers around the outside for the first stage, crosfeeding fuel to S2 and S3, with all engines (except the four little orange radials on the sphere) firing off the pad. I did use a little fuel out of the sphere for orbital insertion and circularizing (with the little orange radial engines, as the last Jumbo and Mainsail was jettisoned with Pe at 20km for no orbital debris), but it was still nearly full upon reaching the 100km final orbit. S3 had a TWR of less than 1:1, so it was a little marginal, but I managed to get it up there. The station itself's TWR with it's dinky little thrusters is something like 0.03:1, so circularizing took a while.

I plan to bring up some more habitation modules and maybe another big sphere tank to complete the station. So, figure two more big launches.

Edited May 29, 2013 by RoboRay

[taniwha]

Just because, I did some more math on the large tank (using a dry mass of 9t).

Assuming titanium alloy (density about 4.4t/m3, rounded to 4.5), there is 2m3 of tank material. Assuming it is all in the spherical shell, the shell thickness is about 11mm. This is enough to sustain (with no margin) an internal pressure of about 15 atmospheres (relative), but with no safety margin.

[willow]

Full at launch.

That's definately the better option, I built an interplanetary based on the big sphere. Took me up to 10 refuelling runs (little spheres) to fill it up completely! (Ok that test flight to the moon could have drained some) I am proud of the result, it's got around 10k deltav and an inbuilt lander that has 5k delta/v to spare when decoupled. And still only about 120 parts which my framerate thanks me for. First mission is to finally put a flag on moho... And then return!

The new 2m docking port is also helping a great deal, keeping the wobble to a decent level.

[Awaras]

I love the tanks. Just one little 'bug report': The large spherical fuel tank seems to be indestructible, except when spashing down in water.

I built this thing just for giggles (almost 8000 dV!!!) and no matter how hard I try to crash it to the ground, the spherical tank just bounces off the ground...

*Edit*

Not even Whack-A-Kerbal can destroy it! :D

*Another Edit*

They are ALL completely indestructible. They don't even separate from each other.

Sorry for the picture spam...

Edited May 29, 2013 by Awaras

[taniwha]

You're not going fast enough Seriously, I managed to get the big tank to explode on impact (after it bounced once), but it barely got warm (about 24 degrees) even though it was subjected to yellow-white hot flames in deadly reentry 2 + FAR (looked awesome going at 3500m/s at 26km altitude, though). I don't remember what speed it was going when it hit, but it was still going 1000m/s at 14km.

[Scotius]

Wow. Tough stuff So far i used only medium sphere for new 2-man lander, and it worked like a charm - even with additional weight on top whole design was stable and easy to maneuver. Can't wait to finally put my space station together.

[willow]

Is it just me? or are ships designed with spherical tanks just automatically "cute" to look at?

[KospY]

Very nice parts They are pretty suited for a orbital fuel station

Should be in the stock game !

[Honeybadga]

My LKO Fuel Depot. About to deorbit the unmanned tug.