The Quest for the Perfect Submarine!

[BagelRabbit]

Hello everyone! I'm Upsilon.

Submarines in KSP 1.0.5 are easy. The hard part, to put it simply, is making good submarines.

Now, I know what you're thinking, namely: "But I've created some submarines that go up and down nicely, and I think they're pretty good!" Well, even though these subs work, I know it's possible to do better. See, the thing is, submarines in the real world don't rely on rocket engines or jet engines for propulsion. Rather, they rely on methods of controlling buoyancy: adding air or water to a particular tank, for example. But is this possible in Kerbal Space Program?

Well, no. But I think I've found the closest alternative.

See, the thing is, some parts have an "open" and "closed" state: think solar panels, radiator panels, antennas, and the like. When these parts are opened, the game thinks they have a larger volume with the same mass as before... meaning their density, according to the game's mechanics, drops dramatically.

Quick example: I sent a negatively-buoyant submarine to the bottom of the ocean, then opened up a Gigantor on top. The submarine promptly started ascending after the solar panel was opened, eventually reaching the surface of the ocean. I'll post a picture here. You can also watch the video link below, although you certainly don't have to:

...and the video: https://youtu.be/DR5rl24PrCI

So.

This submarine became the first to ascend and descend without using any fuel or dumping any mass (so far as I know). But, of course, it's sorta impractical: you can't move around at great speeds unless you like solar panel shards. There's a great deal of improvement to be made.

That's where you come in!

My humble goal is to create a practical, fuel-less submarine in the Kerbal Space Program: capable of controlled descent and ascent, quick sub-nautical navigation, and maybe even having a crew or looking aesthetically nice! And I'd love your help as I strive to reach this goal.

So, a couple of questions: Does the large communications antenna have any effect on crafts' buoyancy when deployed or retracted? Is it possible to "hide" these buoyant parts inside fairings or cargo bays? Could some sort of purely-electric motor be used for horizontal movement (with bearings and rover wheels or SAS, for example)?

I want the answers to these questions, and hopefully you do too! 

Together, let us innovate like mad, test things that probably won't work, and embark on a quest:

The Quest for the Perfect Submarine!

-Upsilon

[PhylumCnidaria]

I never thought that the deployable parts would do this! You must have an R&D team or something.

Anyways... could we do something like a bunch of 1x6 solar panels in a double mk2 cargo bay? That may extend the buoyancy quite a bit in a small package.

What about service bays?

[selfish_meme]

Cargo bays also change buoyancy when opened or closed, combined with ore tanks they can be controlled easily. 

[BagelRabbit]

20 minutes ago, selfish_meme said:

Cargo bays also change buoyancy when opened or closed, combined with ore tanks they can be controlled easily. 

It was my understanding that cargo bays became "filled" with water once they sank, increasing their density; however, I don't know if it is possible to "empty" them and decrease density while underwater. I haven't tested this, though, so please let me know whether I'm correct here.

@PhylumCnidaria: Sorry for not quoting you! I still have to adapt to the new Forum somewhat.

I don't know whether service bays do the same thing as cargo bays. The Mk2 cargo bays, at least initially (before you fill them with water), are extremely buoyant. I think that once filled with water, it may be possible to close the bay and then deploy solar panels in there, thus controlling buoyancy. But again, I don't know. This is a very new field for me (and I suspect not a lot of people have put much thought or effort into this in general), so I suppose the best thing to do at this point is to test things For Science...

-Upsilon

[FlipNascar]

You need to use something like three cargo bays that aren't connected to eachother. While closed, they float well. Open them and it'll start to sink. If you want a working example Scarecrow88's UB40 shows this nicely.

[pTrevTrevs]

I think the best way to make a ballast tank system with th cargo bays would be to use the Mk2 probe core to separate them. That way you can still get all three cargo bays without sacrificing too much space.

[Mad Rocket Scientist]

Looks interesting!  Subbed. 

[BagelRabbit]

12 hours ago, FlipNascar said:

You need to use something like three cargo bays that aren't connected to eachother. While closed, they float well. Open them and it'll start to sink. If you want a working example Scarecrow88's UB40 shows this nicely.

So far as I know (and I may be wrong here. Please let me know if this is the case!), the UB40 descends by taking in water into cargo bays but ascends by burning a jet engine or dumping Ore.

To briefly reiterate, the Perfect Submarine must be capable of ascending and descending without using or dumping any fuel. Parts shouldn't be dropped either. This ensures that the submarine is theoretically capable of an infinite number of journeys to the bottom of the sea. If the UB-40 does what I think it does, this isn't the case.

1 hour ago, pTrevTrevs said:

I think the best way to make a ballast tank system with th cargo bays would be to use the Mk2 probe core to separate them. That way you can still get all three cargo bays without sacrificing too much space.

Again, the ballast tanks are only truly useful if they can be filled with air at the bottom of the ocean. Can someone please let me know whether this is possible? I can't access Kerbal Space Program at the moment...

44 minutes ago, Mad Rocket Scientist said:

Looks interesting!  Subbed. 

Thanks! It will be interesting to see what everyone will come up with. 

-Upsilon

[FlipNascar]

1 minute ago, UpsilonAerospace said:

So far as I know (and I may be wrong here. Please let me know if this is the case!), the UB40 descends by taking in water into cargo bays but ascends by burning a jet engine or dumping Ore.

To briefly reiterate, the Perfect Submarine must be capable of ascending and descending without using or dumping any fuel. Parts shouldn't be dropped either. This ensures that the submarine is theoretically capable of an infinite number of journeys to the bottom of the sea. If the UB-40 does what I think it does, this isn't the case.

Again, the ballast tanks are only truly useful if they can be filled with air at the bottom of the ocean. Can someone please let me know whether this is possible? I can't access Kerbal Space Program at the moment...

Thanks! It will be interesting to see what everyone will come up with. 

-Upsilon

Then good sir, download it and try it. Because the buoyancy is purely controlled through the cargo bays. Propulsion is of course through a jet engine.

[selfish_meme]

1 hour ago, UpsilonAerospace said:

I can't access Kerbal Space Program at the moment...

FlipNascar, this may be problematic for him

[Scarecrow]

3 hours ago, UpsilonAerospace said:

So far as I know (and I may be wrong here. Please let me know if this is the case!), the UB40 descends by taking in water into cargo bays but ascends by burning a jet engine or dumping Ore.

 

-Upsilon

You are wrong.  UB40 submerges by closing all 3 cargo bays.  Once submerged and travelling underwater, the middle cargo bay can be opened again, as it makes fine control of ascending/descending just using the 'flight' surfaces a lot easier.  UB40 can be surfaced without using power or dumping ore just by opening all 3 cargo bays, but it tends to come up rather quickly like that and can suffer damage as it leaps out of the water when reaching the surface and smacks back down again.  By toggling the bays as you ascend, it is possible to control the rate at which you rise, but it's not easy as there is some lag between making the change and the change actually taking affect.

The bays are restricted to open only 5% so it looks as if they are closed when still on the surface, so they do work rather counter intuitively, as you would expect them to be more bouyant when they are closed, but the reverse is actually true.

Edited December 22, 2015 by Scarecrow