A good ballast size/setup ?

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Scuba Recon
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A good ballast size/setup ?

Postby Scuba Recon » Thu Jan 11, 2018 8:55 am

After putting together a few designs for subs so far, I was wondering what size and type of a ballast on a sub determines how well it performs when areas begin to flood and take on water. Last few designs I just made them at the bottom section of the ship in a large centered space. Or do other designs perform better if it's divided into sections of 2-4 ? and the system setup in the mid section of a submarine ? Away from outside hull breaches. And also if that affects how the auto-pilot performs Ascending / Descending maneuvers ?

BugReporter2
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Re: A good ballast size/setup ?

Postby BugReporter2 » Thu Jan 11, 2018 2:33 pm

I prefer making several ballast tanks of equal size in the bottom of the ship, usually closer to the front since bottom frontal parts of the sub usually get damaged most.
When you have ballasts above the very bottom some moron will always open the door/hatch and flood the lower rooms and sink the sub
Having one big ballast is bad for obvious reasons - you get a hole or two and the whole ballast gets flooded instead of just one section of it
When sub gets damaged I'd rather have the damage be in ballast than anywhere else where things may break and people may die, I see no reason to keep ballast away from sub's sides to prevent damages to it.
And obviously try to keep neutral ballast level as close to 0.5 as possible, autopilot cant handle ships with neutral level that's deviating too much, e.g. Slender Shad on autopilot just sinks because its neutral level is too low (ballasts take up about a third of the ship) and when auto half-fills them the ship sinks like a rock.

Scuba Recon
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Re: A good ballast size/setup ?

Postby Scuba Recon » Fri Jan 12, 2018 12:53 am

Depends really, in my previous design I had a bottom centered ballast system, while it was a singular horizontal shape with 3-4 pumps, it was divided by doors to prevent flooding of the entire ballast, alternatively I could push a button to open all ballast doors to allow the other sections to suppress and stabilize the sub enough to repair the section if it's not too seriously damaged. You'd be amazed with what multiple pumps can do, I assumed with my sub's size that it needed a larger ballast system or rather whatever sub design I did, I needed to reserve 1/3rd of the space to the ballast system inside. The current one I've made I suspect I made the ballast size too small as once one or two rooms become flooded the sub cannot stay on course.

BugReporter2
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Re: A good ballast size/setup ?

Postby BugReporter2 » Fri Jan 12, 2018 1:27 am

Scuba Recon wrote:Depends really, in my previous design I had a bottom centered ballast system, while it was a singular horizontal shape with 3-4 pumps, it was divided by doors to prevent flooding of the entire ballast, alternatively I could push a button to open all ballast doors to allow the other sections to suppress and stabilize the sub enough to repair the section if it's not too seriously damaged. You'd be amazed with what multiple pumps can do...

Yeah, it works if there's only a few sections of a floor broken, big ballast like on Vellamo usually can keep up with that and it only slows sub's ascent and quickens descent, but I noticed that if there are more than 2 buttons in command people usually stop paying attention to them and making a special button for rare cases where opening interballast doors is useful takes up that precious button space... Best to just make sub work best in 95% cases and good enough in the other 5%.

Scuba Recon wrote: ... I assumed with my sub's size that it needed a larger ballast system or rather whatever sub design I did, I needed to reserve 1/3rd of the space to the ballast system inside. The current one I've made I suspect I made the ballast size too small as once one or two rooms become flooded the sub cannot stay on course.

You know you can see the neutral level in sub editor, right? Just select several pieces of hull you'll be using for ballast and on top left it'll show you the volume numbers and the neutral level if those hulls you selected were used as ballasts. 1/3 of the sub being ballast means neutral level will be too low, and since nav terminal control is centered around 50% ballast target level when you pilot manually you'll usually sink (unless you compensate for the neutral level difference by moving pointer higher). From my experience ballast should take only like 1/7 of total space for neutral level to be close to 0.5.

Scuba Recon
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Re: A good ballast size/setup ?

Postby Scuba Recon » Mon Jan 15, 2018 9:07 am

BugReporter2 wrote:You know you can see the neutral level in sub editor, right? Just select several pieces of hull you'll be using for ballast and on top left it'll show you the volume numbers and the neutral level if those hulls you selected were used as ballasts. 1/3 of the sub being ballast means neutral level will be too low, and since nav terminal control is centered around 50% ballast target level when you pilot manually you'll usually sink (unless you compensate for the neutral level difference by moving pointer higher). From my experience ballast should take only like 1/7 of total space for neutral level to be close to 0.5.


Seems to be more challenge to setup a system like that on a shuttle, I'm having difficulty designing one that can handle the airlock being fully flooded, which makes me resort to making cramped spaces with hatches for airlock/docking transfers. Any hull section that is taller than a door frame cannot sustain a small shuttle buoyancy on autopilot. Not without a larger ballast section to equalize it. Else it drops like a brick in a matter of seconds before I can exit and shut the hatch externally.

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Re: A good ballast size/setup ?

Postby BugReporter2 » Mon Jan 15, 2018 9:39 am

Scuba Recon wrote:Seems to be more challenge to setup a system like that on a shuttle, I'm having difficulty designing one that can handle the airlock being fully flooded...


You dont really need to do that, if there are no griefers people can usually wait for pilot to land the shuttle on a sub or solid rock before exiting it. And griefers will find a way to sink the shuttle anyway, either by ramming into wall, or cutting it, or repeatedly closing/opening airlock making it flood the sub. There's that shuttle with autoclosing airlock which can only be opened once every 3 seconds, but its still susceptible to being rammed into things.

Scuba Recon
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Re: A good ballast size/setup ?

Postby Scuba Recon » Mon Jan 15, 2018 3:29 pm

BugReporter2 wrote:You dont really need to do that, if there are no griefers people can usually wait for pilot to land the shuttle on a sub or solid rock before exiting it. And griefers will find a way to sink the shuttle anyway, either by ramming into wall, or cutting it, or repeatedly closing/opening airlock making it flood the sub. There's that shuttle with autoclosing airlock which can only be opened once every 3 seconds, but its still susceptible to being rammed into things.


Oh I didn't design this with multiplayer specifically in mind, co-op at best. Basically I wanted the Shuttle itself to maintain it's position in autopilot, so that it would remain in that area for a team to exit and renter the shuttle after a artifact extraction. The flooding was the main issue. To prevent it from falling away and smashing on the seafloor causing issues of the away team in rejoining the main sub afterwards. I've only made one such design that could sustain itself, but the new version I'm putting together I intend to include it with a docking and hatch for both above and below.

BugReporter2
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Re: A good ballast size/setup ?

Postby BugReporter2 » Mon Jan 15, 2018 4:03 pm

Scuba Recon wrote:
BugReporter2 wrote:You dont really need to do that, if there are no griefers people can usually wait for pilot to land the shuttle on a sub or solid rock before exiting it. And griefers will find a way to sink the shuttle anyway, either by ramming into wall, or cutting it, or repeatedly closing/opening airlock making it flood the sub. There's that shuttle with autoclosing airlock which can only be opened once every 3 seconds, but its still susceptible to being rammed into things.


Oh I didn't design this with multiplayer specifically in mind, co-op at best. Basically I wanted the Shuttle itself to maintain it's position in autopilot, so that it would remain in that area for a team to exit and renter the shuttle after a artifact extraction. The flooding was the main issue. To prevent it from falling away and smashing on the seafloor causing issues of the away team in rejoining the main sub afterwards. I've only made one such design that could sustain itself, but the new version I'm putting together I intend to include it with a docking and hatch for both above and below.


I often use shuttle to swim to artifact ahead of the main ship and retrieve it, even if shuttle sinks upon opening airlock its no problem to just land a shuttle on top of ruins and exit only after landing. Seriously, leaving shuttle hovering above ground is just asking to be bulldozed by sub. Shuttle not sinking with open airlock is not a bad feature to have but it isn't that important either.

BugReporter2
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Re: A good ballast size/setup ?

Postby BugReporter2 » Mon Jan 15, 2018 4:19 pm

Also:
Scuba Recon wrote:... The current one I've made I suspect I made the ballast size too small as once one or two rooms become flooded the sub cannot stay on course.


It seems you don't understand how ascending-descending works.
In short: ballasts don't matter. What matters is how much of the sub is flooded.
If the sub is flooded by exactly 7% of its total hull volume - it stays neutrally afloat, you push it down - it travels down at constant speed, you push it up - it ascends at constant speed.
If the sub is flooded by less than 7% - it starts accelerating up, when the sub is completely clear of water it accelerates up at a maximum speed. It doesn't matter if your sub is one big ballast or if it has no ballasts at all - it will not accelerate faster.
On the other hand, if its flooded by more than 7% - it accelerates down, and the more water it has the faster it accelerates. Obviously, if your airlock is more than 7% of total hull volume, then no matter how big your ballasts are your shuttle will always sink when the airlock is flooded. If those two rooms you've written about take more than 7% of total hull volume then the sub will always sink no matter how big your ballasts are, even if they take all the space outside those two rooms.

Making ballast take exactly 14% (btw 1/7 is close to 14%) of hull volume makes its neutral level exactly 50% - your sub will keep its vertical speed if its half-flooded, and a fully flooded ballast will accelerate your sub downwards as fast as it accelerates it upwards when its completely empty. Making a ballast bigger won't allow your sub accelerate upwards faster - it will only allow it to sink much faster and move it neutral level from half-flooded to a lower level.

Scuba Recon
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Re: A good ballast size/setup ?

Postby Scuba Recon » Tue Jan 16, 2018 9:23 pm

BugReporter2 wrote:I often use shuttle to swim to artifact ahead of the main ship and retrieve it, even if shuttle sinks upon opening airlock its no problem to just land a shuttle on top of ruins and exit only after landing. Seriously, leaving shuttle hovering above ground is just asking to be bulldozed by sub. Shuttle not sinking with open airlock is not a bad feature to have but it isn't that important either.


It's more or less cause of my current design's size, if you used measurement of the heavy wall object then my sub's length would be 15 pieces in total, and 4 in height. Which makes it difficult to recover certain artifacts which are located most times 200-400 meters away in cramped cavern spaces from normal submarine access. Which makes the reliance on the shuttle is all the more important and useful for those situations. Though I think I'll stick with making two separated hatch/docking for above and below, as that works better in terms of keeping the shuttle stable when exit and re-entering it.


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