Let us choose what fuel we put in our tanks!

[Wjolcz]

So the gold tank madness and bad decisions from SQUAD about it pushed me to post this thread.

Why break somebody's design if you can let them choose what fuel they want to carry? Do I really have to explain more about the idea? It's been for a while in what? RealFuels? Not sure, because I've never really used it but seems like something that makes a lot of sense to me.

E: Also some sort of indication what fuel they carry as suggested by Captains below VVV

Edited April 17, 2015 by Veeltch

[klgraham1013]

Modular Fuel Tanks. Real Fuels. I think there's another fuel switch mod packaged with Atomic Age. It's been done, just not by Squad. Why it wasn't added when tweakables were added? Only Squad knows for sure.

[Renegrade]

Modular Fuel Tanks. Real Fuels. I think there's another fuel switch mod packaged with Atomic Age. It's been done, just not by Squad. Why it wasn't added when tweakables were added? Only Squad knows for sure.

FireSpitter even has some really basic interface for switching fuel types (less complicated than RF or MFT) that would also work. It's probably ten lines of code or something heh.

The complete and utter lack of features in stock Tweakables is one of the world's greatest mysteries (well, KSP mysteries anyhow)...

[TheXRuler]

I second this. I mean SQUAD has every right to do what they want with their parts and all but tweakables would really usefull. And I'm sure one of the mod developers would be ahppy to help out making the code, even maintain it.

[Wjolcz]

Now with a poll!

End life saver hysteria! Vote for sanity!

Edited April 17, 2015 by Veeltch

[h4didact]

Still, let's not shift our speech now. We know this suggestion is impossible for the 1.0 update. Until then, lets just make sure the ROUND8 will not be repurposed.

I voted "Of course" btw.

[Wjolcz]

Still, let's not shift our speech now. We know this suggestion is impossible for the 1.0 update. Until then, lets just make sure the ROUND8 will not be repurposed.

I voted "Of course" btw.

They could at least assure us we'll get the feature in the next update and tell us not to freak out for now.

[Capt Snuggler]

I voted yes, but I have some reservations.

The tank appearance must change sufficiently to indicate the resource it carries. a colored stripe would be sufficient is most cases.

Ideally, almost all tanks would have a low drag rigid shell configuration (for atmospheric launch vehicles) and a light weight "frame and foil" configuration for tanks operating in vacuum where drag and-or shock heating is not an issue.

You would be trading reduction in mass (loose the aero-shell) for increase in drag and reduced impact tolerance.

like this:

or this:

Once the tank has left the VAB it is locked to the chosen resource and tank configuration and cannot be changed.

Edited April 17, 2015 by Capt Snuggler

[CaptainKipard]

The tank appearance must change sufficiently to indicate the resource it carries. a colored stripe would be sufficient is most cases.

This. At first I thought "How could you possibly put various fuels in the same tank" but this solves the immersion problem nicely.

[Renkov]

As a thought, perhaps quality of fuel, that could improve ISP or thrust. Possibly researched or set with a admin strategy? A poor rocket with one type of fuel may be the perfect rocket with a different compound.

[Starwhip]

I think that this would be an elegant solution, but I also have some restrictions. You shouldn't really be able to put all kinds of fuel in all kinds of tanks. Real-life fuel tanks are not just idle containers. Some of them have sophisticated cooling devices for cryogenic fuel, some don't. Tank shapes (for fuel, not the exterior) vary as well.

I don't know which tanks should hold which kinds of fuel, but something like this: Larger tanks can't carry stuff like XenonGas (The volume is to great to be consistently pressurized), and smaller tanks cannot carry LiquidFuel and Oxidizer (No space for cryogenic storage).

[Alshain]

I think that this would be an elegant solution, but I also have some restrictions. You shouldn't really be able to put all kinds of fuel in all kinds of tanks. Real-life fuel tanks are not just idle containers. Some of them have sophisticated cooling devices for cryogenic fuel, some don't. Tank shapes (for fuel, not the exterior) vary as well.

I don't know which tanks should hold which kinds of fuel, but something like this: Larger tanks can't carry stuff like XenonGas (The volume is to great to be consistently pressurized), and smaller tanks cannot carry LiquidFuel and Oxidizer (No space for cryogenic storage).

True, it should be limited on a case by case basis. I mean, Rockomax orange tank shouldn't have a Xenon or monopropellant option for example, that would be silly and could drastically alter the balance of the game (overpowered O-10's anyone?). However, keep in mind this is a game and we are discussing a change for facilitating best performance of a game, not real life, so it shouldn't be based on what can hold a cryogenic system as much as what would actually be useful to a game. If you think small tanks shouldn't carry LFO, then don't use it, that is your choice. However, your choice shouldn't limit the rest of us.

My suggestion would be to have anything currently LFO or LF, be selectable between the two. Anything Monoprop could also be Xenon and vice versa. There may be a few exceptions to that, again a case by case basis.

[r_rolo1]

Well, if we start discussing realism, I should point out that the current dry masses of all tanks in game is surely enough to consider that all of them have advanced and bulky cryo units or enough subdivisions to allow for consistent cooling of any fuel in game

That said, my vote is Of course! ... of course

[Canopus]

Whats the point in having all those different designed tanks then? Instead of putting everything into the same tank there should just be more tanks to choose from for each type of fuel.

[r_rolo1]

Whats the point in having all those different designed tanks then? Instead of putting everything into the same tank there should just be more tanks to choose from for each type of fuel.

That would be a very, VERY bad idea performance wise, due to the way the game loads parts ATM. In fact, one of the main reasons to propose modular fuels is that you get far more "parts" ( tank A with LF, tank A with LFO, tank A with Xenon, ... ) for actual part load .

[Canopus]

That would be a very, VERY bad idea performance wise, due to the way the game loads parts ATM. In fact, one of the main reasons to propose modular fuels is that you get far more "parts" ( tank A with LF, tank A with LFO, tank A with Xenon, ... ) for actual part load .

Performance of the game will only get better after 1.0. I'm sure adding some Xenon tanks won't be a problem.

[AbacusWizard]

Larger tanks can't carry stuff like XenonGas (The volume is to great to be consistently pressurized)

A compromise that I'd really like: a large tank holding a lot of xenon that represents (and presumably looks like) a bunch of small tanks welded together, but is in game terms just one part. The main problem I have with xenon is that the small tank size leads to a high part count, causing lag and inconvenient refueling procedures. These are problems with the game interface, not real-world problems.

[Greenfire32]

I support this, but I'll carefully point out that this leads to having fuel-to-oxidizer rate problems. If you make the player fill their own tanks, they'll have to also fill it with the right amount of oxidizer and....

...I personally don't want to figure out what those amounts should be on a per-craft basis. Just saying.

[r_rolo1]

Performance of the game will only get better after 1.0. I'm sure adding some Xenon tanks won't be a problem.

Heavy assumption And even if the devs make true of their words and fix all the memory leaks of the game, the fact that the game loads all parts to RAM at game load and only unload them at game close/crash will not change so soon ( definitely not in 1.0 ). And about the RAM extra usage due to adding some parts... well it depends of the models. Some parts in game have a heavy RAM usage ( say the Klaw ) while others have far less...

[Wjolcz]

I support this, but I'll carefully point out that this leads to having fuel-to-oxidizer rate problems. If you make the player fill their own tanks, they'll have to also fill it with the right amount of oxidizer and....

...I personally don't want to figure out what those amounts should be on a per-craft basis. Just saying.

This could be solved by showing the percentage of LF/O. You take less oxidizer - it shows you have 100%> of LF.

And I agree that there should be some sort of indicator on the tanks when fuels are added. Thought about it for a while but forgot to suggest it in the OP @Capt Snuggler @Cpt. Kippard

Edited April 17, 2015 by Veeltch

[Fel]

True, it should be limited on a case by case basis. I mean, Rockomax orange tank shouldn't have a Xenon or monopropellant option for example, that would be silly and could drastically alter the balance of the game (overpowered O-10's anyone?). However, keep in mind this is a game and we are discussing a change for facilitating best performance of a game, not real life, so it shouldn't be based on what can hold a cryogenic system as much as what would actually be useful to a game. If you think small tanks shouldn't carry LFO, then don't use it, that is your choice. However, your choice shouldn't limit the rest of us.

My suggestion would be to have anything currently LFO or LF, be selectable between the two. Anything Monoprop could also be Xenon and vice versa. There may be a few exceptions to that, again a case by case basis.

I have serious reservations against this ideology.

First, at the end of the day, the tank is JUST an empty container with "fancy stuff" attached.

Second, While various types of tanks don't have a nice transition; these tanks can be improved upon.

So let's say we make empty our Orange Friend and fill it with "Classical Xenon Tanks", all we've done is increased the mass by adding an empty orange tank

But lets say we figure we could do without some of the insulation; tear it off... costs more money but lowers the weight...

Then we strip our "Classic tanks" of structural supports and use the orange tank's structure instead.

In the end, the game's balances on tanks are "Empty Weight / Volume", "Stability of Lugging an absurd amount of fuel around", and "Cost".

Saying we can't strip a tank to its shell and re-purpose it isn't something I would ever agree with; it would cost, it likely would be worse than a specialty tank, but it can be done... and gameplay can be setup to penalize attempts to go overboard while still allowing people to be crazy and experiment.

[KrazyKrl]

I have some input about how i feel fuel tanks should work...

---

- Any tank can hold ANY combination of fuel, but any additional type of fuel added to the tank would increase the cost of the dry mass of the tank by more than several smaller "single fuel" fuel tanks on their own.

(A new system of procedural multi-texturing of fuel tanks would be needed. As the tanks would need to outwardly reflect their contents as a whole.)

- Cannot refit fuel tanks in-flight. (Specialty tools and equipment required.)

- Both Rigid, and "Foil" tanks available for any size.

(Foil tanks shouldn't be surface attachable, unless you use radial attachment points(Struts included). Foil tanks should be cheaper and lighter, but have excessive drag and low impact resistances.)

---

For the VAB/SPH; the resource panel would need to be accessible. Possibly as another tab next to "Parts, Resources, Crew, Action Groups".

This panel should give you a "staging panel" readout of any fuel/fueltanks in that stage.

Overall ship fuels, along with a quick LF:O ratio display would be needed above the staging fuel view. Maybe something like "$F Fuel in $T Tanks in $S Stages"

Overall ship fuel weights should be displayed. "$FullMass Fuel Filled, $CurrentMass Fuel Loaded, $DryMass Fuel Empty"

Selected ship fuels, along with selected fuel ratios, should be displayed.

Selected ship fuel weights should be displayed. "$FullMass Fuel Full, $CurrentMass Fuel Loaded, $DryMass Fuel Empty"

Selecting a stage would highlight all tanks associated with that stage in the VAB. Selecting a fuel tank or fuel type would let you display both the ratio of the two fuels to each other, but also their location in the VAB. You should be allowed to select multiples of stages, and fuel tanks; in any order.

[Wahgineer]

I like it, but it should be limited in some way. For example: LFO/jet tanks can hold LF, O, or both, but not MonoProp or Xe. Tanks would have colored stripe added to indicate what type: gray for LF only, blue for O only, no stripe for both.

[panzer1b]

I already have done this on a few occasions, for example i had a version of a SSTO that was atmospheric only. You just edit the .craft file so the fuel tanks have an equivalent total capacity, just swap the O to LF. This i actually do not consider cheating, as im not adding extra fuel, im just changing oxidizer into liquid fuel (and half intelligent space program would allow a tank filled with all LF or all Oxy or a combo of these.

Also, i fully support this decision, ive already been doing this through .craft file hacks (although i actually consider this legit), so why not add it to the normal game? As a benefit, i now get to choose what my tanks look like, what fuel they carry (limited by total mass of fuel), and how much of said fuel they carry (already implemented thru sliders).