Minor Fuel capacity tweek for Mk2 parts

[GarrettKajmowicz]

I noticed the other day that the mk1 and mk2 parts were the same length and held the same amount of fuel, despite the mk2 parts having a cross-section roughly 50% larger. It seems to me that using the Mk2 parts would contain ~50% more fuel per given length. Does this make sense or have I missed a key game balance.

 

-     Garrett

[passinglurker]

I don't know if it could be considered an equal exchange but mk2 parts have higher crash tolerance, higher heat tolerance, and have an integrated lifting body effect as if they were mk1 parts simply mounted in a sturdier aeroshell. you could make the case that some resources could be stored in the chines on the sides to give mk2 parts greater capacity than thier mk1 equivalents but I don't see it as big as other discrepancies in other aspects of stock balance. So it might be a problem but its  pretty low priority one if that.

[OrbitalBuzzsaw]

Yes, but a 25% increase

[Alshain]

The generally accepted reason is that its aeroshell around a Mk1 tank as passinglurker said..  You can see this if you look at the end of it.  Personally I think that's not a very good reason.

[passinglurker]

31 minutes ago, Alshain said:

Personally I think that's not a very good reason.

Yeah the current stats don't do mk2 planes any favors do they? especially when you consider they can only carry the same fuel of a mk1 plane of the same length but mk2 planes are usually fitted with twice the payload, but I don't really have strong feelings about it at the moment. Yes it could be better thought out but at least mk2 parts have some consistency. the same can't really be said of much else in stock.

It just goes to show how deeply kerbal needs a balance pass if the mk2 plane parts are the sanest in the bunch.

Edited August 24, 2016 by passinglurker

[Reactordrone]

Plane parts have more structure since they're required to survive high forces acting on them in flight whereas a rocket fuel tank is a can of fuel that's only meant to handle force acting through its length. If you actually tried to make an aircraft out of rocket fuel tanks the wings would rip off and the tank would buckle if you pulled any kind of Gs.

You could make the rocket fuel tanks unusable for aircraft and drop the jet fuel tank back to 150 fuel if you wanted more realism

[Red Iron Crown]

Greater lift, higher heat tolerance, higher impact tolerance. I think the Mk2 tanks are fine.

[Stoney3K]

15 hours ago, passinglurker said:

I don't know if it could be considered an equal exchange but mk2 parts have higher crash tolerance, higher heat tolerance, and have an integrated lifting body effect as if they were mk1 parts simply mounted in a sturdier aeroshell. you could make the case that some resources could be stored in the chines on the sides to give mk2 parts greater capacity than thier mk1 equivalents but I don't see it as big as other discrepancies in other aspects of stock balance. So it might be a problem but its  pretty low priority one if that.

I discovered the same thing, you can just cram a set of 0,625m fuel tanks in a Mk2 cargo bay next to a Mk1 fuel tank in the center and still have room to spare, while doubling your fuel capacity.

So, yes, I do feel that the Mk2 capacity needs to be bumped somewhat to prevent people from using this "exploit" (which is perfectly legitimate since it doesn't even require tank clipping) or from strapping a million 1,25m tanks to the side of an Mk2 fuselage.

Not that it's high on the priority list to get fixed, though.

[passinglurker]

1 hour ago, Stoney3K said:

you can just cram a set of 0,625m fuel tanks in a Mk2 cargo bay next to a Mk1 fuel tank in the center and still have room to spare, while doubling your fuel capacity.

There may be some fuel:volume ratio inconsistencies a .625m tank the same length of a 1.25m tank has only about a quarter of the volume so with two .625m tanks you should only get about a 50% increase tops.

Edited August 24, 2016 by passinglurker

[Stoney3K]

Just now, passinglurker said:

There may be some fuel:volume ratio inconsistencies a .625m tank the same length of a 1.25m tank only about a quarter of the volume so with two .625m tanks you should only get about a 50% increase tops.

From my research, the short Mk2 cargo bay will take either four Mk0 fuel tanks (which together carry the same amount as a Mk1 jet fuel tank), which gives you double the fuel capacity or the same capacity with empty space in the middle, or ten Oscar-B's (five on each side) with an FL-T400 in the middle. There's only a slight mass penalty from plumbing a few struts and fuel lines, and the space above the narrow tanks is large enough to store fuel cells or batteries, while still enabling the doors to close.

[passinglurker]

@Stoney3K you must be misremembering a mk0 tank only holds 50 units a mk1 tank meanwhile holds 400 so 4 mk0 tanks gives you a 50% increase. There is no fighting math any part that deviates from this trend has been miss-stated and needs to be fixed.

[Magzimum]

While Mk2 has zero benefits over Mk1 in terms of fuel capacity, it makes for a MUCH better airplane, which you notice especially entering the atmosphere and flying back home from your mission.

The discussion where you primarily look at weight and fuel capacity is one that belongs to vertical take-off (rockets), not airplanes. In the space plane discussion, you should certainly take lift and heat tolerance into the equation, and then Mk2 are my #1 choice. So, you could argue that the Mk2 just have thicker bottom-plates and more cooling liquids running through them, which means no extra space for fuel. I would be in favor of a small upgrade of the Mk2 fuel capacity though.

Also, Mk2 has the coolest cockpit, which is the main reason I use it.

 

[passinglurker]

@Magzimum mk2 cockpits are heavier than their mk1 counterparts but mk2 tanks only carry as much fuel as their mk1 counterparts, and since mk2 tanks don't take full advantage of their volume you need a much bigger plane to carry a cockpit the same distance which results in more drag which is generally considered to be bad

[Stoney3K]

5 hours ago, Magzimum said:

While Mk2 has zero benefits over Mk1 in terms of fuel capacity, it makes for a MUCH better airplane, which you notice especially entering the atmosphere and flying back home from your mission.

The discussion where you primarily look at weight and fuel capacity is one that belongs to vertical take-off (rockets), not airplanes. In the space plane discussion, you should certainly take lift and heat tolerance into the equation, and then Mk2 are my #1 choice. So, you could argue that the Mk2 just have thicker bottom-plates and more cooling liquids running through them, which means no extra space for fuel. I would be in favor of a small upgrade of the Mk2 fuel capacity though.

Also, Mk2 has the coolest cockpit, which is the main reason I use it.

 

So tell me what's the advantage of an Mk2 fuel tank over its Mk1 counterpart mounted in a Mk2 cargo bay?

The latter has a crapton of empty space which you can stuff with all sorts of support hardware (or more fuel) and the mass difference is minimal.

[Magzimum]

3 hours ago, passinglurker said:

@Magzimum mk2 cockpits are heavier than their mk1 counterparts but mk2 tanks only carry as much fuel as their mk1 counterparts, and since mk2 tanks don't take full advantage of their volume you need a much bigger plane to carry a cockpit the same distance which results in more drag which is generally considered to be bad

Oh, I am not claiming that the Mk2 cockpit is efficient. It is not. I almost never need any crew with my space plane missions, so if I would go for efficiency, I should just stack an OKTO2 into the cargo bay, and put a pointy fuel tank and a small nosecone on the front. I just don't care. I wanna fly my Kerbals around, a good spaceplane has a co-pilot, and the Mk2 looks butch. 

2 minutes ago, Stoney3K said:

So tell me what's the advantage of an Mk2 fuel tank over its Mk1 counterpart mounted in a Mk2 cargo bay?

Weight. The way you suggest it, you have 0.25 ton cargo bay plus 2.25 fuel tank = 2.5 ton total. The Mk2 fuel tank is only 2.29 ton, saving you 0.21 ton for the same fuel capacity. Sure, you can squeeze two Mk0 fuel tanks next to the Mk1 into that Mk2 cargo bay, but I do not think that ever becomes lighter in terms of tons per unit of fuel. 

But if you just compare the "Mk2 fuselage short" to the Mk1 fuselages (the liquid fuel, and the FL-T400), then the Mk2 are just 0.04 ton heavier. That little extra weight buys you a wing area of 0.35, which is not a bad deal, especially since it can be part of the structural fuselage (and not some floppy wing on the side). Also, it will survive re-entry a bit better. 

That cargo bay has a mass of 0.25 ton, which is heavy. Sure you can stuff more stuff into it, and I personally almost always use one such cargo bay to put science, reaction wheels and batteries in, but you need only so many of those. 

As I said before, I would be in favor of a small upgrade of the Mk2 fuel capacity... but even without it, I use it frequently