stunning MS and stopping power

[Seraphic]

I finally remember what I wanted to ask about!!

So, a bit of a controversy came up a few months ago due to some of the gameplay mechanics in Gundam: Battle Operation. In the game, bazookas, rockets, and cannon shells stun mobile suits when landing a blow. Beam rifles will also do the same thing with a fully charged shot. The mobile suit that's been hit will stop moving and enter a stagger animation.

It's been argued that mobile suits are too massive for this to happen, that "You can't stop 60 tons of metal with such a small bullet". I personally think that this view is too simplistic and doesn't take into account all the things that happen when a mobile suit is hit by an exploding shell.

While I know that in the animation these weapons are supposed to be 1 hit kills and completely destroy the mobile suit, we'll have to ignore this and assume the mobile suit stays intact. What do you think should happen, and why? Should it be possible to stun a mobile suit? Is 'stopping power' applicable in MS warfare?

Thanks.

[Wingnut]

It varies from game to game really. In SDGO for example, an impact with any normal ranged weapon will make a unit flinch (unless it has no-flinch or is a mobile armor), but the hit unit will keep right on going in whatever direction it is heading in. In order to make a unit freeze it must be hit with a weapon that specifically deals what is known as the "stun" status ailment which does bring the hit unit to a dead stop from whatever it was doing on the spot. Anything in SDGO that is large enough to really smack a unit will also be likely to knock it down as well

So I would have to say no and argue in favor of a MS being knocked over as being the more realistic of the results if it survives such an impact. See also the recent 08th Team short where Karen's Ground Gundam takes a hit from a Magella cannon and gets sent down on its backside from the impact.

[BrentD15]

I actually think that this should be passed on to the Games board.

I remember this for Gundam Vs. Series.

For instance, the Giant Bazooka for the Dom/Rick Dom was able to stun targets for a couple hits before knocking them over, while the Zaku Bazooka is capable of knocking opponents over in a single hit.

[Seraphic]

I am NOT asking about game mechanics.

This is a physics discussion.

"IS a mobile suit too massive to knock over or stun with a bazooka?"

[BrentD15]

I am NOT asking about game mechanics.

This is a physics discussion.

"IS a mobile suit too massive to knock over or stun with a bazooka?"

Well, then that depends on the size of said mobile suit.

[MythSearcher]

I've heard that in real life, tank drivers can die simply by the shock of a direct hit that didn't penetrate the armour.
Given that there's much more shock absorption mechanism in an MS, it is possible that the pilots are shocked but still maintain their composition after a really short while.
So the flinch/vibration/etc. are from the shocked pilots who pulled or pushed on the lever(or anything they are controlling)

[Sume Gai]

mobile suits in general are somewhat top heavy (presuming their long legs haven't been weighted in some way), even discounting the potential of rattling the pilot itself, a significant impact near the top of the machine should at least stagger it. Depending on how advanced the automated posture control systems are this may indeed result in a fall.

What constitutes a significant impact will vary, based on the weight and center of mass of the machine. perhaps someone more willing to get down and do the math can give a more exact answer.

[MythSearcher]

mobile suits in general are somewhat top heavy (presuming their long legs haven't been weighted in some way), even discounting the potential of rattling the pilot itself, a significant impact near the top of the machine should at least stagger it. Depending on how advanced the automated posture control seems are this may indeed result in a fall.

What constitutes a significant impact will vary, based on the weight and center of mass of the machine. perhaps someone more willing to get down and do the math can give a more exact answer.

As someone who is willing to do the math, or I should say, I have done the math, knows that it is impossible to do it for all machines.

We don't really have a mass distribution of the MSs designs and thus what you get are estimates that just evenly spread the weight to the whole thing.
With this, the COM is a little bit lower than the cockpit, some models(and designs varients especially the earlier designs by Okawara Kunio with such large feet) should even have the COM in between the thigh.

If we use a complete human analogue, the COM is about around the belly button, and each leg is about 17.5% of your body weight.(female average is higher than male, see here: http://www.exrx.net/Kinesiology/Segments.html)

But MSs have much longer legs and much much more bulky:
http://space.uwants.com/attachments/200 ... 208101.jpg
(picture example of human bones VS GP03S)
and if we disregard the backpack weight, each leg might be up to 25~30% of the total weight.

From an Engineering design POV, the COM should be located at the cockpit, so the turning and spinning creates least g-force for the pilot. Really doesn't matter that much in the OYW models(the 180 degree turn speeds are way too slow) but will be much more preferred in the post war models.(and NT-1)

[Dendrobium Stamen]

But MSs have much longer legs and much much more bulky:
http://space.uwants.com/attachments/200 ... 208101.jpg
(picture example of human bones VS GP03S)
and if we disregard the backpack weight, each leg might be up to 25~30% of the total weight.

Hey, it's my namesake!

On a more serious note: I think it's dangerous to suggest we disregard the weight of an MS' backpack; in some MS, this could make up quite a significant fraction of its mass.

An excellent example of this would be the first protagonist MS of the 21st Century, the GAT-X105 Strike: in its base configuration, its max weight is 64,800kg; with the Aile Striker attached, that rises to 85,100kg - a whopping 31% increase. As anyone who's ever tried to pose a model one of these on its feet can attest, that back unit really tips the machine backward!

Now, of course, Aile Strike isn't really designed as a ground-pounding MS, so as a literal example it isn't ideal; to demonstrate a principle, however, it does an ideal job of reminding us that while MS designs are humanoid, they aren't strict over just how closely they stick to the human form. So, when working out just how tippable an MS is (less than a cow, more than a planet), it's definitely worth remembering to factor in just how its mass is distributed, especially with regard to backpacks.

[MythSearcher]

Hey, it's my namesake!

On a more serious note: I think it's dangerous to suggest we disregard the weight of an MS' backpack; in some MS, this could make up quite a significant fraction of its mass.

An excellent example of this would be the first protagonist MS of the 21st Century, the GAT-X105 Strike: in its base configuration, its max weight is 64,800kg; with the Aile Striker attached, that rises to 85,100kg - a whopping 31% increase. As anyone who's ever tried to pose a model one of these on its feet can attest, that back unit really tips the machine backward!

Now, of course, Aile Strike isn't really designed as a ground-pounding MS, so as a literal example it isn't ideal; to demonstrate a principle, however, it does an ideal job of reminding us that while MS designs are humanoid, they aren't strict over just how closely they stick to the human form. So, when working out just how tippable an MS is (less than a cow, more than a planet), it's definitely worth remembering to factor in just how its mass is distributed, especially with regard to backpacks.

Of course I am not saying we disregard all of them, I am just saying if we disregard the backpack(which human beings don't naturally have), we can use the human body as a quick comparison.

If we add in the backpack weight, we can use the no backpack COM estimation to do the new estimation of the whole unit.

Quite obviously the backpacks are going to shift the COM up a bit and towards the back.

[South Burning]

As a court-qualified exterior ballistics expert, let me suggest a new angle for this discussion. Obviously, the small caliber projectiles from head-mounted guns would not have a stunning effect on a massive mobile suit (their value would be in penetration of the suit exterior), but the larger projectiles from rifles and bazookas might IF DRIVEN TO CURRENTLY UNHEARD OF VELOCITIES, which could be possible with rail gun technologies or some future unrealized scientific breakthrough (like gigantic mobile suits!). However, we are not discussing kinetic energy factors here. The discussion must bear on chemical explosive energy from the large shells or the transfer of energy from an energy weapon. Realistically, we can only speculate on the massive release of energy that some future chemical explosive may realize or that some energy weapon may bring to bear on a target. Remember, current energy weapons are limited to lasers and microwave projectors, all of which rely on heat instead of a kinetic force at the target. Since these battles are fought with as-yet-unrealized weaponry, I believe we must resist the urge to kill the messenger and simply accept that these forces exist in our stories and enjoy the tales.

[MythSearcher]

As a court-qualified exterior ballistics expert, let me suggest a new angle for this discussion. Obviously, the small caliber projectiles from head-mounted guns would not have a stunning effect on a massive mobile suit (their value would be in penetration of the suit exterior), but the larger projectiles from rifles and bazookas might IF DRIVEN TO CURRENTLY UNHEARD OF VELOCITIES, which could be possible with rail gun technologies or some future unrealized scientific breakthrough (like gigantic mobile suits!). However, we are not discussing kinetic energy factors here. The discussion must bear on chemical explosive energy from the large shells or the transfer of energy from an energy weapon. Realistically, we can only speculate on the massive release of energy that some future chemical explosive may realize or that some energy weapon may bring to bear on a target. Remember, current energy weapons are limited to lasers and microwave projectors, all of which rely on heat instead of a kinetic force at the target. Since these battles are fought with as-yet-unrealized weaponry, I believe we must resist the urge to kill the messenger and simply accept that these forces exist in our stories and enjoy the tales.

The problem here would be the beam weaponry is likely comparative to the metal jet from a HEAT shell we have now, which focus more on penetration instead of exploding outside of the target.

UC's Mega Particle weaponries do have an exploding factor, but they are already really good penetrators to begin with and usually penetrates before it explodes until they have beam shields, or really really really thick armour. (beam resistive coatings ablats so the energy is taken away)
with beam shields, the beam explodes in front of the shield, but with VSBR raising the speed of the beam(or specially designed beam weaponries that only shoot at the increased speed) it still penetrates before exploding.

[Bishop]

I'm sure with chemical weapons you could probably boil the effect down to a clinically accurate analysis, seeing how much force such and such quantity of explosive exerts into the impact surface and so forth. I can see how beam weapons are probably not so easy to deal with, but realistically I don't really think it matters for sake of accurate portrayal.

An MS has complex machinery and electronics packed into every bit of it. Any hit that penetrates the armor probably makes something go wrong, and it's easy to see how a misfiring motor could send an MS into a spin, trip it or stunt it's progress.

You could probably portray an MS going on as if nothing happened or being thrown around with equal plausibility.

Most people I've met and read about agree that stopping power is a negligible aspect of firearms compared to shot placement and bleeding. Many people shot with firearms simply don't realize it until later. I believe it's been said a 9mm pistol shot's exerted force on a human is the same as a brick being dropped from a few inches in the air. Negligible when adrenaline is pumping.

I mention this because it's been discussed many a time that persons who trip, fall over and are "knocked down" by bullets in gunfights are probably reacting to pain, shock and surprise rather than physically being thrown or moved in an overt manner.

[Zeonista]

Although MS are quite large, it is not unreasonable to see them being halted in their tracks or knocked down by explosive blasts, kinetic impact, or large beam shots. The projectile weapons are usually of large caliber, with rifles being in AFV main armament in the main, and can b usually be fired in automatic mode, allowing several shot/shell of 70-120mm range to impact on target. almost simultaneously. The bazooka rounds are of similar caliber and size to battleship guns, and travel faster to boot! At the very least, the pilot will be bounced about in the cockpit (as seen in the anime) and will lose control for a few seconds, causing a stunned effect. I am not confident in being able to accurately describe or calculate the effects of megajoule or gigajoule energy weapon blasts on a MS, but those are bound to be noticeable!

[latenlazy]

An MS has complex machinery and electronics packed into every bit of it. Any hit that penetrates the armor probably makes something go wrong, and it's easy to see how a misfiring motor could send an MS into a spin, trip it or stunt it's progress.

Not necessarily. Military hardware is usually designed with redundancies and fail safes.

[Zeonista]

An MS has complex machinery and electronics packed into every bit of it. Any hit that penetrates the armor probably makes something go wrong, and it's easy to see how a misfiring motor could send an MS into a spin, trip it or stunt it's progress.

Not necessarily. Military hardware is usually designed with redundancies and fail safes.

The military equipment inside the MS was made by the lowest bidding company. Malfunctions of the Model 00780809A Widget will occur, even when the temporary (or permanent) interruption in action in said Widget was not caused by a 380mm explosive round detonating on the armor directly above it. There is no perfect technology, only technology that is more perfect, or maybe less imperfect, than others. It is conceivable therefore that systems can temporarily cut out or overload, causing the MS to shudder and stumble.

And think about the size of the ammunition being used, again. Up to the First Gulf War, 90mm cannon were considered adequate tank-killing rounds, and even today with HEAT or APDS ammo they still can't be shrugged off. A GM or Zaku can auto-fire them! Maybe 1 impacting might not make a difference, but 3-4? A 380mm bazooka round from a MS is similar in size and effect to the 16" cannon used by American fast battleships of WW II! Look up some footage of those ships letting loose on targets in post-WW II actions to see the sort of power being unloosed on the target. The MS's gyrostabilizer can only counter so much impact, and then something has got to give.

The stunning effect to my mind anyway also justifies why most MS tote around a shield of some kind. The best way to prevent a jarring weapon impact is to position the MS shield towards the direction of the threat, and let the shield take it. Much less transfer of weapon energy directly to the MS then!

[MythSearcher]

Thought of another reason.
MSs have auto balancing, so after a hit, they might need to recalculate their pose due to external forces acted upon them and the computers are doing balancing calculations and possibly moving all the actuators for that purpose, so it kinda stuns the MS for an instance before the computer gets everything back to normal.

[Zeonista]

Thought of another reason.
MS have auto balancing, so after a hit, they might need to recalculate their pose due to external forces acted upon them and the computers are doing balancing calculations and possibly moving all the actuators for that purpose, so it kinda stuns the MS for an instance before the computer gets everything back to normal.

That is a good technical suggestion, and quite possible given the amount of computer-directed operations required to make an MS operate at the speeds we see in the anime.

[teslashark]

As a court-qualified exterior ballistics expert, let me suggest a new angle for this discussion. Obviously, the small caliber projectiles from head-mounted guns would not have a stunning effect on a massive mobile suit (their value would be in penetration of the suit exterior), but the larger projectiles from rifles and bazookas might IF DRIVEN TO CURRENTLY UNHEARD OF VELOCITIES, which could be possible with rail gun technologies or some future unrealized scientific breakthrough (like gigantic mobile suits!). However, we are not discussing kinetic energy factors here. The discussion must bear on chemical explosive energy from the large shells or the transfer of energy from an energy weapon. Realistically, we can only speculate on the massive release of energy that some future chemical explosive may realize or that some energy weapon may bring to bear on a target. Remember, current energy weapons are limited to lasers and microwave projectors, all of which rely on heat instead of a kinetic force at the target. Since these battles are fought with as-yet-unrealized weaponry, I believe we must resist the urge to kill the messenger and simply accept that these forces exist in our stories and enjoy the tales.

I might be necronizing the topic, though what type of MS-sized firearm would effectively spall off the inside of enemy armor? Clay Bazooka is supposed to be one because of its clay explosive warheard, though how would machinegun rounds behave?