26 replies to this topic

[TheDevilsIncarnate]

I have seen a lot of griping in the forums lately about how when a reactor is breached, the mech doesn't explode like in MWLL or MW4. Well, PGI actually has a partially correct implementation of said mechanic.

Battlemechs use fusion reactors as their primary mode of energy. The energy produced from these reactors is significant enough that they can power both the lasers and the myomers of the mech. However, people have the wrong conception of nuclear power. When a fission reactor goes super critical (meaning s*** just hit the fan) the reactor itself is producing so much heat from the uncontrolled reactions with the uranium fuel cell that it boils off all the water, and turns everything around it into molten slag, as well as spilling radioactive particles into the air and surrounding area. Fusion reactions work differently, in that they fuse two atoms together, usually hydrogen as it is the most abundant element and the lightest, to create another element, mainly helium. This combining of the atoms produces energy in the form of heat, which we can then use and transfer to electricity. The reaction is contained within a protective shield, usually lead or some other neutron absorbent material, while a ball of hot plasma forms in the middle.

This plasma is very reactive with everything it touches, so the container is vacuum sealed. However, when a core breach happens, the container is then exposed to the outside air, often containing oxygen or other flammable elements. When the ball of plasma comes in contact with the outside air, it ignites it, sending out a super hot gout of fire. After that the plasma winks out of existence, and the 'Mech is left a smoldering wreck. When a writer describes the reactor shielding, they are talking about safety mechanisms that destroy the ball of superheated plasma before it hits the outside air and ignites it. So in reality, mechs shouldn't blow up in a super nuclear explosion like Hiroshima, but rather just die in a blazing gout of fire. And it should happen very little, as reactor shielding rarely fails before the mech shuts itself down. Say, around 5-10% of the time.

TLDR- PGI is somewhat correct in how they make 'Mechs die, they should just sometimes die in a ball of fire instead of a huge nuclear explosion.

[Creovex]

Okay.... what was the point again?

[TheDevilsIncarnate]

Creovex, on 25 May 2014 - 11:23 AM, said:

Okay.... what was the point again?

The point is an education, as well as to rid people of another thing to gripe about. You didn't have to post here if you did not enjoy the OP or it's ideas.

[627]

thanks for explaining my magic space robots with your irl physics but you forgot a rule - the rule of cool.

'splodin' mechs look awzoooome! BOOM!!!

no really, those explosions in MW LL? those looked really cool.

[Gigastrike]

They still need to have the pilot eject.

[Scratx]

No Stackpoling for you!

[Creovex]

TheDevilsIncarnate, on 25 May 2014 - 11:38 AM, said:

The point is an education, as well as to rid people of another thing to gripe about. You didn't haveI to post here if you did not enjoy the OP or it's ideas.

Education? So apparently this fictional universe is like ours and you are still the resident expert on explosions. ... gotcha.
To that I say... " Keep firing ********!" < Universe where I am an expert!

[Blue Boutique]

Gigastrike, on 25 May 2014 - 11:42 AM, said:

They still need to have the pilot eject.

Mostly from exploding ammo or irregular charge distribution on the mech that can kill a pilot.

[darkkterror]

When people want things in a video game they don't always care about the "realism" aspect of it. They just want awesome freakin' explosions.

[Kyle Wright]

TheDevilsIncarnate, on 25 May 2014 - 11:19 AM, said:

I have seen a lot of griping in the forums lately about how when a reactor is breached, the mech doesn't explode like in MWLL or MW4. Well, PGI actually has a partially correct implementation of said mechanic.

Battlemechs use fusion reactors as their primary mode of energy. The energy produced from these reactors is significant enough that they can power both the lasers and the myomers of the mech. However, people have the wrong conception of nuclear power. When a fission reactor goes super critical (meaning s*** just hit the fan) the reactor itself is producing so much heat from the uncontrolled reactions with the uranium fuel cell that it boils off all the water, and turns everything around it into molten slag, as well as spilling radioactive particles into the air and surrounding area. Fusion reactions work differently, in that they fuse two atoms together, usually hydrogen as it is the most abundant element and the lightest, to create another element, mainly helium. This combining of the atoms produces energy in the form of heat, which we can then use and transfer to electricity. The reaction is contained within a protective shield, usually lead or some other neutron absorbent material, while a ball of hot plasma forms in the middle.

This plasma is very reactive with everything it touches, so the container is vacuum sealed. However, when a core breach happens, the container is then exposed to the outside air, often containing oxygen or other flammable elements. When the ball of plasma comes in contact with the outside air, it ignites it, sending out a super hot gout of fire. After that the plasma winks out of existence, and the 'Mech is left a smoldering wreck. When a writer describes the reactor shielding, they are talking about safety mechanisms that destroy the ball of superheated plasma before it hits the outside air and ignites it. So in reality, mechs shouldn't blow up in a super nuclear explosion like Hiroshima, but rather just die in a blazing gout of fire. And it should happen very little, as reactor shielding rarely fails before the mech shuts itself down. Say, around 5-10% of the time.

TLDR- PGI is somewhat correct in how they make 'Mechs die, they should just sometimes die in a ball of fire instead of a huge nuclear explosion.

**** am biatches. Owned by science. Good explanation OP.

[Mechteric]

fission != fusion

[OneEyed Jack]

Contrary to the popular belief among trolls, most of the "explosions" portrayed in fiction aren't large blasts, anyway. If the shielding is thoroughly breached before the reaction can't be shut down, which is not unreasonable when it's being breached very suddenly by high-powered weapons, that "blazing gout of fire" is going to create something of a blast wave. Hell, I can feel a small wave when I light the charcoal lighter fluid on a grill. A fusion engine exploding is gonna be a mite stronger than that. It will also likely cause any and all ammo it hits to likewise explode.

Most of the engine explosions portrayed are no more than this. Even the "big one" that is often pointed to, when Kai Allard-Laio blew the Great Gash on Twycross, all the mech's explosion did was set off the mines that were already planted in the cliff faces. Likewise, other examples of exploding mechs doing damage are mostly from a flying limb or being very, very close (like Joanna's Mad Cat in Aidan Pryde's Trial of Refusal).

Edited by OneEyed Jack, 25 May 2014 - 03:01 PM.

[A banana in the tailpipe]

How PGI decided to handle to a reactor breach...

[SirLANsalot]

Scratx, on 25 May 2014 - 11:48 AM, said:

No Stackpoling for you!

Not all of his mechs went boom either.

OneEyed Jack, on 25 May 2014 - 03:01 PM, said:

Contrary to the popular belief among trolls, most of the "explosions" portrayed in fiction aren't large blasts, anyway. If the shielding is thoroughly breached before the reaction can't be shut down, which is not unreasonable when it's being breached very suddenly by high-powered weapons, that "blazing gout of fire" is going to create something of a blast wave. Hell, I can feel a small wave when I light the charcoal lighter fluid on a grill. A fusion engine exploding is gonna be a mite stronger than that. It will also likely cause any and all ammo it hits to likewise explode.

Most of the engine explosions portrayed are no more than this. Even the "big one" that is often pointed to, when Kai Allard-Laio blew the Great Gash on Twycross, all the mech's explosion did was set off the mines that were already planted in the cliff faces. Likewise, other examples of exploding mechs doing damage are mostly from a flying limb or being very, very close (like Joanna's Mad Cat in Aidan Pryde's Trial of Refusal).

for those who want to read about that.

Blood of Kerensky book 1 is where that took place.

Also don't forget when Kai was "testing" and Sun-Tsu (as much of a nutjob as his mom) ejected and left his "cousin" to fight 6 mechs on his own. That he shot at Sun's hulk he left behind and blew the eng, killing a mech and damaging 2 others because of Limbs flying off and armor plates. He took out 5 other mechs and only barley lost to the Archer. This was in Book 2 of Blood of Kerensky.

[Impyrium]

Actually on the contrary, again, BattleTech is a lore more grounded in reality than most other sci fis and, I think, many people enjoy it because of that. Though I think it was better when it ran using 70-80s 'future' tech.

You are correct, OP, reactors don't go a kablooey when they go off. At least not this fusion ones. I think there was a very small chance of them going off though; there is a thread on these forums somewhere that outlines the engines in great detail.

[Xetelian]

All I want is to drop a mech destroying grenade when I die!

[Mawai]

TheDevilsIncarnate, on 25 May 2014 - 11:19 AM, said:

I have seen a lot of griping in the forums lately about how when a reactor is breached, the mech doesn't explode like in MWLL or MW4. Well, PGI actually has a partially correct implementation of said mechanic.

Battlemechs use fusion reactors as their primary mode of energy. The energy produced from these reactors is significant enough that they can power both the lasers and the myomers of the mech. However, people have the wrong conception of nuclear power. When a fission reactor goes super critical (meaning s*** just hit the fan) the reactor itself is producing so much heat from the uncontrolled reactions with the uranium fuel cell that it boils off all the water, and turns everything around it into molten slag, as well as spilling radioactive particles into the air and surrounding area. Fusion reactions work differently, in that they fuse two atoms together, usually hydrogen as it is the most abundant element and the lightest, to create another element, mainly helium. This combining of the atoms produces energy in the form of heat, which we can then use and transfer to electricity. The reaction is contained within a protective shield, usually lead or some other neutron absorbent material, while a ball of hot plasma forms in the middle.

This plasma is very reactive with everything it touches, so the container is vacuum sealed. However, when a core breach happens, the container is then exposed to the outside air, often containing oxygen or other flammable elements. When the ball of plasma comes in contact with the outside air, it ignites it, sending out a super hot gout of fire. After that the plasma winks out of existence, and the 'Mech is left a smoldering wreck. When a writer describes the reactor shielding, they are talking about safety mechanisms that destroy the ball of superheated plasma before it hits the outside air and ignites it. So in reality, mechs shouldn't blow up in a super nuclear explosion like Hiroshima, but rather just die in a blazing gout of fire. And it should happen very little, as reactor shielding rarely fails before the mech shuts itself down. Say, around 5-10% of the time.

TLDR- PGI is somewhat correct in how they make 'Mechs die, they should just sometimes die in a ball of fire instead of a huge nuclear explosion.

Sigh .. reality and battletech physics again. You are absolutely correct that mechs would not go up in nuclear explosions ... but there were some factual errors in your post

Battlemechs have a tokamak fusion reactor built in using semi-imaginary physics. Battletech reactors convert the energy from the fusion reaction to electrical power through an undefined mechanism which is then used to power the mech systems. Fusion reactors do not explode in either the real world or the Battletech world ... the whole idea was inserted into the Battletech books by a disillusioned author who thought it would be cool.

In the real world, fusion reactor plasmas are exceptionally hot (say 5 to 10keV where one 1eV~10,000K) ... but extremely sparse ... the line average density in a typical reactor might be on the order of 1e19 particles/m3 compared to atmospheric densities on the order of 1e25. In addition, fusion reactions stop very suddenly when cooled. An atmosphere leak into a reactor would shut it down almost instantly ... in fact they are testing massive gas injection of Ne or Ar as part of disruption avoidance and mitigation tools in current reactors.

Plasma erodes material surfaces because it is hot. The containment chamber is a vacuum vessel. Plasma is not explosive. Oxygen is not explosive by itself and the atmosphere of an inhabitable planet is not explosive. Plasma coming into contact with air or oxygen does not explode and the hydrogen content of the plasma compared to the high density air entering the vessel is so small that the chemical energy released if the hydrogen reacts with the air is also small.

Material surfaces in fusion reactors are either low atomic number materials like carbon or beryllium where a reasonable amount of surface erosion will not significantly reduce the confined plasma characteristics or refractory metals like molybdenum or tungsten which are resistant to erosion but for which only a very small quantity can be tolerated in the core. Fusion reactors do not have lead lining.

So back to battletech physics ... the nice explosions that were written into the books were retroactively justified as some sort of coolant breach ... the coolant hits the plasma ... they assume a very high energy density in the plasma ... enough to superheat the coolant and the result is essentially a steam explosion. Gives a nice explosion but completely non-nuclear and non-chemical ... and still dubious from a physics standpoint .. but come on! This is Battetech ... giant stompy mechs firing big weapons at each other at ridiculously short ranges .. almost every weapon in battletech performs worse that its existing 20th or 21st centrury counterparts.

My personal choice is a willing suspension of disbelief and just have fun playing the game

Edited by Mawai, 25 May 2014 - 04:35 PM.

[Strum Wealh]

TheDevilsIncarnate, on 25 May 2014 - 11:19 AM, said:

I have seen a lot of griping in the forums lately about how when a reactor is breached, the mech doesn't explode like in MWLL or MW4. Well, PGI actually has a partially correct implementation of said mechanic.

Battlemechs use fusion reactors as their primary mode of energy. The energy produced from these reactors is significant enough that they can power both the lasers and the myomers of the mech. However, people have the wrong conception of nuclear power. When a fission reactor goes super critical (meaning s*** just hit the fan) the reactor itself is producing so much heat from the uncontrolled reactions with the uranium fuel cell that it boils off all the water, and turns everything around it into molten slag, as well as spilling radioactive particles into the air and surrounding area. Fusion reactions work differently, in that they fuse two atoms together, usually hydrogen as it is the most abundant element and the lightest, to create another element, mainly helium. This combining of the atoms produces energy in the form of heat, which we can then use and transfer to electricity. The reaction is contained within a protective shield, usually lead or some other neutron absorbent material, while a ball of hot plasma forms in the middle.

This plasma is very reactive with everything it touches, so the container is vacuum sealed. However, when a core breach happens, the container is then exposed to the outside air, often containing oxygen or other flammable elements. When the ball of plasma comes in contact with the outside air, it ignites it, sending out a super hot gout of fire. After that the plasma winks out of existence, and the 'Mech is left a smoldering wreck. When a writer describes the reactor shielding, they are talking about safety mechanisms that destroy the ball of superheated plasma before it hits the outside air and ignites it. So in reality, mechs shouldn't blow up in a super nuclear explosion like Hiroshima, but rather just die in a blazing gout of fire. And it should happen very little, as reactor shielding rarely fails before the mech shuts itself down. Say, around 5-10% of the time.

TLDR- PGI is somewhat correct in how they make 'Mechs die, they should just sometimes die in a ball of fire instead of a huge nuclear explosion.

• "Though the scientific reality of Fusion Fngines prevents them from exploding, the dramatic effect of such an expensive piece of machinery blowing up in a huge ball of fire is so appealing to the majority of BattleTech players that this rule was created to satisfy the common desire for a good explosion." - Tactical Operations, pg. 77
  
• "The Fusion Engine of a ‘Mech may explode any time four or more of its slots are destroyed in the same phase of a turn, usually when the center torso location is destroyed (also destroying the equipment contained therein)... When the Fusion Engine of a ‘Mech takes four or more critical hits in the same phase, roll 2D6. On a result of 10 or higher, the Engine explodes." - Tactical Operations, pg. 78
  
• "The explosion destroys the unit and all other units in the same hex, and also starts a fire in the hex, regardless of the terrain. Any units in adjacent hexes [< 30 meters away] take damage equal to the engine’s rating divided by 10 (rounded to the nearest whole number; round .5 down). Units 2 hexes away [30 to 60 meters away] take damage equal to the engine’s rating divided by 20. Units 3 hexes away [60 to 90 meters away] take damage equal to the engine’s rating divided by 40." - Tactical Operations, pg. 78

While PGI was correct in not having 'Mechs go up in thermonuclear fireballs every time they are destroyed, BattleTech does specifically provide mechanics to use for modeling the frequency (between needing to take 4 criticals worth of damage simultaneously (which is itself incredibly rare), AND THEN only having a ~16.7% chance of exploding) and effects of Fusion Engine explosions, in order to play up the dramatic effect for gameplay & storytelling purposes.

[Bongo TauKat]

I say we go back to MW4 where EVERY death, including your legs being blown off, results in a core breach.

http://youtu.be/bldhHYv9qdE?t=1m15s

Edited by Bongo TauKat Talasko, 25 May 2014 - 05:23 PM.

[Roland]

In the real world, there are no giant robots powered by nuclear fusion reactors.