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Author Topic: Reactive armour  (Read 1643 times)

XenopusTex

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Reactive armour
« on: 28 March 2022, 22:46:05 »
I am really struggling with the B'tech implementation of this.  Reactive armour comes in two varieties... explosive (various levels of explosive) and non-explosive.  Both types have to be backed by some serious armour to deal with what gets past the reactive armour.   

ERA
Also need to have enough behind it to keep the ERA from killing the vehicle itself when it touches off.  Conversely, you don't want to be anywhere near an ERA block that is detonating.  The ERA block has one or more "sandwiches" consisting of two flyer plates of metal with an explosive layer in between, and ideally is at an angle to the incoming attack.  Old Kontakt-1 provides an illustration with the two sandwiches arranged at an angle.  When the EFP detonates the explosive, the flyer plates move generally in the direction of the EFP's travel and against the direction of its travel.  In doing so, the impart forces on the EFP that cause the "jet" to break up.  Once cohesiveness is lost, penetration goes way, way down.  Ideally, the fragments of the EFP spatter generally harmlessly on the armour plate behind.  If the armour plate behind the ERA is really weak, the detonation of the ERA can damage it.  ERA does not reduce the penetration of an EFP to zero, there still needs to be something backstopping it. 

The one obvious downside to ERA is the one-shot nature of it, and, as demonstrated on some Russian vehicles, the potential for sympathetic detonation of nearby blocks.  Per "sandwich" it's generally more effective than NERA.


NERA
This would be a sandwich of two metal plates and some type of resilient material between them.  When the EFP hits, the energy of it results in the resilient material, such as rubber, causing the plates to bulge in the path of and against the path of the EFP.  The NERA sandwich cannot create disruptive forces as strong as ERA.  However, it has multi-hit capacity as long as projectile doesn't hit in the same path.  It also does not shower nearby units with bits/pieces.  Images of damaged Abrams tanks may show the stacked NERA sandwiches used to protect parts of the tank. 

Based on the description of critical failure of a reactive armour array, it sounds as it the B'tech version is ERA, yet there is no penalty to any infantry in the same hex as the ERA'ed unit when the ERA'ed unit takes a hit that would cause the armour to activate. 

Combat performance has shown that ERA/NERA provides Jack Diddly Squat protection against artillery and other AoE attacks.  Bombs, heavy howitzer hits (see Pion v. T-64, T-72, T-80, and probably T-90 as well), etc. reduce the protected vehicle to a mangled mess of metal, with some of the ERA blocks scattered across the landscape.  Not sure how B'Tech ERA is supposed to help against arty, when it can't actually do that.

Reactive armour on battle armour... How does the trooper not get Swiss cheesed when the armour's own explosive cook off and send a flyer plate back at him?  Can't just strap some Kontakt-1/5/Relikt on an infantryman and call it good :)  Also, what about the necessary backing plate to stop the remnants that always come through ERA/NERA? 

MoneyLovinOgre4Hire

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Re: Reactive armour
« Reply #1 on: 28 March 2022, 22:55:13 »
Battletech armor is literally magic.  Seriously, it only pretends to obey the laws of physics.
Warning: this post may contain sarcasm.

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SteelRaven

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Re: Reactive armour
« Reply #2 on: 29 March 2022, 01:18:09 »
Like standard armor,  Auto Canons and Missiles: it works the way you think it should work.

BT has never been realistic nor should it be considered as such. It's one step closer to hard sci-fi than that setting with chain swords and that other with laser swords but that only seems to make things worse as people never qestion the settings with actual space magic in the narrative. Just reach the conclusion that makes the most sense in your head and tell the writers to leave it a vague as possible so they don't give away how little they actual know nor how little Fasa actual knew when they first cooked up this stuff. 
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BrianDavion

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Re: Reactive armour
« Reply #3 on: 29 March 2022, 23:29:44 »
the current date is 2022, the current date in battletech is 3151. that's over a thousand years in the future. terminology and technology changes. I think it's safe the say the reactive armor on a battlemech isn't the same as that on the M1A1

MarauderD

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Re: Reactive armour
« Reply #4 on: 30 March 2022, 10:03:23 »
Hand Wavium, my friends.  Just like we aren't supposed to understand the replicator on Star Trek: TOS.  It makes the game interesting, and therefore it exists.  Trying to science up an abstraction is folly--that way lies madness.

BrianDavion

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Re: Reactive armour
« Reply #5 on: 30 March 2022, 11:22:46 »
Hand Wavium, my friends.  Just like we aren't supposed to understand the replicator on Star Trek: TOS.  It makes the game interesting, and therefore it exists.  Trying to science up an abstraction is folly--that way lies madness.

because SOMEONE'S gonna note this and it might as well be me, the replicator was a TNG thing, not a TOS thing :)

MarauderD

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Re: Reactive armour
« Reply #6 on: 30 March 2022, 15:09:53 »
I was thinking of the thing that made their food--like chicken soup.  I'm almost positive I remember Kirk using one in TOS.  Then again, I'm old. 

Reactive armor is also pretty cool too, just to stay on topic!

SteelRaven

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Re: Reactive armour
« Reply #7 on: 30 March 2022, 16:19:40 »
Reading up, the had the food synthesizer in tos that became the replicator in tng, but enough about that particular brand of space magic.

Reactive Armor on Battle Armor should be insane but considering the armor can absorb the shock wave from explosives and take the hit from a .50 round from a MG without slowing the dude inside down, those frames seem to have the amazing protective qualities. I often chuck this up to the Myomer of the suite absorbing a good chuck of the punishment as Battlemechs and Battle Armor that use Myomer tend to also be capable of obscuring damage than more conventional combat vehicles. So the Myomer along with the bulkier frame (additional armor? ) required for reactive armor (crit space) allows said armor to do it's job without turning the suit into a playdoh fun factory for the dude inside. 

In short, Battletech Magic *image of Atlas with wizard hat goes here*
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JureSimich

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Re: Reactive armour
« Reply #8 on: 01 April 2022, 07:01:39 »
There are several areas where the game rules do not match with reality.
-hit points. While magicked away as highly complex ablative armor, later added rules no longer follow.
- the bigger the cannon, the SHORTER the range.
-PPCs do not suffer from atmosphere diffusing the beam
-a tank is somehow not significatly better than a mech, despite the mech being a larger target
-mechs are more mobile thank vehicles, despite ground pressure issues
-missile launchers are suspiciously heavy compared to the the ammo they use
-aerospace fighters have never heard of reaction mass

As always - that's the price for having a universe that has BIG stomoy robots as the main combat arm.

And feel smug that you know that the authors got that wrong , if it helps.

:)

Demiurge

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Re: Reactive armour
« Reply #9 on: 21 April 2022, 17:54:28 »
I'm the first to criticize the game rules for being old, clunky, and diverging from sensible real-world mechanics for no good reason.

however

I'm willing to give the writers a pass on this one.  The first iteration of reactive armor was called blazer armor, and I'm pretty sure it came from Unbound or some similar level 3 rules supplement.

Those of you familiar with real-world tanks may perk up at the name Blazer.  It's actually a brand name of an Israeli-made brand of reactive armor design.  I'm pretty sure that the writers didn't realize this was actually a brand name, and were incorporating it into the game because at the time of writing, it was quite new technology (first fielded in ~1982).

So, late eighties or early nineties.  The writers pull something that they'd seen in a news headline or Jane's or something and put it in the game.  It's brand spanking new.  The internet is a lot smaller and weaker than the firehose of information it is now.  I think it's perfectly reasonable, given those conditions, that they had no idea how it worked.

mbear

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Re: Reactive armour
« Reply #10 on: 25 April 2022, 08:50:10 »
Does reactive armor still explode on a critical hit?
Be the Loremaster:

Battletech transport rules take a very feline approach to moving troops in a combat zone: If they fits, they ships.

You bought the box set and are ready to expand your BT experience. Now what? (Thanks Sartis!)

Fat Guy

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Re: Reactive armour
« Reply #11 on: 25 April 2022, 12:30:43 »
Does reactive armor still explode on a critical hit?

Yes.
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Demiurge

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Re: Reactive armour
« Reply #12 on: 29 April 2022, 08:49:42 »
I'm not sure how well that works as a game rule, but IRL explosive reactive armor does occasionally chain-detonate and denude large areas of the vehicle it's protecting.

More evidence that the early writers read Jane's can be found in the fluff text descriptions of 'mech armor as ceramic.  At the time, it was thought that a lot of next-generation tank armor composites included large amounts of ceramics.  This turned out not to be true, and it sticks out very much as an artifact of the times.

Colt Ward

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Re: Reactive armour
« Reply #13 on: 29 April 2022, 11:50:16 »
More evidence that the early writers read Jane's can be found in the fluff text descriptions of 'mech armor as ceramic.  At the time, it was thought that a lot of next-generation tank armor composites included large amounts of ceramics.  This turned out not to be true, and it sticks out very much as an artifact of the times.

Ceramic is still used to defeat EPWs afaik, in fact some of the protection uses glass from what I was told.

Key thing is, it is sandwiched.
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Moonsword

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Re: Reactive armour
« Reply #14 on: 29 April 2022, 14:57:10 »
I've moved this thread to the appropriate section of the boards.  Please follow the rules on where things like this belong going forward.

Demiurge

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Re: Reactive armour
« Reply #15 on: 11 May 2022, 01:08:47 »
Ceramic is still used to defeat EPWs afaik, in fact some of the protection uses glass from what I was told.

Key thing is, it is sandwiched.

US armor research in the 1950s was indeed looking at silica-cored armor, although this was not fielded.  Early Soviet T-64 armor packages also contain big aluminum oxide spheres.  That's old technology now, and large ceramic elements are rare in tank armor arrays designed within the last few decades.  Ceramic tiles are not unheard of in some light vehicle armors as a standoff layer, but there's really no evidence of them in tanks.

Lots of evidence of ERA/NERA though, as well as liquid layers.