Abrams Side Armor

[Assassin 7]

No penetration.

1-37 had a tank in Karbala take 16 hits in April/May 2004.

The point is that the tank uses the concept of sacrificial armor, it's nothing new.

The tank save many lives and the frontal armor is made to defeat rounds that is shot at you. You stated you would rather be shot in the rear. Not the front. And you stated that there is a ammo bunker in the rear of the tank that protects you. Not true. The Hull ammo stowage just protects you from your own rounds cooking off in the turret basket.

this was your statement:

The M1 uses sacrificial armor on the turret rear (ammo bunker), rear of hull (engine), and fuel cells on the side of the driver. I would rather be hit into the rear of the hull by a RPG, than hull side. Though the tank will possibly shut down on me (depending on what gets hit), the crew will be OK. Between the rear armor, and inner hull there is too much "crap" and distance. That jet rapidly loses penetration with distance. As to the fuel cells, they are behind a ballistic skirt, followed by a hollow space, possibly road wheels or track (depending on exactly where hit), an outer hull, and then the plastic fuel cells that are basically in an encased box. They are hard to set afire (no air) even when they are penetrated or if the outside is set afire, and then they are still separated from the crew compartment by another inner hull. Do you see what's happening here? Outer hull, inner hull, and everything flammable and explosive is sandwiched between those and because of that, things that can go boom, or burn can actually add to the protection of the crew. This is different from placing a thin skinned fuel tank that can catch on fire with WP arty, a Molotov cocktail, etc on the rear exposed, or having ammo stored the way it is on a T72. The ammo bunker turret rear of an M1 actually provides protection.

[Assassin 7]

Anyways, from this conversation I think you know what Theory of Operations is for the abrams. Maybe you should read them. later

[Red6]

Yes on Tanknet

I don't think so. Unless someone else took a pic as well or its a similar pic that's not the same (benefit of the doubt). That's my pic. My camera was my hobby while deployed.

[Red6]

Anyways, from this conversation I think you know what Theory of Operations is for the abrams. Maybe you should read them. later

It never hurts to study/learn more.

[Red6]

The tank save many lives and the frontal armor is made to defeat rounds that is shot at you. You stated you would rather be shot in the rear. Not the front. And you stated that there is a ammo bunker in the rear of the tank that protects you. Not true. The Hull ammo stowage just protects you from your own rounds cooking off in the turret basket.

this was your statement:

The M1 uses sacrificial armor on the turret rear (ammo bunker), rear of hull (engine), and fuel cells on the side of the driver. I would rather be hit into the rear of the hull by a RPG, than hull side. Though the tank will possibly shut down on me (depending on what gets hit), the crew will be OK. Between the rear armor, and inner hull there is too much "crap" and distance. That jet rapidly loses penetration with distance. As to the fuel cells, they are behind a ballistic skirt, followed by a hollow space, possibly road wheels or track (depending on exactly where hit), an outer hull, and then the plastic fuel cells that are basically in an encased box. They are hard to set afire (no air) even when they are penetrated or if the outside is set afire, and then they are still separated from the crew compartment by another inner hull. Do you see what's happening here? Outer hull, inner hull, and everything flammable and explosive is sandwiched between those and because of that, things that can go boom, or burn can actually add to the protection of the crew. This is different from placing a thin skinned fuel tank that can catch on fire with WP arty, a Molotov cocktail, etc on the rear exposed, or having ammo stored the way it is on a T72. The ammo bunker turret rear of an M1 actually provides protection.

That's not what I said. The front is where you want to get hit, but the rear will also protect fairly well using a sacrificial concept in how it protects you. You can't armor everything like the turret front. While possibly or even likely to cause a mobility kill, I "personally" would rather take a hit (without the special sauces added) from an advanced RPG in to the rear than hull side. My argument is one of lesser evils when things don't go the way you want.

[dejawolf]

The tank save many lives and the frontal armor is made to defeat rounds that is shot at you. You stated you would rather be shot in the rear. Not the front. And you stated that there is a ammo bunker in the rear of the tank that protects you. Not true. The Hull ammo stowage just protects you from your own rounds cooking off in the turret basket.

by ammunition bunker, Red6 probably means the secure ammunition storage in the turret bustle. it adds fairly decent protection to the rear of the turret. massive airgap and pretty thick blast doors. dunno if it'd stop an RPG though.

as for the merkava, it's a pretty cool tank. there's no other tank in the world that can double as a very heavy IFV, although you'd have to sacrifice a lot of your ammunition in order to do so. the ammunition storage does leave something to be desired, but at least it's stored in spallproof containers, so it'd take a direct hit to blow off it's top.

having the engine in the front adds some serious drawbacks to the tank.

first it makes the tank a lot taller. the merkava mk2 is about 22cm taller than the abrams.

second it reduces the amount of composite armour you can have, at least in front of the engine. so you're pretty much guaranteed that the tank is immobilized if it's hit in the front hull. the engine itself doesn't add that much armour, probably around 250mm KE, and 650mm HEAT. with a glacis about 60-70mm thick, and angled at around 75 degrees, thats another 250mm or so, so a total of 500mm vs KE for the older merkavas. the mk.4 front hull glacis seems to be roughly twice as thick. if it's all steel, a rough estimate would be 120mm@75 degrees = 460mm + 250mm = 710mm. but it's probably some sort of composite. lower front hull would be a lot less protected though, maybe even possible to penetrate and immobilize with the 40mm bofors, or some old-ass T-62 round.

[lavictoireestlavie]

by ammunition bunker, Red6 probably means the secure ammunition storage in the turret bustle. it adds fairly decent protection to the rear of the turret. massive airgap and pretty thick blast doors. dunno if it'd stop an RPG though.

as for the merkava, it's a pretty cool tank. there's no other tank in the world that can double as a very heavy IFV, although you'd have to sacrifice a lot of your ammunition in order to do so. the ammunition storage does leave something to be desired, but at least it's stored in spallproof containers, so it'd take a direct hit to blow off it's top.

having the engine in the front adds some serious drawbacks to the tank.

first it makes the tank a lot taller. the merkava mk2 is about 22cm taller than the abrams.

second it reduces the amount of composite armour you can have, at least in front of the engine. so you're pretty much guaranteed that the tank is immobilized if it's hit in the front hull. the engine itself doesn't add that much armour, probably around 250mm KE, and 650mm HEAT. with a glacis about 60-70mm thick, and angled at around 75 degrees, thats another 250mm or so, so a total of 500mm vs KE for the older merkavas. the mk.4 front hull glacis seems to be roughly twice as thick. if it's all steel, a rough estimate would be 120mm@75 degrees = 460mm + 250mm = 710mm. but it's probably some sort of composite. lower front hull would be a lot less protected though, maybe even possible to penetrate and immobilize with the 40mm bofors, or some old-ass T-62 round.

So basically it is a Challenger 2 armor profile wise at least in the hull area?

What are your thoughts about the turret front and sides ? Ought to have some pretty good CE protection but possibly not so great KE protection.

[Damian90]

@Djawolf

Merkava design have also one problem more. Large internal volume which makes it weight inefficent compared to protection levels it's offers.

Even if it is comfortable, I think I would reduce that comfrot to the levels of standard NATO tanks, but have lighter and more mobile vehicle.

It is interesting that Merkava Mk2 weights approx 60 metric tons, while having worse protection than Leopard 2A4 and M1A1 weighting below 60 metric tons.

[dejawolf]

So basically it is a Challenger 2 armor profile wise at least in the hull area?

What are your thoughts about the turret front and sides ? Ought to have some pretty good CE protection but possibly not so great KE protection.

it's the opposite for the older merkavas with spaced armour, good KE protection, poor CE.

merkava Mk.4 however uses NERA so it should be impervous to most RPGs from the front, possibly even from the side.

based on LOS thicknesses in this drawing

just the air gap on the side turret should provide about 220mm vs CE.

doing some really crappy estimates based on approximate thickness of 40mm and assuming linear increase in protection with thickness for the NERA elements, with NERA consisting of 2 steel plates with rubber interlayer they should provide about 320mm vs CE@60 degrees.

seems like there's also an about 20mm thick cover plate, and i'm assuming the inner wall is about 40mm thick.

so you get 220+320+(20@70° = 60) + 40 = 640mm vs HEAT

but it wouldn't surprise me if the side turret is actually capable of defeating the RPG-29.

if for example the NERA element is 50mm instead of 40mm thick, it would be 400mm vs CE instead of 320mm.

this is also assuming only a single NERA element.

vs KE, dunno, absolute minimum of ~710mm vs KE i'd say, as the turret would never be thinner than the hull. according to a book on the merkava there was X-ray photographs pinned to the walls in tel aviv showing some of the "latest" penetrators being shattered.

the design of the turret itself seems to be very good, weakspots are small, pretty much only the coax port.slit.

[dejawolf]

actually, just found a picture showing the damaged side turret on merkava Mk.4 and it has 2 elements in it instead of 1. and air gap is 220mm only at the extreme tip of the V.

air gap is probably only there because the NERA elements needs to be at a certain angle to work efficiently.

likely, the formula should instead be 320*2+60+40 = 740mm vs HEAT. RPG-29 is rated at 750mm, so yeah..

[Froggy]

Powerpack might add some protection against small calliber weapons or obsolete ammunition. But powerpack does not have enough hardness or density to efficently defeat modern ammunition, so in the end it is reducing protection of a tank like vehicle against modern ammunition.

During the prospect of the Leclerc developpement, they test the protection offered by an front monted engine, taking an AMX30, and reversing it. They fired 4 HOT missiles at it (pen 800mm RHA).

2 were blocked by the gear box, 2 entered in the engine, the farest at 2m from the entry point, under the 2,5m of the engine compartiment lenght. And there was only a 2cm armor plate.

[Damian90]

During the prospect of the Leclerc developpement, they test the protection offered by an front monted engine, taking an AMX30, and reversing it. They fired 4 HOT missiles at it (pen 800mm RHA).

2 were blocked by the gear box, 2 entered in the engine, the farest at 2m from the entry point, under the 2,5m of the engine compartiment lenght. And there was only a 2cm armor plate.

Then it is not impressing protection.

9M133 fielded in 1994 was capable to defeat 1000-1200mm RHA, and these were ATGM's that Merkava also faced in Lebanon. Other ATGM was 9M131 which is smaller and capable to defeat 900-950mm.

Besides this, it seems that in the end engineers were disatisfied with front mounted engine, and choosen rear mounted configuration, which seems to serve well Leclerc.

[DarkLabor]

Then it is not impressing protection.

9M133 fielded in 1994 was capable to defeat 1000-1200mm RHA, and these were ATGM's that Merkava also faced in Lebanon. Other ATGM was 9M131 which is smaller and capable to defeat 900-950mm.

We're talking about tests that were conducted in the late 70's, early 80's.

Besides this, it seems that in the end engineers were disatisfied with front mounted engine, and choosen rear mounted configuration, which seems to serve well Leclerc.

Well, the protection is a thing, but thermal signature is another one.

Designers were more confortable with an engine at the rear providing a white spot in the back of the tank, rather than a frontal engine providing a white spot at the front.

Not to talk about the evolutivity of the tank (wich is a core concept)...

[Froggy]

Then it is not impressing protection.

9M133 fielded in 1994 was capable to defeat 1000-1200mm RHA, and these were ATGM's that Merkava also faced in Lebanon. Other ATGM was 9M131 which is smaller and capable to defeat 900-950mm.

Remenber that was the power pack only, there was no armor to protect it.

Besides this, it seems that in the end engineers were disatisfied with front mounted engine, and choosen rear mounted configuration, which seems to serve well Leclerc.

No, it's more a question of natural stabilisation. The axis of the turret had to be exactly at the gravity centrer of the tank, which can not be done with a front monted engine. And the heat of the engine (hoter than the Merkava one) made a big spot on thermal imager.

[DarkLabor]

Oh forgot the stab! Thanks for the reminder Froggy!

[Damian90]

We're talking about tests that were conducted in the late 70's, early 80's.

Merkava during 2006 Lebanon war also did not fared much better against ATGM's hitting front hull armor.

Well, the protection is a thing, but thermal signature is another one.

Designers were more confortable with an engine at the rear providing a white spot in the back of the tank, rather than a frontal engine providing a white spot at the front.

Not to talk about the evolutivity of the tank (wich is a core concept)...

Well I dare to say that Leclerc with rear mounted engine have better front hull protection than Merkava with front mounted engine.

No seriously, from what I seen, Leclerc have a really large cavity for composite armor with large enough volume to provide adequate protection against mos threats.

[12Alfa]

During the prospect of the Leclerc developpement, they test the protection offered by an front monted engine, taking an AMX30, and reversing it. They fired 4 HOT missiles at it (pen 800mm RHA).

2 were blocked by the gear box, 2 entered in the engine, the farest at 2m from the entry point, under the 2,5m of the engine compartiment lenght. And there was only a 2cm armor plate.

And some would say that the engine in front has no usefulness.:c:

[DarkLabor]

No seriously, from what I seen, Leclerc have a really large cavity for composite armor with large enough volume to provide adequate protection against mos threats.

It's just a matter of where you shoot, just like the basic (bare?) Challenger 2.

[Damian90]

And some would say that the engine in front has no usefulness.

For example most engineers that build tanks for decades, choose to use engine at rear. You dare to say they don't know what they doing?

Yes, engine at front for a tank is useless for it's protection.

And what is more important, will not provide any possibility for upgrading protection against future threats.

One of DARPA future tank projects, had a vehicle weighting 55 metric tons, with 1300mm thick front hull armor designed to protect against for example APFSDS fired from 152mm smoothbore gun of projected Soviet future tank.

It is possible that in future such armament for tanks will be inducted. Engine at front will not provide adequate protection.

Besides this, immobilized tank is a dead tank, and most likely a dead crew to. Engine at rear that is more difficult to hit is a better idea.

It's just a matter of where you shoot, just like the basic (bare?) Challenger 2.

IMHO from what I seen, "naked" Challenger 2 have large weak spot at lower front hull surface, there is no composite armor there, only on glacis plate. Leclerc have both surfaces protected by composite armor, at least model of front hull protection tested in Sweden sugests so.

Lower front hull of Leclerc looks to be similiary protected like Leopard 2 and M1, approx 600-650-700mm thick, but it seems that there is also additional protection for glacis plate, most likely because it is inclined less extremely than in case of Leo2 and M1, so it needed to be made thicker to compensate.

[DarkLabor]

Wrong.

[Damian90]

What is wrong?

[DarkLabor]

I don't know, you're the expert.

Tell me.

[EDIT]C'mon a little clue :

[/EDIT]

[Damian90]

I don't see anything wrong there. This is Leclerc front hull model prepared for ballistic tests in Sweden.

Source: http://www.ointres.se/projekt_stridsvagn_ny.htm

[DarkLabor]

Well then think what you want.

I asked you to think; you just vomited me one of your link...

[Damian90]

Well I think and I don't see anything wrong. The shape is similiar to front hull of Leclerc. Obviously there won't be any details as this is only model prepared for ballistic tests without armor inserts installed.

So I ask again, what is wrong in your opinion? Or this this is just "wrong" to be wrong?

I wonder what actually you expect from ballistic test armor model? To be 100% accurate in all details to the real tank?

In the link there are photos of M1A2 hull and turret models prepared for the same tests, these are also not 100% accurate representations of the real tank.