The Merkava 4 MBT

[loktarr]

A firing hatch and observation window was also opened in the rear access door, where a sniper or sharpshooter can operate, from a protected position.

I think that this rear door must be a really good to fire at for a RPG bearer, it musst be quite unarmored...

I'm not a specialist but the turret seems to be a good "shell trap", I mean when a shell did hit the tank on the top hull or end of the turret, he can slide and hit at the jointing point of the turret and the hull. That's not good, german had this problem with the Panther A during WW2 and added in D a little steel protection over the hull. This is the same problem with Leopard, but Challenger and M1A2 don't have this problem...

just an edit for Jam:
go there to see the M1A2 SEP armor:
http://www.fprado.com/armorsite/abrams.htm
it is given tree times depending on the year and version...

[Backis]

loktarr said:
I think that this rear door must be a really good to fire at for a RPG bearer, it musst be quite unarmored...

***-protection ain't that hot for any MBT, if there is a door there or not, you're pretty much toast if you let them shoot you up the rear.

I'm not a specialist but the turret seems to be a good "shell trap", I mean when a shell did hit the tank on the top hull or end of the turret, he can slide and hit at the jointing point of the turret and the hull. That's not good, german had this problem with the Panther A during WW2 and added in D a little steel protection over the hull. This is the same problem with Leopard, but Challenger and M1A2 don't have this problem...

Long-rod penetrators doesn't really richochet, its not really a problem having "shot traps" against APFSDS.

[Backis]

PlasmaKrab said:
Got it, just dug out the reference.

The book is FM 7-8 "Infantry Rifle Platoon and Squad", 04/22/1992, chapter2, section 2-47 "riding on armored vehicles".

I DLed it long ago from the Army library website, which has much changed since, so I don't know if you can still get it from there.

You got it in digital format?

Would you be interested in sharing?



ulven@chello.se

[loktarr]

Long-rod penetrators doesn't really richochet, its not really a problem having "shot traps" against APFSDS.

I don't know, because I readed that during WW2 the shell who does 'ricochet' where the german tungstene penetrators, against flat inclinated armors...
Are you sure about what you said?

[Backis]

loktarr said:

I don't know, because I readed that during WW2 the shell who does 'ricochet' where the german tungstene penetrators, against flat inclinated armors...

Nobody used APFSDS in WW2. Closest thing was spin-stabilized APDS, which couldn't be stabilized at nearly the same L/D ratio.

loktarr said:Are you sure about what you said?

I applied an oversimplified absolute, which is always a bad idea...

Complaining about JaM doing just this and then doing it myself is a sign of dumbarseness, so I'd better start to think about what the hell I'm writing... especially in areas where I'm barely a semi-enlightened amateur, if that...

Sorry, I only meant to say that I think the problem I responded to isn't that big or relevant. A lot of engineers with fancy titles designing armour does seem to believe that creating shot-traps isn't a big deal, I don't think they're just stupid (I reserve that comment for myself) and "forgot" about it. Long-rod penetrator structural failure/breakup will probably occur before it being deflected so much it will be a threat to the deck hull or turret ring, but most likely it will be embedded in the front turret armour.

However, I'll indulge myself and writing down what I've come to believe so far...

The inertial stability of high length to diameter (L/D) ratio penetrators makes ricochet yaw practically irrelevant when applying the ricochet effect on armour penetration unless we're talking very extreme angles. At lower angles the effect will be to small to significantly affect the penetrator. This is of course varied relative to the exact constitution of penetrator and armour material.

Still, long-rods most likely will not bounce off, and the armour need to be strong enough not to simply be overmatched.

So, simplified and unabsolute, I think that unless at extreme angles, LOS increase by angled armour will likely be more relevant to protection against long-rods than angle induced ricochet.

Angle-induced yaw short of a ricochet is probably still desirable though, since the increased stress put on the penetrator may cause it to fail structurally and break up.