Turret Popping With Smoke and mirrors

[Max_Power]

Tank turrets may pop off due to a magazine explosion.  I don't know how frequent or likely this is, especially on modern tanks.  Something not modelled very well in OFP is that modern tanks are so tough (like, invulnerable to nuclear attack tough), that the munitions employed to kill them usually only poke needle thin (I exaggerate) holes in the armour, and maybe fragment the inside of the hull a bit, killing the crew with shrapnel.  Even the famed maverick missile will only put a pinky finger width hole (more exaggeration) in the composite armour of an abrams.  Hammering a tank in the same 'hitbox' over and over again is not really going to increase your chances of a catastrophic fuel/magazing explosion that reduces the tank to a flaming wreck.



The above Abrams was 'mobility killed' in iraq, and the Americans bombed he heck out of it in order to make it unlikely to be usable to their opposing forces in any way.  It was hit with 2 mavericks, a sabot round, and some thermite grenades, if I recall correctly.

The point is that a magazine explosion is sort of unlikely, and even then, I don't know how likely it would be for the turret to come flying off.  I like this idea, but if it is to be implimented I think it would work best as a rare occurance.

Sources: http://www.strategypage.com/gallery/articles/default.asp?target=abrams_lessons_learned.htm

The second page of that link has the information about the extent to which one has to go to to 'finally destroy' a main battle tank.

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

The crack about tanks being immune to nuclear weapons refers to the context mentioned in the introduction of the above training document.

[Grendel]

I don't know how frequent or likely this is, especially on modern tanks.

Granted it is pretty infrequent with most modern western MBTs, as they have been designed with crew survivability in mind (separate ammunition compartments with blow off panels and such).  It does happen though.  Please refer to an article I linked to in this thread. That was just an anti tank mine and it blew the turret off an M1. The effect will be suitably rare on M1s though, don't worry.

Soviet designed armor is much more vulnerable to this however, as they often design their tanks with a 'carousel' (sp?) style rack with rounds freely exposed to the crew around the circumfrence of the turret compartment.

I remind everyone that magazine explosion is not the only mechanic involved in turret launching k-kills.  The ammount of energy created by a sabot round as it transfers it's kenetic energy on impact is huge.  Just because they don't have a 'warhead' doesn't matter much when you are dealing with the velocities achieved by these rounds.

For gameplay purposes, the 'default' random chance values I am considering are:
M2 and BMP series: 30%
M1:5%
T-series (up to 72):25%
T-series 80-90:Still researching, but probably 15%

They will be user definable BTW so instead of wrangling over 10 million premutations of these values...you can set them yourselves quite easily.

-Grendel

[Max_Power]

I remind everyone that magazine explosion is not the only mechanic involved in turret launching k-kills.  The ammount of energy created by a sabot round as it transfers it's kenetic energy on impact is huge.  Just because they don't have a 'warhead' doesn't matter much when you are dealing with the velocities achieved by these rounds.

If the impact of a sabot round hitting the turret of a tank was enough to rip it off, the recoil of the gun would be enough to rip the turret off of the tank that fired it.  There is no possible way that the impact of a round designed specifically not to give its energy up upon impact- but rather to retain its energy for as long as possible to drive through as much armour as it can- is going to contribute to the de-turretting of an MBT in any way.  Moreover, the explosive force generated by a shaped or hollow charge warheads is used to focus a jet of vaporous copper that causes a thermodynamic chemical reaction, causing the armour to flow away from the jet.  There is no 'punching through' armour with blunt explosive or raw impact power  on the scale that a cannon is able to deliver.  The energy needs to be focussed into a point, like the point of the sabot dart or the point of a laser-like gas-jet.  Based on these premises, I submit that the only mechanism that's capable of deturreting a tank is pressure inside the tank on the scale of thousands of pounds per sqaure inch against the weight and seals of the turret (which must weigh several tonnes).  The only mechanism that would be capable of this would be a magazine or some other massive explosion inside the tank.

Regarding your link:

It's fallacious to think that because it's possible that it's common.  Also, anti-tank mines are shaped charges that fire upwards through the relatively very weak under-armour of a tank.  What I think is that some spall from the floor or the armour piercing jet hit the magazine.  It was not 'merely' the mine, but rather a catastophic failure caused by chance when the mine detonated in such a way to affect explosives within the tank.

Let me clarify that I don't think your idea is bad- in fact I think it's good.  IRL, though, this occurance is rather rare.  I think it's probably much less likely than you think.

[Coldfire]

If the impact of a sabot round hitting the turret of a tank was enough to rip it off, the recoil of the gun would be enough to rip the turret off of the tank that fired it.

Not neccacarily, keep in mind the turrret has alot more mass than a sabot round, and is still partially attached to the tank. Furthermore the barrel of the main gun recoils to absorb the shock of each shot fired. Hence, most of the energy created by the round leaving the barrel would be absorbed and disapated between the mass of the tank and the shock-absorbant properties of the barrel.

I'd guess it's possible, but still extreamly unlikley, that a sabot round slamming into where the turret meets the main chassis of the tank might be enough to knock the turret off... but it wouldn't go flying of the tank it'd probably just tilt sidways and roll off. I'd say the chances of internal explosion causing the turret to pop off is much higher.

Just a sugestion, but I'd suggest making a form of anti-tank mine with the turret-popping scripts built in.

[Max_Power]

That would never happen.  The penetrator is designed to penetrate, not tear off.   I cannot stress enough that this is impossible.  It's simple physics.  

This is sort of off topic, though.  Since I'm new I don't really want to make bad with the admins.  If you would care to email me I could put something together to better explain the situation, if you like.

Edit:  I tried to edit my profile to allow people to see my email addy but it seems to be broken.  I'll keep trying in the meantime.

[Max_Power]

Oh, and I forgot to mention.. turret popping I think would only be possible with somethign with an enclosed turrent.  Any pressure that would pop off a tank's turret would just vent through the hole of an open turret, so I think that while it would probably be mangled beyond recognition, I don't think an m113's 'turret' would actually come off.

[Pilot]

A lot of what I'm about to say is assumption on my part, but I think it is all right.

If the impact of a sabot round hitting the turret of a tank was enough to rip it off, the recoil of the gun would be enough to rip the turret off of the tank that fired it.

SABOT Rounds may not be able to pop the turret off a tank without igniting the magazine, but I am quite sure that a HEAT shell will (IIRC, HEAT stands for High Explosive Anti-Tank).  It is a matter about the concetration of energy.  When a tank fires a round, the energy from that shot is disbursed throughout the WHOLE tank.  The energy is so tremendous that even with a recoil the tank still rocks back and forth.  When a shell hits a tank, all the the energy from the shell is transfered to a localized area of the tank.  This is part of the reason why shells can punch through armor.  If the shell hits in the right place, the localized burst of energy can be enough to lift a turret off the hull, and sometimes to great hieghts.  The fact is, it does happen, and to eastern bloc tanks, I would think it would be reasonably common.

-Student Pilot

[Max_Power]

A HEAT shell uses its explosive power to crush a cone shaped blank of copper into a superheated, pin-shaped jet.  The copper hits the armour, and due to its thermodynamic and heat transfer properties, the armour is vapourized and flows around the jet.  It is pushed asside as the jet flows forth.  The explosive itself may cause the inner armour to spall due to the creation of uneven compression and sheering shockwaves within the armour itself, but the actual HEAT round acts much like a KE penetrator.  In fact, the HEAT copper jet stream is so coherent, that an RPG round detonated in a screen or some trees will have sufficient energy to pop an M113 from 12 feet away, or 6 inches of concrete from 25 feet.  I have a feeling that this is why those stryker anti-rocket cages worked so poorly.  So, HEAT works by penetrating a very small bit of armour, just like APFSDS.  The armour of modern MBT's is actually more effective in stopping HEAT rounds.  They are usually made up of a kind of ceramic composite which is very heat (the energy and the round) resistent.  When a HEAT round hits the ceramic, the ceramic shatters and flows backwards out towards the blast.  THis acts sort of like ERA, reducing the velocity and energy of the copper stream.  Usually, MBT's have 200 cm more resistance to HEAT rounds than KE rounds in RHA (rolled, homogenous steel armour) equivalent.

As discussed earlier, I think that the reason why eastern block tanks have a tendency to lose their turrets has to due with their autoloader, and the fact that their ammunition is left exposed to be hit by spall or some other secondary effect.  There is actually some some eastern tank rounds that have a fuse setting so delicate, that the round must be fired from a stationary tank so that the round won't blow up in the barrel!  Obviously, these rounds aren't stored at that fuse setting.

[Pilot]

oi, I feel inadequate ;D

Ok, last ditch effort, let's take a look at this:

KE=1/2 mass (velocity squared)

Kenetic Energy is equal to one half times Mass times Velocity squared

The mass (weight) of an M1A1 M829 APFSDS tank shell is roughly 9 pounds.
The velocity is roughly equal to 1670 meters/second (we'll use 5500 feet/second):

KE = .5(9)(5500 squared)
So,
KE=136,125,000 ft-lbs  or KE=5,600,000 joules

Let's assume the turret weighs 8 tons or 16000 lbs (7300 kg), if all the energy is transfered to the turret (which is impossible, just bear with me), the turret, at that energy level, will pop off at close to 90 mph.  Now remember, not all the energy is ever fully transfered, and I am also assuming the energy is applied vertically.  However, under optimum conditions, a turret can be popped off just by the shell alone.  Physics do allow it.

-Student Pilot

*Credit for some of the math involved with this goes to my dad, I didn't figure all this out myself

[Max_Power]

It is the physical design of the rounds that do not allow for it, though.  You can't say that physics allow it, because they don't allow it.  If physics did allow it, they would make the AT rounds blunt headed or frangible.

Also, you're neglecting the actual resistance to sheering forces of the turret and its assembly.  I'm sure if that happened (a force instantaneously accellerated a tank's turret to those kinds of speeds, the turret coming off would be the least of the crew's worries.  You'd have a weapon that would effectively liquify the crew.

[Dubieman]

 
Honestly, let them do their thing. OFP is a game and while it has a lot to do with realism, not everything is perfect. And from the sound of it, turret popping does happen. Not all the time, but I've read a little bit on it and I think the eastern tanks do have a greater chance of going pop. As for the western ones, I really don't know. And I'm puzzled as to why we have to go through all these physics lessons to prove something.

I have to agree with Grendel (earlier post) that AT weapons are now better than ever and MBTs and armor are playing catch up right now. Anyways, by the sound of the script, turret popping won't happen all the time. Only with certain weapons in certain conditions. So Max, just drop it and let them finish the project.

[Pilot]

And I'm puzzled as to why we have to go through all these physics lessons to prove something.

I know, my head is hurting  But I am going to give this one more shot...no pun intended

If we are going off-topic with this, moderators, please accept my apologies and tell me to knock it off

It is the physical design of the rounds that do not allow for it, though.  You can't say that physics allow it, because they don't allow it.

The physical design has little to do with it.  Any object with the energy of a tank shell will do a lot of damage

Also, you're neglecting the actual resistance to sheering forces of the turret and its assembly.

What do you mean by shearing forces?

Anyway, if a round hits the turret in the right place (I've heard right where the turret meats the hull), the shell should be able to "wedge" itself between the turret and hull, and with the tremendous energy of the shell, it should be enough to pop off the turret.

For example, lets say only 5% of the energy of a shell is transfered vertically to the turret.  That is 6,806,250 ft/lbs of energy that is still transfered.  Now, if my calculations are correct, that equates to about 29 feet/second or about 20 mph.  This is assuming the turret weighs 16,000 pounds.  I don't know exactly how much a turret weighs.  If anyone could give me a figure for a T72 turret, or something comperable, I would appreciate it.

So, even at a low energy transfer, physics still allow it.  Weapon design, as I said above, has little to do with it.  The big factor is where the shell impacts the tank.

-Student Pilot

[Max_Power]

And I'm puzzled as to why we have to go through all these physics lessons to prove something.

Certainly not.  I just enjoy this kind of discussion.  I mean, I suppose I could have them at that abovetopsecret.com forums, but from what I've seen, they're all about trying to prove that that pinhole in the armour was not made by some kind of HEAT round, but some kind of microwave plasma laser death ray from area 51.  That isn't really my scene.

How this discussion started was I was just saying that I think that turrets popping off would be unlikely, but I certainly would love to see it.  It evolved from there, as I was championing why I thought it would be unlikely, and if the conversation is now off topic I'm willing to accept that.  I'm argumentative, for sure, in the sense that I enjoy debate- but really do enjoy these discussions and I'm not out trying to belittle anyone.  I feel that open discussion is how fresh ideas are tempered and new ideas are born.

The physical design has little to do with it.  Any object with the energy of a tank shell will do a lot of damage

Well, that said, there are ways of enhancing the amount of damage that you do by shaping the rounds and playing with their material composition.  What I was getting at is that the best way to expend all of that energy in tank busting is by designing a round that will not give up its energy.  It is designed to hold on to it, even as it's flying through incredibly hard and thick tank armour.  A flat-headed shell with that kind of energy hitting a tank turret may do some damage, but it would not be sufficient enough to kill the tank.  This I assume because no tank shells have flat heads.

What do you mean by shearing forces?

Sheering forces happen when one part of a solid is moving the a different direction that another part.  Resistence to tearing.

Anyway, if a round hits the turret in the right place (I've heard right where the turret meats the hull), the shell should be able to "wedge" itself between the turret and hull, and with the tremendous energy of the shell, it should be enough to pop off the turret.

I think that the shell itself would be crushed long before that- however, even if that is possible, the likelihood is rather slim given the size of the crack compared to the size of the rest of the tank, resulting in a low frequency of tank-turrets-popping-off-ness.  I don't think that wedging somethign in there would pop the turret off, I think that the more likely scenario would be that the turret would jam.

Eh, if this is off topic and you want to continue the conversation you can PM me.  I'm always happy to reply to PMs

[Planck]

Emmmmm........yes its getting ever so slightly off-topic guys.

Can we steer it back on course please?


Planck

[Pilot]

Sorry, I'll continue the discussion through the IM.

-Student Pilot