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5 hours ago, Serge said:

So, some countries can leave a crew a year to train. 

Funny. 

If terms of enlistment in the Army are what I remember, that's half a tour.

USAF minimum tour was four years. 

 

Makes me wonder if the U.S. is having issues with retention of a solid NCO cadre.

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How much of the results of this tank competition reflect on the merits of the crew vs the technological advancements of the tank?

 

For example, I saw that they had pistol portion. You cant even get people in a combat MOS, sans SOF, proficient with a handgun and you expect that out of your tankers? Are they even trying to correlate the stages with real world situations? 

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2 hours ago, Meplat said:

If terms of enlistment in the Army are what I remember, that's half a tour.

USAF minimum tour was four years. 

 

Makes me wonder if the U.S. is having issues with retention of a solid NCO cadre.

 

Anecdotally, EUCOM ordered 2-70 to send a platoon a month and a half before event while they were getting ready to head back to Fort Riley from their European deployment.

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5 hours ago, Sgt.Squarehead said:

 

You are kidding.....They almost missed the yellow car!  :lol:

 

The Challenger was clearly the winner with its perfect execution of the white people-carrier.  ;)

A white people carrier? Segregation much!?

 

:ian:

 

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Very late to the party, but in the swedish document where it describes the protection estimates for the Leopard 2 improved, it assumes a single charge for the CE protection value, right? I'm curious as to how tandem charges would affect those estimates, as pretty much all serious atgm threats these days are tandem charges.

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http://viewer.zmags.com/publication/a42b8bf8#/a42b8bf8/34

Article on the Queen's Royal Hussars participation at Tank Challenge.
Claims they placed 4th. Which was also posted on their Facebook page shortly after the competition finished.
Won 
CASEVAC serial. Podium'd others including defensive live firing, pistol shoot and obstacle course.
Struggled in others because of weight and agility.


Has a tank comparison page. Usual "rifled gun more accurate", "3-piece quicker", "moar armour" but then says the CR2's fire control computer was better at hitting moving targets than the Leopard 2's. wat?
 

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On 6/29/2018 at 10:23 PM, DD000 said:

Very late to the party, but in the swedish document where it describes the protection estimates for the Leopard 2 improved, it assumes a single charge for the CE protection value, right? I'm curious as to how tandem charges would affect those estimates, as pretty much all serious atgm threats these days are tandem charges.

Unless your precursor is shit, you can (almost) simply do precursor penetration + main charge penetration = total penetration. Actual penetration will be a bit less because the main charge also has to penetrate the slug left by the precursor jet.

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51 minutes ago, Bronezhilet said:

Unless your precursor is shit, you can (almost) simply do precursor penetration + main charge penetration = total penetration. Actual penetration will be a bit less because the main charge also has to penetrate the slug left by the precursor jet.

 

If that were the case, then I don't expect the precursor to do much at all, since most precursors are tiny in comparison to the main charge. However, I was thinking that since apparently NERA is a major component in a lot composite armors, then the precursor could pacify an entire NERA plate or two for the main charge, which I imagine would be fairly significant. It all depends on the exact layout and design of the armor. Although given how long tandem warheads have been around, I would be surprised if modern armors didn't take them into account.

 

Also, there are modern shaped charge designs such as the K-charge that are designed to produce minimal slug, and are used as the precursor in a lot of modern western ATGMs for that reason.

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3 minutes ago, DD000 said:

 

If that were the case, then I don't expect the precursor to do much at all, since most precursors are tiny in comparison to the main charge. However, I was thinking that since apparently NERA is a major component in a lot composite armors, then the precursor could pacify an entire NERA plate or two for the main charge, which I imagine would be fairly significant. It all depends on the exact layout and design of the armor. Although given how long tandem warheads have been around, I would be surprised if modern armors didn't take them into account.

 

Also, there are modern shaped charge designs such as the K-charge that are designed to produce minimal slug, and are used as the precursor in a lot of modern western ATGMs for that reason.

Eh, a 40mm precursor still has a fair amount of penetration. I'm not at my PC so I can't check my papers, but I think it's around 100-150mm depending on type.

 

It could do that yes, but I think a jet from a 40mm shaped charge will be beat up pretty easily by a NERA layer (with the exception of the jet precursor).

 

I don't think I've seen a K-charge precursor actually. (Or I haven't looked hard enough)

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23 minutes ago, Bronezhilet said:

Eh, a 40mm precursor still has a fair amount of penetration. I'm not at my PC so I can't check my papers, but I think it's around 100-150mm depending on type.

 

It could do that yes, but I think a jet from a 40mm shaped charge will be beat up pretty easily by a NERA layer (with the exception of the jet precursor).

 

I don't think I've seen a K-charge precursor actually. (Or I haven't looked hard enough)

 

I tried looking through my papers for where I first saw it referenced, but all I could find were references to how a K-charge was used as the main charge in the Hellfire. It's possible that I was misremembering things, but considering that the reduced slug for precursors was one of the original selling points for the K-charge, it would be strange if it wasn't used for that purpose.

 

A jet from a 40mm shaped charge would get pretty messed up from any typical NERA layer, but the overall influence of it would depend on how many NERA layers there are. If there were multiple NERA layers, then the precursor wouldn't do much. If there was only a single thick NERA layer, then the influence of the precursor would be much greater.

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8 hours ago, David Moyes said:

http://viewer.zmags.com/publication/a42b8bf8#/a42b8bf8/34

Article on the Queen's Royal Hussars participation at Tank Challenge.
Claims they placed 4th. Which was also posted on their Facebook page shortly after the competition finished.
Won 
CASEVAC serial. Podium'd others including defensive live firing, pistol shoot and obstacle course.
Struggled in others because of weight and agility.


Has a tank comparison page. Usual "rifled gun more accurate", "3-piece quicker", "moar armour" but then says the CR2's fire control computer was better at hitting moving targets than the Leopard 2's. wat?
 

More British propaganda about the Challenger 2 having better armor than the Leopard 2A6 or M1A2 SEP. Nationalistic/biased publications do not help much. I wonder what they were thinking writing this stuff.

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Regarding the SETC 2018 events, this article goes into quite a bit of detail.

 

It also says the UK came in fourth.

 

Quote

As part of the competition the participating teams had to score at twelve different stands and perform the Shoot-Out:


    Stand 1: Offensive Operation; platoon size attack live fire tank shoot – maximum of 500 points possible.
    Stand 2: Defensive Operation; platoon size live fire tank shoot – maximum of 500 points possible.
    Stand 3: Tank Recovery under Chemical, Biological, Radiological and Nuclear (CBRN) conditions; crews had to recover a damaged tank under NBC conditions, wearing personal protection equipment – maximum of 100 points possible.
    Stand 4: Medical Evacuation (MEDEVAC) and Battle Damage Assessment and Repair (BDAR); crews had to provide first aid to a wounded soldier and repair damage to the running gear, which meant they had to split the vehicle track and assemble it again – maximum of 100 points possible.
    Stand 5: Precision Driving; the MBTs had to be driven around a pre-marked course and navigated around obstacles – maximum of 100 points possible.
    Stand 6: Call of Fire; the teams had to call for indirect fire support and direct it – maximum of 100 points possible.
    Stand 7: Vehicle Identification; the crews had to identify vehicles of NATO and non-NATO nations – maximum of 100 points possible.
    Stand 8: Range Determination; crews had to estimate the distance to targets without using a laser range finder – maximum of 100 points possible.
    Stand 9: Pistol Shooting; maximum of 100 points possible with points given for accuracy and time.
    Stand 10: Reporting; crews had to identify and report targets in an urban environment – maximum of 100 points possible.
    Stand 11: Obstacle Course; maximum of 100 points possible.
    Stand 12: Tankers Olympics; special physical fitness and skill test during which the crews had to transport tank-related items such as road wheels, towing cables and ammunition from one point to another – maximum of 100 points possible.
    Shoot Out ; Evaluation of the effectiveness of the tank platoon to neutralise given targets within a limited presentation time – maximum of 400 points possible.

 

 

Quote

Depending on the type of stand points were given, for example, for the number of hits scored, the amount of ammunition saved, the time in which the given mission was achieved and so on.


At the Offensive Operation stand the teams could, for example score a total of 500 points. For every vehicle target hit with the MBT’s main gun 10 points were given (240 total possible), every group of dismounted infantry hit by machine gun fire scored 5 points (60 total possible), for every tank gun round returned another 5 points could be scored (80 total possible), while a total of 120 additional points could be scored for tactics.

 

 

Quote

In total the battle run was scheduled to take 180 minutes, including the after action review and presentation of scores. During this period the teams were to engage ten MBT vehicle targets (1.9m x 1.8m) showing in open terrain , eight MBT targets (1.9m x 1m) depicting emplaced vehicles, six armoured infantry fighting vehicle targets (1.25m x 1.35m) and twelve groups of dismounted troops, with targets only being presented for 15 seconds. To execute the shoot the teams were issued a total of 40 main gun rounds and 600 rounds for the coaxial machine guns.

 

Quote

Final Results: The winner of the Strong Europe Tank Challenge 2018 was Germany. Second place went to the team from Sweden and the Austrian team became third, with fourth place going to the team from the United Kingdom.

 

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Last year there was a similar discrepancy between various Polish, French and Ukranian reports on the SETC, each claiming one of the other two teams placed last, but definetly not their own team. Only the first three spots are officially revealed, the placement of the other teams is not announced and there is a "gentlemen's agreement" to not disclose any ranking. The reported score difference between the UK (at place 6) and France (at place 4) was just 46 points, a relatively small lead that would be somewhat possible to catch up - maybe these scores were not the final result? Or did the British author(s) consider this negible? Were the leaked scores the final results or the results during the competiiton (although according to an Austrian article, the Swedes were in lead until the last day of the competition)? Did one of the British sources copy the other?

 

 

The tasks in this year's edition of the SETC are identical to last years, but the grading (amount of points) has been altered.

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14 hours ago, Laviduce said:

More British propaganda about the Challenger 2 having better armor than the Leopard 2A6 or M1A2 SEP. Nationalistic/biased publications do not help much. I wonder what they were thinking writing this stuff.


To be fair it was written by a soldier, who was probably just parroting what he's been told.

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I was going to comment on this yesterday, but I wanted to confirm something first.

 

You can't really find the total RHAe penetration of two charges by just simply adding the precursor penetration to the main charge penetration. The crater produced by the precursor is small in diameter, so when the jet from the main charge arrives some of its energy is expended widening the crater due to the interactions between the jet particles and the walls of precursor crater.

 

But even if the target material were sufficient low strength/low density that the precursor could create a crater wide enough that the entire main jet could reach the bottom without interacting the walls, there would still be issues. You'd run into a situation where the inner crater produced by the main jet is wider than the crater produced by the precursor closer to the surface. This crater profile redirects the penetration ejecta towards the path of the proceeding jet, disrupting it. Also, when material is inhibited from leaving the crater, penetration is degraded.

 

When trying to optimize penetration with multiple charges/penetrators of different sizes, it's much more efficient to go from big to small than small to big. But this is a silly ordering when trying to defeat stuff like ERA.

 

 

In the paper "Behavior of Segmented Rods During Penetration" by G. E. Hauver, there were experiments with segmented tungsten rods. They found that the tungsten segments were leaving too much residue at the bottom of the craters, that the subsequent segments had to penetrate, so they tried using gold segments. Gold being much weaker than the tungsten segments they used, and would thus erode more completely and leave less residue. But what they found was that the subsequent gold segments were getting destroyed by the redirected ejecta from the previous segments (due to the "scalloped" profile of the penetration craters).

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23 minutes ago, DD000 said:

I was going to comment on this yesterday, but I wanted to confirm something first.

 

You can't really find the total RHAe penetration of two charges by just simply adding the precursor penetration to the main charge penetration. The crater produced by the precursor is small in diameter, so when the jet from the main charge arrives some of its energy is expended widening the crater due to the interactions between the jet particles and the walls of precursor crater.

 

But even if the target material were sufficient low strength/low density that the precursor could create a crater wide enough that the entire main jet could reach the bottom without interacting the walls, there would still be issues. You'd run into a situation where the inner crater produced by the main jet is wider than the crater produced by the precursor closer to the surface. This crater profile redirects the penetration ejecta towards the path of the proceeding jet, disrupting it. Also, when material is inhibited from leaving the crater, penetration is degraded.

 

When trying to optimize penetration with multiple charges/penetrators of different sizes, it's much more efficient to go from big to small than small to big. But this is a silly ordering when trying to defeat stuff like ERA.

 

 

In the paper "Behavior of Segmented Rods During Penetration" by G. E. Hauver, there were experiments with segmented tungsten rods. They found that the tungsten segments were leaving too much residue at the bottom of the craters, that the subsequent segments had to penetrate, so they tried using gold segments. Gold being much weaker than the tungsten segments they used, and would thus erode more completely and leave less residue. But what they found was that the subsequent gold segments were getting destroyed by the redirected ejecta from the previous segments (due to the "scalloped" profile of the penetration craters).

I'll get back to this when I have access to my PC (and papers) again, so... poke me in 2 weeks time or so. :)

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While we're on the topic of tandem charges, what's up with the 3BK-31?

 

Image result for 3BK-31

 

Why is there an auxiliary cone behind the main cone? I know the main cone has a hole in the bottom of it (does this affect penetration?), but why not place the auxiliary where the main cone is and move the main cone back? It's just strange to me. 

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3 hours ago, Lord_James said:

While we're on the topic of tandem charges, what's up with the 3BK-31?

 

Image result for 3BK-31

 

Why is there an auxiliary cone behind the main cone? I know the main cone has a hole in the bottom of it (does this affect penetration?), but why not place the auxiliary where the main cone is and move the main cone back? It's just strange to me. 

 

3 hours ago, LoooSeR said:

Maybe to increase after-armor effect? @Bronezhilet may know something better on that subject.

 

Couple of options here:

  1. It's a third charge for extra penetration
  2. It's a reactive liner charge
  3. It's something else

1. Third charge for extra penetration

Could be simple an extra charge crammed in the shell go get a little bit of extra penetration of the whole package. All other Soviet/Russian HEAT shells have quite a bit of empty room behind the main charge, they could have just simply thrown in an extra charge. It's a low angle (or high, depending on how you look at it) shaped charge to fit through the hole the main charge made. Point against this option is that it has to penetrate (part of) the slug the main charge left behind, so the added penetration is anyone's guess.

 

2. Reactive liner charge

It could also be a reactive liner shaped charge for extra after-armour effect (and a little bit of extra fuck you in case of an incomplete penetration). Main charge penetrates armour, reactive liner flies through, goes boom inside a vehicle. It's basically like a Bunkerfaust, but instead of a fragmentation warhead you have a reactive liner exploding inside whatever you shoot at. A fragmentation warhead doesn't work because the hole an anti-tank HEAT jet leaves isn't big enough for a proper warhead. But it is big enough for a HEAT yet. It's a low angle shaped charge so that the jet can fly through the hole the main jet made without having to penetrate anything so it'll end up behind the armour in time. 

 

3. It's something else

It's also possible that it acts as a super high velocity precursor designed to smash through all (N)ERA sandwiches before they can react properly. It's basically an un-interceptable due to its speed. But it still has to penetrate all the (N)ERA layers and I don't know how long the jet from this charge is. The reason it's behind the main charge is weight distribution. While shape stabilisation is quite nifty, you still have to pay attention to a whole bunch of things. Oh, and the main jet still has to actually form properly, which needs a certain amount of area (and doesn't need a charge in front of it fucking it up). Point for this setup is that it looks like the main fuse is behind the auxiliary charge, with a booster going to the main charge. Keywords here being "looks like". It's also a low angled charge so that the jet will pass through the hole in the main charge before the main jet forms. 

Huge point against this: ...they could just make the whole main charge at a lower angle.

 

 

It's also interesting to note that the auxiliary charge has a constant explosive layer thickness. I don't have my papers handy so I can't check, but it should result in a more even jet velocity (Gurney equations and all that).

 

More things to note about the shell in general:

  • Russians still don't know how to shape stabilise
  • It has a telescoping nose, probably so it fits in the autoloader. I wonder how/when they'll extend the nose
  • Shorter fins
  • More boattail-y than previous shells
  • What's the bit in front of the main charge? What's in there?
  • Looks like the precursor has 2 types of explosive. No idea why. 

 

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12 hours ago, Bronezhilet said:

Couple of options here:

  1. It's a third charge for extra penetration

1. Third charge for extra penetration

Could be simple an extra charge crammed in the shell go get a little bit of extra penetration of the whole package. All other Soviet/Russian HEAT shells have quite a bit of empty room behind the main charge, they could have just simply thrown in an extra charge. It's a low angle (or high, depending on how you look at it) shaped charge to fit through the hole the main charge made. Point against this option is that it has to penetrate (part of) the slug the main charge left behind, so the added penetration is anyone's guess.

 

I can explain a lot here ;-)

3BM31 and 3BK31M was attempd to incarase penetration in HEAT round without changing working method of cumulative warhed. Now in west we have SC whit 10-12 and even mor CD penetration. In the end of the 80's it was impossible so choosen operation method was diffrend.

Precursor in BK31M is just normal  precursor - nothing to do here exept that in some sources this precursor have abilitiest to work like in HOT3/PARS so beeing lunched in to target before main round part had optimum stand-off distance. In  other - just slinding to have bigger distance.

Main charge - here is funny - axuilary cone (second charge) was to just incarase armour penetration. This SC was ignit first and milisecond after ignit was first (main) SC - two jets where joined together and become one long "super jet". Wery sophisticated idea but dead end.

Just googled pdf:

23 RD INTERNATIONAL SYMPOSIUM ON BALLISTICS
TARRAGONA, SPAIN 16-20 APRIL 2007
STUDY ON TANDEM SHAPED CHARGES TECHNIQUE
Huang zhengxiang 1 , Zhang xianfeng

 

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According to this link:

 

Quote

3BK31? is designed to defeat vehicles with external ERA, integral ERA and/or composite armor main structure; the precursor charge trips the external ERA, the first main charge trips the integral ERA/"conditions" the composite and the last achieves destructive penetration. The sequence of charges detonation is precursor -> rear charge -> middle charge.

 

I think it's worth comparing these super-HEAT rounds for the 125mm with the RPG-29.  Both achieve something like 750-800mm penetration in RHA, but the RPG-29 is 105mm vs 125mm, and the RPG-29 has two charges rather than three.

 

So, for all its technical sophistication, 3BK31 isn't poking much better than a considerably smaller rocket-propelled projectile.  But then, a gun-launched HEAT projectile has a lot of issues that a rocket-propelled one doesn't have to deal with, like much greater axial acceleration and fitting inside an autoloader.  So this design is probably not the most efficient, in terms of armor penetrated relative to explosive used.  But perhaps it's a very good design in terms of armor penetrated relative to fitting inside a very restrictive envelope.

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3 hours ago, Collimatrix said:

According to this link:

 

 

I think it's worth comparing these super-HEAT rounds for the 125mm with the RPG-29.  Both achieve something like 750-800mm penetration in RHA, but the RPG-29 is 105mm vs 125mm, and the RPG-29 has two charges rather than three.

 

So, for all its technical sophistication, 3BK31 isn't poking much better than a considerably smaller rocket-propelled projectile.  But then, a gun-launched HEAT projectile has a lot of issues that a rocket-propelled one doesn't have to deal with, like much greater axial acceleration and fitting inside an autoloader.  So this design is probably not the most efficient, in terms of armor penetrated relative to explosive used.  But perhaps it's a very good design in terms of armor penetrated relative to fitting inside a very restrictive envelope.

It's not better at poking a hole in solid steel, but it should be way better at poking a hole in a NERA package.

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      Now, we head back to that chart:


       
      On the left side of the graph, we put our cursor on the line that corresponds to approximately 3,150 ft/s velocity, and follow it over until it hits the curved line that corresponds with the angle of plate we care about - arbitrarily, let's pick 20 degrees. Then, we follow that point straight down until it hits the x-axis:


       
      Therefore, we estimate that at 2,000 yards, my 85mm has just over 10 inches of RHA penetration - not bad at all for a lowly APCR round!
    • By Walter_Sobchak
      Since we don't have a thread for British and Commonwealth tanks of WWII, I thought I would start one.  
       
      Check out this manufacturers instructional video on the Crusader.
       
       
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