T-90.t94

[scout 0]

on the metalurgy stuff im positive. western metalurgy was supirior to the soviet. it was apparent in many areas other then this. thats why western tanks were kinda late to adopt ERA

and again, all u need is one small top-attack missile!

[Guest]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (scout @ April 03 2002,20:18)</td></tr><tr><td id="QUOTE">on the metalurgy stuff im positive. western metalurgy was supirior to the soviet.<span id='postcolor'>

I don't know much about the armour of tanks. I can however tell you about Soviet subs vs. western subs. While US Submarines are still built of steel, the Russkies used all forms of metals and alloys in theirs starting from circa 1960. Their Alfa submarines are built *entirely* of titanium. The reason why western submarines are still steel is because the western designers have so far failed to find any good metal/alloy that can handle the stress.

The two things that the Russians have traditionally been better at is materials and lasers. The Japanese are catching up nowdays on the laser part. If you don't believe me, check the number of Physics Nobel prizes that scientists from USA and from Soviet have won in the two fields.

[DodgeME 0]

Does the new Russian ERA explode(tank looses it's protection) after only 1 sabot hit or does it hold more?

[Guest]

AFIK it should be able to handle several. That's what I've been told anyway. I don't know how reliable that is because it's nothing the Russians go around telling everybody.

There are rumors of Kontakt-6 now, but I know nothing about it.

[scout 0]

on the sub issue i can tell u that a titanium body is too expensive while the revenue.

the US, smartly, decided to invest in silencing the subs. a thing that proved to be worth.

the "Alfa"s and "Akula"s are fast, and can dive better but are noisy. and in the sub game, thats the key.

again, metalurgy was a weak spot in the soviet developers.

mind this: they developed ERA only after it was apparent (from Arab-Israeli wars) that the armour on the tanks is too weak. again the west put more into passive armour development and the soviets into ERA.

i know israel played a bit with the ERA but conculded thats no worth the pain. something more: ERA tend to damage the optics and electronics (thats why israel is stripping the MAGAH from its ERA in favor of better passive armour)

[Satchel 0]

Explosive Reactive Armor protection is measured as the main armor upon it´s RHA rating.

RHA stands for Rolled Homogeneous Armor, in this case an equivalent RHA thickness of a given armor package against a given type of threats in terms of penetration resistance.

Kontakt-5 ERA has an RHA protection rating of 250 mm vs. APFSDS, and 600 mm vs HEAT. Add this up to the T-90´s 740 mm RHA on the front turret vs. APFSDS, and you theoretically have 990 mm RHA protection vs long rod penetrators on the front turret.

But since the Kontakt-5 ERA has thicker steel plates housing the explosives and is heavily angled, a long rod penetrator will loose about 30 % of it´s penetration power after hitting a Kontakt-5 module, making it virtually incapable of penetrating the vehicles armor.

In addition, thanks to their heavier front plate, the Kontakt-5 elements are harder to trigger by the precursor charges of tandem warheads, forcing the producers of tandem ATGMs to allocate more mass to precursor charge and, making an MBT more resistant to tandem HEAT warheads, as well.

While light ERA containers are completely destroyed in the process of detonation, Kontakt-5 sections are not, as their detonation is contained by the outside armor plates. Therefore even after detonation Kontakt-5 sections continue to provide some applique protection.

[Satchel 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">

We've done a lot of work to analyze how effective Kontakt-5 is and by what methods it defeats the incoming APFSDS rounds. The results of the analysis are quite impressive in their own rough and limited way. We assumed that the Kontakt-5 brick was 10.5 cm wide by 23.0 cm long by 7.0 cm thick, with a mass of 10.35 kg. We arrived at a total mass of 2.8 t for the array. We later found out from Steven Zagola's literature that the array is supposed to be around three tonnes, so we were pretty happy. Assuming the use of Semtex for the interlayer, I found that the configuration was most likely a 15 mm plate up front, backed by 35 mm of explosive, and then a 20 mm plate. This assymetrical configuration had improved effectiveness because the APFSDS rod could still 'catch' the retreating rear plate while the front plate would retain a charateristic high velocity. This is completely opposite to the model that the US Army used in the late 1980s to discribe 'heavy' ERA. In their model, the front plate was on the order of 60 mm thick and the rear a standard 5 mm plate. They thought that the thick plate simply moved up into the path of the incoming long rod and forced it to make a 'slot' (thickness x height) rather than a hole (thickness). This is bogus; the front plate would tamp the explosive and would be barely set in motion.

Anyway, back to the point. Without getting into the actual math, after a couple of analyses, we arrived at our conclusion as to what defeat mechanisms were being imployed. These conclusions have not yet been conclusively proved and we hope to do that soon. We assumed that the massive areal density of the long rod perforated the thin plates with relative ease. Actual ablatic penetrator mass loss was set at about 2%. What we found was that we had these two plates, each individually with about 60% the momentum of the long rod penetrator, were moving oppositely up/down to each other, and that the path of the penetrator was such that it was moving between them. The forces exerted on the penetrator are apparently very large, so large in fact that they were in the region of plastic failure for most (read: all) metals. Essentially, when the penetrator touches the rear plate, the front plate guillotines off the first 5 - 6 cm of the rod. For a round such as the 120 mm M829A1 this represents a loss of about 8% of the total mass. More importantly, the nose is blunted. You would not believe how important that sharp point on the penetrator is. The difference in penetration between an equivalent hyper-sonic spike tipped penetrator and a blunt nose one is at least 20% (to a maximum of around 30%). This is mainly because a blunt nose is very inefficient in the initial phase of penetration before the ablatic shear phase can begin. The penetrator has to actually sharpen itself to the optimum Von Karam plastic wave theory shape for penetration of the target material before it can begin radially displacing the target material. This resolves itself in the form of a lot of wasted work and thus penetrator mass. The blunted penetrator also suffers structural damage and more mass loss as a shock wave travels down its length and blows spall off the tail. The main secondary effect of Kontakt-5 EDZ against APFSDS rounds is yaw induced by the front plate before contact with the rear plate is established. The total is about two to three degrees of yaw, which suddenly becomes a lot more in a denser material such as steel. Reduction in penetration due to a 2° yaw is about 6% and it grows exponentially worse from there, and on the 67° slope of the front glacis of the T-64/72/80/90, this is increased to about 15%.

Total loss in penetration amounts to about 2% + 8% + 22% + 6% = 38%, or in other words the penetrator is now only capable of penetrating 62% its original potential. Conversely we could say that the base armour is increased by the factor of the reciprocal of 62%, which is - surprise! - 161%.

<span id='postcolor'>

As you can take from the article, the applying of Kontakt-5 has little to do with cost effectiveness, or unability to build armor with very high RHA ratings, but rather is a very effective design in terms of protection, and that´s all what counts.

Russian MBT´s are all build for low silhouette and high mobility, the application of extremely heavy armor, like used on our western tanks conflicts with these design guidelines and principles.

[scout 0]

and u forgot to mention that the farther the sabot travels the less penetraing power it has.

and again: thats all and well. but the real threat are missiles that are top-attackers.

[Guest]

0--></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (scout @ April 03 2002,210)</td></tr><tr><td id="QUOTE">on the sub issue i can tell u that a titanium body is too expensive while the revenue.

the US, smartly, decided to invest in silencing the subs. a thing that proved to be worth.

the "Alfa"s and "Akula"s are fast, and can dive better but are noisy. and in the sub game, thats the key.

again, metalurgy was a weak spot in the soviet developers.<span id='postcolor'>

The subs weren't silent because they put a bloody noisy two-loop BM-40 reactor. That has nothing to do with the titanium alloy it was built from.

As for the the ERA - The ERA that the US currently uses is an Israelly design which they in turn stole from the Soviets (Kontakt EDZ if I am not misstaken).

And again. Count the Nobel prizes that Russian scientists have collected in the area of solid state physics. They were and still are superior to the west in metalurgy. This was reflected in everything from ICBM physics package design (the warhead) to ships, subs and tanks.

[Satchel 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (scout @ April 03 2002,22:29)</td></tr><tr><td id="QUOTE">and u forgot to mention that the farther the sabot travels the less penetraing power it has.

and again: thats all and well. but the real threat are missiles that are top-attackers.<span id='postcolor'>

and i havn´t forgot to mention that the T-90´s top is protected by Kontakt-5...just go back a few pages in this thread.

[scout 0]

im not saying that the titanium body had anything to do with it.im sayin that the titanium body wasnt a big deal.

consider this: its known that the blades of the propelors are the weakest parts. and that the soviets never managed to get over the problem: the rate of propelor change in the soviet navy was always higher than in the US navy for that reason. there is the metalurgy aspect and the physics aspect.

idont say the soviets are bunch of monkeys, i just say that they had many weaknesses in this area. btwa large part was because of inferior computers.

[Guest]

The sound of the Soviet subs wasn't the effect of bad qual blades it was the result of cheap bad reactors. You can trust me on this - intelligence analysis of Soviet subs was my primary task when I did my military service and I know more about them then any other military hardware. Russian subs are considered one of the greatest military threats to Swedish national security, so we know a bit about them. After my basic training I spent 10 months learning about those damned things.

And yes, you are right about the computers. That was however not related to the noise of the submarine but to the quality of both passive and active sonar. The Americans and French have the very best ones. The Russian ones are pretty crappy and having a bad sonar also leads to bad torpedoes as well as a sub that can't hear anything.

[WKK Gimbal 0]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Satchel @ April 03 2002,13:54)</td></tr><tr><td id="QUOTE">You can only compare based upon technical data, well unless you´ve operated both vehicles yourself...what hardly will be the case.

Of course every forum member thinks his country has the best equipment and best trained personal, that´s normal and the usual exaggeration normally rises parallel to a posters national fanatism, but in the end it says very little.<span id='postcolor'>

Boy, I wish I could have said that half as good myself. It's true enough to be carved in stone!

[RedRogue 0]

I would think from my research, that the United States Navy decided to continue use of steel alloy hulls for a multitude of reasons. Nuclear subs are expensive as it is, forgot the cost but the Seawolf class was so expensive that only after a few where produced the Navy began developing a newer type to be more cost effective. Adding a Titanium alloy hull (As titanium is rarely used in pure form as its more brittle then steel) would have shot costs thru the already elevated roof.

1. Titanium is expensive to refine and make alloys when compared to steel.

2. Titanium is extremely hard to weld, infact it takes an electron beam welder to be able to weld it completely thru, which also requires extemely precision cut pieces.

3. Titanium allows a hull to be made of similar strength to steel but at a lower weight (mass). One of the things you can do to design quieter subs is increase the mass. Greater mass allows sounds such as pumps and machinery for nuclear reactors to be damped more before being passed to the ocean.

The quietest subs out there are still Disel/electric subs, the Kilo class being a well regarded one if I remember.  These subs run off batteries while submerged and have no pumps and noisy machinery running to propel the boat. However even with modern technology their maximum submergence is 2 weeks and they are considerably slower underwater than their nuclear bretheren.

[Tex -USMC- 0]

ERA is good against HEAT rounds, and has in fact made em almost useless on todays battlefield, but Army Ordinance is coming up with a new Sabot round that can defeat ERA with a "kinetic-energy precursor" as well as increased velocity through an advanced propellant load. Its called the M829E3. Good stuff.

[Oligo 1]

I think the main problem with Iraqis failing to kill any M1s had mostly to do with their sucky ordinance. There are several examples mentioned in Gen. Franks's book Into the Storm, where the Iraqis managed to outmaneuver the yanks and hammer the rear armor of M1s with fire.

So it's not that the Iraqis didn't hit the M1s, it's the problem of getting no penetration. You can boast that the armor of M1 is just so fabulous, which I am not going to deny, but you have to remember the Iraqis used STEEL ROD SABOTs. Now I don't even want to go to describing how screwed ordinance that is, because everubody here probably realizes that the penetration power of this ammo is puny.

Reast assured, if the Iraqis had DU rounds, there would have been a bunch M1 casualties. The outcome of the war would probably have been the same, though.

[Guest]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (RedRogue @ April 04 2002,06:43)</td></tr><tr><td id="QUOTE">Adding a Titanium alloy hull (As titanium is rarely used in pure form as its more brittle then steel) would have shot costs thru the already elevated roof.<span id='postcolor'>

Yes, the Russians used a Alpha/Beta Titanium alloy - actually to be more precise Titanium Ti-4.5Al-5Mo-1.5Cr (Corona 5), basically 90% Titanium 5% Aluminium and 5% rest.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">

1. Titanium is expensive to refine and make alloys when compared to steel.

<span id='postcolor'>

Yes, Titanium is bloody expensive.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">

2. Titanium is extremely hard to weld, infact it takes an electron beam welder to be able to weld it completely thru, which also requires extemely precision cut pieces.

<span id='postcolor'>

Not really. As far as I know the GTAW (gas tungsten arc welding) is the most common and the one that the Russians used.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">3. Titanium allows a hull to be made of similar strength to steel but at a lower weight (mass). One of the things you can do to design quieter subs is increase the mass. Greater mass allows sounds such as pumps and machinery for nuclear reactors to be damped more before being passed to the ocean.

<span id='postcolor'>

Titanium is much stronger then steel. It also doesn't corrode and is easier to maintain. Titanium is also an excellent thermal and acustic insulator - about twice as good as steel.

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">The quietest subs out there are still Disel/electric subs, the Kilo class being a well regarded one if I remember. These subs run off batteries while submerged and have no pumps and noisy machinery running to propel the boat. However even with modern technology their maximum submergence is 2 weeks and they are considerably slower underwater than their nuclear bretheren.

<span id='postcolor'>

The quietest sub are the Ohio class subs which are nuclear boomers. They are basically the definition of what silent is.

Diesel subs are not very good actually. Yes, when they use the batteries they are very silent, but for instance the Kilo class can only run on cells for about 10 hours. Otherwise it uses a noisy diesel generator. The fact that diesel subs must vent the exhaust gases from the engine now and then makes them vulnerable for satellite detection.

[DodgeME 0]

Nice info here

Also one question.

Why aren't there tanks without a cannon but using missiles for destorying tanks? I know that MTB have one of those missiles but how about a tank that is currying many like 10-20 of em. It would be a pain

[Guest]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Why aren't there tanks without a cannon but using missiles for destorying tanks? I know that MTB have one of those missiles but how about a tank that is currying many like 10-20 of em. It would be a pain <span id='postcolor'>

The T-90 gun can actually also fire the 9M119 Refleks (NATO designation AT-11 Sniper) anti-tank guided missile system. The range of the missile is 100 - 4,000 m. The system is intended to engage tanks fitted with ERA as well as low-flying air targets such as helicopters, at a range of up to 5 km. The missile system fires either the 9M119 or 9M119M missiles which have semi-automatic laser beamriding guidance and a hollow charge warhead. The guns automatic loader will feed both ordnance and missiles.

The constituent parts of the 9M119M Laser-guided Missile of the Refleks Guided Weapon System:

[DodgeME 0]

Nice how many of those a T-80,T-90 carry?

[scout 0]

here's couple of reasons, why missiles arent popular in tanks:

1. u need to stay exposed until the missile hits in case of wire and laser guided missiles. and staying exposed is a BIG no-no for tankers

2. there are too few of them. in a space of 20 missiles u can have 60 warshots.

3. they are too sensitive. when a tank gets hit, even if there is no real damage the optics and electronics usually melfunction. u dont want to have a melfunction in a missile.

4. if your laser or guidence system is damaged ur meat.

5. tanker prefer usually to have as many warshots as can be possible. (i do understand them on this point.)

6.the least interference and the missile is off.

7. u can shoot up to 5 shots in the time of flight of one missile. in this case ur meat too

8. if we're talkin a fire'n'forget missile u can skip 1 and 7.

thats all for now.

[DodgeME 0]

How about using fire and forget missiles in a small and very fast tank. With a huge radar and shit. It would be a real pain.

I name like MTBCPA. Main Battle Tank's Certified Pain in the ASS

[Guest]

Actually the Refleks (used by the t90) missile system has support for GLONASS targeting.. which is the Russian version of GPS (supposedly more accurate). So the missiles can be fire-and-foget.