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Kontakt-1

Kontakt-1 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kontakt-1 rather than just read about it. In short: Kontakt-1 (Russian: Контакт-1; GRAU indice: 4S20) is an explosive reactive armour (ERA) created in 1982 by Soviet NII Stali to protect tanks from shaped charges. The first tank with Kontakt-1 put into service was T-64BV in 1985.

Kontakt-1 — main illustration
Kontakt-1 — illustration

Key takeaways

  • Kontakt-1 belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Kontakt-1 to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Kontakt-1 from memory before moving on to harder problems.

Reference excerpt

Kontakt-1 (Russian: Контакт-1; GRAU indice: 4S20) is an explosive reactive armour (ERA) created in 1982 by Soviet NII Stali to protect tanks from shaped charges. The first tank with Kontakt-1 put into service was T-64BV in 1985. The system is still widely used by different countries within T-55, T-62, T-64, T-72, T-80 tank families among others. Kontakt-1 was the first Soviet ERA system, and its successor is Kontakt-5, put into the service in 1988.

Description Kontakt-1 is a first-generation ERA, which means it is used as appliqué ‘bricks’. Its second-generation successors, such as Kontakt-5 and Relikt, have heavier built-in discharging plates. The ERA system consists of hundreds of standalone containers often referred to as "bricks." Each container includes two 252×130×10 mm ERA panels positioned at an angle relative to each other. A single panel is 5.4 mm thick with a 260g explosive (85% hexogen) liner, surrounded by a 2.3 mm thick steel sheet. The container weighs 5.3 kg, and the full complement's weight varies from 1.2 to 2 tons depending on the number of containers used The explosive liner is highly insensitive so that it doesn't explode from bullets or fragmentation. Even tank ammunition cook-off events do not detonate the ERA. This characteristic also prevents chain reactions for Kontakt-1, but it makes the system ineffective against kinetic energy penetrators. However, due to the fragility of the blocks, they can be easily destroyed by a hit: a HEAT round can destroy up to 85% of all the ERA from the tank's front. When a shaped charge's jet stream hits the explosive liner, it detonates, throwing the metal plates at the stream obliquely. As a result, the jet is deformed and defocused, losing its energy. Its efficiency is low at a straight angle and increases significantly as the angle changes, explaining why Soviet tanks have a prominent wedged ERA configurations on their turrets. Kontakt-1 is effective only against regular non-tandem shaped charges and has no effect on kinetic energy (KE) penetrators. According to the manufacturer, Kontakt-1 generally reduces penetration by 86% for Konkurs-type ATGMs, by 92% for rocket grenades, and by 52% for tank HEAT rounds.

Advantages

Can be easily attached to any vehicle by its crew; has much greater protection/mass ratio than regular armor; is safe as doesn't explode from mechanical damage, firearms, fragmentation and even ammo cook-off; immune to chain reaction.

Disadvantages Significant (up to 27%) of frontal projection is not covered by ERA, turret bottom is especially vulnerable; containers are very fragile and can by easily wiped out by any explosion; as with any ERA, it is disposable is useless against KE penetrators and has very little effect on tandem warheads; the explosive nature without isolation makes it totally unsuitable for light-armored vehicles. the nature of ERA means that dismounted troops face danger if they are too close to the vehicle

History A common misconception is that Kontakt-1 was inspired by the Israeli Blazer, which proved efficient during the 1982 Lebanon War. According to the story, the USSR received an Israeli Magach tank following the war and managed to design its own ERA soon afterwards. However, this account is not accurate. The USSR started researching ERA in the 1950s, and the first tests were conducted in the early 1960s. Interestingly, one of the employees involved in the process was named Bleyzer G.A. (Russian: Блейзер Г. А.), who later moved to Israel. His last name sounds similar to the Israeli Blazer ERA, but there is no evidence that this is anything more than a notable coincidence. NII Stali was working on an integrated KDZ-68 ERA since the 1960s. It was highly effective but was deemed too heavy to be mounted. At the time, the armor of T-64 and T-72 tanks was strong enough, and the priority was to reduce the weight of the tanks. Thus, for various reasons, including an unverified claim that contemporary Soviet Chief marshal of the armored troops Hamazasp Babadzhanian was totally against explosive armor, it was abandoned. In the late 1970s, Soviet armor was not strong enough against new Western guns and ammunition, so in 1982, a new ERA system was tested, and in 1985, the first Kontakt-1-equipped T-64BV was put into service. It is likely that the demonstration of Blazer effectiveness and the capture of the Israeli tank broke the prejudices of Soviet generals against carrying high explosives on the armor and opened the door for Kontakt-1 adoption.

Operators All the countries which possess T-55AMV (see T-54/55 operators), T-62MV (see T-62 operators), T-64BV (see T-64 operators), T-72AV, T-72B, T-72AMT, T-72EA, T-72UA1, T-72MS (see T-72 operators), T-80BV (see T-80 operators) and some other tanks, are the operators of Kontakt-1. Due to the modularity and installation simplicity, it's a common practice to put it on different vehicles in the field or factory conditions to increase protection. During the 2022 Russian invasion of Ukraine, both sides use Kontakt-1 to provide additional protection for different vehicles. Even some production vehicles equipped with more advanced Kontakt-5/Relikt ERA, such as T-72B3, receive additional Kontakt-1 at factories.

Ukraine In 2018 Ukrainian UAM company claimed to produce Kontakt-1 and Kontakt-5 elements named 4S20U and 4S22U respectively, with brand-new explosives. They also claimed that Kontakt-1 was actually being put into the service. Since May 2023 Ukraine has been receiving a Kontakt-1 variant produced by Czech STV Group. Polish and Czech T-72M1 and T-72M1R and Slovenian M-55S are equipped with Kontakt-1 in Ukraine.

Western vehicles During the delivery of Western tanks to Ukraine, Ukrainian armor experts speculated that Kontakt-1 could be a viable solution to complement weaker armor of some tanks such as the lightly armored Leopard 1. They also mentioned that such improvements should be coordinated with manufacturers and thoroughly tested. In July 2023 a Ukrainian Leopard 2A4CAN appeared with a Kontakt-1 set and some other ‘customizations’. In May 2024, photos of a Ukrainian M1 Abrams equipped with Kontakt-1 surfaced.

Gallery

See also Kontakt-5 Relikt Nizh

References

Illustrations

Kontakt-1: Kontakt-1 on the upper glacis and turret of a T-80BV
Kontakt-1 on the upper glacis and turret of a T-80BV
Kontakt-1: Highly insensitive Kontakt-1 can even survive after ammo cook-off
Highly insensitive Kontakt-1 can even survive after ammo cook-off
Kontakt-1 illustration
Kontakt-1 illustration
Kontakt-1 illustration

Worked examples

Example 1 — a first encounter with Kontakt-1

Start with the simplest possible case. Write down what Kontakt-1 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kontakt-1 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kontakt-1 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kontakt-1

In research
Kontakt-1 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Kontakt-1 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Kontakt-1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Armoured fighting vehicle equipment, Science and technology in the Soviet Union, Soviet inventions, so understanding it makes those chapters shorter.
In everyday life
Look for Kontakt-1 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Kontakt-1 in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Kontakt-1 means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Kontakt-1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kontakt-1 in simple terms?

Kontakt-1 (Russian: Контакт-1; GRAU indice: 4S20) is an explosive reactive armour (ERA) created in 1982 by Soviet NII Stali to protect tanks from shaped charges. The first tank with Kontakt-1 put into service was T-64BV in 1985.

Why does Kontakt-1 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kontakt-1?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kontakt-1.

Tags

  • Armoured fighting vehicle equipment
  • Science and technology in the Soviet Union
  • Soviet inventions
  • Vehicle armour
  • Weapons countermeasures

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