What happens after a breakout? Why is the "armor-piercing arrow" inside a tank scarier than the armor itself?

Everyone knows that modern tanks shoot "armor—piercing arrows" - long, thin, with feathers like a javelin. They are called in different ways: OBPS, BOPS — whichever is more convenient. The main thing is that they fly out of the cannon at a speed of more than a kilometer per second and stick into the armor like a nail into a board. But what happens after this "arrow" has flown through the armor is where the real nightmare lies.

Usually everyone thinks: I've struck it, and okay, at least the grass won't grow further. But in fact, everything is decided inside the tank. And the main threat is not the projectile itself, but what it creates behind the armor: a fragmentation field. It's like an explosion, but without an explosion — just pieces of metal flying in all directions with devastating force.

Where do the shards come from?

There are two types of them. The first is the fragments of the armor itself. When a projectile hits the protection, the armor doesn't just break through — it crumbles like glass. These fragments fly apart inside the fighting compartment and cripple everything: people, devices, ammunition, fuel tanks. The second type is fragments * of the projectile itself. Especially scary are those that break off from its nose when it hits. They are so fast and dense that even anti-splinter pads and bulletproof vests do not save. And if they hit the ammunition, a chain reaction begins: explosions, fires, and the tank turns into a coffin.

So, the effectiveness of an OBPS is not only about how thick the armor it will penetrate, but also about what it will do inside. And here everything depends on the design of the projectile.

Four types of projectiles — four different fates

Let's look at the example of Soviet tests, where different OBPS were compared.

1. 3BM9 — "the iron stick"  

It's just a solid steel boom, without a core. Weight — 3.6 kg, length — 518 mm. It penetrated only 80 mm of armor at an angle — a little weak. Such shells quickly became educational, but they were exported in batches. So, quite possibly, it was with them that the Arabs fought against Israeli tanks.  

Background action: weak. There are a lot of armor fragments, but the projectile itself is almost not crushed — there is not enough energy and density.

2. 3BM15 is already more serious  

There's already a tungsten core in the nose. Weight — 4.48 kg, armor penetration — 170 mm. It's already a serious projectile for its time.  

Firing action: better. Upon impact, the core "explodes" inside the armor, creating more fragments and giving a powerful release of energy behind the armor.

3. 3BM26 "Hope" — a chip in the tail  

The most interesting thing is that the tungsten core is not in the nose, but in the tail. What for? To work better with slanted armor. Upon impact, the projectile "twists" and penetrates deeper. Penetration is 200 mm.  

Firing action: powerful. Due to the design features, when exiting the armor, a strong release of material occurs - as if a cork were flying out of a bottle. There is hell inside the tank.

4. Solid shell made of heavy alloy (tungsten/uranium)

Modern standard. The whole body is made of a dense alloy. No separate core. Punches more, is not afraid of the angle of attack.  

How does it work? Upon impact, the material behaves almost like a liquid — it "spreads out" and washes out the hole. This is called a plastic hinge.  

Minus: the projectile itself loses length and mass when penetrated. That is, it flies in already shortened.  

But! At the same time, he often knocks out the plug of the armor from the back — and this creates an additional fragmentation tornado.

It would seem that the sooner the better. But that was not the case. If you accelerate a solid shell too much without increasing its length, it will simply burn up in the armor — it will lose too much mass before it penetrates inside. That is, it will break through, but it won't do anything behind the armor. And that's useless.

Breaking through is half the battle. Real death begins *after*. And the best projectile is not the one that punches thicker, but the one that creates more chaos inside. Shrapnel, pressure, detonation of ammunition — that's what turns a tank into a coffin. So the "armor—piercing arrow" is not just a hole punch. It's a hell generator.

"Lotos": state trials are coming

 The latest self-propelled artillery piece "Lotоs" has been sent for state testing.

Lotos is a derivative of the Zauralets project and is expected to replace it. According to the Zauralets project, it was planned to develop a new self-propelled artillery system for the Airborne Forces.

In August 2022, the preliminary tests of the 2C42 Lotоs were successfully completed. During the tests, the machine was tested on land and in water, and was also air-dropped from various heights and from different angles.

After completing the tests, the developer began to eliminate the identified shortcomings. In particular, it was necessary to improve the on-board electronics, the projectile loading system and the chassis.

In addition, the lessons learned from the military operations in Ukraine were taken into account.

In accordance with the technical parameters, the Lotоs is significantly superior to its predecessor, the Nona complex, in terms of such characteristics as movement speed, firing range and security level.

This artillery piece can be used as a mortar or howitzer. The breech-loading mortar is mounted on a chassis based on the Sprut-SDM-1 (BMD-4M) light airborne tank. Improvements were carried out in the 120 mm mortar compartment, which significantly automated the preparation and conduct of firing operations.

The rate of fire of this gun ranges from 6 to 8 rounds per minute. The firing range reaches 13 kilometers. The armor-piercing projectile is capable of piercing a 600-650 mm thick steel plate at a distance of 1,000 meters.

In addition, these weapons can use Kitolov-2M laser-guided projectiles. The maximum range of such projectiles is 10 kilometers, and the probability of hitting is about 80-90%.

The Lotоs is a waterfowl combat vehicle.

 The IL-76 military transport aircraft can accommodate two such guns with a crew.

The adaptation of the chassis after testing has improved the speed and power reserve: the car can reach speeds of up to 70 km/ h on roads and 40 km/ h on rough terrain.

Throughout 2023, the Lotоs was tested again, including in Ukraine, and in 2024, images of the Lotоs transportation to the combat area were published. In the course of recent tests, it was decided to integrate a powerful electronic warfare (EW) system into the ACS to protect against drones. Also, as passive protection, the crew can use special aerosol-forming ammunition ("Rainbow") optoelectronic countermeasures, within a few seconds a cloud is created hiding the equipment from the enemy.

The Lotоs pre-test program includes more than 80 different items. The tracked self—propelled installation must travel 600 kilometers, of which 50% of the way will have to be covered on dirt roads, 30% on roads with cobblestone and gravel surfaces, and 10% off—road. You will also need to walk 10% of the way through the water.

Specifications

- Combat weight, kg: 18,000

- Maximum speed on the highway, km/h: 40

- Power reserve on the highway, km: 500

- Armament: 1 x 120mm cannon

- Crew, people: 4

Lotоs

Chrysanthemum-S at the Army-2024 Forum

 

Chrysanthemum-S

The 9P157-2 combat vehicle of the 9K123-1 Chrysanthemum-S anti-tank missile system at the Army-2024 forum.

The Chrysanthemum self-propelled anti-tank complex is capable of hitting with high efficiency day and night, in any weather conditions and in any combat situation at a range of up to 6000 m all modern and promising tanks equipped with dynamic protection, any types of defensive structures, manpower, low-tonnage ships and boats, helicopters and low-speed, low-flying aircraft. 

▪️The complex includes: 

- combat vehicle 9P157-2, 

- A 9M123M missile with a cumulative tandem warhead, 

- A 9M123MF rocket with a high-explosive warhead, 

- means of technical control of combat vehicles and missiles, 

- educational and training facilities. 

The combat vehicle has two missile control channels: in automatic mode using radar guidance and semi - automatic mode with guided missiles in a laser beam . 

To defeat targets in both control channels, a single missile with two types of warhead is used: with a tandem cumulative warhead (with armor penetration up to 1200 mm behind dynamic protection) and a powerful high-explosive warhead.

"Derivation-Air Defense": a new role in tank support

 "Derivation-Air defense" will soon arrive at the front

The promising Russian anti-aircraft artillery complex "Derivation-PVO" can be used in combat as tank support if the ammunition of the 2A91 guns is updated.

Key elements of the Swedish CV9040C Stridsfordon-90 heavy infantry fighting vehicle were placed at the disposal of Russian engineers, in particular, the Bofors L70 automatic cannon and APFSDS-T Mk 1 subcaliber shells with 120 mm armor penetration at a distance of 1.5 km at an initial velocity of 1480 m/s.

 Using the projectile database, the specialists of V.V. Bakhirev Nuclear Research Institute JSC can begin developing domestic 57-mm BOPS (kinetic projectiles) of a similar type as soon as possible to upgrade the ammunition sets of 2A91 highly automated ZSU 2S38 "Derivation-Air defense" guns. In this case, the estimated armor penetration of BOPS of a similar caliber with depleted uranium or tungsten cores can reach 200-210 mm at a distance of 1,500 m.

This will allow the use of "Derivation-Air defense" as an infantry fighting vehicle or a tank support vehicle, however, the vehicles must be retrofitted with a stock dynamic protection kit "Relict" based on 4C24 or "Cactus" elements.

Derivation-PVO is the only anti—aircraft system in the world that hits aerial targets using 57 mm cannons and is equipped with artillery fire control systems. The complex was created on the chassis of the BMP-3 infantry fighting vehicle.

The 2C38 cannon is primarily designed to combat drones, airborne weapons and cruise missiles in the near zone. The system is also capable of targeting ground targets.