Why does a tank have two barrels?
Experimental "German" VT-2 in the forest
Tank vs. tank
The more guns you have tank, so much the better. For its time, this was logical. This is how the British five-turret Vickers A1E1 Independent tank was born. It never went into production, but it demonstrated the advantages of combat vehicles with more guns. The layout had advantages, and they seemed significant. The tank could engage several targets simultaneously, and multiple pairs of eyes watching all sides increased the crew's situational awareness. When the enemy has nothing more than a few machine gun emplacements, a multi-turret vehicle is truly effective.
The British, as the founders of tank design, were the first to propose a multi-turret tank – the Vickers A1E1 Independent.
The concept's apotheosis was the Soviet monster T-35, carrying eleven soldiers. The tank was intended to break through enemy defenses with infantry support. But initial combat experience showed that a heavy breakthrough tank would have to be completely different. Five turrets with artillery The guns made the T-35 slow, bulky, and poorly protected. The tank commander simply couldn't cope with his tasks in battle—his crew was too large.
If World War II hadn't devalued the multi-turret design, it's unknown what vehicles our tankers would have been using today. Incidentally, the Nazis, towards the very end of the war, also managed to experiment with two guns on a single tank, and in a single turret at that. This was the world-famous Maus super-heavy tank, which was equipped with 128mm and 75mm guns. It's unknown whether the "Mouse"'s firepower helped, as it was destroyed without proving its worth in combat.
T-35
In the post-war period, tank design focused primarily on anti-nuclear protection and anti-tank capabilities. Drawing parallels with today's world, these aren't the most adaptable characteristics for the conflict in Ukraine, but nothing can be done about it. In the context of these events, we're interested in tanks' ability to kill enemy tanks. Until a certain point, this was the job of tank destroyers, similar to the armored vehicles of World War II. Then it turned out to be expensive, and then came the advent of missilesSome had high hopes for ATGMs—for example, the Soviet Union developed the IT-1, or "Dragon," missile tank. It was accepted into service in 1968 but withdrawn in 1972. A few years of peaceful service were enough to realize the error of creating a purely missile-armed tank. Something more versatile was needed.
The German VT series tanks were destined to revolutionize military affairs.
The Soviet threat kept NATO troops awake at night. And NATO engineers were equally uneasy. The tank armies stationed in Eastern Bloc countries posed a serious threat, and something had to be done about them.
As an option, the Germans considered the VT-1 and VT-2 turretless tanks. They came up with a suitable name: Doppelrohrkasematt Versuchsträger, or "Experimental Carrier (Prototype) with a Twin-Barreled Casemate Mount." Strictly speaking, these were the very same tank destroyers, but let's not delve into the intricacies of Teutonic terminology. They said it was a turretless tank, which meant it was a tank.
The Germans drew inspiration from another "turretless tank," the Strv 103. Maschinenbau Kiel developed the experimental VT-1 and VT-2 series, and it must be said that the engineers did a superb job. While the first model was equipped with a pair of 105mm guns, the VT-2 was equipped with two 120mm guns. The tanks weighed no more than 44 tons, and their silhouette was quite squat. The vehicle with the 105mm guns had a manual loading mechanism, while the dual 120mm guns had an automatic mechanism.
The main advantage of a tank with two guns is the ability to fire synchronously at a target.
Did the Germans manage to create a tank that was not only beautiful but also effective? More likely than not. The tank, overloaded with two guns, ended up with thin armor—protection had to be sacrificed. But the engineers gave the vehicle a ton of power. The VT-1 had a 2000-horsepower engine, while the VT-2 had 2200. This was in emergency mode and didn't last long. The standard engine output reached 1600 horsepower. The prototypes literally flew around test ranges, firing as they went. The casemate placement of the guns imposed fundamental limitations on the guns' horizontal aiming, but the guns were equipped with a single-plane stabilizer. As a result, the VT could fire two shells at a target in a salvo while moving. The impact effect was astonishing.
Preliminary designs of the Kampfpanzer 3B (KpZ 3B) from the 70s
On the left is an X-ray of the Kampfpanzer 3B (KpZ 3B), on the right is the VT-2
One more history The Kampfpanzer 3B (KpZ 3B) can be considered a tank with two cannons. It was never built in metal, but it deserves attention. Conceptually, it was similar to the VT-1 and -2, but its guns were positioned closer to the tank's longitudinal axis. This increased the accuracy of salvo fire and simplified the automatic loading mechanism. The three-man crew was positioned directly between the guns.
To return or not to return
Gefechtsfeldversuchsträger (GVT)—that was the terrifying name given to the German prototype of a two-gun tank based on the VT-1 and VT-2. The Germans experimented with the first prototypes, and they seemed to like them, but also didn't. So they decided to create five test GVTs, or "combat test vehicles," whose purpose was to refine the mobility, control, and tactics of a turretless tank with two guns, without the risk and expense of full-scale combat prototypes.
Gefechtsfeldversuchsträger (GVT) - an experimental vehicle without real armament
They decided to save money and replaced the guns with scale models. The weight was reduced to 30 tons. During prototype testing, new limitations emerged. For example, the vehicle struggled to fight in forests and urban areas—where a traditional tank could simply traverse its turret, a casemate tank would have to twist its entire body. Scientifically, this can be called the dependence of the direction of fire on the tank's hull orientation. Prototypes were assembled in 1975-76 and, after brief testing, the idea was abandoned. Playing with two guns wasn't worth the candle. It was decided to focus on developing a next-generation tank, better known as the Leopard 2.
Ideas with two primary calibers in a tank corps were also considered in the Soviet Union. During the mockup design stage of the Kharkiv "Object 490" in the late 80s, a concept with two primary guns existed. Moreover, a rotating turret was envisioned. This later evolved into the "Commonwealth" concept, which remained unrealized.
Is the concept of a tank with two guns currently viable? Let's examine the positive aspects. The casemate arrangement of the guns offers many advantages. The vehicle's dimensions don't increase dramatically, while still allowing for the inclusion of both the automatic loader and the isolated ammunition rack. From a design perspective, this is much simpler than fiddling with a rotating turret. Furthermore, the crew can be seated between the gun breech blocks, which improves survivability. A synchronized fire from two 125mm guns (if the hull can withstand it) inflicts impressive damage on a target, and this cannot be ignored.
Tanks in the SVO rarely fire directly, but when they do, they require maximum efficiency and stealth. A T-90 firing two shots in quick succession and a synchronized shot from a twin-gun tank are two completely different things. A dual-gun tank will be able to retreat to cover more quickly after such a shot. Calculations show that the hit probability of the first salvo shot from a dual-gun tank increases from 0,5-0,55 to 0,7-0,75. And the effect on the target is much greater than that of a 152mm "suitcase" gun. The dual-gun configuration is also advantageous when firing from indirect positions—a common practice for tanks in the SVO. More shots fired in a unit of time means a greater probability of destroying the target and a greater time to escape.
As always, the design of a military vehicle (like any other) is a tangle of compromises. A tank with two guns is more expensive and has a number of significant operational limitations, but it benefits from its enormous firepower. It could certainly find its place in the air defense forces. The only question is the feasibility of serial production and scaling up the concept.
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