In the 1970s Germany investigated a novel approach to tank design when attempting to replace its Leopard 1. This vehicle was small, extremely mobile and, most importantly, carried two 120 mm guns.
It was named the Versuchsträger, meaning “test-bed”, but was known simply as the VT tank. The motivation behind the VT tank was to increase first hit probability by increasing the number of guns on the vehicle – more guns equals a higher chance of hitting something, right?
Like the Swedish S-tank, the VT completely ignored conventional tank design philosophy of a hull and rotating turret.
Also like the S-tank, the VT was a main battle tank (MBT), not a tank destroyer, even though it follows many design principles of older tank destroyers.
However, despite taking a radical approach to address the requirements of MBTs, the VT tank offered too little advantages over normal designs to justify its adoption into service.
Today, the generally accepted layout of a tank is a hull, two tracks and turret. This is popular because it enables a tank to perform well in a multitude of areas.
However just because this is the “standard” layout, it is by no means perfect. Many other less conventional, more specialised approaches have been attempted.
For example, oscillating turrets are excellent for enabling a small tank to carry a large caliber gun. Casemate-type vehicles lack a turret, but are much lighter and can also carry a large gun.
The Swedish S-tank omitted a turret and independent gun movement entirely, instead locking the gun to the hull and using the hull itself to aim.
Similarly, the VT double barrelled tank broke many design traditions. It was a turretless, twin-gun design developed in West Germany in the 1970s.
At this time the Leopard 1 was due a replacement and the VT tank was seen as a novel design, but one with potential. The VT tank was all about efficiency.
It was well established that in tank-on-tank engagements whoever fired first would likely win. First hit probability (the likelihood of your first shot actually hitting the target) is crucial in this situation.
Stabilisers and fire control systems had greatly improved first hit probability since WWII, but for a suitable replacement for the Leopard 1, they needed to do even better.
The VT aimed to increase first hit probability by literally having more guns. The idea behind this was that you have a higher chance of hitting the target with two shots than you do with one.
Mobility was also extremely important to the project. Instead of a turret, the VT housed its guns in a casemate style hull, similar to the WWII-era Jagdpanzers. This reduced both the tank’s size and weight, greatly improving mobility and survivability.
VT Tank Design
The VT double barrelled tank was built upon the chassis of the recently cancelled MBT-70, albeit slightly shortened.
By removing the turret the VT was able to save a considerable amount of weight and better facilitate the mounting of two large caliber main guns.
Two test vehicles were built, VT 1-1 and VT 1-2.
The VT 1-1 was built by the German company Maschinenbau Kiel (MaK) 1974 and was armed with two 105 mm guns. To operate the vehicle the VT 1-1 contained a crew of four, with each gun being loaded manually.
The following year MaK built an even beefier double barrelled tank; the VT 1-2. The VT 1-2 was equipped with two 120 mm Rh120 smoothbore guns, the same type used on Leopard 2.
These cannons were tremendously powerful, so carrying two would have made the VT 1-2 a deadly force on the battlefield. The guns were fed by 6-round autoloaders, eliminating the need for a loader and increasing the guns’ rate of fire.
With this change the crew was reduced to three – a driver, commander and gunner. All three sat side-by-side at the front of the hull. The small number of crew increased the chances of survival in the case of a penetrating hit.
As it was designed from the start strictly as a test vehicle, it lacked any proper armor and was instead covered in mild steel.
It weighed over 40 tons and was powered by an immensely powerful MTU MB803 twin turbo diesel engine. This produced 1,500 hp, but could put out 2,400 hp for short durations. With an excellent power-to-weight ratio of 33-53 hp per ton, the VT 1-2 could reach 43 mph on road.
Between 1975 and 1976 another five similar vehicles were constructed. However these were armed with laser gun simulators instead of real working guns and were named GVT, for “Gefechtsfeldversuchträger”, meaning “battlefield test-beds”.
The guns of the VT tanks could move up and down, but lateral movement was controlled by moving the entire hull. In fact, the process of aiming their guns was one of the most unique in any tank.
Firing the VT Tank
As the main guns were located on the extreme left and right of the VT tanks and couldn’t traverse side-to-side, the Germans created a novel method of aiming and firing.
After finding a target, the gunner would lock it into the tank’s aiming computer. The VT tank would then drive toward the enemy in a zig-zag pattern.
When ready to fire the gunner held the trigger. The fire control system would automatically fire each gun as its muzzle passed over the target during the zig-zag course. This enabled both guns to fire when over the target and, and simultaneously made the double barrelled tank a difficult target to hit.
This was asking alot from 1970s technology, but the Germans proved it could be done. In tests the VT tank was found to have a similar first hit probability to the new Leopard 2, despite its completely unorthodox nature.
However the Leopard 2 was a conventional design that could achieve the same hit probability with a single gun and a whole host of other advantages.
While the Germans made the double barrelled tank concept work, the advantages it offered over conventional designs were not enough to justify the technological efforts needed for its success.
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In 1985 Germany cancelled the VT tank project in favour of pursuing the Leopard 2.