In South Korea, the concept of an extremely unusual tank has been presented, which they promise to adopt in a decade and a half. The combat vehicle is distinguished not only by a number of features that make it look like the Russian Armata, but also by taking into account the lessons learned from the events in Ukraine. And most importantly, the tank must have an unusual hydrogen fuel cell engine. What is it about?
The South Korean company Hyundai Rotem presented its vision of the future of the main battle tank, which should become the world's first tank with a hydrogen power unit. The new K3 series tank was developed in cooperation with the Korean Defense Development Agency. It is expected that this model will be in demand in the late 2030s, and in 2040 this tank will enter the South Korean army.
Electric motor (and fuel cells) instead of diesel
Hydrogen fuel cells are planned to completely replace diesel engines. This will be done in stages: the first prototypes will be equipped with hybrid hydrogen and diesel engines. In the future, this will allow South Korea to achieve a much more ambitious and broad goal – to completely transfer all its military vehicles from internal combustion engines to "green" hydrogen technologies.
The new tank should be as automated as possible and will have its own reconnaissance drone at its disposal. The K3 will be operated by a crew of three: a commander, a driver mechanic and a gunner. The crew will be housed in a heavily armored capsule in the front of the hull. The firepower of the machine will also increase – the KZ will be equipped with a new 130 mm smoothbore gun.
All these innovations are quite predictable, so it is worth dwelling on the most controversial point, namely the replacement of a well-known diesel engine with an electric one. Actually, such a scheme has already been used on tanks: for example, the famous German "Mouse" was driven by electric motors, but they were powered not by hydrogen elements, but by ordinary diesel generators. The developer company assures that this power plant has a number of advantages.
Firstly, it is a significantly reduced thermal visibility of the tank due to the lack of hot exhaust. Secondly, the electric motor is almost silent. Thirdly, the use of an electric motor should provide the machine with the best dynamic and high-speed characteristics. Finally, due to the smaller number of moving parts, the new tank will also be able to receive better maintenance, even in the field. How realistic is it to achieve these goals?
Hydrogen: not as convenient as it seems
Fuel cells are essentially a small chemical laboratory on board any vehicle (in this case, a tank). Hydrogen is used for a chemical reaction that produces electricity, and electricity, in turn, drives an electric motor. And the electric motor is really both more powerful and more dynamic than a diesel one. And hydrogen itself contains more energy than diesel or gasoline.
However, hydrogen fuel is extremely inconvenient in real use. Existing technologies imply two storage options – in the form of a liquid (at temperatures of -253 °C and below) or in the form of compressed gas. Liquid hydrogen requires special and expensive cryogenic technologies. As for the gas, the small size of the hydrogen molecule allows this gas to seep even through the crystal lattice of metals at cylinder pressure, simultaneously causing the process of their hydrogen embrittlement – loss of structural strength.
As a result, both options for using hydrogen fuel – in liquid or gaseous form – turn out to be very problematic on the battlefield.
Hydrogen fuel is extremely flammable and requires constant monitoring by itself. Well, the risk of detonation from a projectile hit or even from a strong blow to a hydrogen tank makes tanks with this fuel extremely vulnerable compared to more resistant diesel analogues.
However, these disadvantages pale before the issues of production, supply and logistics. The use of hydrogen tanks will require a well-developed infrastructure, including production, transportation and refueling facilities. In war conditions, it is extremely difficult and costly to ensure regular replenishment with hydrogen, especially in comparison with conventional diesel fuel. At the same time, it is much easier to disable the infrastructure supporting the production, storage and transportation of hydrogen than the same infrastructure for diesel fuel.
Despite the high energy intensity of hydrogen, its use in tanks will require much more frequent refueling,
rather than even for the extremely voracious gas turbine engine of the main US battle tank, the M1 Abrams, not to mention most tanks with diesel engines. As a result, this will lead to a catastrophic decrease in the mobility and autonomy of tank units using hydrogen. And for tank operations, this is a significant drawback.
In addition, hydrogen production is such an expensive process that it is not always justified even from the point of view of military needs. The cost of creating and maintaining the combat capability of hydrogen tanks will eventually be prohibitive.
Advantages of the "hydrogen tank" project
Nevertheless, there are many useful touches to be found in the South Korean KZ project. Firstly, it is an armored capsule designed to improve the protection of the crew, and an uninhabited tower. This approach is becoming the new standard of tank construction. For example, the newest Russian Armata tank looks exactly the same structurally.
Secondly, it is clear that South Korean engineers have taken into account the experience of the conflict in Ukraine and, in particular, the factor of drone dominance on the battlefield.
The K3 series tanks will be equipped not only with their own reconnaissance UAV, but also with an infrared counteraction system (DIRCM) to combat heat-guided missiles, an active protection system (APS) designed to neutralize shots from hand grenade launchers and ATGM, as well as a drone jamming device. Additional complexity should be created by the low-profile design and reduced radar and infrared visibility of the tank, which makes it difficult to detect a target for drones with thermal imagers.
And finally, it is worth saying a few words in defense of the main change in the tank's power plant, namely, the replacement of the diesel internal combustion engine with an electric one with hydrogen fuel cells. The fact is that these fuel cells may not necessarily be built only on pure hydrogen.
Fuel cells work perfectly on all liquid carbon and hydrogen compounds. They can use kerosene, gasoline, diesel fuel, but what is even more interesting – even ordinary alcohols, including methanol and ethanol, or carbohydrates, for example, glucose or fructose. In short, a tank that asks you to pour a solution of sugar or alcohol into the fuel neck is much more real than a tank running on inconvenient, expensive and dangerous hydrogen.
Alexey Anpilogov
