Looking from the side, the bodies of the South Korean K-1 main battle tank (left) and K-2 main battle tank (right) in the picture are squatting, with the front low and the back high, and the gun barrels almost touching the ground. The passengers in the car are still training in an orderly manner, indicating that this situation is not a malfunction. In fact, the peculiar posture of these two main battle tanks is a masterpiece of their suspension system. Unlike the "external attachments" of tanks such as active defense systems, the suspension system is located inside the vehicle and plays a crucial role. For example, a tank without a suspension system is like a hard "iron lump". Only with the support of the suspension system can this "iron lump" become an "armored fortress" for galloping on the battlefield, greatly improving the stability and comfort of the vehicle. So, what exactly is a suspension system? The suspension system is a force transmission device that connects the tank body and the load wheels, used to distribute the weight of the tank body on each load wheel, buffer the impact force generated by collisions with the tank body, and ensure smooth driving at high speeds. Early tanks used rigid connections, where the load-bearing wheels were directly fixed to the body without a suspension system. The riding experience may be summed up in one word: bumpy! Subsequently, many simple suspension systems emerged one after another, although in various styles, they all used springs as buffers in principle to assist tanks in achieving high-speed travel. Tank suspension systems mainly include Christie suspension, balanced suspension, torsion bar suspension, and liquid air suspension. Christie suspension is the first suspension system that enables tanks to achieve high-speed travel. It has a simple structure and high reliability, and has been used in many types of Soviet tanks such as T-34. Balanced suspension, also known as chain suspension, was popular before and after World War II. This non independent suspension has good shock absorption performance, but limited buffering capacity. The torsion bar suspension is widely recognized as the most successful suspension system currently available, and many tanks since World War II have used this suspension system. Liquid air suspension appeared the latest and has the most advanced technology. This suspension system with active adjustment capability has stronger buffering ability, making the tank more stable during high-speed travel, which is very advantageous for tank shooting during movement. The German tank's "muzzle wine glass" skill also benefits from this. In addition, the active adjustment function of the liquid air suspension allows the tank to actively adjust the tilt of the vehicle's front, back, left, and right, thereby having a larger shooting angle. The South Korean K-1/2 main battle tank and the Japanese Type 90 main battle tank both use this technology, and these types of tanks are often able to perform "forward and backward" movements such as "squatting" or "kneeling down". Although the liquid air suspension system is considered the best suspension system, its structure is complex and it is actually quite troublesome. Therefore, many tanks adopt both liquid air suspension and torsion bar suspension, which greatly improves the reliability of the tank. (New Society)