Vertical launch system (VLS) is a launch method that installs missiles vertically on ships, which can improve the reaction speed and launch density of missiles, and is an important equipment for modern sea boats. Different countries have different technical characteristics of vertical hair systems, the main difference of which is cold and hot launch.
Cold launch means that the missile is not ignited before launch, but relies on external air pressure or mechanical force such as springs to push the missile out of the launch canister, and then ignites it in the air. The advantages of cold launch are high security, no thermal damage to the launcher and surrounding missiles, and no smoke exhaust, reducing the risk of being detected by the enemy. The disadvantages of cold launch are the complexity of the system, the heavy weight, the slow launch speed, and the limited variety of missiles that can be applied.
The inventor of the cold launch was the Soviet Union, which was first applied to submarine-launched ballistic missiles, because the structure of the submarine could not withstand the high temperatures and pressures of the hot launch. Later, the Soviet Union used cold launches for surface ships, mainly to launch long-range anti-aircraft missiles, such as the S-300 family. Cold launches in the USSR used a unique pull-up rod design, in which the missile was lifted out of the launch canister with two pull-up rods and then ignited in the air. This design is simple and reliable, but only half of the launch stroke can be used, which is a bit of a waste of space.
A hot launch means that a missile is ignited before it is launched and is fired directly from the canister under its own power. The advantages of thermal launch are that the system is simple, light weight, fast launch, and there are many types of missiles that can be applied, which can realize the versatility of multiple bombs in one pit. The disadvantage of thermal launch is that it is not safe, it can cause thermal damage to the launcher and surrounding missiles, and it can also produce smoke and smoke, increasing the risk of being detected by the enemy.
The representative of the thermal launch is the American Aegis warship, which adopts the MK 41 VLS and can launch various types of missiles, such as anti-aircraft missiles, anti-submarine missiles, cruise missiles, etc. The U.S. thermal launch uses a J-shaped tube design, that is, there is a curved pipe at the bottom of the launch canister to direct the missile's flame exhaust to the side of the ship, while spraying water to cool down and reduce thermal damage. In order to increase the emission density, the thermal emission in the United States also adopts the design of a common flame exhaust tube, that is, multiple launch canisters share a single flame exhaust tube, which can save space.
Cold and hot launches have their own advantages and disadvantages, but after the end of the Cold War, there was a gradual increase in interest in cold launches in Western countries, especially France, which adopted a cold launch system on its Lafayette-class frigates, which can launch anti-aircraft missiles and anti-submarine missiles. The French cold launch used a traditional piston butt design, in which a sealed piston pushes the missile out of the launch canister and then ignites it in the air. Although this design has a longer launch stroke than the pull-up rod type, it has high sealing performance requirements and is not suitable for large-caliber missiles.
After coming into contact with the cold launch of the USSR and the hot launch of the United States, China, after a period of exploration and development, finally created its own universal vertical hair system, which is already ahead of the US Navy. The core technology of China's universal vertical hair system is a concentric circle module, that is, there is a layer of cylinders inside and outside the launch canister, and a loop is formed in the middle. This loop can be used both as a flame exhaust path for thermal firing and as a space for a lifting rod mechanism for cold firing. In this way, China's universal vertical hair system can realize the co-use of cold and hot, and choose different launch methods according to different missiles, which not only ensures safety, but also improves versatility.
Another advantage of China's universal vertical hair system is that its frame structure is very simple, that is, a large frame, there is no common flame exhaust tube, and each launch canister has its own flame exhaust channel, which can achieve simultaneous firing without interfering with each other, and the firing interval is almost zero. Moreover, China's universal vertical launch system can also flexibly match different missiles, and can even achieve a super-caliber launch of four barrels and one cylinder, which can be used to launch drones or anti-ship ballistic missiles. In addition, China has also developed an electromagnetic cold vertical launch system, which uses electromagnetic force to push missiles out of the launch canister, which can reduce the launch acceleration, increase the launch weight, improve the launch conditions of the missile, and raise the vertical launch technology to a new level.
In short, the vertical hair system is an important equipment of sea boats, and the vertical hair system of different countries has different technical characteristics, among which cold launch and hot launch are the main differences. China's universal vertical hair system has achieved hot and cold co-shelf, with a high degree of safety and versatility, has been ahead of the US Navy, demonstrating the strong strength and innovation ability of the Chinese Navy.