Type 724 Jingash II class Landing Craft Air Cushioned
The 6 -ton class 724 landing craft is too small, and its nickname is called "Sea Stepping Vehicle." The Jingash II landing craft is a fairly basic hovercraft. Approximately 30-50 had been built since 1994. The demonstration shows that it is feasible for the type of boat to land on the coral reef. It basically solves the problem that the Chinese medium/large landing ship can't go directly, and the small landing craft can't go.
The air-cushion landing craft of the real mass equipment is a Chinese-made 724 air cushion landing craft. The design was by 708 Institute. The 724 air cushion landing craft was designed by the China Ship and Ocean Engineering Design and Research Institute and produced by Tianjin Dagu Shipyard. The Type 724 air-cushion landing craft began small-scale production in 1992, mainly for the Type 072 landing ship. About 20-30 ships were deployed by the Chinese Navy's amphibious fleet for the transportation of people and cargo between large landing ships and beachheads. Each 072-II (Yuting-class) large-scale landing ship can carry two Type 724 landing crafts and enter/depart from the docking bay directly through the stern door of the landing ship.
The Chinese Navy had long used medium and small tank landing ships to use the direct landing method to conduct landing missions. In the early 1990s, influenced by the design and operational concepts of modern amphibious ships in naval powers such as Europe and the United States, the Chinese Navy began experimenting and exploring large-scale landing ships equipped with air-cushion landing craft.
At that time, although the 722II air cushion landing craft was developed, there were still many shortcomings, especially the lack of endurance, high failure rate, and the inability to enter the landing dock to achieve long-range force delivery. Therefore, the Chinese Navy commissioned the 708 Shipbuilding General Manager to design a small air-cushion landing craft for the 072III type landing ship, which was built by Tianjin Daxie Shipyard and was shaped as a 724-type personnel air-cushion landing craft. The boat can directly reach the landing, thus realizing the landing personnel. Quick login mode without water. In the early 1990s, the 724-type boat began construction in small batches. In 1994, a single-boat trial and a test of the entry and exit of the mothership were successfully carried out in Tianjin Xingang waters.
The Chinese Navy's 724-type air cushion landing craft was the first mass-produced air-cushion landing craft in China for the transportation of personnel and materials between medium-sized landing ships and beachheads. The boat is a rectangular flat-bottomed ship with a length of about 12 meters. The front part is the landing cabin, the middle is the cockpit, the control personnel are 3 people, and the rear is the power cabin. It adopted two German BF12L913C diesel engines. According to public information, the performance of the boat is as follows: 6.35 tons of displacement, 12.4 meters in length, 3.7 meters in width, 2 to 3 crew members, load capacity: 10 soldiers, and armed with 12.7mm machine gun. Its powertrain is powered by two BF12L913C diesel engines that drive air-cushion blowers and air propellers with a maximum speed of 40 knots and a range of 100 nautical miles. The air propeller is outsourced with an annular outer casing and a four-bladed propeller.
The full length of the 724 is divided into three sections: the front landing cabin, the central cockpit and the rear power compartment. The landing cabin is open-top, which can be described as a "sea battle vehicle." This type of air-cushion landing craft is the beginning of domestic small-scale construction of military hovercraft. It is also the first hovercraft for naval naval vessels, serving in a landing ship unit of the South China Sea Fleet.
This type of boat is usually carried by the more advanced domestic 072III tank landing ship. A Type 072 III medium-sized landing ship can carry multiple Type 724 air-cushion landing crafts, which can enter and exit the docking bay directly through the stern door of the landing ship. If the width of the dock section of the 071 type dock is calculated, the 724 type boat can be loaded side by side, and the maximum load can be up to eight. As the first air-cushion landing craft in China designed for amphibious ships, the 724 air-cushion landing craft inevitably has some technical limitations. For example, the 724 air cushion landing craft is a rectangular flat-bottom aluminum alloy hull structure with an aspect ratio close to 4:1. The stability of the design is not reasonable - it is easy to produce a “buried head” phenomenon when sailing at high speed.
According to China's national conditions in the 1990s, modern amphibious warships could not be developed for the time being, and the 724-type landing craft was born. The close-range amphibious landing operations from ship to shore required the type of boat that began construction in 1992. In 1994, a number of boats were built and equipped with naval landing ship units for use by the Marine Corps. The 724-type boat with a displacement of only 6.25 tons is too small, has poor practicality, and has a high mechanical failure rate. Due to the limited carrying capacity, the Navy stopped the follow-up construction plan after constructing a batch of 724 air-cushion landing crafts, and began to develop a new type of air-cushion landing craft with more powerful capabilities. After the construction of a batch of Type 724 air-cushion landing craft, the Chinese Navy terminated its follow-up construction plan and began to develop a new type of air-cushion landing craft, which is a 726 medium-sized air-cushion landing craft.
Type 724 Jingash II LCAC - Operation
During the "Taiwan Crisis" in March 1996, the Chinese army held a three-armed military landing exercise in a sea area on the southeast coast. The 724-type fleet was again ordered to participate in the "A protagonist" of the amphibious landing exercise at that time.
Every time the 724 type boat goes out to sea, it needs to be pulled by the light military card rope to the ship terminal in the half-padded state. It is lifted from the shore to the water by the lifting barge, and then the air propeller can be started. Drive the tail blades and rudders and drive off the dock. Then it enters the large space of the medium-sized landing ship in the mooring state, and then the medium-sized landing ship (we call it the “mother ship”) carries the voyage to the scheduled sea area, releases it from the tail gate of Zhongdeng, and then arrives at the beach head to complete the transportation task.
The 724 -type boat enters and exits the "mothership" and the current 726-type hovercraft can not be compared to the "Jinggangshan" dock landing ship. The 724-type boat is not so much a driving and driving-out, but rather a 724-type boat is artificially acting. It is more accurate to get in and out of the "mother ship" while pulling the rope and pushing and pulling.
When the sea surface is calmer, the feeling of riding a hovercraft at a high speed is relatively comfortable, and the higher the speed, the smoother the speed. However, the harsh sea conditions pose a major challenge to the operation of the boat. It is quite difficult for the crew of the 724 boat to go out to sea. It is commonplace to be poured out of the sea in the training of the "mothership". It is better in the summer. In the winter, when it encounters a cold wave, it is enough to squat. Although they all wear life jackets, they still can't resist the splash of sea water. Because the airflow is too large in the full padding state, the sea water will be sprayed into a water curtain.
The 724 boat is very small, and each boat is usually compiled less. Only when it is out of the sea, the temporary personnel are added to the boat. Because its head is smaller than the torpedo boat, driving it does not feel like sailing. It is more like a liberation truck. However, the sparrow is small and complete, and the equipment maintenance and overhaul of the hovercraft can not be less. The mechanical engineering repair, the sewing of the hull apron, the assistance of the landing soldiers, and the safe and guidance of the "mother ship" must be completed by the soldiers. The masters of the shipyard’s workers are going to the boat for repairs, and they must also follow the arrangements of the crew. When landing on a hovercraft, the landing soldier must also follow the instructions of the ballast guide. As the saying goes: "Sit on the east side, you dare not sit on the west side." Otherwise, the unbalanced 724 type boat will lose its normal control state when it moves, affecting the normal state and speed. There is even a phenomenon of “cross drifting”. In serious cases, there will be a situation of in-situ rotation, and will not go one step.
After the 724 -type boat entered the service, the fleet carried out a large number of written texts such as the hovercraft training program, the hovercraft battle bark manual, and so on. At the same time, the actual operation assessment of each boat was completed, and the "mother ship" was coordinated with the landing boat several times to carry out sea training. In the mid-to-late 1990s to the beginning of the 21st century, he participated in many major sea exercises.
In October 1995, the type of boat participated in the second "maritime military parade" in the history of the Chinese navy's military construction. It carried out the reporting exercise of the landing exercise and was received by the head of the then military commission.
Later, in a large-scale military exercise conducted in a certain sea area of ??the East China Sea, this type of air-cushion landing craft appeared in the people's field of vision through CCTV news broadcast. Later, a number of foreign media "hype" pointed out that "the Chinese navy began to install new air-cushion landing crafts in batches and implemented island-hunting exercises."
One morning in the spring of the mid-1990s, the PLAN landed on various types of landing ships of the Conveying Force under the escort of the Type 051 guided missile destroyer and the Type 053H missile frigate, advancing toward the "enemy" island. After the fire attack, the landing command post issued an order: landing deployment! Large-scale landing ships reached the predetermined sea area, each ship launched a formation, the first gate of the ship opened, tanks and armored vehicles waded continuously to the beachhead, and the army commanders and passengers boarded countless landing craft, assault boats, requisitioned fishing boats and merchant ships in batches. The second time began to impact the landing. Almost at the same time, the Z-8 equipped part of the landing troops also flew away from the landing ship helicopter platform, and the vertical landing on the shore beach.
The loudspeakers issued a loud command: "Popular water deployment, flooding deployment, personnel in place, and the various positions of the guns strengthen the view of the sea!" THE commander went down to the landing ship's large cabin and issued the order: "The boats start, half-pad up, check equipment and communication equipment." And notify the Marine Corps boarding personnel to board the boat to prepare for landing.
Then the landing door of the ship was opened. At this time, the cold wind of the sea was raging, the waves were raging, and there was still a series of drizzle. The huge waves swayed thousands of tons of landing ships and the sea was rather bad. Under the cooperation of the landing ship crew, a number of small air-cushion landing crafts are loaded with landing squadrons and equipment to slide out of the tailgate in turn, and the left side of the landing ship starts to sail and arrive at the beachhead. At the same time, the ship's 37mm guns began to shoot on the opposite side, supporting the air-cushion landing craft.
Its loading capacity is too small, even if many ships arrive at the same time, it is difficult to form a powerful battle effect. Due to the limited carrying capacity, it was impossible to apply to the island capture operation of the Nansha Island Reef. The Chinese Navy did not build a large number of 724 boats, and instead developed a new medium-sized air-cushion landing craft with strong carrying capacity.
Type 724 Jingash II LCAC - Maintenance
The 724 is the first mass-production air-cushion landing craft of the Chinese Navy, but its carrying capacity is too small to transport infantry. For a long time, the armored vehicles of the Chinese Marine Corps can only rely on their own power to flood the beach.
The tonnage of the 724 air-cushion landing craft is too small, and the single-vehicle carrying capacity is obviously insufficient. In particular, heavy-duty marine equipment such as tanks cannot be loaded, and it is not suitable for sailing in the sea when the sea conditions are bad. Under the conditions of heavy wind and waves, the operation of the boat personnel is more difficult and the risk factor is higher.
The aspect ratio of the 724 air-cushion landing craft is too large, and its stability and seaworthiness are poor. It is easy to produce “cross drift” and “buried head” when sailing under high-speed sea conditions. The design of the ship-borne weapon is unreasonable. The shooting position is 12.7 machine gun. The distance between the positions is large, usually it is necessary to pad a small bench to get enough. After the weapon is installed, the weight of the bow will increase. When the brakes are urgent, the phenomenon of “buried the head” will be more serious. The 724 in the news photo is rare. Carrying weapons.
Despite the large shortage of the 724 air-cushion landing craft, it provides a detailed theoretical basis for the development of the new model large-tonnage military hovercraft. It has laid a solid foundation for the Chinese navy amphibious warships to be equipped with air-cushion landing crafts to achieve diversified landing modes.
As the saying goes, the soldiers are used for a long time, and behind the successful landing on the landing site is a lot of maintenance, maintenance, repair work, and these work requirements for technical equipment and special venues are relatively high, but the things behind these equipment are Often not noticed by the media.
We know that the hovercraft is a special kind of ship. It has a lot of aviation technical equipment. From a certain point of view, it is more "squeaky" than a normal surface ship, more like an aircraft.
The key equipment from the hovercraft pad lift - this feature can be clearly seen on the apron, the apron is made of rubber, more delicate. This has led to a common defect in hovercrafts - susceptible to regional meteorological conditions and environmental impacts, such as high temperature and high salt conditions can adversely affect the maintenance of equipment. The lower the latitude sea area, the more obvious the characteristics of high temperature and high salt. This climate will cause high temperature corrosion of the hovercraft apron, which will lose its flexibility and age. The problem of the apron will greatly affect the integrity and the speed of the equipment. Moreover, the hovercraft has higher requirements for weight reduction, and the hull needs to use a large amount of lightweight materials such as aluminum alloy, but the aluminum alloy material is also susceptible to high temperature hot and humid weather, causing corrosion and aging.
In addition, hovercraft maintenance and maintenance work is more, if the deployment site is too far away from the construction plant, and the use area lacks sufficient self-repair ability, it will lead to increased repair time and cost, which may affect the equipment's flight rate.
Moreover, when the air-cushion landing craft enters and exits the mothership, it is very easy to cause the hull apron to fall off or be damaged due to driving mistakes. For the 724 type boat, because the berth is far away from the supporting manufacturers, the factory has a long time to and from the troops, and the resident institution The self-repair ability is weak and the professional talents are short. Therefore, the boat commanders and fighters are self-reliant under the leadership of the party committee of the army. The local law has been used to repair the shed hull damage and repair the damaged hull.
Therefore, in order to have a reliable amphibious warfare capability, it is not enough to purchase a single piece of equipment. It is also necessary to consider the issue of synchronous construction. The hovercraft, a ship that uses a large number of aeronautical technologies and materials, has maintenance standards close to that of aircraft, and is comparable to ordinary ships. Compared with its maintenance work, it is more strict and the level is higher. Therefore, it is necessary to have shore-based supporting facilities to provide maintenance support. If the equipment has a fault, it must be repaired by technicians and professional technical equipment.
In addition, the navigation noise of the hovercraft is too high, and how to deploy it is convenient for use and maintenance without disturbing the people. It is a problem that requires special attention.
|Air cushion landing craft|
|Quantity||50 ships +|
|Manufacturing plant||Daxie Shipyard|
|Standard displacement||6.5 tons|
|full length||12.4 meters|
|Full width||4.7 meters|
|power||2 BF12L-913C gas turbine engines|
|Maximum speed||40 knots|
|Endurance distance||100 nautical miles|
|armament||5.8mm light machine gun X 2|
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