Landing amphibious armored personnel carrier LVTP7 / AAV7A1 (USA)
The development of a promising amphibious amphibious assault vehicle began in the late sixties. At this time, the Marine Corps continued to use the amphibious LVTP5 amphibious armored personnel carriers, which no longer fully met the existing requirements. To replace the aging technology, it was decided to develop a new sample of a similar purpose, but with enhanced characteristics. Several defense industry companies presented their versions of the project to the Pentagon. Among the developers was the company FMC Corporation, whose project was soon approved.
In 1972, the newest amphibian was put into service under the designation LVTP7 (Landing Vehicle, Tracked, Personnel-7 - “Landing vehicle, tracked, for soldiers, 7 model”). Soon, the Marine Corps began to receive serial equipment and begin its development. In the first version of the project were formed the main features of the appearance of the machine, some of which have not changed until now. Nevertheless, over the past decades LVTP7 has managed to go through several upgrades, including quite large ones. It is noteworthy that after one of the first major updates, the car even changed its name.
After the first decade of operation, in 1982, FMC received an order for a deep modernization of the existing amphibious amphibious assault. By this time, the military had compiled a list of the required improvements, which were planned to be eliminated with the further development of technology. It was assumed that the elimination of existing shortcomings will allow you to keep updated equipment in the ranks for a long time. The modernization project stipulated the replacement of power plant units, the revision of the weapon system and other changes to the original version of the landing craft. Initially, the modernization project received the designation LVTP7A1.
After the completion of all modernization work, in 1984, the amphibian received a new designation. Now the official name of the vehicle is AAV7 (Assault Amphibious Vehicle-7 - “Landing Amphibious Vehicle, 7-I”) or AAV7A1. In addition, over time, the armored personnel carrier received the unofficial name of “amphibious tractor” or abbreviated as “amtrack”. Despite the rather long-term renaming of technology, in some materials, the designation of the base machine LVTP7 is still used with respect to the upgraded version of the amphibian AAV1A7.
LVTP7 comes ashore. Photo Militaryfactory.com
Modernization of the first half of the eighties made some changes to the design of individual machine units, but some of the ideas and solutions remained without modifications. As a result, it was possible to maintain a high unification, which simplified the production of new equipment and the modernization of the existing machines. Despite the similarity of the design, the two types of armored vehicles have some differences, allowing to determine the specific model at a glance. Thus, the frontal part of the LVTP7 had two characteristic circular recesses for the installation of lighting equipment, while on the AAV7 the headlights were placed in rectangular recesses. In addition, a newer machine has a wave deflector hinged on the lower front plate.
Even in the first project LVTP7, the design of an armored hull was proposed, which later did not undergo major changes, although some modifications were used. Armored hull machines were made of aluminum sheets of various thicknesses. In the frontal part of the machine there were sheets with thickness up to 45 mm, in the composition of the sides and stern - 30 or 35 mm. When developing the armored hull, the need to overcome water obstacles by swimming with the payload on board was taken into account, which resulted in a fairly large structure with an acceptable margin of buoyancy, having a recognizable shape.
LVTP7 on the water. Photo Militaryfactory.com
The LVTP7 / AAV7 armored personnel carrier has a wedge-shaped frontal part of the hull with a large inclined bottom sheet that improves performance on the water. The front half of the upper part of the hull retains a large width, which is associated with the installation of the hatches and the tower, and the aft has upper side sheets tilted inwards. The stern sheet is set with a slight slope backwards. The layout of the hull was determined in accordance with the various requirements of the car. In the front part, with a shift to the starboard side, is placed the engine-transmission compartment, to the left of which there is a control compartment with places for the driver and the commander. Behind them is a manned compartment with a gunner’s workplace and a troop compartment for soldiers or cargo.
The very first version of the landing armored vehicle was equipped with a Cummins VT400 diesel engine. In the AAV7A1 project, it was replaced with a Cummins VTA-525 HP 400 product. In the latest versions of the modernization used 525-strong diesel VTAC 525 903. Transmission HS-400-3A1 from FMC is used. C using the latter is the transfer of torque to the drive wheels of the front location.
The chassis is built on the basis of six road wheels with a torsion suspension and additional springs on each side. Front and rear pairs of rollers are additionally equipped with hydraulic shock absorbers. In front of the hull drive wheels are placed in the stern - guides. Between the third and fourth track rollers is a supporting roller. In the course of later upgrades, the suspension of the machine underwent some modifications, but the general principles remained the same.
To move through the water, which is one of the main tasks of the project, the AAV7A1 machine has a set of special tools. On the frontal part of the body there is a wave-reflecting shield, in the transport position it is laid on the bottom sheet. In the base project, this device was missing. In the stern, above the tracks, two jet propulsion units are placed. For control on the water earlier it was proposed to use drives that ensure the rotation of water cannons around the vertical axis. Like other units of the machine, jet propulsion during the development of technology several times refined and improved. In particular, instead of turning the entire water cannon over time, control was introduced with the help of movable covers that regulate the direction of water release.
For self-defense and fire support of the landing force, the amphibious crew LVTP7 had to use a small turret with a large-caliber machine gun. The tower was placed on the roof of the hull, directly at the starboard. For guidance weapons used hydraulic actuators. With the modernization of the eighties, hydraulics, for reasons of fire safety, were replaced by electric motors. In addition, the weapon was boosted: an 2-mm Mk 40 automatic grenade launcher was added to the M19HB machine gun. An interesting feature of the new weapons was the placement of the machine gun and grenade launcher not on a single unit, but on two separate rocking blocks. Weapon control is carried out by the gunner, located in the tower. When using a machine gun and a grenade launcher, the ammunition consists of 1200 cartridges and 864 grenades.
Armored personnel carriers in the hold of the universal amphibious assault ship USS Rushmore (LSD 47), 2005 g. US Navy Photo
The crew of the floating AAV7A1 armored personnel carrier consists of three people: the driver, the commander and the gunner. The control post with the driver's workplace is located in front of the case, to the left of the engine compartment. Directly behind it is the commander’s place. The gunner is placed in the tower on the starboard. The driver and commander are equipped with small height towers with outwardly curved manhole covers. To avoid contact with other machines and accidents, the covers fold back and to the right. Due to this, the open driver's hatch does not interfere with the commander. Gunner hatch placed in the roof of the tower. The driver has several viewing instruments, the commander also has a periscope device.
The main task of the armored vehicle is the transportation of troops or cargo. For their placement in the aft hull provides a large troop compartment. Along the sides of the compartment, as well as on the longitudinal axis of the machine, there are three rows of seats of fairly simple design. Used benches with a soft surface. Part of the seats was made stationary, others could recline to the sides. The size of the troop compartment allows you to carry up to 25 soldiers with weapons. If necessary, the central shop can be dismantled, after which the armored personnel carrier is capable of transporting relatively large loads with a total weight of up to 4,5 tons.
The main means of embarkation and disembarkation is a lowered ramp, which actually represents the entire stern sheet. Ramp size 1,8х1,7 m is lowered using the appropriate mechanisms and allows the troops to dismount with relative comfort. In the left half of the ramp there is a door that can also be used for disembarkation. In the roof of the troop compartment are two hatches of great length, complementing the main ramp.
The amphibious assault vehicle AAV7A1 has a length of 7,94 m, a width of 3,27 m and a height of 3,26 m. The combat weight can vary within 23-29 t, depending on the payload and the use of additional equipment. A relatively powerful engine allows an armored personnel carrier to develop on land speed to 65 km / h. Water cannons speed the car up to 10-13 km / h. When damage to jet propulsion movement can be carried out by rewinding the tracks, however, this leads to a significant reduction in maximum speed.
On the basis of the original draft amphibious armored vehicle AAV7A1 by the mid-eighties, several major modifications were made, which remain in service until now. The most massive was AAVP7A1 (P-Personal), designed to transport soldiers to the landing site. Such vehicles received a full-fledged troop compartment with seats for the marines.
To manage the combat work of the units on the AAVP7A1 should have been an officer in the commander machine AAVC7A1 (C - Command). The commander differed from the base machine by the absence of a turret with weapons and layout of the troop compartment. The entire aft part of the hull was allocated for the placement of communications and workplaces of their operators. In addition to its own crew of three, AAVC7A1 had to carry five radio operators, two commanders and three assistants. For several decades of service, commander equipment was repeatedly subjected to modernization with the replacement of radio equipment.
To solve auxiliary tasks, a repair machine AAVR7A1 (R - Recovery) was created. Like the commander's armored personnel carrier, this model did not receive a turret, instead of which they mounted a small dome with viewing devices. Behind this dome on the roof was placed a turntable with a boom of a crane. Inside the troop compartment were placed various tools and devices necessary for the repair of equipment in the field, as well as boxes for spare parts.
A number of linear armored personnel carriers were later converted into carriers of the Mk 154 MCLC demining system. Modernization meant the installation of the launch guide and a box for ammunition. Inside the troop compartment, a volume box for storing the lengthened charge was mounted, and in the upper part of the hull, at the level of the hatches, was placed a rocking launcher for a solid fuel engine responsible for the release of demining material. The rest of the design, weapons, etc. engineering vehicles consistent with the base armored personnel carrier.
According to some reports, as early as the late seventies, one of the LVTP7 serial machines was used as a carrier of an experienced laser anti-aircraft system, but after the tests were completed, the unusual prototype was disarmed and returned to service in its original quality.
Amphibious LVTP7 of the Armed Forces of Argentina. Photo of Wikimedia Commons
For several decades, the United States industry managed to build more than 1500 machines LVTP7 / AAV7A1 of all modifications. The vast majority of this technology (over 1300 units) went to serve in the United States Marine Corps. The remaining amphibians were sold to friendly states. So, Argentina was handed 21 car LVTP7. In the future, the equipment was upgraded by the forces of the country-operator. More than fifty cars of several modifications ordered Brazil and Taiwan. Fewer vehicles were purchased by Indonesia, Italy, Spain, Thailand, and Venezuela. Also noteworthy is the KAAV7A1 armored personnel carriers operated by South Korea. They were built as part of the baseline AAV7A1 modernization project by BAE Systems and Samsung Techwin. Currently, the South Korean army is armed with more than 160-like machines.
For more than four decades of service, AAV7A1 armored personnel carriers managed to take part in several armed conflicts. The first combat use case of LVTP7 dates back to the beginning of April 1982, when two dozen amphibians took part in the landing of Argentine troops on the Falkland Islands. According to reports, these forces suffered no losses and returned to the mainland until the end of hostilities. Soon, a number of LVTP7 American KMPs went to Lebanon to work as part of the international peacekeeping force, which lasted about two years. In October, armored vehicles 1983 were used in the operation of Urgent Fury, during which they landed troops on the coast of Grenada.
The truly serious and massive operation of amphibious amphibious assault vehicles under combat conditions began in the 1991 year. During the war with Iraq, the US marines made the most active use of their equipment. In 1992-93, AAV7A1 again took part in the battles, this time in Somalia, as part of the UNITAF coalition. The last major conflict at the moment with the use of amphibious armored vehicles was the war in Iraq 2003 of the year.
In the late eighties, it was decided to create an additional reservation for existing machines, which is necessary to increase the survivability of equipment in combat conditions. In 1993, KMP received the first sets of EAAK (Enhanced Applique Armor Kits - “Advanced Hinged Armor Kit”), which included a set of additional security features to be installed on an existing armored hull. Elements of the new set were mounted on the front and side sheets, on the roof, and also on the crew hatches. In the future, new options have been created hinged booking.
It should be noted that the latest invasion of Iraq clearly showed the prospects of the available technology. During the fighting in various parts of the country, it was found that the characteristics of AAV7A1 no longer fully meet the requirements of the time. According to the results of several battles, the armored personnel carrier was subjected to sharp criticism, the main reason for which was an insufficient level of protection. For example, it was particularly emphasized that in this parameter, the Marine Corps technique is noticeably inferior to the M2 Bradley infantry fighting vehicles, which are in service with the ground forces. Existing deficiencies led to certain losses of equipment. During the battle for Nasiriyah (23-29 in March 2003), the KMP lost eight AAV7A1 vehicles from enemy fire. In the summer of 2005, one of the amphibians exploded on an improvised explosive device, killing 14 paratroopers. The available means of additional protection made it possible to increase the survivability of equipment, but in some cases their characteristics were not enough.
In the two thousand years, the US industry was engaged in the project AAV RAM / RS (AAV Reliability, Availability, Maintainability / Rebuild to Standard), the purpose of which was to rework the existing structure with an increase in the basic characteristics. Thus, the original undercarriage was replaced by modified units borrowed from the Bradley infantry fighting vehicle. In addition, the technique received the VTAC 525 903 engine, thanks to which the power density was significantly increased. In parallel, some other onboard systems were upgraded. It was assumed that the modernization of AAV RAM / RS will allow to keep the existing equipment in the troops until the full replacement in the form of an amphibious AAAV / EFV, which was planned for the 2013 year. Nevertheless, the promising project was eventually closed, which is why AAV7A1 RAM remained the only technique of its class at the ILC.
In the middle of 2013, plans were approved regarding the future of the existing technology. In accordance with them, in 2016, the renewal of serial armored troop carriers on the new project was to begin. Of the 1064 armored vehicles available in the troops, about 40% will have to undergo repairs, refurbishment and modernization. First of all, the improvements will consist in installing an additional reservation, which is a further development of the EAAK system. 49 is proposed to install ceramic ballistic protection panels with a total weight of 4,5 t, as well as 57-mm aluminum armor plates on the bottom. External fuel tanks should receive additional protection, and in the troop compartment there will be seats that absorb part of the energy of the explosion. After installing them, the vehicle will be able to transport 18 soldiers with weapons.
The modernization project also proposes the use of an 675 hp engine. and the corresponding transmission. As part of the chassis will appear reinforced torsion bars and new additional shock absorbers, due to which the hull will be higher by 76 mm. Planned modernization of jet propulsion, aimed at improving maneuverability. According to the results of the upgrade of the power plant and the undercarriage, the AAV7A1 machine should improve the mobility indicators, even taking into account a noticeable increase in the combat mass. In addition, the level of ballistic and mine protection will increase significantly.
According to existing calculations, upgrading one floating armored personnel carrier will cost the military department 1,62 million, but the estimate may be revised later. In 2016, it is planned to upgrade several machines that will become prototypes for testing. The checks will be completed by the end of the year, after which the issue of deploying a serial upgrade will be decided. Fully upgrade 40% fleet vehicles planned for 2023 year.
The current plans of the Pentagon involve upgrading more than 400 amphibious armored vehicles AAV7A1, while the remaining 600 units of equipment will remain in their current state. It is assumed that the implementation of these plans will allow to maintain the landing potential of the Marine Corps at the required level, as well as to increase the safety of crews and landing forces in various situations. In this form, the equipment will be operated at least until the 2030 year. In the late twenties, the United States plans to create a promising means of landing amphibious assault forces, which will later replace the existing technology. The development of the latter is carried out under the program Amphibious Combat Vehicle or AVC ("Amphibious Combat Vehicle").
As follows from the published data, as the AVC promising armored vehicles are built and supplied, the AAV7A1 armored personnel carriers that have not undergone modernization under the newest project will be phased out. In the future, the equipment will be replaced, updated in 2017-23. Approximately by the end of the thirties, the last AAV7A1 will be incapacitated and sent for recycling. Their place will be taken by the new AVC. Replacing the existing technology with the newly developed one will allow the ILC to obtain new armored vehicles, which initially have the required characteristics.
To date, one of the main amphibious landing craft of the US Marine Corps in the form of an armored personnel carrier AAV7A1 retains its place in the army and continues to be used to transport and drop personnel or cargo. It is noteworthy that next year marks 45 years from the beginning of the operation of these armored vehicles. In accordance with current plans, the latest machines of this type, which only have to undergo the next upgrade, will be written off no earlier than 2030-35. Thus, the amphibious amphibious assault vehicle LVTP7 / AAV7A1 in the future will get every chance to become one of the "record holders" in terms of length of service.
On the materials of the sites:
http://marines.mil/
http://globalsecurity.org/
http://armyrecognition.com/
http://militaryfactory.com/
http://military-today.com/
http://saper.etel.ru/
http://dogswar.ru/
http://fas.org/
http://defensenews.com/
http://marinecorpstimes.com/
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