Advanced Amphibious Assault Vehicle
The US Marine Corps is set to replace its aging fleet of AAV-7 vehicles with the results of the Amphibious Combat Vehicle program.
Authored By: Staff Writer | Last Edited:
The AAV-7 series of assault amphibious vehicles was born as the LVTP-7 in the late 1960s. The initiative called for an armored personnel carrier with sea-going qualities that could serve the United States Marine Corps in transporting men and supplies from off-shore ships to positions inland. The tracked nature and distinct hull design of the vehicle ensured that it could fulfill both requirements and the AAV-7 series has since served with distinction for several decades now. The vehicle is also known as the "Amtrack" or "Battle Bus" and is utilized by the Assault Amphibian Battalions of the USMC. It is expected to be replaced by the results of the ongoing "Amphibious Combat Vehicle" (ACV) program. The AAV-7 has served beyond the USMC with the forces of Argentina, Brazil, Mexico, Italy, South Korea, Taiwan, Spain, Thailand, Venezuela and Indonesia. However, the USMC is, by far, the largest supporter of the AAV-7 vehicle - managing some 1,300 examples in inventory. South Korea is second with approximately 162 units.
For centuries there lived the long-standing challenge in warfare of moving the fighting man from sea to land. This proved a central challenge to the United States Navy/Marines during World War 2 which - along with her allies - was pitted against the entrenched forces of the Empire of Japan across the vastness of the Pacific. The campaign would require the transporting of soldiers, machinery and supplies across thousands of miles of water and land utilizing massive concentrated assaults which proved critical to victory in the Pacific.
One of the key (though largely unsung) heroes the American march to Tokyo was the landing craft. These coastal-minded vessels were launched with a full complement of infantry, support material, fire support equipment and the like against fortified locations across enemy-held beaches. In time, thought was given to a better-armed and armored landing vehicles that could not only traverse bodies of water in transporting infantry but also go ashore and continue the fight inland in support of advancing ground personnel. In essence, a new kind of infantry fighting vehicle would be born and - for the Americans - this came in the form of the "LVT-1" and culminated in the "LVT-4". After the war, the massive "LVT-5" was developed for the same purpose and replaced all preceding types. The LVT-5 held the capability to move up to 34 armed infantry from offshore ships to awaiting beaches while its tracked nature assured mobility beyond that, capable of bringing the fight to the enemy in a whole new way. Armed with a 7.62mm machine gun and powered by a Continental 700 horsepower engine, the LVT-5 was utilized by the United States and several allies (Chile, Philippines and Chile) and eventually emerged in a command vehicle form, a fire support version, an armored recovery variant and a dedicated mine sweeper. The LTV-5 was followed by the limited-run LVT-6.
In the 1960s, the United States Marines began to focus on a replacement for their aging fleet of LVT-5. FMC Corporation was charged with the design and development of a new amphibious armored personnel carrier (APC). This carrier would be capable of operations from US Navy/Marine amphibious assault vessels and carry a full complement of 25 combat-ready personnel or 10,000lbs of cargo. As such, the design would be made buoyant with basic seaworthy qualities while still retaining a capable on-shore infantry fighting vehicle (IFV) component. In September of 1967, the first pilot vehicles (known as the LVTPX12) were made ready for evaluation to which they were then formally adopted for service with the USMC as the LVTP -7 ("Landing Vehicle, Tracked Personnel, Model 7"). Serial production followed with initial deliveries beginning in 1971. Formal operational service of the new vehicle was attained in 1972 with the last LVT-7 delivered in 1974 (FMC Corporation has since been absorbed by defense powerhouse BAe Systems).
The LVTP-7 certainly held a distinct appearance about her with her raised boat-like bow, wheeled-tracked system and slab-sided hull superstructure. The vehicle was given six double-tired road wheels to a track side with the drive sprocket at the front and the track idler at the rear. Ground clearance was 16 inches with an 8-foot trench crossing capability. The front hull held a well-sloped raised underside and near horizontal glacis plate leading up to the flat hull superstructure roof. The hull sides were vertical in their design as was the rear hull facing. The rear facing sported a power-operated large rectangular door for unloading troops and supplies via the door-turned-ramp at speed. There was also a smaller nested door within the door/ramp assembly for a more protected entry-exit. The hull was constructed of all-welded aluminum (up to 45mm thick). The internal configuration saw the driver seated at the front left of the hull with the vehicle commander to his immediate rear (these positions were noted for their individual cupolas along the hull roof). A periscope allowed for outward vision when the vehicle was fully "buttoned" down. A turret was offset to the right-front side of the hull and this served to provide suppression firepower as the unit neared the shoreline and enemy positions inland. The engine was fitted to the front which not only helped to increase frontal protection but also freed the rear internal volume of the hull for the passenger cabin. Up to 25 personnel could be seated across three benches running the length of the design and fixed along the sides and center portion of the cabin. The passenger cabin was also completed with overhead hatches for loading/unloading cargo prior to launch. As completed, the LVTP-7 held an inherent amphibious capability, being able to propel itself in water by its own tracks or via a pair of waterjets fitted aft of the track idlers at the rear.
The original LVTP -7 was powered by a Detroit Diesel 8V-53T 8-cylinder, water-cooled, diesel-fueled turbocharged engine developing 400 horsepower at 2,800rpm. This supplied the vehicle with a top speed of nearly 40 miles per hour on ideal surfaces with a range out to 300 miles. The internal makeup of the LVTP -7 was modular to a certain extent, being able to accept various "kits" for dedicated battlefield roles including MEDEVAC, winterization and dedicated command vehicles. Self-defense was via 1 x 12.7mm Browning heavy machine gun which could be used against enemy infantry, light armored vehicles or low-flying aircraft. Interestingly, the LVTP-7 lacked any vision blocks or firing ports for its passengers and NBC protection was not included.
In 1982, the LVTP-7 series was given a definitive modernization assessment which introduced the LVTP-7 Service Life Extension Program (SLEP). An improved powertrain was incorporated that included a Cummins VT 400 903 series engine of 400 horsepower. 8 x smoke dischargers were added to the turret station while the suspension system was reinforced. The driver's cockpit was revised for the better and night vision was added. A new Cadillac Gage weapons station was introduced which increased the base firepower of the LVTP-7 family - incorporating the original 1 x 12.7mm M2HB Browning heavy machine gun with a 40mm Mk 19 automatic grenade launcher. The new vehicle was designated as the "LVTP-7A1" to help differentiate it from the preceding operational mark. However, the United States Marine Corps redesignated the new production mark as the "AAV-7A1" (AAV = "Amphibious Assault Vehicle") in 1984. Several key identifying features of the new variant were its squared headlight installations (as opposed to the original's round types) and its dual-weapon turret station. An optional mine clearance kit was made available prior to 1991.
To compensate with the growing threats of the modern battlefield, the EAAK (Enhanced Applique Armor Kit) was later devised which would increase the AAV-7A1s baseline protection through a shaped-steel external armor fitting. This, in turn, forced the RAM/RS (Reliability, Availability, Maintainability, Rebuilt to Standard) program to be instituted to counter the weight gains of the EAAK installation. Updates therefore included a more powerful engine and revised suspension system (these based on the existing M2 Bradley IFV though appropriately modified) which all served to bring the AAV-7 back to its original pre-weight gain specifications. All AAV-7A1s have since been upgraded to this new standard.
The AAV-7A1 exists in two other primary forms beyond the basic combat vehicle (AAVP-7A1). This includes the "AAVC-7A1" command vehicle which noticeably lacks the turret emplacement and includes additional communications equipment in the passenger cabin. The other variant is the "AAVR-7A1" which is a dedicated armored recovery vehicle (ARV) also lacking its turreted armament. The recovery vehicle does include a heavy-duty powered crane (which folds down onto the right hull roof side) among other recovery-minded features.
The LVTP-7/AAV-7 has since been utilized in a variety of high-profile conflicts since its inception in 1972. The type was used by Argentine marine forces in the 1982 Falklands War with Britain. LVTP-7s were part of the multi-national effort to ensure peace in war-torn Beirut during the early-to-mid 1980s. Such vehicles were also part of the US Invasion of Grenade during 1983 (as part of Operation Urgent Fury). The vehicle family received much notoriety in the 1991 Gulf War with USMC forces during the liberation of Kuwait and subsequent destruction of the Iraqi Army though they proved susceptible to enemy rocket and mortar attacks in turn. Following its Persian Gulf deployment, AAV-7s were back in action in support of humanitarian requirements concerning Somalia. More recent operational use has included stints in both the US Invasion of Afghanistan (2001) and the US Invasion of Iraq (2003) - these conflicts precipitated by events surrounding 9/11. AAV-7s maintain an operational service status with the USMC to date (2012) though it is expected that the type will have maximized its service potential in the next few years.
As such, the proposed "Expeditionary Fighting Vehicle" (EFV) program was developed to take the reins of the AAV-7 family. However, this program was cancelled leading to the introduction of the "Amphibious Combat Vehicle" (ECV) program to take its place. The program intends to produce an all-modern vehicle complete with digitally-stabilized and modular armament, full amphibious support, low-profile/stealth-minded design features mobility to keep pace with the current US Marine Corps mechanized offerings including the Bradley IFV and M1 Abrams MBT vehicles. The initiative is ongoing as of 2012.