June 14, 2024: The U.S. Marine Corps used their new ACV (Amphibious Combat Vehicle) in an overseas training operation in the Philippines. This involved a live fire exercise in Oyster Bay using the marine ACV vehicles. The ACV automatic 40mm grenade launchers fired training rounds that contained yellow chalk. These rounds are often used to mark a target for other weapons.

The current version of the ACV has a V shaped hull instead of the original flat bottom. The V shaped hull, plus high ground clearance, provides more protection for personnel on board when the vehicle encounters a roadside bomb, landmine, or any other nearby explosions, like artillery shells landing. So far, the marines have received 184 ACVs. Each of these armored 8x8 wheel amphibious vehicles weigh 35 tons with a 3.3 ton payload. There is a crew of three and room for 13 passengers plus over a ton of cargo. Road speed is 105 kilometers an hour and 12 kilometers in the water for a distance of up to 21 kilometers.

In late 2020 the U.S. Marine Corps was able to begin receiving production versions of its new ACV 1.1 because the vehicle was declared to have achieved IOC (Initial Operational Capability). This ends more than two decades of effort and over three billion dollars spent to come up with a suitable replacement for the AAV7 amphibious armored vehicle. The AAV7 entered service in 1972 with an initial order for 942 and that was completed by 1974. Eventually over 3,000 were built with most being exported to eleven countries.

When the search for a AAV7 replacement began in the late 1990s, the U.S. Marine Corps had over 1,100 in service and many of these had already been refurbished and upgraded in the 1980s and would need further refurbishment to keep them in service when the marines failed to develop a suitable replacement. In 2011 the $3 billion EFV (Expeditionary Fighting Vehicle) project was declared a failure. Proposals for a new AAV7 were requested and by 2015 there were five proposals for the new ACV. The marines spent $240 million so the two finalists could each build sixteen of their vehicles for competitive testing that began in 2016. Selection of the winning design, by European defense firm BAE, was made in 2018.

BAE offered a variant of an existing vehicle; the SuperAV 6x6 already used by the Brazilian Army as the VBTP-MR Guarani. This was important because the marines, and their budget, could not afford another vehicle design that looked good on paper but impossible to make work in reality. The ACV version is an 8x8 vehicle weighing 31.5 tons and carrying 13 marines plus 3 crew. Among the modifications required were amphibious capability, the use of lighter modular composite armor including ceramics, and design features that make ACV equal, if not better at resisting mine and IED explosions than MRAP (Mine Resistant Ambush Protected) vehicles using steel armor. ACV has an improved V shaped hull design with additional blast protection features for the floors as well as blast resistant seats attached to the troop compartment’s ceiling instead of the bottom of the vehicle’s hull. All these features had already been found, by trial and error in Iraq and Afghanistan, to greatly reduce casualties for vehicles attacked by landmines or roadside bombs. Such features had been successfully added to existing armored vehicles like the Stryker and this reassured the marines.

The initial production contract was for 30 ACV 1.1 vehicles that were delivered by late 2019 for testing and an effort to achieve IOC and allow full production of the remaining 184 vehicles. Each ACV 1.1 costs about $5.9 million. Prolonged use of ACV 1.1 is expected to produce a number of proposals for modifications and upgrades that will result in ACV 1.2. When that happens all ACVs will be upgraded to the 1.2 standard to produce a more reliable and capable ACV. How far these upgrades go depends on how much the marines can afford to spend on the project. Some of the items on the 1.2 to-do list have priority because they have to do with survivability and reliability. For example, the ACV is cramped inside, more so than the AAV7 and it takes longer for passengers to get out in an emergency. This is crucial if the ACV sinks while swimming ashore or finds itself still aboard an amphibious ship and ready for deployment when the amphibious ship itself takes a hit and starts to sink. That’s an extreme situation but individual vehicles sinking does happen during peacetime training. Another urgent fix is the reliability of some of the electronic devices on the vehicle. Many of these are being fixed or replaced even as production is underway and then existing ACVs are upgraded. Eventually the marines want over 500 ACVs to replace over a thousand AAV7s.

As good as the ACV sounds, this was not how it was supposed to be. Before 2014 marine doctrine mandated an improved amphibious vehicle to replace the AAV7s. In 2014 the marines revised their view of the future. Gone were the prospects of large amphibious operations, requiring hundreds or thousands of landing craft, that occurred frequently during World War II. The last operation of this type occurred in 1950, at Inchon, Korea. In 2014 the marines decided that the future was more likely to include the need to conduct raids, from ships up to 200 kilometers offshore. No amphibious armored vehicles could handle that, so landing tactics have to be changed. This resulted in major revisions to the specs for the new marine ACV amphibious armored vehicle.

The 2015 reality turned out to be different, and better. Given the prototypes offered and growing budget reductions it looked like the ACV 1.1 finalist would have the capability of moving from 20 kilometers offshore under its own power. To accomplish this the marines had to accept a vehicle that carried fewer marines and was somewhat less capable in the water. The AAV7 has 30 percent reserve buoyancy enabling it to cross 36 kilometers of water in sea state 5 at speeds of up to 12 kilometers an hour. The ACV 1.1 has 21 percent reserve buoyancy enabling it to cross 36 kilometers of water in sea state 3 at speeds of up to 11 kilometers an hour. On the plus side the ACV has wheels, not a track laying system, and can do 105 kilometers an hour on roads versus 72 for the AAV7. In addition, wheeled armored vehicles require far less maintenance that tracked ones (which need their tracks replaced far more frequently than wheels wear out.)

Meanwhile the marines refurbished the existing 1970s era AAV7 amphibious armored vehicles to prolong service life until ACV can replace them. In addition to better protection, the elderly AAV7s will be refurbished so they can remain in use until the mid-2020s. At that point there should be enough ACVs to replace them. The marines never expected the AAV7s to last this long but several attempts to develop a replacement came up short and that meant it was essential to extend the life of their thousand AAV7 amphibious armored vehicles. Many of these had entered service in the 1970s and 80s and were falling apart. Moreover, some two thirds of the AAV7s saw service in Iraq, where they got as much use in two months as they normally did in two years of peacetime operations. In 2018 400 AAV7s began a refurbishment program that took several years. The refurbished AAV7s could be used into the 2030s, or whenever the ACV are available in large enough numbers to replace them. With the recent ACV IOC and full production of ACV 1.1 it looks like the AAV7s will be needed until about 2025. That’s over fifty years for an amphibious vehicle that did a lot more than it was expected to.

The 29-ton AAV7s have crews of four (driver, commander, gunner and rear crewman) and carry 25 combat-ready marines as passengers. The vehicle is armed with a 40mm automatic grenade launcher and a 12.7mm machine-gun. When new their top land speed was 72 kilometers an hour on roads, 32 off road and 13 in water.

Back in 2011 the marines gave up on high-speed (sea skimming) amphibious assault vehicles and turned to a new ACV design to replace the AAV7s. DARPA (the Defense Advanced Research Projects Agency) was called in to help design the new vehicle. This may sound either very innovative or very desperate, and in reality, it was both. The marines had spent three billion dollars in an unsuccessful attempt to design and develop the EFV, a high-speed amphibious vehicle, and its failure made it clear that some original thinking was required. In the end the ACV was the EFV without most of the expensive stuff that didn't work. In effect, the ACV was a 21st century version of the AAV7, optimized to pass all its development tests and go into service as quickly as possible. DARPA quickly did its job but the resulting ACV was still more expensive ($12 million) than the shrinking marine budget could handle. The ACV design was tweaked until an affordable price was achieved.

In retrospect, the marines could have just built the EFV without the high-speed capability but that was eventually considered technically and politically impractical. The problem remains that the technology simply does not yet exist yet to make the high-speed capability workable. The budget situation was grim, leaving the usually unstoppable Marine Corps running into an immovable object and improvising as best they could. For example, the marines asked the navy to develop a high-speed amphibious craft (or “connector”) to get ACVs to shore quickly but the navy budget is also shrinking and proved unable to handle the cost of developing and building the connector. Some marine analysts point out that the need for moving amphibious vehicles 200 kilometers from ship to shore is probably unrealistic for any likely future marine operations. For that sort of thing the marines have nearly 300 tilt-wing V-22 aircraft. These entered service in 2007 and proved very useful for getting marines somewhere faster than any other option.