and only require an oil change every two years! Working through an automatic transmission, it will drive a pair of powerful 23-in./60-cm-diameter water jets, which will drive it through the water at speed approaching 43 mph/70.5 kph in calm seastates. The propulsion system is so powerful that the twin sets of impeller blades will puree a four- inch-by-four-inch log without a blink. Once it approaches to within a few hundred yards/meters of the beach, the track system will take over, still pushing the AAAV through the surf at around 8 mph/13 kph. Once on dry land, the AAAV will have better mobility than an M 1 Abrams tank, while only using about 800 hp from the engine.
• Retractable Track System—If the AAAV is to obtain high speeds through the water, the track system must be shrouded from the water flow under the vehicle. To this end, the AAAV's track system retracts into the vehicle, and is dropped when it approaches the beach. All of this takes place in just under twenty seconds. Once on dry land, it utilizes the same kind of hydropneumatic suspension system as the M1, which will give it excellent mobility.
• Armor Protection System—The armor-protection system of the AAAV will likely take advantage of the advanced composite armor development being done by United Defense. This will allow the relatively large (27 ft/8.2 m long, 12 ft/3.7 m wide, and 10 ft/3 m tall) AAAV to weigh in at only thirty to thirty-six tons, yet still have better protection than the M2/3A3 variant of the Bradley IFV. In addition, there appears to be some effort to reduce the acoustic, infrared, visual, and possibly even radar signatures of the AAAV.
• Vehicle Electronics System—Like the M1A2 Abrams and M2/3A3 Bradley, the AAAV will be equipped to operate on the planned digital battlefield of the 21st century. This will include second-generation FLIR viewer systems for the driver and gunner/commander. In addition, the AAAV will be equipped with the same kind of vehicle electronics as the M1A2 and MZ/3A3, including a digital data bus with onboard diagnostics, GPS tied to a moving map display, a combat identification system to avoid fratricide, and a digital data link fed through three of the new SINCGARS jam-resistant radios. All of this will be controlled by a vehicle software package that will be composed of between 300,000 and 500,000 lines of Ada code, over a Mil. STD-1553 data bus. The driver will even control the throttle, steering, and brakes through a computer, what the Marines call a 'drive-by-wire' system!
• Armament Package — While this particular item is still being decided upon, current planning has the AAAV equipped with an M242 25mm Bushmaster cannon and a 7.62mm machine gun, like those on the M2/3 Bradley and the LAV-25. There had been plans to perhaps arm the new amtrac with a special 35mm cannon firing time-fused ammunition, but this will probably not happen. But it may carry a twin launcher for the new fire-and-forget Javelin anti-armor missile, if all goes well. All of the AAAV's armament will be usable both in the water and on dry land, and is designed to provide it with the firepower to survive and overmatch other armored vehicles on the battlefield.
• Payload/Range—Each AAAV will be capable of transporting a thirteen-man rifle squad and a heavy weapons team — about eighteen personnel plus the three-man crew. Given this load, the AAAV will be capable of swimming up to 65 nm/120 km, or traveling up to 300 mi/483 km on dry land. A normal mission configuration would have the vehicle swimming in from about 25 nm/46 km offshore, moving about 100 mi/161 km to and from the objective, and then swimming back to the mother ship. The minimum high water speed will be 25 mph/40.2 kph, and maximum 43 mph/69.2 km. All of this in seas up to 10 ft/3 m. In the event an AAAV is overturned, it is capable of righting itself automatically in up to Seastate 5.
• Production Variants—Current USMC plans call for a total of 1,013 AAAVs to be produced by 2012, the planned termination date of the contract. Of these, there will be 948 transport versions, and 75 configured as mobile command posts. Planned IOC will be in 2006, and the 1,013 AAAVs will replace a force of 1,323 LVTP-7/AAV-7 amtracs. There will not be a recovery version, since it is planned that other chassis (the M88 carried for the M1A1s) can do double duty for this job. Unit cost has yet to be fixed, but will likely be between $2 and $4 million a copy (comparable to the cost of a new M1A2 MBT). Hard work is being done to drive this cost down.
It is likely that the AAAV will be the last armored vehicle procured by the Marine Corps in the foreseeable future. It therefore must be able to survive and dominate its chosen battlespace for most of the first half of the 21st century. It is an ambitious program, though all of the technologies are well proven and understood by all of those involved.
Transportation
While Marine units are anything but 'heavy' where vehicles are concerned, they still require their share of trucks and other transportation assets to keep themselves supplied and mobile. For this reason, the Corps has carefully selected a few varieties of transport vehicles to support their expeditionary units, and is generally quite happy with them. A proper complement of transport vehicles is vital for a unit like a MEU (SOC), since there is only so much room aboard its amphibious ships to stow its gear. In fact, while you will find about thirty armored vehicles in such a unit, it will have over one hundred trucks of different types, including those mounting machine guns, mortars, and missiles. Here are the most important of these:
AM General M998 High-Mobility Medium Wheeled Vehicle (HMMWV)
The vast majority of vehicles in the Army and Marine Corps today derive from the classic M998 High-Mobility Medium Wheeled Vehicle (HMMWV). Like the Army, the Corps has embraced the 'Hummer,' and it has performed nobly in a vast variety of tasks. Produced for over a decade by AM General of South Bend, Indiana, the HMMWV is used for everything from ambulance duty to air defense. Powered by a diesel V-8 engine, it is practically indestructible and can climb anything that a member of any military force in the world might want to take and hold. Today, the Marine Corps' buy of Hummers is pretty much complete, though there will probably be additional buys in the 21st Century as older models wear out. As it is, the M998s that the Marines use are being heavily used, and will probably require a mid-life service life-extension program (SLEP) sometime in the next ten years or so. In the short term, if a Marine offers you a ride, expect it to be in an HMMWV
M923 5-Ton Truck
No implement of war seems less glamorous than the 5-ton truck, but none is more vital, or causes more sleepless nights for the commander. During World War II, the rapid advance of General Eisenhower's armored spearheads was only made possible by a stream of rugged, reliable GM 4X6 trucks. Today's 5-ton trucks are very similar to that 1940s-era design, except that diesel engines replace the old gasoline models. Unfortunately, today's 5-ton trucks are also very old. To put it simply, the Marines' truck fleet is worn out and undersized. With 8,300 vehicles in inventory, you might think there are plenty of trucks to go around, but large numbers of them are tied up on maritime prepositioning ships, in depots, and in support of fixed bases in the rear.
The term '5-ton' describes the nominal cargo capacity, not the empty weight of the vehicle, which is 21,600 1b/9,800 kg. The 5-ton is 25.6 ft/7.8 m long and 8.1 ft/2.5 m wide, and has three axles. The two rear axles are powered and have twin tires on each side, which are tied to a five-speed automatic transmission. The engine is a six-cylinder in-line, liquid-cooled diesel of 250 hp, and the fuel tanks hold 81 gal/306 L, sufficient to take the truck 350 mi/560 km down the highway. The 24-volt electrical system is sufficient to power a radio when one is fitted, and many are also equipped with SLGR GPS receivers. Engineer units are equipped with dump truck and wrecker models, which are subject to particularly severe wear and tear. A major rebuild and SLEP are currently under way to keep the Corps' truck fleet rolling into the 21st century.
