Thursday, August 13, 2015

HMMWV Alternatives

The army has purchased a purpose-built armored car, the M1117 Armored Security Vehicle in limited numbers for use by the United States Army Military Police Corps. In 2007, the Marine Corps announced an intention to replace all HMMWVs in Iraq with MRAPs due to high loss rates, and issued contracts for the purchase of several thousand of these vehicles, which include the International MaxxPro, MATV, the BAE OMC RG-31, the BAE RG-33 and Caiman, and the Force Protection Cougar, which have been deployed primarily for mine clearing duties. Heavier models of infantry mobility vehicles (IMV) can also be used for patrol vehicles. The Maxxpro Line has been shown to have the highest rate of vehicle rollover accidents to its very high center of gravity and immense weight. The massive weight of these vehicles combined with their high center of gravity also greatly reduces their utility in off road situations versus the HMMWV which was the primary cause for the push for the M-ATV to be developed quickly. 

Humvee replacement process The Humvee replacement process, now being undertaken by the U. S. military, is focused on interim replacement with MRAPs and long-term replacement with the Joint Light Tactical Vehicle (JLTV). The HMMWV has evolved several times since its introduction, and is now used in tactical roles for which it was never originally intended. The military is pursuing several initiatives to replace it, both in the short and long terms. The short term replacement efforts utilize commercial off-the-shelf vehicles as part of the Mine Resistant Ambush Protected (MRAP) program. These vehicles are procured to replace Humvees in combat theaters. The long term replacement for the Humvee is the Joint Light Tactical Vehicle which is designed from the ground up. The Future Tactical Truck Systems (FTTS) program was initiated to make an analysis of potential requirements for a Humvee replacement. Various prototype vehicles such as the Millen Works Light Utility Vehicle, and the ULTRA AP have been constructed as part of these efforts. 

The U. S. Marine Corps issued a request for proposals (RFP) in 2013 for its Humvee sustainment modification initiative to upgrade 6,700 expanded capacity vehicles (ECVs). The Marines plan to field the Joint Light Tactical Vehicle, but do not have enough funding to completely replace all Humvees, so they decided to continue sustaining their fleet. Key areas of improvement include the suspension, engine, and transmission. Upgrades to the suspension would reduce the amount of force transferred to the chassis, lowering operation and maintenance costs. Additionally, upgrades to the engine and transmission would help to make the vehicles more fuel efficient, and enhancements to the cooling system will better prevent overheating. The Marine Corps is also looking at incorporating a central tire inflation system to allow for reduced tire pressures during off-road use to improve mobility and ride quality. They are also seeking to increase the underbody survivability. Testing of upgraded Humvees will occur in 2014, with production and installation occurring from 2015 through 2018. 

Older A2 series Humvees make up half the current fleet, and 4,000 are to be disposed of through foreign military sales and transfers. By 2017, the Marines’ light tactical vehicle fleet is to consist of 3,500 A2 series Humvees, 9,500 ECV Humvees, and 5,500 JLTVs, with 18,500 vehicles in total. Humvees in service with the Marine Corps will be upgraded through 2030. Oshkosh Corporation is offering Humvee upgrades to the Marine Corps in addition to its JLTV offering. Oshkosh has developed modular and scalable Humvee upgrade solutions, providing varying levels of capabilities at a range of price points, that can be provided individually or as complete solutions for upgrading all critical vehicle systems. Their approach addresses requirements for engine and powertrain, suspension, driveline, hubs and brakes, frame and hull, electrical, cooling, and auxiliary automotive improvements. The TAK-4 independent suspension system delivers 70 percent off-road profile capability, improved ride quality, and a 40 percent increase in maximum speed. It also gives greater whole vehicle durability, a restored 2,500-pound payload capacity, and a restored ground clearance of 17 inches. Oshkosh also can deliver a modern engine option that's more powerful than the Humvee's stock engine and provides increased fuel efficiency. The U. S. Army and Marine Corps have vowed commitment to buying nearly 55,000 JLTVs even in the face of sequestration cuts. This level of support is given while major acquisition programs like the Ground Combat Vehicle were in danger of cuts (and eventually cancelled), which potentially meant the Army favored replacing Humvees more than the M2 Bradley. How many light vehicles that will need to be reduced are still being determined, but they are hoped to direct the effects to the existing Humvee fleet. 

In October 2014, Northrop Grumman unveiled a new chassis and power train for the Humvee that would combine the mobility and Payload capabilities of original vehicle variants while maintaining the protection levels of up-armored versions. During operations in Iraq and Afghanistan, the threat of IEDs and close-range combat prompted the addition of armor to Humvees to increase protection, but it was heavy which decreased fuel economy and mobility and increased stress on the chassis. Lower fuel efficiency increased the need for tanker trucks to supply them, threatening logistics through more traffic on vulnerable roads. The new chassis increases fuel efficiency to 16-18 miles per gallon and allows the vehicle to accelerate to over 60 mph (97 km/h) in 22 seconds. Installation can be done through removing the six attachment bolts and the electrical connections, lifting the body of the Humvee off, rolling the old chassis out, and rolling the new chassis in; the chassis includes a new power train, Transmission, and transfer case. Although the Army has not signed off on the upgrades, the company has installed the new chassis on four Humvees through a cooperative agreement with the Army, two of which have been delivered for trials.


Textron has offered another Humvee upgrade option to rival Northrop Grumman's. Called the Survivable Combat Tactical Vehicle (SCTV), it not only restores mobility but improves survivability over armored Humvee levels. It was developed as a blast protected cab solution with a stronger frame and suspension with underbody armor and the ability to mount additional B-kit armor. It has a 6.7L 275 hp engine system with 2500 SP Allison transmission that can power an increased gross vehicle weight of 18,500 lb (8,400 kg) (verses 13,450 lb (6,100 kg)) with four more inches of ground clearance, one-inch larger brakes, larger wheels and tires, and an improved internal layout with four inches of additional headroom. The battery pack was moved from under the passenger seat to outside under the hood and the 27-gallon plastic fuel tank was changed to a 40-gallon stainless steel container moved from under the transmission tunnel to behind the back wall. 

Available in four-door, two-door ambulance, and nine-seat troop carrier variants. The SCTV costs $200,000 compared to $145,000 for Northrop Grumman's solution, but the company claims It can restore the Humvee for operational use while the JLTV takes time to be introduced; both the Army and Marines have acquired about half a dozen vehicles each for testing.

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