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| Sujet: Armored Combat vehicules APC/IFV (blindés..) Jeu 17 Sep 2009 - 3:52 | |
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- M113 into the next Millennium
More than 80,000 M113 Family of Vehicle (FOV) systems have been produced over the past 34 years. As of this writing, new M113 FOV systems are being built while existing chassis are being upgraded to modern configurations.
Since their initial introduction in 1960, M113-based systems have entered service in more than 50 countries. The systems have been modified into more than 40 identified specific variants, with many times that number of minor field modifications. Many of these modifications have been developed by foreign governments to meet their specific national requirements. While some older M113 derivatives are being retired and removed from selected inventories, other FOV members are being upgraded, reconfigured, and introduced as entirely new systems. The original M113 Armored Personnel Carrier (APC) helped to revolutionize mobile military operations. The vehicles were able to carry 11 soldiers plus a driver and track commander under armor protection across hostile battlefield environments. More importantly, the new vehicles were air transportable, air-droppable, and swimmable, allowing planners to incorporate APCs in a much wider range of combat situations, including many "rapid deployment" scenarios. The M113s were so successful that they were quickly identified as the foundation for a family of vehicles. Early derivatives included both command post (M577) and mortar carrier (M106) configurations. The first major upgrade came in 1964 with the introduction of the M113A1 package which replaced the original gasoline engine with a 212 horsepower diesel package. The new power train was soon incorporated into the existing vehicle family as the M113A1, M577A1, and M106A1, as well as several new derivative systems. Some of these new derivatives were based on the armored M113 chassis (the M125A1 mortar carrier and M741 "Vulcan" air defense vehicle) while others were based on an unarmored version of the chassis (including the M548 cargo carrier, M667 "Lance" missile carrier, and M730 "Chaparral" missile carrier). Continuing modernization efforts led to the introduction of the A2 package of suspension and cooling enhancements in 1979. As with previous enhancements, these upgrades resulted in further proliferation of the FOV. Today's M113 fleet includes a mix of these A2 variants together with other derivatives equipped with the most recent A3 RISE (Reliability Improvements for Selected Equipment) package. The standard RISE package includes an upgraded propulsion system (turbocharged engine and new transmission), greatly improved driver controls (new power brakes and conventional steering controls), external fuel tanks, and 200 AMP alternator with 4 batteries. Additional A3 improvements, include incorporation of spall liners and provisions for mounting external armor. The future M113A3 fleet will include a number of vehicles that will have high speed digital networks and data transfer systems. The M113A3 digitization program supports the Army's Modernization Plan by applying applique hardware, software, and installation kits and hosting them in the M113A3 FOV. Current plans call for these systems to be integrated into the M113A3 FOV by the year 2006.
Engine Upgrades A major component of the RISE powertrain incorporated into the original M113A3 and M730A2 vehicles is the turbocharged 275 hp 6V53T engine from Detroit Diesel Corporation. Replacing the earlier 212 hp M113A2 engine with the turbocharged 275 hp model paved the way for improvements in performance as well as survivability enhancements such as the incorporation of spall liners and the possible addition of add-on armor. The improved performance and higher chassis load capacity has also opened the way for planners to consider additional M113 FOV derivatives. Moreover, industry and government initiatives have revealed that the RISE engine rating can be increased to 300 hp through the conversion of injectors. Further testing is currently being conducted on a possible engine upgrade to 350 hp (6V53TA-350 hp) while still retaining the X-200-4A transmission. This additional upgrade requires the installation of glow plug heads (eliminating the need for the current air box heater) as well as changes to the air system and a few other components. The glow plug cold starting system also provides for improved engine starting down to -25°F unaided while utilizing 85 percent less battery power during cold starts (the cold starting system is adaptable to the M113A1, M113A2, and M113A3 engines). The glow plug system is now being installed in the 275 hp RISE engine. Initial testing indicates that the 350 hp engine retains the same external envelope size with a gain of only 45 pounds in weight. The higher horsepower makes a heavier vehicle possible; allowing heavier mission payloads and/or greater armor protection.
Transmission Upgrades The new engine packages have also been accompanied by improvements in the RISE transmission component. The RISE program was introduced with the X200-4 transmission from Allison Transmission. The X-200-4 transmission replaces the three component A2 vehicle drive train (transfer gear case, transmission, steering differential). The new transmission, designed to provide longer life than the previous configuration, has proven durability that is five times greater than the TX-100-1 transmission that it replaced. The Model X200-4 Transmission went into production in 1986 for both the M113A3 and M730A2 RISE powered vehicles. It was designed for use in vehicles up to 32,000 pounds, a top speed of 41 mph, a maximum engine speed of 2800 RPM, and a power rating up to 275 hp. Development of the Model X200-4A Transmission was prompted by the heavier derivative vehicles that will utilize the 300 hp and 350 hp engines noted above. The "4A" model features durability and performance improvements in 6 separate areas. It is capable of operating in vehicles up to 40,000 pounds with a top speed of 41 mph. Most importantly, the new model allows for vehicle power growth up to 350 hp. Because of its application from 275- 350 hp, the X200-4A has been phased into production and is the only transmission currently being produced for the M113A3 RISE variants.
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M113A3 The M113A3 is a product improved version of the M113A2 with improved transmission and engine. The U.S. Army first identified the need to up-power the M113A2 carrier in the mid-1970s. This need was driven by increases in vehicle weight and a requirement to increase the mobility and survivability of the system. As a result, the "RISE" powertrain was developed and tested at Yuma and Aberdeen Proving Grounds. However, application of the new powertrain was deferred due to a lack of funds. In 1984 a decision was made to incorporate the RISE package, improved driver controls, spall liners, external fuel tanks and provisions for installation of an external armor kit on an M113 chassis. Additionally, a bolt-on armor kit providing 14.5 mm ballistic protection was developed and tested. Except for the mounting provisions the external armor applique was not incorporated for production. The new X200-4/4A hydrostatic steer transmission permits use of a more powerful engine, the 275 HP turbocharged Detroit Diesel 6V53T, and eliminates the transfer case and controlled differential. The RISE powerpack increases fuel economy, acceleration, hill climbing speed and braking capabilities and allows the vehicle to maintain speed through corners by accelerating the outer track rather than braking the inner track as on the A2. The increase in horsepower also allows installation of an external armor kit (which increases the gross vehicle weight to 31,000 pounds) and provides mobility comparable to currently fielded vehicles such as the M1 tank and M2/M3 Bradley Fighting Vehicles. Steering is improved with an automotive-type steering yoke and foot brake arrangement which improves driver control, lessens fatigue and simplifies driver training from that of the A1/A2 steering/braking laterals. Due to load matching ability and increased steering capability, cross country performance is also improved. Crew survivability is increased by the addition of spall suppression liners and locating the fuel tanks externally, on the rear of the vehicle. The inside of the vehicle (sides, roof and rear) are covered with spall suppression liners which limit troop injuries from the effect of overmatching weapons by restricting the spread of spall when a round penetrates the hull. External fuel tanks free up 16 cubic feet of usable space inside the vehicle and reduce the fire hazard inside the crew compartment. Two tanks and independent valving provide redundancy in the fuel system allowing continued operation when one tank is damaged. - Citation :
- M113A3+/M113A4 Infantry Fighting Vehicle Light (IFVL)
the Infantry Fighting Vehicle Light (IFVL) is a light infantry fighting vehicle based on the proven MTVL chassis and featuring a one-man stabilized turret is convertible from existing assets or available as new production. It offers the exceptional automotive performance of the MTVL chassis combined with the substantial firepower of the stabilized 25mm chaingun and 7.62mm machinegun. The vehicle is powered by a 400hp 6V53TIA electronically controlled engine driving through the latest X200-4B cross drive transmission. The IFVL uses many common M113/MTVL components that help insure high reliability, availability, and maintainability, plus a proven design, common maintenance techniques and an established logistics infrastructure. Applique armor provides the flexibility to alter the armor package as the threat level changes or technology advances. The vehicle carries a crew of two or three and up to 10 dismount soldiers. As with all M113 variants,it is roll-on/roll-off transportable on a C130. _________________ "La stratégie est comme l'eau qui fuit les hauteurs et qui remplit les creux" SunTzu
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