page_title: M1 Abrams
section_title: Tactical
hierarchical_section_title: M1 Abrams / Design / Mobility / Tactical
caption_attribution_description: Marines from 1st Tank Battalion, Twentynine Palms, California, load a Honeywell AGT1500 gas turbine engine from an M1A1 Abrams tank engine back into the tank at Camp Coyote, Kuwait during Operation ENDURING FREEDOM. Location: TA COYOTE
context_page_description: The M1 Abrams is a third-generation American main battle tank designed by Chrysler Defense. Conceived for modern armored ground warfare and now one of the heaviest tanks in service at nearly 68 short tons, it introduced several innovative features, including a multifuel turbine engine, sophisticated Chobham composite armor, a computer fire control system, separate ammunition storage in a blow-out compartment, and NBC protection for crew safety. Initial models of the M1 were armed with a licensed-produced 105 mm Royal Ordnance L7 gun, while later variants feature a licensed Rheinmetall 120 mm L/44.
  The M1 Abrams was developed from the failure of the MBT-70 project to replace the obsolescent M60 Patton. There are three main operational Abrams versions, the M1, M1A1, and M1A2, with each new iteration seeing improvements in armament, protection, and electronics. Efforts to develop an M1A3 version were first publicly disclosed in 2009. Extensive improvements have been implemented to the latest M1A2C and D versions such as improved composite armor, better optics, digital systems and ammunition.
context_section_description: The M1 Abrams's powertrain consists of a Honeywell AGT 1500 (originally made by Lycoming) multifuel gas turbine capable of 1,500 shaft horsepower (1,100 kW) at 3,000 rpm and 3,950 lb⋅ft (5,360 N⋅m) at 1,000 rpm, and a six-speed (four forward, two reverse) Allison X-1100-3B Hydro-Kinetic automatic transmission, giving it a governed top speed of 45 mph (72 km/h) on paved roads, and 30 mph (48 km/h) cross-country. With the engine governor removed, speeds of around 60 mph (97 km/h) are possible on an improved surface; however, damage to the drivetrain (especially to the tracks) and an increased risk of injuries to the crew can occur at speeds above 45 mph (72 km/h). The tank was built around this engine and it is multifuel–capable, including diesel, kerosene, any grade of motor gasoline, and jet fuel (such as JP-4 or JP-8). For logistical reasons, JP-8 is the U.S. military's universal fuel powering both aircraft and vehicle fleets. On the other hand, Australian M1A1 AIM SA burn diesel fuel, since the use of JP-8 is less common in the Australian Army.
  The gas turbine propulsion system has proven quite reliable in practice and combat, but its high fuel consumption is a serious logistic issue (starting up the turbine alone consumes nearly 10 US gallons (38 L) of fuel). The engine burns more than 1.67 US gallons (6.3 L) per mile (60 US gallons (230 L) per hour) when traveling cross-country and 10 US gallons (38 L) per hour when idle. The high speed, high temperature jet blast emitted from the rear of M1 Abrams tanks makes it hazardous for infantry to take cover or follow behind the tank in urban combat. The turbine is very quiet when compared to diesel engines of similar power output and produces a significantly different sound from a contemporary diesel tank engine, reducing the audible distance of the sound, thus earning the Abrams the nickname "whispering death" during its first Reforger exercise.
  Honeywell was developing another gas turbine engine with General Electric for the XM2001 Crusader program that was to be a replacement for the Abrams's AGT-1500 engine. The new LV100-5 engine was lighter and smaller (43% fewer parts) with rapid acceleration, quieter running, and no visible exhaust. It also featured a 33% reduction in fuel consumption (50% less when idle) and near drop-in replacement. The Abrams-Crusader Common Engine Program was shelved when the Crusader program was canceled, however Phase 2 of Army's PROSE (Partnership for Reduced O&S Costs, Engine) program called for further development of the LV100-5 and replacement of the current AGT-1500 engine.
  General Dynamics has been working on a drop-in diesel engine to replace the gas turbine engine. It is smaller than the turbine, 14% cheaper to operate per mile, and has a four-fan cooling system that is to greatly reduce the tank's heat signature. General Dynamics is offering the Tognum America/12V883 diesel engine with new Diehl 570P3 tracks. The engine represents advancements in diesel engine design since the Abrams was first designed, including a common rail fuel injector system where fuel is pressurized and atomized in the cylinder rather than mechanically sprayed. It also has greater torque, an altered nuclear, biological, and chemical protection system that operates independently of the engine, uses less fuel while idle, is quieter, and gives off significantly less heat and pollutants. Incorporating the diesel engine into the Abrams would decrease the operating cost of an armored brigade combat team by 14 percent per mile, increase its operating range from 205 miles to 300+ miles, and use half the amount of fuel on a combat day than the turbine engine. The tracks are a version of the Leopard 2's tracks with different rubber pads and a larger center guide. The improved engine and tracks are not part of an Army upgrade program, but may be included in a near-term engineering change proposal (ECP) phase.
  Using a high power density 330 cc (20 in³) Wankel rotary engine modified to use diesel and military grade jet fuel, the Army's TARDEC developed a 220-pound (100 kg) A
caption: Marines from 1st Tank Battalion load a Honeywell AGT1500 multi-fuel turbine back into the tank at Camp Coyote, Kuwait, February 2003.
exif: {"Image ImageDescription": "Marines from 1st Tank Battalion, Twentynine Palms, California, load a Honeywell AGT 1500 gas turbine engine an M1A1 Abrams tank engine back into the tank at Camp Coyote, Kuwait during Operation ENDURING FREEDOM.", "Image Orientation": "Horizontal (normal)", "Image XResolution": "172", "Image YResolution": "172", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Adobe Photoshop 7.0", "Image DateTime": "2004:06:10 10:20:04", "Image Artist": "SGT PAUL L. ANSTINE II, USMC", "Image ExifOffset": "420", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "558", "Thumbnail JPEGInterchangeFormatLength": "5547", "EXIF ColorSpace": "Uncalibrated", "EXIF ExifImageWidth": "1728", "EXIF ExifImageLength": "1152"}