This sensor also will be added to older M1A2s starting in FY 2001. When the SEP enters production, the Army will have a total of 627 M1A2s, all of which will eventually be converted to the SEP configuration. Further M1A2 improvements, called the System Enhancement Program (SEP), are underway to enhance the tank's digital command and control capabilities and to to improve the tank’s fightability and lethality. The M1A2 SEP (System Enhancement Package), is the digital battlefield centerpiece for Army XXI. It is the heavy force vehicle that will lead Armor into the next century and transition the close combat mission to the Future Combat System (FCS). The M1A2 SEP is an improved version of the M1A2. It contains numerous improvements in command and control, lethality and reliability. M1A2 SEP is in final operational testing, and scheduled to start fielding in 2000. M1A2 SEP tanks are scheduled to begin fielding in 3QFY00. The M1A2 System Enhanced Program (SEP) is an upgrade to the computer core that is the essence of the M1A2 tank. The SEP upgrade includes improved processors, color and high resolution flat panel displays, increased memory capacity, user friendly Soldier Machine Interface (SMI) and an open operating system that will allow for future growth. Major improvements include the integration of the Second Generation Forward Looking Infared (2nd Gen FLIR) sight, the Under Armor Auxiliary Power Unit (UAAPU) and a Thermal Management System (TMS). The 2nd Generation Forward Looking InfraRed sighting system (2nd Gen FLIR) will replace the existing Thermal Image System (TIS) and the Commander's Independent Thermal Viewer. The incorporation of 2nd Gen FLIR into the M1A2 tank will require replacement of all 1st Gen FLIR components. From the warfighter perspective, this is one of the key improvements on the SEP. The 2nd Gen FLIR is a fully integrated engagement-sighting system designed to provide the gunner and tank commander with significantly improved day and night target acquisition and engagement capability. This system allows 70% better acquisition, 45% quicker firing and greater accuracy.
The commander's station is equipped with six periscopes, providing 360 degree view. The Raytheon Commander's Independent Thermal Viewer (CITV) provides the commander with independent stabilised day and night vision with a 360 degree view, automatic sector scanning, automatic target cueing of the gunner's sight and back-up fire control. The M1A2 Abrams tank has a two-axis Raytheon Gunner's Primary Sight- Line of Sight (GPS-LOS) which increases the first round hit probability by providing faster target acquisition and improved gun pointing. The Thermal Imaging System (TIS) has magnification x10 narrow field of view and x3 wide field of view. The thermal image is displayed in the eyepiece of the gunner's sight together with the range measurement from a laser rangefinder. The Litton Laser Systems Eyesafe Laser Rangefinder (ELRF) has a range accuracy to within 10 m and target discrimination of 20 m. The gunner also has a Kollmorgen Model 939 auxiliary sight with magnification x8 and field of view 8 degrees. The digital fire control computer is supplied by Computing Devices Canada. The fire control computer automatically calculates the fire control solution based on: lead angle measurement; bend of the gun measured by the muzzle reference system; velocity measurement from a wind sensor on the roof of the turret; data from a pendulum static cant sensor located at the centre of the turret roof. The operator manually inputs data on ammunition type, temperature, and barometric pressure. The driver has either three observation periscopes or two periscopes on either side and a central image intensifying periscope for night vision. The periscopes provide 120 degrees field of view. The Raytheon Driver's Vision Enhancer (DVE), AN/VSS-5, is based on a 328 x 245 element uncooled infrared detector array, operating in the 7.5 to 13 micron waveband. A Raytheon Driver's Thermal Viewer, AN/VAS-3, is installed on the M1A2 Abrams tanks for Kuwait.
In addition, a gain of 30% greater range for target acquisition and identification will increase lethality and lessen fratricide. The Commander’s Independent Thermal Viewer (CITV) provides a hunter killer capability. The 2nd GEN FLIR is a variable power sighting system ranging from 3 or 6 power (wide field of view) for target acquisition and 13, 25 or 50 power (narrow field of view) for engaging targets at appropriate range. The UAAPU consist of a turbine engine, a generator, and a hydraulic pump. The generator is capable of producing 6 Kilowatts of electrical power at 214 Amps, 28 vdc, and the hydraulic pump is capable of delivering 10 Kilowatts of hydraulic power. The UAAPU can meet the electrical and hydraulic power to operate all electronic and hydraulic components used during mounted surveilance operations and charge the tank's main batteries. The UAAPU will reduce Operational and Support cost by utilizing the same fuel as the tank at a reduced rate of 3-5 gallons per operational hour. The UAAPU is mounted on the left rear sponson fuel cell area and weighs 510 pounds. Another improvement in the M1A2 SEP is the Thermal Management System (TMS) which keeps the temperature within the crew compartment under 95 degrees and the touch temperature of electronic units under 125 degrees during extreme conditions. By reducing the temperature in the crew compartment for the crew and electronic units, this increases the operational capability for both soldiers and the vehicle. The TMS consists of an Air Handling Unit (AHU) and a Vapor Compression System Unit (VCSU) capable of providing 7.5 Kilowatts of cooling capacity for the crew and Line Repairable Units (LRUs). The AHU is mounted in the turret bustle and the VCSU is mounted forward of the Gunner's Primary Sight (GPS). The TMS uses enviromentally friendly R134a refrigerant and propylene glycol/water mixture to maintain the LRU touch temperature at less than 140 degrees Fahrenheit. The TMS is mounted in the left side of turret bussel and weighs 384 pounds. The Army requires that all systems operate in the Army Common Operating Environment (ACOE) to improve combined arms operations. Digitization and information dominance across the entire Army for tactical elements is accomplished using Force XXI Battle Command for Brigade and Below (FBCB2) software. In Abrams, FBCB2 software is hosted on a separate card that enables situational awareness across the entire spectrum of tactical operation. It improves message flow, through 34 joint variable message formats, reports ranging from contact reports to logistic roll ups, as well as automatically providing vehicle location to friendly systems. The SEP allows for digital data dissemination with improved ability to optimize information based operations and maintain a relevant common picture while executing Force XXI full dimensional operation. This enhancement increases capability to control the battlefield tempo while improving lethality and survivability. Finally to ensure crew proficiency is maintained, each Armor Battalion is fielded an improved Advanced Gunnery Training System (AGTS) with state-of-the-art graphics.
Changes to the M1A2 Abrams Tank contained in the System Enhancement Program (SEP) and "M1A2 Tank FY 2000" configuration are intended to improve lethality, survivability, mobility, sustainability and provide increased situational awareness and command & control enhancements necessary to provide information superiority to the dominant maneuver force. The Abrams Tank and the Bradley Fighting Vehicle are two central components of the dominant maneuver digital force. System Enhancement Program upgrades are intended to: improve target detection, recognition and identification with the addition of two 2nd generation FLIRs. incorporate an under armor auxiliary power unit to power the tank and sensor suites. incorporate a thermal management system to provide crew and electronics cooling. increase memory and processor speeds and provide full color map capability. provide compatibility with the Army Command and Control Architecture to ensure the ability to share command & control and situational awareness with all components of the combined arms team. Additional weight reduction, embedded battle command, survivability enhancement, signature management, safety improvement, and product upgrade modifications to the M1A2 will comprise the "M1A2 Tank FY 2000" configuration fielded to units of the digital division beginning in FY 2000. The M1A2 IOT&E was conducted from September-December 1993 at Fort Hood, TX and consisted of a gunnery phase and a maneuver phase. The Director determined that the test was adequate, the M1A2 was operationally effective, but not operationally suitable and unsafe. That assessment was based on poor availability and reliability of the tank, instances of the uncommanded tube and turret movement, inadvertent .50 caliber machine gun firing, and hot surfaces which caused contact burns. FOT&E #1 was conducted in September-October 1995 in conjunction with the New Equipment Training for two battalion sized units. Despite assurances from the Army that all corrective actions were applied, numerous instances of uncommanded tube and turret movement, Commander's Independent Display (CID) lockup and contact burns continued during FOT&E #1. The follow-on test was placed on hold and the Army "deadlined" the two battalions of M1A2 tanks at Fort Hood for safety reasons.
The PM isolated 30 "root causes" of the safety problems and completed hardware and software upgrades in June 1996 which were assessed in FOT&E #2. The M1A2 TEMP was approved during 2QFY98. This TEMP includes a coordinated plan for FOT&E #3 of the M1A2 in conjunction with the IOT&E of the Bradley Fighting Vehicle in FY99 at Fort Hood, TX. This combined operational test will consist of 16 force-on-force battles between a Bradley Fighting Vehicle System-A3/M1A2 SEP combined arms team and M1A1/ Bradley-ODS combined arms team. Additionally, it will serve as the operational test for the 2d Generation FLIR. This approach implements the Secretary of Defense theme of combining testing in order to save resources and ensure a more realistic operational environment. The Army and DOT&E completed vulnerability assessment efforts and concluded that the "M1A2 Tank FY 2000" is a significant change from the original M1A2 design and will require a system-level survivability evaluation. This evaluation will rely on full-up system level testing of two systems, component and sub-system level testing, modeling and simulation, existing data, and previous testing to assess susceptibility and vulnerability of the "M1A2 Tank FY 2000" and its crew to the expected threat and to assess battle damage repair capabilities. The M1A2 Abrams Tank with the corrective actions applied by the Program Manager during FY96 is assessed to be operationally effective and suitable. The availability, reliability, fuel consumption, and safety problems observed in previous testing have been corrected. FOT&E #2 was adequately conducted in accordance with approved test plans and the Abrams TEMP. There were no observed instances of the uncommanded tube and turret movement, inadvertent .50 caliber machine gun firing, and hot surfaces which caused contact burns in previous testing. The largest area of technical risk to the program is the development of the Embedded Battle Command software which is intended to provide friendly and enemy situational awareness and shared command & control information throughout the combined arms team. This software is being developed as a Horizontal Technology Insertion program and will be provided to the weapon systems and C2 nodes of the combined arms team in FY00. This development schedule is high risk and could adversely impact the M1A2 schedule.
The M1 is equipped with a Honeywell AGT 1500 gas turbine engine. The Allison X-1100-3B transmission provides four forward and two reverse gears. The US Army has selected Honeywell International Engines and Systems and General Electric to develop a new LV100-5 gas turbine engine for the M1A2, in common with the Crusader self-propelled howitzer, as part of the Abrams/Crusader Common Engine Program. The new engine is lighter and smaller with rapid acceleration, quieter running and no visible exhaust. One L8A1 six-barrelled smoke grenade discharger is fitted on each side of the turret. A smoke screen can also be laid by an engine operated system. The M1A1 tank incorporates steel encased depleted uranium armour. Armour bulkheads separate the crew compartment from the fuel tanks. The top panels of the tank are designed to blow outwards in the event of penetration by a HEAT projectile. The tank is protected against nuclear, biological and chemical (NBC) warfare.