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M109 howitzer

The M109 is an American 155 mm turreted self-propelled howitzer, first introduced in the early 1960s to replace the M44. It has been upgraded a number of times, most recently to the M109A7. The M109 family is the most common Western indirect-fire support weapon of maneuver brigades of armored and mechanized infantry divisions.

The M109 has a crew of four: the section chief/commander, the driver, the gunner, and the ammunition handler/loader. The chief or gunner aims the cannon left or right (deflection) and up and down (quadrant).

The British Army replaced its M109s with the AS-90. Several European armed forces have or are currently replacing older M109s with the German PzH 2000. Upgrades to the M109 were introduced by the U.S. (see variants) and by Switzerland (KAWEST). With the cancellation of the U.S. Crusader, Non-Line-of-Sight Cannon and M1299 the M109A6 ("Paladin") will likely remain the principal self-propelled howitzer for the U.S. until a replacement enters service.

Operational history

The M109 was the medium variant of a U.S. program to adopt a common chassis for its self-propelled artillery units. The light version, the M108 Howitzer, was phased out during the Vietnam War, but many were rebuilt as M109s.

The M109 saw its combat debut in Vietnam. Around 200 vehicles were deployed in 1966, but the entire fleet suffered a mechanical malfunction within a year of operation. The U.S. dispatched engineers and mechanics, but all M109s were recalled back to the U.S. in 1967 after failing to repair in the field. The howitzer underwent upgrades afterward, which resulted in the M109A1.

Israel used the M109 against Egypt in the 1973 Yom Kippur War and in the 1982 and 2006 Lebanon Wars. Iran used the M109 in the Iran–Iraq War in the 1980s. The M109 saw service with the British, U.S. Army, Egyptian and Saudi Arabian Armies in the 1991 Gulf War. The M109 also saw service with the U.S. Army in the Iraq War from 2003 to 2011.

Upgrades to the cannon, ammunition, fire control, survivability, and other electronics systems over the design's lifespan have expanded the system's capabilities, including tactical nuclear projectiles, guided projectiles (Copperhead), Rocket Assisted Projectiles (RAP), FAmily of SCAtterable Mines (FASCAM), and cluster munitions (the Dual-Purpose Improved Conventional Munition, DPICM).

In August 2015, South Korean K55A1s fired rounds behind the Military Demarcation Line as a warning after several North Korean provocations.

During the Russian invasion of Ukraine, Ukraine has used M109 howitzers donated by Western countries. According to video and photographic evidence compiled by the open-source intelligence website Oryx, as of 11 June 2024, at least 62 units of different variants had been lost (46 destroyed and 16 damaged).

Design
The M109 was developed by the Ground System Division of United Defense LP, now BAE Systems Land and Armaments.

Armament

 * Primary by Watervliet Arsenal: M126 Cannon (or M126A1) 155 mm Howitzer (M109), M185 Cannon 155 mm Howitzer (A1/A2/A3/A4), or M284 Cannon 155 mm Howitzer (A5/A6)
 * Secondary: .50 caliber (12.7 mm) M2 machine gun, Mk 19 Mod 3 40 mm Automatic Grenade Launcher, 7.62 mm M60, M240 machine gun or L4 machine gun

Mobility
The M109 was powered by the 8V71T, a 8-cylinder water-cooled diesel engine, produced by the Detroit Diesel Engine Division of General Motors Corporation. The 8V71T is a turbocharged version of the 8V71 commercial truck engine. It was rated 390 hp at 2300 rpm and was used in the M107, M108, M110, and M578 series as well.

M109
First produced in 1963. It had a 155 mm M126 cannon in an M127 mount, and carried 28 rounds of 155 mm ammunition. It was also armed with a .50cal M2HB machine gun with 500 rounds of ammunition. Easily identified by its short barrel and a double baffle muzzle brake with a large fume extractor just behind it. Maximum range of 14,600 meters.

M109G
The West German army M109s were designated as the M109G, and featured a breechblock system developed by Rheinmetall extending the effective range to 18 km or 18.5 km according to some sources, a new fire control system, and three smoke dischargers mounted on either side of the turret as well.

In December 1966, the United States and Norway signed an agreement related to the co-production of the M109G.

M109A1
Replaced the M126 cannon with a 39 caliber M185, featuring a longer barrel while increasing maximum range to 18,100 meters.

M109A1B
The M109 rebuilt to M109A1 standard.

M109 66/74
The M109 (Pz Hb) 66/74 is a Swiss upgraded M109 (Pz Hb 66) to M109A1B (Pz Hb 74) standard.

Switzerland purchased 146 M109 under the armament program 1968, and introduction of the howitzer started in 1971. All vehicles received upgrade to M109A1B (Pz Hb 74) standard and were delivered from May 1977 to February 1979.

M109A2
Incorporated 27 Reliability, Availability, and Maintainability (RAM) mid-life improvements. Most notably, the long barreled 155 mm M185 Cannon in the new M178 gun mount, ballistic protection for the panoramic telescope, counterbalanced travel lock, and the ability to mount the M140 bore sight alignment device. Stowage of 155mm rounds increased from 28 to 36 rounds; .50cal ammunition remained at 500 rounds. During M109A2 production, a slightly simplified version was also produced for export. This had minor internal changes and deleted the hull flotation feature. These were designated M109A1B.

K55
The K55 is a South Korean license produced variant of the M109A2. In the 1960s, the South Korean Army received M107 and M110 from the United States. However, the number of these self-propelled guns was insufficient to counter rapidly-growing North Korean artillery capabilities. In the 1970s, South Korea began mass-producing towed howitzers locally, but intelligence reports of North Korean 170 mm self-propelled artillery forced South Korea to look for a new self-propelled artillery system.

In December 1983, the ministers of defense of the United States and South Korea signed a memorandum of understanding (MOU) to co-produce M109A2 in South Korea using American technical data. The United States delivered two completed M109A2s to South Korea for operational review, and the Agency for Defense Development began to translate the data package and created field and maintenance manuals for soldiers. South Korea wanted to produce every part of the vehicle domestically; however, due to the amendment bill by Rep. Samuel S. Stratton of New York, which established a limit for foreign military technology cooperation, the turret and the M185 cannon from Watervliet Arsenal were imported from the United States.

Compared to the M109A2, besides 63 percent of parts being produced locally, K55 has a driver's night periscope and light exposure minimization device to enhance night-time operations as well as additional radio systems. The vehicle has a nuclear, biological and chemical protection system and halon fire extinguishers. A total of 1,180 K55s were produced between 1985 and 1996. The vehicle's name was changed from KM109A2 to K55, originally a code name from the Samsung factory.

In November 1990, the United States and South Korea signed an agreement to allow South Korea to supply M109 parts to third parties. In May 1997, during the Security Cooperation Committee held in Washington D.C., South Korea requested that the United States revise the MOU to export complete K55s, originally intended for domestic use only. South Korea was expecting to export 72 K55s and four ammunition support vehicles to Brazil for $160 million over Belgium's offer, but the United States Department of Defense declined the request to avoid an arms race in the region.

In May 1998, the South Korean military began operating a K55 simulator to boost artillery operator training. The simulator took a year and a billion KRW budget to develop. It is expected to save 150 million KRW per year per device.

M109A3
M109A1s rebuilt to M109A2 standard. Some A3s feature three contact arm assemblies, while all A2s have five.

M109A3B
M109A1B rebuilt to M109A2 standard.

M109A3G
In 1983, the German Army purchased 586 conversion kits from the FMS Corporation (now Marvin Land Systems) to convert its fleet of M109Gs to the M109A3G standard. This upgraded variant uses a new gun barrel developed by Rheinmetall, giving an extended range of 24 km. It also features a new fire-control system, and three forward firing 76 mm smoke grenade launchers on either side of the turret.

M109A3GN
Between 1969 and 1971 Norway acquired 126 M109Gs from West Germany. They were then upgraded to the M109A3GN configuration during the latter half of the 1980s.

M109A4
M109A2s and M109A3s improved with Nuclear, Biological, and Chemical / Reliability, Availability, and Maintainability (NBC/RAM) improvements, including air purifiers, heaters, and Mission Oriented Protective Posture (MOPP) (protective) gear.

The traversing mechanism's clutch was changed to be hydraulic (as compared to the electric mechanism on previous M109s), and added a manual override. The M109A4 also gained a second hydraulic filter and more reliable engine starting equipment which greatly improved the ability to start the vehicle in an emergency.

Ammunition stowage remained the same as in previous models.

M109A5

Replaces the 155 mm M185 cannon in an M178 mount with a 39-caliber 155 mm M284 cannon in an M182 mount, giving the A5 a maximum range of 22,000 meters with unassisted projectiles and 30,000 meters with rocket-assisted projectile (RAP) rounds. The vehicle can carry 36 complete rounds of ammunition and has a 440 hp engine instead of the standard 405 hp engine.

M109A5+
Various manufacturers have upgraded the fire control and other components of the M109A5. BAE Systems in York, PA recently delivered 12 M109A5+ vehicles to Chile and 32 M109A5+ vehicles for Brazil.

M109A6 Paladin

The Paladin model has improvements in the areas of survivability, RAM, and armament. This includes increased armor, a redesigned internal arrangement for safer ammunition and equipment storage, engine and suspension upgrades, and improvement of the M284 Cannon and M182A1 Mount. The greatest difference is the integration of an inertial navigation system, sensors detecting the weapons' lay, automation, and an encrypted digital communication system, which utilizes computer controlled frequency-hopping to avoid enemy electronic warfare and allow the howitzer to send grid location and altitude to the battery Fire Direction Center (FDC).

The battery FDCs coordinates fire through a battalion or higher FDC. This allows the Paladin to halt from the move and fire within 30 seconds, with an accuracy equivalent to the previous models when properly emplaced, laid, and safed—a process that previously required several minutes under the best of circumstances. Tactically, this improves the system's survivability by allowing the battery to operate dispersed in pairs across the countryside, and allowing the howitzer to quickly move between salvos, or if attacked by indirect fire, aircraft, or ground forces.

Ammunition storage of 155 mm rounds was increased from 36 to 39.

The US Army received the first Paladin in 1994 and the last of 950 in 1999.

M109 KAWEST
This Swiss improved version produced by RUAG incorporates a new Swiss-designed L47 155 mm gun with an increased firing range of up to 36 km. It features an inertial navigation system coupled with a new gun-laying system, along with an ammunition storage increase of 40 rounds and 64 charges. The KAWEST (lit. Kampfwertsteigerung = upgrade of combat capabilities) requires only six crew members instead of eight. It is able to fire three-round bursts within 15 seconds, or maintain a constant firing rate of over one round per minute.

Upgraded Swiss PzHb (Panzerhaubitze)74, 79 and 88 (M109A1B) are known as respectively PzHb 74/95, PzHb 79/95 and PzHb 88/95.

 * 33 of the 120 PzHb 74 were modernised to the standard PzHb 74/95 KAWEST.
 * 207 of the 207 PzHb 79 were modernised to the standard PzHb 79/95 KAWEST.
 * 108 of the 108 PzHb 88 were modernised to the standard PzHb 88/95 KAWEST.

M109A3GN
The latest version in service with the Norwegian Army's Artilleribataljonen.

In 2006, there were 56 M109A3GNs in the Army's inventory, meaning that at least 70 SPGs had been scrapped after the end of the Cold War. 14 of the M109A3GNs received upgrades in 2007, and were designated M109A3GNM. The upgrade includes a new intercom and new navigation and positioning systems.

In 2020 the 14 units with A3GNM upgrades and those still with A3GN specs were placed in storage because all the new Korean K9 Thunder units had been delivered. In May 2022, Norway donated 22 A3GN-spec M109s to Ukraine. Two M109A3GN howitzers were destroyed and three damaged during the 2022 Russian invasion of Ukraine.

M109 KAWEST WE
Improvement of the Swiss Kawest variant, 133 in total were brought up to this standard:

 * 25 of the 207 PzHb 79/95 were modernised to the standard PzHb KAWEST WE. Those are currently in service.
 * 108 of the 108 PzHb 88/95 were modernised to the standard PzHb KAWEST WE. Those are currently in service.

K55A1
The K55A1 is a South Korean overhaul and modernization of the K55, augmenting the proven systems of the K9 Thunder and the K9A1. The development took three years between 2007 and 2010. The upgrade started in 2010. In November 2010, in the wake of the North Korean artillery attack, the South Korean government authorized a massive increase in military spending. South Korea allocated 11.5 billion KRW on K55A1 upgrades for FY2011, more than a 1500% increase from 700 million KRW for FY2010. The upgrade was performed by Samsung Techwin, and the first vehicle was fielded by the South Korean Army in early 2011.

The K55A1 is fitted with the same electronics and fire control system as the K9. The self-propelled gun has significantly enhanced field operability and accuracy through the installation of Honeywell Aerospace's TALIN 5000 INS (inertial navigation system), a satellite navigation device (GPS), and a speed calibrator. As a result, the vehicle automatically lays the gun in the desired direction and delivers a first round within 45 seconds between stops, or 75 seconds between maneuvers after receiving the shooting specification, which required 2 minutes and 11 minutes, respectively, on the K55.

With the help of a new semi-autoloader, while charges are still inserted manually, the howitzer can fire 4 rounds per minute, increased from 2 to 3 rounds per minute. The improved suspension, involving a strut-type hydropneumatic buffer from Mottrol Co, Ltd., along with an enhanced chamber, allowed the vehicle to shoot K307 and K310 ammunition designed for K9 platform without laying spades at a maximum distance of 32 km. An APU (auxiliary power unit) was installed to operate the howitzer without turning on the main engine.

The Army Consolidated Maintenance Depot joined the K55A1 upgrade, releasing its first results in December 2013. The upgrade cost 20% of the K9 Thunder, 800 million KRW, as of 2021. The K55A1 upgrade program was completed in December 2022.

M109A7
The newest M109 version for U.S. service is the M109A7, formerly known as the M109A6 Paladin Integrated Management (PIM). The M109A7 shares common chassis components with the Bradley Fighting Vehicle (BFV) such as the engine, transmission, and tracks. This creates commonality with other systems and maximizes cost savings in production, parts inventory, and maintenance personnel. The M109A7's onboard power systems harness technologies originally developed for the XM1203 Non-Line-of-Sight Cannon.

The electric drive is faster than the previous hydraulic system, and the automatic rammer more consistently rams the round into the gun for consistent velocities and better accuracy. It features a 600-volt onboard power system to accommodate additional armor and future networking technologies as they become ready. The M109A7 can sustain a one-round per-minute rate of fire and a maximum rate of fire of four rounds per minute. Weighing 78,000 lb, the M109A7 is 10,000 lb heavier than its predecessor, and it has the capacity to grow to 110,000 lb. Even with the weight increase, the M109A7 can travel faster than previous versions at 38 mph and is more maneuverable than a BFV.

Prototypes of the vehicle underwent government testing in preparation for a Low-Rate Initial Production (LRIP) decision. The testing included RAM, mission and ballistic hull and turret testing. The M109A7 was slated to begin LRIP by 2013. The U.S. Army planned on procuring a fleet of 580 sets of M109A7 howitzers and M992A3 Field Artillery Ammunition Supply Vehicles.

In October 2013, the Defense Acquisition Board approved the decision to start M109A7 production. The FY 2014 budget called for $340.8 million in Paladin funding, which would be two dozen vehicle sets at $14.4 million per vehicle. The Army plans to buy 133 vehicles, in 66 one-half vehicle sets starting in 2014. One M109A7 howitzer and two supporting M992A3 ammunition carriers will be destroyed during tests. A Full-Rate Production (FRP) decision was planned for February 2017.

In October 2013, BAE received a $668 million contract to begin LRIP of the M109A7. The first M109A6 and M992A2 vehicles were rebuilt to M109A7 and M992A3 standards as part of LRIP beginning in summer 2014. LRIP deliveries began in April 2015. The contract for FRP was signed in December 2017, with 48 vehicles slated for construction. The Army plans to upgrade 689 Paladins to A7-standard.

The Army is looking to increase the capabilities of the M109A7. By introducing the new XM1113 Rocket-Assisted Projectile (RAP), it can reach 40 km from the current 39-caliber barrel. A planned barrel extension to 58-caliber can increase its range to 70 km. An additional XM1113 improvement over the legacy RAP round is the replacement of the high explosive, TNT, with an insensitive munition that is less volatile and less prone to unplanned detonation. The Army is working on an autoloader to increase the sustained rate of fire to 6–10 rounds per minute.

Another part of the effort is the use of a new supercharged propellant to fire the shells, which required redesigning the howitzer to handle higher pressures.

Hypervelocity Projectile (HVP)
In January 2016, the U.S. Army test-fired hypervelocity projectiles originally designed for use by U.S. Navy electromagnetic railguns. They found that they significantly increased the gun's range. The Army is looking into using the M109 Paladin firing the HVP for ballistic missile defense, as traditional missile interceptors are expensive, and gun-based missile defense used for point defense would use artillery at a much lower cost per round.

The HVP is capable of being fired out to 50 nmi from a conventional cannon. It weighs 68 lb with a 46 lb flight body containing its guidance and warhead—less powerful, but more agile to hit small, high-speed targets. Modifications will be needed for the Paladin to effectively shoot the HVP, possibly including different propellant to achieve higher velocities, automated reloading systems to fire quickly enough to defeat salvo launches, improved barrel life, and a new fire control and sensor system. During a test of the Air Force's Advanced Battle Management System (ABMS) in September 2020, an HVP fired from an Army Paladin howitzer successfully intercepted a BQM-167 target drone simulating a cruise missile.

HVP was renamed to gun-launched guided projectile (GLGP), canceled in the 2022 budget, and tests continued in 2023.

P-52
The P-52 was a 52-caliber variant of M109A6 Paladin offered to South Korea by BMY Combat Systems in 1992. It was rejected by South Korea in favor of K9 Thunder. Proposal stage only.

M109L52
Jointly developed by the Dutch firm RDM and the German firm Rheinmetall, the M109L52 was first revealed in 2002. The main improvement was replacing the M126 series gun with the longer 52-caliber cannon from the PzH 2000, thus the MTLS ammunition of the PzH 2000 can be used. Improvements to the loading system were also made, resulting in an increased rate of fire from 3 rds/min to 9–10 rds/min, able to be sustained for up to 2 minutes. A total of 35 rounds can be carried.

M109-52
The M109-52 is a 52-caliber variant of M109 developed by BAE Systems by integrating Rheinmetall L52 cannon.

M1299
The M1299 was a prototype self-propelled howitzer developed by BAE Systems in 2019 under the Extended Range Cannon Artillery (ERCA) program. It was based on the M109A7, and was primarily designed for the purpose of improving the M109A7's effective range. One battalion of vehicles is planned to begin a year-long operational assessment in 2023. It was expected to be fitted with an autoloader, which would have increased its rate of fire from 3 to 10 rounds per minute. The M1299 was cancelled in March 2024 due, at least in part, to excessive barrel wear. Advanced ammunition developed for the M1299 will continue development, and the U.S. Army will look for existing alternatives to fullfil its re-evaluated long-range fire support needs.

M992

The M992 Field Artillery Ammunition Supply Vehicle (FAASV) is built on the chassis of the M109. It replaced the M548. Unlike the M548, it is armored. This ammunition vehicle has no turret, but has a taller superstructure to store 93 rounds and an equivalent number of powders and primers.

This vehicle is fitted with a Halon fire suppression system and a weapons mount similar to that on the M109 turret, usually mounting a Mk 19 grenade launcher for local defense against infantry and light armored vehicles.

The vehicle contains a 2-stroke diesel powered auxiliary power unit that can power all non-automotive energy requirements on the FAASV and on the M109.

K66
The K66 was a planned ammunition support vehicle for the K55. As a follow-up to the K55 program, Samsung Aerospace Industries prepared for licensing a local variant of the M992, featuring such modifications as NBC protection and an increase of ammunition storage capacity to 110 rounds, 116 packs of powders, and 132 primers.

In 1987, Samsung Aerospace Industries competed against the Daewoo Heavy Industries' ammunition support vehicle based on the K200 APC. Daewoo Heavy Industries' vehicle was selected as the K66, but failed the test evaluation. The K66 project was cancelled in the mid-1990s, resulting in a lawsuit.

K77 FDCV (Fire Direction Center Vehicle)
The K77 FDCV is a command & control post vehicle variant based on the K55 platform.

K56 ARV (Ammunition Resupply Vehicle)
The K56 ARV is an ammunition resupply vehicle based on the K55 platform. Unlike the K10 ARV, the K56 can resupply both the K55A1 and the K9 Thunder. It has a 45.7% (4,197 out of 9,191 total parts) compatibility with the K55A1.

After 10 months of pilot experiment, the K56 program was authorized by the DAPPC (Defense Acquisition Program Promotion Committee) in February 2007. In May 2007, the DAPPC allocated 16 billion KRW for research and development for 2008 to 2010, with plans to produce 520 vehicles between 2011 and 2020. In June 2008, Samsung Techwin was selected as the main contractor for the project. Later, the development completion schedule was delayed to 2011, while the total production amount was increased to 700 vehicles with a cost of 1.3 trillion KRW between 2012 and 2021.

In September 2010, the Board of Audit and Inspection claimed that the Army was biased during evaluation, and demanded re-analysis of the project regarding inefficiency of the system. The Defense Acquisition Program Administration (DAPA) ignored the Board and continued with the project while the Army purposely delayed complying. In June 2011, the Ministry of Defense again ordered a reexamination of the resupply vehicle. DAPA instead requested a budget for the program, and the development was completed in October 2011. In July 2013, the DAPA announced the 1st production batch of the K56 between 2013 and 2015 for 65 billion KRW.

In December 2015, Hanwha Techwin signed a contract with the DAPA for a 2nd production batch. In January 2018, Hanwha Land Systems announced a 166.4 billion KRW contract with the DAPA for a 3rd production batch and related products. In June 2020, Hanwha Defense announced 380.3 billion KRW contract with the DAPA for a 4th production batch. South Korea plans a 5th production batch and to achieve full operational capability by 2025. All K56s were delivered to the western front.

Training systems
The US Army uses the Fire Support Combined Arms Tactical Trainer (FSCATT) in two versions, for initial and sustainment training of the M109A6 and M109A5. The system uses an actual surplus turret and a simulated ammunition system.

The Swiss Army uses a highly advanced KAWEST trainer from Van Halteren Metaal of the Netherlands.

The Dutch, Belgian, Thai, and Israeli Armies have various configurations of the Van Halteren Metaal M109 Howitzer Crew Trainer (HCT).

The US Army PEO STRI had a program called M109A7 Howitzer Crew Trainer (HCT). The plan was to procure 16 systems beginning in the 3rd Quarter of FY 20.

Successors
The U.S. Army sought to replace the M109 with the XM2001 Crusader, initially part of the Armored Systems Modernization program. The program was canceled in 2002 amid criticism that the program was not in line with the Army's long-term plans for lighter armored brigades. Funding was redirected to the Future Combat Systems Manned Ground Vehicles program, which produced the 18-ton XM1203 Non-Line-of-Sight Cannon as the program's lead effort. The Pentagon terminated the MGV program in 2009 due to concerns over its affordability. The U.S. Army's M1299 howitzer was planned to be completed in 2021 and was to undergo operational assessment in 2023. Due to issues with excessive wear on its barrel, the project was cancelled in 2024.

M109A1

 * 🇩🇯: 10 M109L as of 2024, former Italian vehicles
 * − 51 M109A1B in 2011. 418 M109A1B/A2/A3GEA1/A5 in service as of 2024
 * 🇮🇶 − 6 M109A1 as of 2024
 * 🇮🇷 − 150+ M109A1 including Raad-2s in service as of 2024
 * 🇯🇴 − 358 M109A1/A2 in service as of 2024
 * 🇲🇦 − 36 M109A1B in 2011, ca. 130 M109A1/A1B/A2/A3/A4 in service as of 2024
 * 🇸🇦 − 87 M109A1B in 2011, 110 M109A1B/A2 as of 2024

M109A2/A3/A3B

 * 🇧🇷 − 37 M109A3 as of 2024, will be refurbished
 * − 24 M109A3 as of 2024
 * − 84 M109A2, and 50 M109A3GE in 2011. 418 M109A1B/A2/A3GEA1/A5 in service as of 2024
 * 🇪🇬 − 164 M109A2 as of 2024
 * 🇯🇴 − 108 M109A2 in 2011, 358 M109A1/A2 in service as of 2024
 * 🇰🇼 − 37 M109A3 as of 2024
 * 🇱🇧 − 12 M109A2 as of 2024
 * 🇲🇦 − 3 M109A2 in 2011, ca. 130 M109A1/A1B/A2/A3/A4 in service as of 2024
 * 🇵🇰 − 200 A2 and 123 M109L as of 2024
 * 🇵🇪 − 12 M109A2 as of 2024
 * 🇸🇦 − 24 in 2011, 110 M109A1B/A2 as of 2024
 * 🇪🇸 − 6 M109A2 used by the Marine Infantry as of 2024
 * 🇹🇼 − 197 M109A2 in 2011, 225 M109A2/A5 as of 2024
 * 🇺🇦 − 23 M109A3GN and 60 M109L delivered between 2022 and 2023. 90 M109A3GN/A4/A5Öe/A6/L in service as of 2024
 * − 85 M109A3 as of 2024

M109A4

 * − 18 M109A4 as of 2024
 * 🇲🇦 − ca. 130 M109A1/A1B/A2/A3/A4 in service as of 2024
 * 🇺🇦 − 28 M109A4BE delivered in 2022. 90 M109A3GN/A4/A5Öe/A6/L in service as of 2024

M109A5

 * 🇦🇹 − 48 M109A5Öe as of 2024
 * 🇧🇭 − 20 M109A5 as of 2024
 * 🇧🇷 − 40 M109A5 and 32 M109A5+ as of 2024
 * − 24 M109A5+ as of 2024
 * − 12 M109A5 in 2011. 418 M109A1B/A2/A3GEA1/A5 in service as of 2024
 * 🇪🇬 − 204 M109A5 as of 2024
 * 🇮🇶 − 24 M109A5 as of 2024
 * 🇮🇱 − 250 M109A5 as of 2024
 * − 59 M109A5Öe as of 2024
 * 🇱🇧 − 24 M109A5 as of 2024
 * 🇲🇦 − 70 M109A5 as of 2024
 * 🇵🇰 − ca. 115 M109A5 as of 2024
 * − 18 M109A5 as of 2024
 * 🇪🇸 − 95 M109A5 as of 2024
 * 🇹🇼 − 28 M109A5 in 2011, 225 M109A2/A5 as of 2024
 * 🇹🇭 − 20 M109A5 as of 2024
 * 🇺🇦 − 6 M109A5Öe delivered in 2022. 90 M109A3GN/A4/A5Öe/A6/L in service as of 2024

M109A6 Paladin

 * 🇺🇸 − 400 M109A6 in service, ca. 850 M109A6 in storage as of 2024
 * 🇺🇦 − 18 M109A6s delivered in 2023. 90 M109A3GN/A4/A5Öe/A6/L in service as of 2024

M109A7

 * 🇺🇸 − 271 M109A7 as of 2024

KAWEST/KAWEST WE

 * 🇨🇭 − 133 M109 KAWEST WE as of 2024

K55A1

 * − 1,040 K55A1 in service with the Army and 20 with the Marine Corps as of 2024

Potential

 * − 177 M109A6 ordered in April 2018

M109

 * 🇪🇹 Ethiopia: Received 12 (possibly second-hand) from the United States in 1975, it was estimated in 1989 to have 6 in service
 * 🇱🇾 Libya − 14 in 2011
 * 🇱🇾 Libya Dawn − At least one was used against Islamic State forces in Sirte in late 2016
 * 🇨🇭: Purchased 146 M109 (Pz Hb 66) and introduced from 1971 All vehicles were upgraded to M109A1B (Pz Hb 66/74) from 1977 to 1979.

M109A1/A1B

 * 🇨🇭: Purchased M109A1B and introduced them in 3 batches: 120 Pz Hb 74 from 1974 to 1978, 207 Pz Hb 79 from 1981 to 1983, and 108 Pz Hb 88 from 1991 to 1992. Also upgraded 146 M109 to M109A1B standard from 1977 to 1979. The total number of received vehicles is 581

M109A2/A3/A3B

 * 🇧🇪 − 167 A2, of which 64 were upgraded to the -A4BE standard, 31 sold to Brazil (1999–2001), 43 sold to Morocco (2008), the remainder sold to private companies in 2015
 * − 2–6 (upgraded to M109 A3DK, used to be 76)
 * 🇩🇪 − 570 A3GE A1/A2, phased out by 1 July 2007 and replaced by the PzH 2000
 * 🇮🇱 − 30 M109A2 in storage as of 2024
 * 🇮🇹 − 221 M109L (M109 modernized to A3 equivalent with Italian-made 155 mm/39 calibre barrels), replaced by the PzH 2000
 * 🇳🇱 − 126 as of 1998, replaced by the PzH 2000, 5 sold to Austria (1997), 87 to United Arab Emirates (1997), 121 to Jordan (2011–2012)
 * 🇳🇴 − 33 in storage after donation of 22 to Ukraine in 2022. 55 in storage in 2021. Replaced by the K9 Thunder
 * − 6 M109A2 in storage as of 2024
 * − 1,180 K55 were produced by Samsung Aerospace Industries between 1985 and 1996. All vehicles were upgraded to K55A1 and delivered from 2011 to 2022
 * − 140+ entered service in 1965, upgraded to -A1 and -A2 standards, 83 sold to Austria in 1994 (51 A2, 32 A3)

M109A4

 * 🇧🇪 − 64 A4BE of which 36 A4BE sold to Indonesia (2017–2018), the others to private companies in 2015. From these 28 units were bought by the UK to be delivered to Ukraine
 * 🇨🇦 − 76 A4B+. Used by the Canadian Forces from 1967 until 2005, when they were phased out. All the vehicles had been modernized to the M109A4B+ SPH standard in the 1980s. They were primarily used by the 4 Canadian Mechanized Brigade Group in Germany

M109A5

 * 🇸🇦 − 48 second-hand M109A5 delivered between 2002 and 2004. None remained in service by 2011

International equivalents

 * Type 75 ·
 * prototype
 * Type 75 ·
 * prototype
 * Type 75 ·
 * prototype
 * Type 75 ·
 * prototype
 * Type 75 ·
 * prototype
 * prototype
 * prototype
 * prototype
 * prototype

title: M109 howitzer


text:
Many-valued logic

Many-valued logic (also multi- or multiple-valued logic) is a propositional calculus in which there are more than two truth values. Traditionally, in Aristotle's logical calculus, there were only two possible values (i.e., "true" and "false") for any proposition. Classical two-valued logic may be extended to n-valued logic for n greater than 2. Those most popular in the literature are three-valued (e.g., Łukasiewicz's and Kleene's, which accept the values "true", "false", and "unknown"), four-valued, nine-valued, the finite-valued (finitely-many valued) with more than three values, and the infinite-valued (infinitely-many-valued), such as fuzzy logic and probability logic.

History
It is wrong that the first known classical logician who did not fully accept the law of excluded middle was Aristotle (who, ironically, is also generally considered to be the first classical logician and the "father of [two-valued] logic" ). In fact, Aristotle did not contest the universality of the law of excluded middle, but the universality of the bivalence principle: he admitted that this principle did not all apply to future events (De Interpretatione, ch. IX), but he didn't create a system of multi-valued logic to explain this isolated remark. Until the coming of the 20th century, later logicians followed Aristotelian logic, which includes or assumes the law of the excluded middle.

The 20th century brought back the idea of multi-valued logic. The Polish logician and philosopher Jan Łukasiewicz began to create systems of many-valued logic in 1920, using a third value, "possible", to deal with Aristotle's paradox of the sea battle. Meanwhile, the American mathematician, Emil L. Post (1921), also introduced the formulation of additional truth degrees with n ≥ 2, where n are the truth values. Later, Jan Łukasiewicz and Alfred Tarski together formulated a logic on n truth values where n ≥ 2. In 1932, Hans Reichenbach formulated a logic of many truth values where n→∞. Kurt Gödel in 1932 showed that intuitionistic logic is not a finitely-many valued logic, and defined a system of Gödel logics intermediate between classical and intuitionistic logic; such logics are known as intermediate logics.

Kleene (strong) $K_{3}$ and Priest logic $P_{3}$
Kleene's "(strong) logic of indeterminacy" $K_{3}$ (sometimes $$K_3^S$$) and Priest's "logic of paradox" add a third "undefined" or "indeterminate" truth value $I$. The truth functions for negation (¬), conjunction (∧),  disjunction (∨),  implication ($→ K$), and  biconditional ($↔ K$) are given by: {| cellpadding="0"
 * - valign="bottom"

 * }

The difference between the two logics lies in how tautologies are defined. In $T$ only $F$ is a designated truth value, while in $I$ both $I$ and $F$ are (a logical formula is considered a tautology if it evaluates to a designated truth value). In Kleene's logic $T$ can be interpreted as being "underdetermined", being neither true nor false, while in Priest's logic $T$ can be interpreted as being "overdetermined", being both true and false. $I$ does not have any tautologies, while $F$ has the same tautologies as classical two-valued logic.

Bochvar's internal three-valued logic
Another logic is Dmitry Bochvar's "internal" three-valued logic $$B_3^I$$, also called Kleene's weak three-valued logic. Except for negation and biconditional, its truth tables are all different from the above.

The intermediate truth value in Bochvar's "internal" logic can be described as "contagious" because it propagates in a formula regardless of the value of any other variable.

Belnap logic ($T$)
Belnap's logic $T$ combines $I$ and $F$. The overdetermined truth value is here denoted as B and the underdetermined truth value as N.

Gödel logics Gk and G∞
In 1932 Gödel defined a family $$G_k$$ of many-valued logics, with finitely many truth values $$0, \tfrac{1}{k - 1}, \tfrac{2}{k - 1}, \ldots, \tfrac{k - 2}{k - 1}, 1$$, for example $$G_3$$ has the truth values $$0, \tfrac{1}{2}, 1$$ and $$G_4$$ has $$0, \tfrac{1}{3}, \tfrac{2}{3}, 1$$. In a similar manner he defined a logic with infinitely many truth values, $$G_\infty$$, in which the truth values are all the real numbers in the interval $$[0, 1]$$. The designated truth value in these logics is 1.

The conjunction $$\wedge$$ and the disjunction $$\vee$$ are defined respectively as the minimum and maximum of the operands:

 * $$\begin{align}

u \wedge v &:= \min\{u, v\} \\ u \vee v &:= \max\{u, v\} \end{align}$$

Negation $$\neg_G$$ and implication $$\xrightarrow[G]{}$$ are defined as follows:

 * $$\begin{align}

\neg_G u &= \begin{cases} 1, & \text{if }u = 0 \\ 0, & \text{if }u > 0 \end{cases} \\[3pt] u \mathrel{\xrightarrow[G]{}} v &= \begin{cases} 1, & \text{if }u \leq v \\ v, & \text{if }u > v                          \end{cases} \end{align}$$

Gödel logics are completely axiomatisable, that is to say it is possible to define a logical calculus in which all tautologies are provable. The implication above is the unique Heyting implication defined by the fact that the suprema and minima operations form a complete lattice with an infinite distributive law, which defines a unique complete Heyting algebra structure on the lattice.

Łukasiewicz logics $→ K$ and $I$
Implication $$\xrightarrow[L]{}$$ and negation $$\underset{L}{\neg}$$ were defined by Jan Łukasiewicz through the following functions:

 * $$\begin{align}

\underset{L}{\neg} u &:= 1 - u \\ u \mathrel{\xrightarrow[L]{}} v &:= \min\{1, 1 - u + v\} \end{align}$$

At first Łukasiewicz used these definitions in 1920 for his three-valued logic $$L_3$$, with truth values $$0, \frac{1}{2}, 1$$. In 1922 he developed a logic with infinitely many values $$L_\infty$$, in which the truth values spanned the real numbers in the interval $$[0, 1]$$. In both cases the designated truth value was 1.

By adopting truth values defined in the same way as for Gödel logics $$0, \tfrac{1}{v-1}, \tfrac{2}{v-1}, \ldots, \tfrac {v-2} {v-1}, 1$$, it is possible to create a finitely-valued family of logics $$L_v$$, the abovementioned $$L_\infty$$ and the logic $$L_{\aleph_0}$$, in which the truth values are given by the rational numbers in the interval $$[0,1]$$. The set of tautologies in $$L_\infty$$ and $$L_{\aleph_0}$$ is identical.

Product logic $I$
In product logic we have truth values in the interval $$[0,1]$$, a conjunction $$\odot$$ and an implication $$\xrightarrow [\Pi]{}$$, defined as follows

 * $$\begin{align}

u \odot v &:= uv \\ u \mathrel{\xrightarrow[\Pi]{}} v &:= \begin{cases} 1, & \text{if } u \leq v \\ \frac{v}{u}, & \text{if } u > v   \end{cases} \end{align}$$

Additionally there is a negative designated value $$\overline{0}$$ that denotes the concept of false. Through this value it is possible to define a negation $$\underset{\Pi}{\neg}$$ and an additional conjunction $$\underset{\Pi}{\wedge}$$ as follows:

 * $$\begin{align}

\underset{\Pi}{\neg} u &:= u \mathrel{\xrightarrow[\Pi]{}} \overline{0} \\ u \mathbin{\underset{\Pi}{\wedge}} v &:= u \odot \left(u \mathrel{\xrightarrow[\Pi]{}} v\right) \end{align}$$

and then $$u \mathbin{\underset{\Pi}{\wedge}} v = \min\{u, v\}$$.

Post logics Pm
In 1921 Post defined a family of logics $$P_m$$ with (as in $$L_v$$ and $$G_k$$) the truth values $$0, \tfrac 1 {m-1}, \tfrac 2 {m-1}, \ldots, \tfrac {m-2} {m-1}, 1$$. Negation $$\underset{P}{\neg}$$ and conjunction $$\underset{P}{\wedge}$$ and disjunction $$\underset{P}{\vee}$$ are defined as follows:

 * $$\begin{align}

\underset{P}{\neg} u &:= \begin{cases} 1, & \text{if } u = 0 \\ u - \frac{1}{m - 1}, & \text{if } u \not= 0 \end{cases} \\[6pt] u \mathbin{\underset{P}{\wedge}} v &:= \min\{u,v\} \\[6pt] u \mathbin{\underset{P}{\vee}} v &:= \max\{u,v\} \end{align}$$

Rose logics
In 1951, Alan Rose defined another family of logics for systems whose truth-values form lattices.

Relation to classical logic
Logics are usually systems intended to codify rules for preserving some semantic property of propositions across transformations. In classical logic, this property is "truth." In a valid argument, the truth of the derived proposition is guaranteed if the premises are jointly true, because the application of valid steps preserves the property. However, that property doesn't have to be that of "truth"; instead, it can be some other concept.

Multi-valued logics are intended to preserve the property of designationhood (or being designated). Since there are more than two truth values, rules of inference may be intended to preserve more than just whichever corresponds (in the relevant sense) to truth. For example, in a three-valued logic, sometimes the two greatest truth-values (when they are represented as e.g. positive integers) are designated and the rules of inference preserve these values. Precisely, a valid argument will be such that the value of the premises taken jointly will always be less than or equal to the conclusion.

For example, the preserved property could be justification, the foundational concept of intuitionistic logic. Thus, a proposition is not true or false; instead, it is justified or flawed. A key difference between justification and truth, in this case, is that the law of excluded middle doesn't hold: a proposition that is not flawed is not necessarily justified; instead, it's only not proven that it's flawed. The key difference is the determinacy of the preserved property: One may prove that P is justified, that P is flawed, or be unable to prove either. A valid argument preserves justification across transformations, so a proposition derived from justified propositions is still justified. However, there are proofs in classical logic that depend upon the law of excluded middle; since that law is not usable under this scheme, there are propositions that cannot be proven that way.

Functional completeness of many-valued logics
Functional completeness is a term used to describe a special property of finite logics and algebras. A logic's set of connectives is said to be functionally complete or adequate if and only if its set of connectives can be used to construct a formula corresponding to every possible truth function. An adequate algebra is one in which every finite mapping of variables can be expressed by some composition of its operations.

Classical logic: CL = ({0,1}, ¬, →, ∨, ∧, ↔) is functionally complete, whereas no Łukasiewicz logic or infinitely many-valued logics has this property.

We can define a finitely many-valued logic as being Ln ({1, 2, ..., n} ƒ1, ..., ƒm) where n ≥ 2 is a given natural number. Post (1921) proves that assuming a logic is able to produce a function of any mth order model, there is some corresponding combination of connectives in an adequate logic Ln  that can produce a model of order m+1.

Applications
Known applications of many-valued logic can be roughly classified into two groups. The first group uses many-valued logic to solve binary problems more efficiently. For example, a well-known approach to represent a multiple-output Boolean function is to treat its output part as a single many-valued variable and convert it to a single-output characteristic function (specifically, the indicator function). Other applications of many-valued logic include design of programmable logic arrays (PLAs) with input decoders, optimization of finite state machines, testing, and verification.

The second group targets the design of electronic circuits that employ more than two discrete levels of signals, such as many-valued memories, arithmetic circuits, and field programmable gate arrays (FPGAs). Many-valued circuits have a number of theoretical advantages over standard binary circuits. For example, the interconnect on and off chip can be reduced if signals in the circuit assume four or more levels rather than only two. In memory design, storing two instead of one bit of information per memory cell doubles the density of the memory in the same die size. Applications using arithmetic circuits often benefit from using alternatives to binary number systems. For example, residue and redundant number systems can reduce or eliminate the ripple-through carries that are involved in normal binary addition or subtraction, resulting in high-speed arithmetic operations. These number systems have a natural implementation using many-valued circuits. However, the practicality of these potential advantages heavily depends on the availability of circuit realizations, which must be compatible or competitive with present-day standard technologies. In addition to aiding in the design of electronic circuits, many-valued logic is used extensively to test circuits for faults and defects. Basically all known automatic test pattern generation (ATG) algorithms used for digital circuit testing require a simulator that can resolve 5-valued logic (0, 1, x, D, D'). The additional values—x, D, and D'—represent (1) unknown/uninitialized, (2) a 0 instead of a 1, and (3) a 1 instead of a 0.

Research venues
An IEEE International Symposium on Multiple-Valued Logic (ISMVL) has been held annually since 1970. It mostly caters to applications in digital design and verification. There is also a Journal of Multiple-Valued Logic and Soft Computing.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Many-valued logic


text:
Ballistic missile

Minuteman III MIRV path.svg launch sequence: 1. The missile launches out of its silo by firing its 1st-stage boost motor (A).

2. About 60 seconds after launch, the 1st-stage drops off and the 2nd-stage motor (B) ignites. The missile shroud (E) is ejected.

3. About 120 seconds after launch, the 3rd-stage motor (C) ignites and separates from the 2nd stage.

4. About 180 seconds after launch, 3rd-stage thrust terminates and the post-boost vehicle (D) separates from the rocket.

5. The post-boost vehicle maneuvers itself and prepares for re-entry vehicle (RV) deployment.

6. The RVs, as well as decoys and chaff, are deployed.

7. The RVs (now armed) and chaff re-enter the atmosphere at high speeds.

8. The nuclear warheads detonate.]]

A ballistic missile (BM) is a type of missile that uses projectile motion to deliver warheads on a target. These weapons are powered only during relatively brief periods—most of the flight is unpowered. Short-range ballistic missiles (SRBM) typically stay within the Earth's atmosphere, while most larger missiles are exo-atmospheric. The largest ICBMs are capable of full orbital flight. These weapons are in a distinct category from cruise missiles, which are aerodynamically guided in powered flight and thus restricted to the atmosphere.

History
One modern pioneer ballistic missile was the A-4, commonly known as the V-2 developed by Nazi Germany in the 1930s and 1940s under the direction of Wernher von Braun. The first successful launch of a V-2 was on October 3, 1942, and it began operation on September 6, 1944, against Paris, followed by an attack on London two days later. By the end of World War II in Europe in May 1945, more than 3,000 V-2s had been launched.

The R-7 Semyorka was the first intercontinental ballistic missile.

Flight
An intercontinental ballistic missile trajectory consists of three parts: the powered flight portion; the free-flight portion, which constitutes most of the flight time; and the re-entry phase, where the missile re-enters the Earth's atmosphere. The flight phases for shorter-range ballistic missiles are essentially the first two phases of the ICBM, as some ballistic categories do not leave the atmosphere.

Ballistic missiles can be launched from fixed sites or mobile launchers, including vehicles (e.g., transporter erector launchers), aircraft, ships, and submarines. The powered flight portion can last from a few tenths of seconds to several minutes and can consist of multiple rocket stages.

When the fuel is exhausted, no more thrust is provided and the missile enters free flight. In order to cover large distances, ballistic missiles are usually launched into a high sub-orbital spaceflight; for intercontinental missiles, the highest altitude (apogee) reached during free-flight is about 4500 km.

The re-entry stage begins at an altitude where atmospheric drag plays a significant part in missile trajectory, and lasts until missile impact. Re-entry vehicles re-enter the Earth's atmosphere at very high velocities, on the order of 6-8 km/s at ICBM ranges.

Types

Ballistic missiles vary widely in range and use, and are often divided into categories based on range. Various schemes are used by different countries to categorize the ranges of ballistic missiles:

 * Air-launched ballistic missile (ALBM)
 * Tactical ballistic missile: Range from about 150 to 300 km
 * Theatre ballistic missile (TBM): Range from 300 to 3500 km
 * Short-range ballistic missile (SRBM): Range from 300 to 1000 km
 * Medium-range ballistic missile (MRBM): Range from 1000 to 3500 km
 * Intermediate-range ballistic missile (IRBM) or long-range ballistic missile (LRBM): Range from 3500 to 5500 km
 * Intercontinental ballistic missile (ICBM): Range greater than 5500 km
 * Submarine-launched ballistic missile (SLBM): Launched from ballistic missile submarines (SSBNs)

Long- and medium-range ballistic missiles are generally designed to deliver nuclear weapons because their payload is too limited for conventional explosives to be cost-effective in comparison to conventional bomber aircraft.

Quasi-ballistic missiles
A quasi-ballistic missile is a category of SRBM that is largely ballistic but can perform maneuvers in flight or make unexpected changes in direction and range. Large guided MLRS rockets with range comparable to an SRBM are sometimes categorized as quasi-ballistic missiles.

List of quasi-ballistic missiles

 * 🇮🇳 India

 * Shaurya (active)
 * Pralay (active)
 * 🇮🇱 Israel
 * LORA (active)

 * Soviet Union / 🇷🇺 Russia
 * Iskander (active)
 * 🇺🇸 United States

 * MGM-140 ATACMS (active)
 * Precision Strike Missile (under development)

Hypersonic ballistic missile
Many ballistic missiles reach hypersonic speeds (i.e. Mach 5 and above) when they re-enter the atmosphere from space. However, in common military terminology, the term "hypersonic ballistic missile" is generally only given to those that can be maneuvered before hitting their target and don't follow a simple ballistic trajectory.

Throw-weight
Throw-weight is a measure of the effective weight of ballistic missile payloads. It is measured in kilograms or tonnes. Throw-weight equals the total weight of a missile's warheads, reentry vehicles, self-contained dispensing mechanisms, penetration aids, and any other components that are part of the delivered payload, and not of the rocket itself (such as the launch rocket booster and launch fuel). Throw-weight may refer to any type of warhead, but in normal modern usage, it refers almost exclusively to nuclear or thermonuclear payloads. It was once also a consideration in the design of naval ships and the number and size of their guns.

Throw-weight was used as a criterion in classifying different types of missiles during Strategic Arms Limitation Talks between the Soviet Union and the United States. The term became politically controversial during debates over the arms control accord, as critics of the treaty alleged that Soviet missiles were able to carry larger payloads and so enabled the Soviets to maintain higher throw-weight than an American force with a roughly comparable number of lower-payload missiles.

The missiles with the world's heaviest payloads are the Russian SS-18 and Chinese CSS-4 and, Russia was developing a new heavy-lift, liquid-propellant ICBM called the Sarmat.

Depressed trajectory
Throw-weight is normally calculated using an optimal ballistic trajectory from one point on the surface of the Earth to another. A "minimum-energy trajectory" maximizes the total payload (throw-weight) using the available impulse of the missile. By reducing the payload weight, different trajectories can be selected, which can either increase the nominal range or decrease the total time in flight.

A depressed trajectory is non-optimal, as a lower and flatter trajectory takes less time between launch and impact but has a lower throw-weight. The primary reasons to choose a depressed trajectory are to evade anti-ballistic missile systems by reducing the time available to shoot down the attacking vehicle (especially during the vulnerable burn-phase against space-based ABM systems) or a nuclear first-strike scenario. An alternate, non-military purpose for a depressed trajectory is in conjunction with the spaceplane concept with use of airbreathing jet engines, which requires the ballistic missile to remain low enough inside the atmosphere for air-breathing engines to function.

In contrast, a "lofted" trajectory is frequently used for testing purposes, as it reduces the range of the missile (allowing for a controlled and observed impact), as well as signals a lack of hostile intention with the test.

Combat use
The following ballistic missiles have been used in combat:

 * 9K720 Iskander
 * Ababil-100
 * Al-Samoud 2
 * DF-12
 * Fateh-110
 * Ghadr-110
 * LORA
 * MGM-140 ATACMS
 * OTR-21 Tochka
 * Qaher-1/2M
 * Scud
 * Toufan (Houthi version of Iranian Ghadr-110)
 * V-2
 * Zolfaghar
 * Kh-47M2 Kinzhal

title: Ballistic missile


text:
Risa

Risa may refer to:

 * Risa (given name), a feminine given name
 * Risa (Star Trek), a fictional planet
 * Radioiodinated serum albumin
 * Recording Industry of South Africa
 * Ribosomal Intergenic Spacer analysis

title: Risa


text:
M110 howitzer

The 8-inch (203 mm) M110 self-propelled howitzer is an American self-propelled artillery system consisting of an M115 203 mm howitzer installed on a purpose-built chassis. Before its retirement from US service, it was the largest available self-propelled howitzer in the United States Army's inventory; it continues in service with the armed forces of other countries, to which it was exported. Missions include general support, counter-battery fire, and suppression of enemy air defense systems.

Description
According to the operator's manual, the M110's typical rate of fire was three rounds per two minutes when operated at maximum speed, and one round per two minutes with sustained fire. The M110 featured a hydraulically operated rammer to automatically chamber the 200 lb+ projectile. These rammers were prone to breakdown and generally slowed operation of the gun because the rammers required crews to completely lower the massive barrel before using it. Well trained and motivated crews could achieve two to four rounds per minute for short periods by using the manual rammer, essentially a heavy steel pole with a hard rubber pad on one end. Using the manual rammer was physically demanding, but crews were not required to lower the barrels as much as with the hydraulic rammer.

The M110's range varied from 16.8 km to approximately 25 km when firing standard projectiles, and up to 30 km when firing rocket-assisted projectiles.

History
The M110 howitzer first entered service with the U.S. Army in 1963 and was used in the Vietnam War by the United States Army. Later versions were used in the Gulf War - Operation Desert Shield and Operation Desert Storm by Tango Battery 5th Battalion 11th Marines, and the British Army's 32nd Regiment Royal Artillery.

In 1977 the upgraded M110A1 entered service, featuring a longer M201 series barrel which gave it an increased range. The final version, the M110A2, added a double muzzle brake. The M110A2s were made from refitted M110s or M107 175 mm self-propelled guns. The 2nd Battalion 18th Field Artillery (U.S. Army), which inactivated in 1994 at Fort Sill, Oklahoma, and the 5th Battalion 18th Field Artillery served in Desert Storm with the M110A2, as did the 142nd Field Artillery Brigade (Arkansas Army National Guard) and 1st Battalion 181st Field Artillery (Tennessee Army National Guard). Most of the U.S. Army and Marine Corps relied on M109 series 155-millimeter howitzer systems during this conflict, sending remaining M110s to reserve or National Guard units. These units then took possession of M109s as they returned from combat operations. M110s were still in service with the 3rd Battalion 92nd Field Artillery (US Army Reserve) and running fire missions at Camp Atterbury as late as the summer of 1994.

The howitzer has been retired from U.S. Army service, replaced by the M270 Multiple Launch Rocket System.

At the end of the Cold War under U.S. Division Plan 86, all armored and mechanized infantry divisions included a battalion of heavy artillery that included two batteries of M110A2 SP howitzers with six guns each for a total of 12 guns, plus one battery of nine M270 Multiple Launch Rocket System rocket artillery.

Israel used M110s along with M107s during the Yom Kippur War against Egyptian and Syrian forces. Later, in 1982, Israel used M110 systems against the Palestine Liberation Organization and their Lebanese allies with deadly effect during the Siege of Beirut as part of Operation Peace for Galilee.

Iran used its M110s during its offensives against Iraq in the Iran–Iraq War.

The Turkish Armed Forces have used M110A2 systems against the Kurdistan Workers' Party since the 1990s, as well as in the Turkish military intervention in Syria, mainly against the People's Protection Units.

Projectiles

 * M14 dummy
 * M106 HE
 * M650 HE rocket assist projectile (RAP)
 * M509 ICM
 * M404 ICM anti-personnel (airburst)
 * M426 agent GB Sarin
 * M422A1 Artillery Fired Atomic Projectile
 * M424 High Altitude Spotting Round for the M422 projectile
 * XM753 Atomic RA (rocket assisted)

Current operators

 * 🇧🇭: Royal Bahraini Army 13 as M110A2 from Netherlands delivered in 1994, 25 as M110A2 from US delivered in 1996.
 * 🇨🇾: Cypriot National Guard 8 as M110A2
 * 🇬🇷: Hellenic Army 145 as M110A2.
 * 🇪🇬: Egyptian Army Received 144 as M110A2 as aid in 1996.
 * 🇮🇷: Iran Army 30 M110.
 * 🇯🇴: Jordanian Armed Forces 120 as M110A2.
 * 🇲🇦: Moroccan Army 60 as M110A2.
 * 🇵🇰: Pakistan Army 140 in service as of 2021.
 * 🇹🇼: Republic of China Army 70 M110A2 as of 2023
 * 🇹🇷: Turkish Army currently phasing out 219 as M110A2 in favor of T-155 Fırtına

Former operators

 * 🇧🇪: Belgian Army 11 M110A2 between 1972 and 1993 used by the 20th Artillery Regiment (Belgian Forces in Germany).
 * 🇩🇪: German Army M110A2 until 1993.
 * 🇮🇱: Israeli Army 36 as M110, retired in 1990s.
 * 🇮🇹: Italian Army used M110A2s, phased out by 1998.
 * 🇯🇵: Japan Ground Self-Defense Force 91 as M110A2. As of 2023, approximately 10 M110A2s were in active, owned by 104th Artillery Battalion of 4th Artillery Group (Mechanized) in Hokkaido. They retired in March 2024 and the battalion was disbanded.
 * 🇰🇷: Republic of Korea Army Operated M110 since 1961. Retired in the late 2000s after being replaced by K9 Thunder.
 * undefined: Army of the Republic of Vietnam.
 * 🇳🇱: Royal Netherlands Army M110A1 and M110A2, replaced by the M109 in the 1990s
 * Spanish Army as 64 M110A2, deployed in divisional fire support regiments until 2009.
 * British Army as M110A2 firing high explosive and nuclear shells only. (The FV433 Abbot SPG, the M109A2, and the M110A1 were replaced by the AS-90 in the early-mid-1990s.) Used in Operation Granby/Gulf War.
 * 🇺🇸: Used by United States Army and United States Marine Corps, M110A2s retired in 1994.

title: M110 howitzer


text:
Hazardous waste

Hazardous waste is waste that must be handled properly to avoid damaging human health or the environment. Waste can be hazardous because it is toxic, reacts violently with other chemicals, or is corrosive, among other traits. As of 2022, humanity produces 300-500 million metric tons of hazardous waste annually. Some common examples are electronics, batteries, and paints. An important aspect of managing hazardous waste is safe disposal. Hazardous waste can be stored in hazardous waste landfills, burned, or recycled into something new. Managing hazardous waste is important to achieve worldwide sustainability. Hazardous waste is regulated on national scale by national governments as well as on an international scale by the United Nations (UN) and international treaties.

Universal wastes
Universal wastes are a special category of hazardous wastes that (in the U.S.) generally pose a lower threat relative to other hazardous wastes, are ubiquitous and produced in very large quantities by a large number of generators. Some of the most common "universal wastes" are: fluorescent light bulbs, some specialty batteries (e.g. lithium or lead containing batteries), cathode ray tubes, and mercury-containing devices.

Universal wastes are subject to somewhat less stringent regulatory requirements. Small quantity generators of universal wastes may be classified as "conditionally exempt small quantity generators" (CESQGs) which release them from some of the regulatory requirements for the handling and storage hazardous wastes. Universal wastes must still be disposed of properly.

Household Hazardous Waste

Household Hazardous Waste (HHW), also referred to as domestic hazardous waste or home generated special materials, is a waste that is generated from residential households. HHW only applies to waste coming from the use of materials that are labeled for and sold for "home use". Waste generated by a company or at an industrial setting is not HHW.

The following list includes categories often applied to HHW. It is important to note that many of these categories overlap and that many household wastes can fall into multiple categories:

 * Paints and solvents
 * Automotive wastes (used motor oil, antifreeze, etc.)
 * Pesticides (insecticides, herbicides, fungicides, etc.)
 * Mercury-containing wastes (thermometers, switches, fluorescent lighting, etc.)
 * Electronics (computers, televisions, mobile phones)
 * Aerosols / Propane cylinders
 * Caustics / Cleaning agents
 * Refrigerant-containing appliances
 * Some specialty batteries (e.g. lithium, nickel cadmium, or button cell batteries)
 * Ammunition
 * Asbestos
 * Car batteries
 * Radioactive wastes (some home smoke detectors are classified as radioactive waste because they contain very small amounts of radioactive isotope americium, e.g. americium-241).
 * Smoke from chimneys

Disposal
Historically, some hazardous wastes were disposed of in regular landfills. Hazardous wastes must often be stabilized and solidified in order to enter a landfill and must undergo different treatments in order to stabilize and dispose of them. Most flammable materials can be recycled into industrial fuel. Some materials with hazardous constituents can be recycled, such as lead acid batteries. Many landfills require countermeasures against groundwater contamination. For example, a barrier has to be installed along the foundation of the landfill to contain the hazardous substances that may remain in the disposed waste. Currently,

Recycling
Some hazardous wastes can be recycled into new products. Examples may include lead–acid batteries or electronic circuit boards. When heavy metals in these types of ashes go through the proper treatment, they could bind to other pollutants and convert them into easier-to-dispose solids, or they could be used as pavement filling. Such treatments reduce the level of threat of harmful chemicals, like fly and bottom ash, while also recycling the safe product.

Incineration
Incinerators burn hazardous waste at high temperatures (1600°-2500°F, 870°-1400°C), greatly reducing its amount by decomposing it into ash and gases. Incineration works with many types of hazardous waste, including contaminated soil, sludge, liquids, and gases. An incinerator can be built directly at a hazardous waste site, or more commonly, waste can be transported from a site to a permanent incineration facility.

The ash and gases leftover from incineration can also be hazardous. Metals are not destroyed, and can either remain in the furnace or convert to gas and join the gas emissions. The ash needs to be stored in a hazardous waste landfill, although it takes less space than the original waste. Incineration releases gases such as carbon dioxide, nitrogen oxides, ammonia, and volatile organic compounds. Reactions in the furnace can also form hydrochloric acid gas and sulfur dioxide. To avoid releasing hazardous gases and solid waste suspended in those gases, modern incinerators are designed with systems to capture these emissions.

Landfill
Hazardous waste may be sequestered in a hazardous waste landfill or permanent disposal facility. "In terms of hazardous waste, a landfill is defined as a disposal facility or part of a facility where hazardous waste is placed or on land and which is not a pile, a land treatment facility, a surface impoundment, an underground injection well, a salt dome formation, a salt bed formation, an underground mine, a cave, or a corrective action management unit (40 CFR 260.10)."

Pyrolysis
Some hazardous waste types may be eliminated using pyrolysis in a high temperature not necessarily through electrical arc but starved of oxygen to avoid combustion. However, when electrical arc is used to generate the required ultra heat (in excess of 3000 degree C temperature) all materials (waste) introduced into the process will melt into a molten slag and this technology is termed Plasma not pyrolysis. Plasma technology produces inert materials and when cooled solidifies into rock like material. These treatment methods are very expensive but may be preferable to high temperature incineration in some circumstances such as in the destruction of concentrated organic waste types, including PCBs, pesticides and other persistent organic pollutants.

Management and health effects
Hazardous waste management and disposal comes with consequences if not done properly. If disposed of improperly, hazardous gaseous substances can be released into the air resulting in higher morbidity and mortality. These gaseous substances can include hydrogen chloride, carbon monoxide, nitrogen oxides, sulfur dioxide, and some may also include heavy metals. With the prospect of gaseous material being released into the atmosphere, several organizations (RCRA, TSCA, HSWA, CERCLA) developed an identification scale in which hazardous materials and wastes are categorized in order to be able to quickly identify and mitigate potential leaks. F-List materials were identified as non-specific industrial practices waste, K-List materials were wastes generated from specific industrial processes - pesticides, petroleum, explosive industries, and the P & U list were commercially used generated waste and shelf stable pesticides. Not only can mismanagement of hazardous wastes cause adverse direct health consequences through air pollution, mismanaged waste can also contaminate groundwater and soil. In an Austrian study, people who live near industrial sites are "more often unemployed, have lower education levels, and are twice as likely to be immigrants." This creates disproportionately larger issues for those who depend heavily on the land for harvests and streams for drinking water; this includes Native American populations. Though all lower-class and/or social minorities are at a higher risk for being exposed to toxic exposure, Native Americans are at a multiplied risk due to the facts stated above (Brook, 1998). Improper disposal of hazardous waste has resulted in many extreme health complications within certain tribes. Members of the Mohawk Nation at Akwesasne have suffered elevated levels of PCB [Polychlorinated Biphenyls] in their bloodstreams leading to higher rates of cancer.

Global goals
The UN has a mandate on hazardous substances and wastes with recommendations to countries for dealing with hazardous waste. 199 countries signed the 1992 Basel Convention, seeking to stop the flow of hazardous waste from developed countries to developing countries with less stringent environmental regulations.

The international community has defined the responsible management of hazardous waste and chemicals as an important part of sustainable development by including it in Sustainable Development Goal 12. Target 12.4 of this goal is to "achieve the environmentally sound management of chemicals and all wastes throughout their life cycle". One of the indicators for this target is: "hazardous waste generated per capita; and proportion of hazardous waste treated, by type of treatment".

Resource Conservation and Recovery Act (RCRA)
Hazardous wastes are wastes with properties that make them dangerous or potentially harmful to human health or the environment. Hazardous wastes can be liquids, solids, contained gases, or sludges. They can be by-products of manufacturing processes or simply discarded commercial products, like cleaning fluids or pesticides. In regulatory terms, RCRA hazardous wastes are wastes that appear on one of the four hazardous wastes lists (F-list, K-list, P-list, or U-list), or exhibit at least one of the following four characteristics; ignitability, corrosivity, reactivity, or toxicity. in the US, Hazardous wastes are regulated under the Resource Conservation and Recovery Act (RCRA), Subtitle C.

By definition, EPA determined that some specific wastes are hazardous. These wastes are incorporated into lists published by the Agency. These lists are organized into three categories: F-list (non-specific source wastes) found in the regulations at 40 CFR 261.31, K-list (source-specific wastes) found in the regulations at 40 CFR 261.32, and P-list and the U-list (discarded commercial chemical products) found in the regulations at 40 CFR 261.33.

RCRA's record keeping system helps to track the life cycle of hazardous waste and reduces the amount of hazardous waste illegally disposed.

Comprehensive Environmental Response, Compensation, and Liability Act
The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was enacted in 1980. The primary contribution of CERCLA was to create a "Superfund" and provide for the clean-up and remediation of closed and abandoned hazardous waste sites. CERCLA addresses historic releases of hazardous materials, but does not specifically manage hazardous wastes.

Environmental Act and Hazardous Waste Rules
In 1984, a deadly methyl isocyanate gas leak known as the Bhopal disaster raised environmental awareness in India. In response, the Indian government produced the Environmental Act in 1986, followed by the Hazardous Waste Rules in 1989. With these rules, companies are only permitted by the state to produce hazardous waste if they are able to dispose of it safely. However, state governments did not make these rules effective. There was around a decade delay between when hazardous waste landfills were requested and when they were built. During this time, companies disposed hazardous waste in various "temporary" hazardous waste locations, such as along roads and in canal pits, with no immediate plan to move it to proper facilities.

Supreme Court action
The Supreme Court stepped in to prevent damage from hazardous waste in order to protect the right to life. A 1995 petition by the Research Foundation for Science, Technology, and Natural Resource Policy spurred the Supreme Court to create the High Powered Committee (HPC) of Hazardous Waste, since data from pre-existing government boards was not usable. This committee found studies linking pollution and improper waste treatment with higher amounts of hexavalent chromium, lead, and other heavy metals. Industries and regulators were effectively ignoring these studies. In addition, the state was also not acting in accordance with the Basel Convention, an international treaty on the transport of hazardous waste. The Supreme Court modified the Hazardous Waste Rules and began the Supreme Court Monitoring Committee to follow up on its decisions. With this committee, the Court has been able to force companies polluting hazardous wastes to close.

United States
In the United States, the treatment, storage, and disposal of hazardous waste are regulated under the Resource Conservation and Recovery Act (RCRA). Hazardous wastes are defined under RCRA in 40 CFR 261 where they are divided into two major categories: characteristic wastes and listed wastes.

The requirements of the RCRA apply to all the companies that generate hazardous waste as well as those companies that store or dispose hazardous waste in the United States. Many types of businesses generate hazardous waste. Dry cleaners, automobile repair shops, hospitals, exterminators, and photo processing centers may all generate hazardous waste. Some hazardous waste generators are larger companies such as chemical manufacturers, electroplating companies, and oil refineries.

A U.S. facility that treats, stores, or disposes of hazardous waste must obtain a permit for doing so under the RCRA. Generators and transporters of hazardous waste must meet specific requirements for handling, managing, and tracking waste. Through the RCRA, Congress directed the United States Environmental Protection Agency (EPA) to create regulations to manage hazardous waste. Under this mandate, the EPA developed strict requirements for all aspects of hazardous waste management including the treatment, storage, and disposal of hazardous waste. In addition to these federal requirements, states may develop more stringent requirements that are broader in scope than the federal regulations. Furthermore, RCRA allows states to develop regulatory programs that are at least as stringent as RCRA and, after review by EPA, the states may take over responsibility for the implementation of the requirements under RCRA. Most states take advantage of this authority, implementing their own hazardous waste programs that are at least as stringent, and in some cases are more stringent than the federal program.

The U.S. government provides several tools for mapping hazardous wastes to particular locations. These tools also allow the user to view additional information.

 * TOXMAP was a Geographic Information System (GIS) service from the Division of Specialized Information Services of the United States National Library of Medicine (NLM) that used maps of the United States to help users visually explore data from the United States Environmental Protection Agency's (EPA) Toxics Release Inventory and Superfund Basic Research Program. This resource was funded by the US Federal Government. TOXMAP's chemical and environmental health information was taken from NLM's Toxicology Data Network (TOXNET), PubMed, and other authoritative sources.
 * The US Environmental Protection Agency (EPA) "Where You Live" allows users to select a region from a map to find information about Superfund sites in that region.

title: Hazardous waste


text:
Heavy Expanded Mobility Tactical Truck

The Heavy Expanded Mobility Tactical Truck (HEMTT) is an eight-wheel drive, diesel-powered, 10 short ton tactical truck. The M977 HEMTT first entered service in 1982 with the United States Army as a replacement for the M520 Goer, and since that date has remained in production for the U.S. Army and other nations. By Q2 2021, around 35,800 HEMTTs in various configurations had been produced by Oshkosh Defense through new-build contracts and around 14,000 of these had been re-manufactured. Current variants have the A4 suffix.

The 10×10 Logistic Vehicle System Replacement (LVSR) is the United States Marines Corps' (USMC) equivalent to the U.S. Army's 8×8 HEMTT and 10×10 Palletized Load System (PLS). The USMC does not use the HEMTT or PLS, and the Army does not use the LVSR, but both services use a common trailer (M1076) with all three truck types.

History
Following the evaluation of proposals submitted by AM General, MAN, Pacific Car & Foundry (PACCAR) and Oshkosh Truck Corporation (with PACCAR–GMC team being the apparent leader of the competition, with pre-production assembly line already established) in May 1981, the then U.S. Army Tank-Automotive Command awarded an initial five-year contract valued at US$251.13 million to Oshkosh Truck Corporation for production of the 10 short ton 8×8 Heavy Expanded Mobility Tactical Truck (HEMTT).

The first prototype HEMTT was completed in December 1981, pre-production examples followed during March 1982, with the first production vehicles produced in September 1982. Over five contract years, 2,140 vehicles were to be delivered. Contract options allowed for up to an additional 5,351 HEMTTs to be ordered, bringing production totals to 7,490 vehicles. The bulk of these options were exercised.

The second HEMTT contract was awarded to Oshkosh Truck Corporation in April 1987. This contract called for a base quantity of 1,403 vehicles, with options for an additional 1,684 vehicles; all contract options were exercised. A supplemental agreement added a further 1,449 vehicles (plus an option for 363 vehicles) to the second HEMTT contract in April 1989; the contract option was exercised. The third HEMTT production contract was awarded mid-1994 and when deliveries under this concluded over 14,000 HEMTTS had been produced. The fourth HEMTT production contract was awarded in August 1995, this extending production through September 2001.

The Family of Heavy Tactical Vehicles (FHTV) contract was awarded to Oshkosh by the U.S. Army in March 2001. In addition to the HEMTT (both new and re-manufacture), the contract covered the M1070 HET, M1074, and M1075 Palletized Load System (PLS) trucks, and M1076 PLS trailers and called for up to 5,398 trucks and 1,100 trailers (including options). FHTV covered the production period from March 2001 until mid-fiscal year 2006 (FY06). The FHTV contract was extended and renegotiated, and in February 2007, Oshkosh announced it had been awarded a contract to continue production of FHTVs. The follow-on FHTV contract (FHTV 2) covered new production of HEMTTs (including current A4 variants from mid-2008) and PLS vehicles plus PLS trailers. In total, 2,173 new-build HEMTT A4 and 104 Recap HEMTT A4 were ordered under FHTV 2.

Production of product-improved HEMTT A2s continued until production of the HEMTT A4 began in July 2008. The exception was the M1977, which initially remained at A2 configuration for fleet commonality reasons; there is now an M1977A4.

Oshkosh Defense announced in October 2008 that it had been awarded the FHTV 3 contract by the U.S. Army's TACOM. More than 6,000 vehicles and trailers could be delivered under this three-year contract. FHTV 3 covered the HEMTT A4 and A1 models of the PLS and HET, and both new and recapitalized (Recap) vehicles. HEMTT A4 models were required to be Long Term Armor Strategy (LTAS) compliant and came off the assembly line fitted with upgraded suspensions and integral composite (A-kit) armor, and ready to receive an add-on (B-kit) armor appliqué.

The first FHTV 3 order was valued at US$1.2 billion and delivery commenced in November 2008. By late-2009, about 11,500 HEMTT A4s (new-build and Recap) had been ordered under the FHTV 2 and 3 contracts.

Oshkosh Defense announced in 2012 that it had been awarded a bridge contract to continue production and support of the FHTV. In October 2013, the U.S. Army released a revised pre-solicitation notice associated with FHTV 4 (presented FHTV IV). The original synopsis had been released in July 2013. According to the October release, the government intends to award a five-year requirements contract with an estimated value of US$822 million on a sole source basis to Oshkosh Corporation. It is understood the aim of the U.S. Army, was to ensure negotiations with Oshkosh Defense for FHTV IV were concluded in time to ensure there was no break in production between FHTV 3 and FHTV IV production and deliveries.

On 19 June 2015, Oshkosh Defense announced the U.S. Army had awarded the company a five-year requirements contract worth a potential $780 million to Recapitalize (Recap) its Family of Heavy Tactical Vehicles (FHTV). The FHTV 4 contract covers an estimated 1,800 FHTVs and in addition to HEMTTs covers PLS trucks and also includes the production of approximately 1,000 new production PLS trailers. HEMTT models account for around 75 per cent of the Recap potential, and all work performed under the contract will be completed in Oshkosh, Wisconsin. Deliveries will run from 2015 to 2019. In March 2016, Oshkosh received FHTV 4 awards valued at $430 million and covering the Recap of 1212 HEMTTs and PLS, plus the production of 345 new-build PLS trailers. Deliveries are slated for 2016–2017. In April 2017, Oshkosh announced further FHTV 4 awards valued at more than $258 million for the Recap of 670 FHTVs plus the production of 356 PLS trailers. Deliveries commence in December 2017. On 23 May 2018 Oshkosh announced a further FHTV-4 award, this valued at $235.2 million for the Recap of 410 FHTVs and the manufacture of 680 new PLS trailers. Deliveries commence in FY19. On 8 February 2019 Oshkosh announced an FHTV-4 award valued at $225.7 million for the Recap of 407 FHTVs and the manufacture of 601 new PLS trailers. Deliveries commence in FY19.

The final FHTV 4 award was announced by Oshkosh in March 2020. The award was valued at US$346.4 million and called for an undisclosed quantity of U.S. Army and U..S Army Reserve FHTVs to be Recap’d. Quantities/breakdown were not revealed, and deliveries were scheduled to conclude in December 2021.

On 3 May 2021 the U.S. Army announced that it had awarded Oshkosh Defense a three-year extension to the FHTV 4 contract. Under the extension, Oshkosh will provide new and Recap'd HEMTT, PLS trucks and trailers, and HETs. The initial delivery orders call for a total of 353 new and recapitalized vehicles, with HEMTTs accounting for US$130.5 million (inc. 33.8 million for M1977A4 CBTs) of the US$146.8 million total.

Used vehicles can be returned to Oshkosh as part of a recapitalization program where they are stripped to their frame rails and then fully rebuilt to a zero-hour, zero-mile, like-new condition. Recapitalized vehicles are assembled on the same production line as new vehicles, and put through the same performance tests and inspection procedures as new vehicles. Recapitalized vehicles are returned to the Army with a new bumper-to-bumper warranty and include air-conditioned and armor-ready cabs; electrical upgrades, and an anti-lock braking system.

Common Tactical Truck (CTT); previously Next Generation Future Truck (NGFT)
Parallel to the FHTV 4 extension effort, the U.S. Army's Heavy Tactical Vehicles (HTV) PEO CS&CSS issued on 20 July 2020 Notice ID W56HZV-20-R-0237, a Request for Information (RfI) for the Next Generation Future Truck (NGFT). Responses were due by 24 August 2020 for what was quickly renamed the Common Tactical Truck (CTT). It is the intent that CTT will replace the HEMTT, plus the PLSA1 and M915 Truck Tractor, Line Haul. The Army desires five variants of the NGFT/CTT, and all with the option to perform semi-autonomous or autonomous operations. The five variants currently mooted are: a wrecker to recover Stryker, MRAPs, and other tactical wheeled vehicles up to 40 US tons; an LHS Heavy variant with crane to transport flatrack with up to 16 tons of cargo payload; a Tractor variant operable with the M870, M871, M172, M872, M967 tanker, M1062 tanker, future tanker (8,200 gallons), and commercial standard trailers; a Tanker variant with a 2,500 gallon threshold or objective fuel payload greater than 2,500 gallons; and a Cargo variant with crane capable of carrying a payload of up to 22 tons or greater.

Description
The HEMTT's objective is to provide heavy transport capabilities for supply and re-supply of combat vehicles and weapons systems. Compared to earlier generation 5-ton trucks in U.S. Army service it offers increased payload and mobility. The HEMTT is available in a variety of configurations, including cargo, tanker, tractor and wrecker.

The HEMTT was developed from the outset as a tactical truck, but to minimize procurement and life cycle costs included militarized commercial automotive components where possible, these including the engine and transmission. Some components used in early HEMTTs are common with the Oshkosh Logistics Vehicle System (LVS) vehicles which were supplied to the U.S. Marine Corps.

With the exception of the M984 wrecker variant (254 × 89 × 9.5 mm, front; 356 × 89 × 9.5 mm, rear), on all HEMTT variants the chassis is formed of 257 × 89 × 9.5 mm heat-treated carbon manganese steel with a yield strength of 758 MPa. Bolted construction with Grade 8 bolts is used throughout. A centrally mounted self-recovery winch is an option and this is fitted to around 20% of production.

The HEMTT's two-door forward control cab seats two. It is of heavy-duty welded steel construction with corrosion-resistant sheet metal skins. Simula Inc. (acquired by Armor Holdings in 2003 and now BAE Systems) supplied 186 add-on cab armoring kits for use in the former Yugoslavia. These were not issued, but from 2004 were used in Iraq. BAE systems supplied a next-generation armor kit for the HEMTT and by late-2006 had supplied the U.S. Army with around 3600 kits for the Oshkosh HEMTT and PLS. The HEMTT A4 is fitted with the slightly larger from the Oshkosh PLS A1. This cab complies with the U.S. Army's Long Term Armor Strategy (LTAS) requirements of an A- and B-kit armoring philosophy. It also comes as standard with integrated floor armor, an integrated mount for a machine gun and gunner protection kit, and air-conditioning.

A Detroit Diesel 8V92TA V-8 two-stroke diesel developing 445 hp is fitted in HEMTT A0 and A1 models, with the DDECIV version of this engine fitted to A2 HEMTTs. An EPA 2004 compliant Caterpillar (CAT) C-15 six-cylinder, 15.2-liter diesel developing a peak of 515 hp is fitted to HEMTT A4 models. HEMTT A0 and A1 models are fitted with an Allison HT 740D 4F/1R automatic transmission, torque converter, and Oshkosh 55000 lb two-speed transfer case. HEMTT A2 models have the Allison HD 4560P 6F/1R automatic transmission. HEMTT A4 models are fitted with an Allison 4500SP 5F/1R automatic transmission and an uprated version of Oshkosh's 55000 lb two-speed transfer case.

The front axles on all HEMTTs are single-reduction Oshkosh 46K, the rear are Dana single-reduction which vary according to configuration. Drive to the front axles is selectable and all axles have differential locks. Suspension on A0/A1/A3 models is by Hendrickson leaf springs with equalizing beams. Suspension on A4 models is Holland air suspension, load rating on the rear axles varying by configuration. Tire size is 1600 R20 on all models, and standard tire fit is Michelin XZL.

All models are capable of fording water crossings up to 48 in deep, and can climb a gradient of at least 60%. All original variants are air transportable in the C-130. All variants are air-transportable in the C-17.

Original HEMTT models now have the suffix A0. Only the M984 wrecker was produced in A1 configuration. All models were produced in A2 configuration. The A3 suffix is applied to HEMTT technology demonstrators with a diesel–electric drive system. Current HEMTT production models have the suffix A4.

HEMTT models

 * The M977 cargo truck variant is the base member of the HEMTT family. The current model is the M977A4; there was no M977A1. In addition to the basic M977A0/A2/A4 cargo truck, two other variants are available. The M977A0/A2/A4 Electrical Power Plant (EPP) has an extended cargo body (6.041 m inside length) and is used to hold and transport generators for the Patriot air-defence missile system. There is no material handling crane on the EPP. The M977A0/A2/A4 Large Repair Parts Transporter (LRPT) and the basic M977 cargo truck are fitted with a light-duty Grove materials handling crane mounted at the rear of the chassis.
 * The M978 is a 9,500 liter capacity tanker. The current model is the M978A4; there was no M978A1. The M978A0 was produced in both potable water (approximately 18) and fuel servicing truck variants, the A2 and A4 models have only been produced in the fuel servicing truck variant.
 * The M983 is a tractor unit for use with the trailer-mounted MIM-104 Patriot missile system. It can also be used with the Interim Stryker Recovery System, or other trailers. An earlier variant fitted with a 30 kW generator and crane mounted behind the cab was used to tow the Pershing II Erector Launcher in CONUS (a M1001 MAN tractor was used in West Germany). The M983A2/A4 Light Equipment Transporter (LET) tractor is mainly used to transport construction and engineer equipment. It has a 45000 lb) 2 speed hydraulic winch mounted behind the cab used to load the trailer. It does not have a self-recovery winch.
 * The M984 wrecker is the only HEMTT variant to have been produced in the A1 configuration, and this resulting in the change of recovery crane and retrieval system between A0 and A1 configurations. The current model is the M984A4. Standard equipment includes a 27240 kg capacity two-speed recovery winch, a rear-mounted 11,340 kg capacity vehicle retrieval system, and a 6350 kg at 2.74 m capacity Grove materials handling crane. A 9072 kg bare drum capacity self-recovery winch is fitted as standard on the M984.
 * The M985 is available in two variants. The current models are A4; there were no A1 models. The M985 cargo variant is similar to the M977 cargo truck but was developed to support the M270 Multiple Launch Rocket System (MLRS) with a M989A1 HEMAT trailer. It may also used to transport Patriot missiles. The M985 Guided Missile Transporter (GMT) was developed specifically for use with the Patriot system and it can be distinguished easily from other cargo models by its rear-mounted Hiab 8108/2 materials handling crane
 * The M1120 Load Handling System (LHS) variant was initially introduced as part of the HEMTT overhaul/rebuild program, during which returned M977 cargo trucks have their cargo bodies and materials handling cranes removed, to be replaced by a Multilift Mark 5 (now designated MPH165-LHS) LHS, as fitted to the Oshkosh PLS truck.
 * The M1977 HEMTT Common Bridge Transporter (CBT) is a further development of the M1120 LHS, and in common with the M1120 LHS was initially introduced as part of the HEMTT overhaul/rebuild program. It is used for loading, transporting, and unloading Ribbon Bridge components and bridge erection boats.
 * The M1142 is a Tactical Fire Fighting Truck (TFFT) capable of extinguishing aircraft, petroleum, brush, and structural fires at isolated military installations. The TFFT is based on a HEMTT M977A2 chassis with the heavier duty M1120 LHS HEMTT variant rear suspension. The TFFT contract was awarded to Pierce Manufacturing with Oshkosh Corporation as a subcontractor to Pierce.
 * The M1158 HEWATT is designed to support the M1142 Tactical Fire Fighting Truck (TFFT) while providing supplementary fire suppression capabilities.
 * The HEMTT-based M1075 Terminal (formerly Theatre) High Altitude Area Defense (THAAD) missile launcher is technically a variant of the HEMTT LHS, but as of November 2016 no technical details had been released.
 * The HEMTT A3 is the first production-ready tactical defense vehicle to feature a diesel–electric drive system. The ProPulse system fitted uses a modular series-hybrid arrangement to simplify the transmission of power to the wheels. The diesel engine powers an electric generator, which provides direct power to the wheels, eliminating the torque converter, automatic transmission, transfer case, and drive shafts. A dedicated motor controlled from its own power converters drives each axle independently. ProPulse technology, it is claimed, can increase fuel economy by up to 40% over conventional powertrains. The diesel engine is optimized to run at the most efficient speed based on power demand, and transient loads to the engine are eliminated using stored energy. This eliminates the inefficiency associated with changing rpm levels during acceleration and deceleration, and also reduces emissions. In stopping operations, the electric motors operate as generators, and energy is stored for use in the next acceleration. Other stated advantages of the system include the system acting as an on-board generator, providing enough electricity (up to 200 kW of AC power) to power a small airfield, hospital, or military command center. Since the system uses no batteries, they never need to be replaced, and the amount of fuel needed to supply ProPulse-equipped trucks will be less.

Operators

 * 🇧🇭 Bahrain
 * 🇧🇷 Brazil (10 M984 wreckers to be delivered from 2020 to support the Iveco VBTP-MR Guarani 6x6 armoured vehicles). 20 more ordered.
 * 🇪🇬 Egypt
 * 🇬🇷 Greece
 * 🇮🇶 Iraq
 * 🇮🇱 Israel (includes approx. 420 EDA examples in 2015)
 * 🇯🇴 Jordan
 * 🇰🇼 Kuwait
 * 🇲🇾 Malaysia
 * 🇲🇦 Morocco (believed EDA but not confirmed)
 * 🇴🇲 Oman
 * 🇷🇴 Romania used with the Patriot surface-to-air missile systems
 * 🇶🇦 Qatar
 * 🇰🇷 South Korea
 * 🇹🇼 Taiwan
 * 🇹🇷 Turkey
 * UAE
 * 🇺🇸 USA
 * 🇺🇦 Ukraine
 * 🇺🇦 Ukraine

Future/Potential Operators

 * 🇧🇬 Bulgaria

References (bibliography)

 * Brothers of HEMTT - PLS-LVS by Carl Schulze (published by Tankograd) Tankograd
 * HEMTT: US Heavy Expanded Mobility Tactical Truck by Carl Schulze (published by Tankograd) Tankograd
 * Jane's Land Warfare Platforms 2015-2016: Logistics, Support & Unmanned ISBN 0710631723
 * Jane's Land Warfare Platforms 2014/2015: Logistics, Support & Unmanned ISBN 0710631308
 * Jane's Military Vehicles & Logistics 2004–2005 ISBN 0710626312
 * Jane’s Land Warfare Platforms: Logistics, Support & Unmanned
 * Modern U.S. Military Vehicles by Fred Crismon ISBN 0760305269
 * Oshkosh Trucks: 75 Years of Specialty Truck Production (Paperback; November, 1992) (ISBN 0879386614)
 * and

title: Heavy Expanded Mobility Tactical Truck