Basic Information

Name

M109A6 Paladin American 155mm Self-Propelled Howitzer (SPH)

Designation

M109A6 Paladin

Alternate Designation

M109A6 Paladin

Equipment Type

Self-Propelled Howitzer (SPH)

Manufacturer

developed by the ground system division of United Defense LP (now BAE Systems Land and Armaments) and manufactured at the Paladin Production Operation centre at Chambersburg, Pennsylvania.

Date of Introduction

1991

Description

The M109A6 Paladin American 155mm Self-Propelled Howitzer (SPH) is a further upgrade of the M109 self-propelled howitzer, which was introduced in the early 1960s. This M109A6 Paladin self-propelled howitzer entered service with the US Army in 1991. Production ceased in 1999. A total of 950 artillery systems were built for the US Army. Export operators are Israel and Taiwan. With the cancellation of Crusader and NLOS-C programs the US Army will continue to rely on the M109A6 Paladin artillery system until it will be upgraded to the M109A7 standard. The M109A6 has a larger turret than its predecessor. It is armed with the M284 155 mm/L39 howitzer, fitted with a semi-automatic loading system. The maximum range of fire is 24 km with standard projectiles and 30 km with rocket-assisted projectiles. The maximum rate of fire is 4 rounds per minute. The sustained rate is one round every three minutes. Some of the US Army M109A6 Paladins were fitted with modification kits to fire M982 Excalibur extended-range precision-guided projectiles. The Excalibur is GPS-guided and has a maximum range of 40 km. The Paladin can stop and fire the first round in under 60 seconds. Brief redeployment time allows to avoid counter-battery fire and gives shoot-and-scoot capability. The secondary armament consists of a roof-mounted 12.7 mm heavy machine gun. Some vehicles were fitted with 40 mm automatic grenade launchers in place of machine guns. The M109A6 is fitted with an automatic fire control system with integrated navigation and an inertial positioning system. It is also fitted with a muzzle reference system. Armor of the M109A6 Paladin provides protection against small arms fire and artillery shell splinters. The vehicle is fitted with an NBC protection system. The turret is fitted with Kevlar anti-spall lining.

Ground Specifications

Crew 4

Mobility Type Tracked

Main Weapon M284 155 mm/L39 howitzer

Engine V-8 diesel (440 hp)

Range 344.0 km

Variants

M109 First produced in 1963. It had a 23 caliber 155 mm M126 gun in an M127 Howitzer 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.

M109A1 Replaced the M126 gun with a longer barreled, 39 caliber M185 gun, increasing maximum range to 18,100 meters.

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 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.

M109A3 and M109A3B M109A1s and M109A1Bs rebuilt to M109A2 standard respectively. Some A3s feature three contact arm assemblies, while all A2s have five.

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) gear. The traversing mechanism's clutch is hydraulic, as compared to the electric mechanism on previous M109s, and features a manual override in the event of an electrical failure. The A4 also adds an additional hydraulic filter, for a total of two. Also included is an improvement to the engine starting equipment, greatly improving the ability to start in an emergency. Ammunition amounts remain the same as two 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 Projectiles (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 for Brazil.

M109A6 "Paladin" Overall product improvement 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 product 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 in turn coordinate fires through a battalion or higher FDC. This allows the Palladin 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 required several minutes under the best of circumstances. Tactically, this improves the system's survivability by allowing the battery to operate dispersed by pairs across the countryside and allowing the howitzer to quickly displace between salvos, or if attacked by indirect fire, aircraft, or ground forces. Ammunition storage is increased from 36 to 39 155 mm rounds.

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 inertial navigation system coupled with a new gun-laying system and more ammunition storage(40 rounds, 64 charges). The KAWEST (lit. Kampfwertsteigerung = upgrade of combat capabilities) requires only 6 crew members instead of 8, and is able to fire 3-round bursts within 15 seconds or maintain a constant firing rate of over one round per minute. Upgraded Swiss PzHb (Panzerhaubitze) 79 and 88 (M109A1) are known as respectively PzHb 79/95 and PzHb 88/95

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. In addition, improvements to the loading system were made. This resulted in an increase of the rate of fire to 9–10 rds/min from the original 3 rds/min, and this high rate of fire can be sustained for up to 2 minutes. A total of 35 rounds can be carried.

M109A3GNM The current version in service with the Norwegian Army's Artilleribataljonen. 126 M109Gs were acquired from West Germany between 1969–1971. They were then upgraded to the M109A3GN configuration during the latter half of the 1980s. In 2006, there were still 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 additional upgrades in 2007, and were designated M109A3GNM. The upgrade includes, among other things, new intercom and new navigation and positioning systems. The M109A3GNMs are currently the only SPGs that remain in active service with the remainder of the M109s having been put in storage.

K55/K55A1 K55/K55A1 are South Korean variants of the M109A2 , originally named KM109A2 with additional domestic augmentations, license-produced by Samsung Techwin. They are fitted with M178 155 mm 39 caliber gun, NBC protection, automatic fire extinguishing system, and a modified ammunition reception module for K56 automatic ammunition resupply vehicle. The Performance Improvement Program variant, K55A1, is a complete domestic overhaul of the K55 which is further augmented by Samsung Thales with modern digital ballistic computers, multifunctional data display and controllers, GPS navigation and target acquisition system, wireless datalink equipment, and upgraded fire control storage battery and power supply unit, to closely match the US military's modernization of the Paladin into next-generation standard. Many improved technologies of the South Korean K9 Thunder were retrofitted on the K55A1. 1,040 howitzers of these variants were produced.

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 components with the Bradley Fighting Vehicle 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 on-board power systems harness technologies originally developed for the 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 on-board 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.

System

Alternative Designation M109A6 Paladin

Type Self-Propelled Howitzer (SPH)

Caliber 155 mm

Manufacturer developed by the ground system division of United Defense LP (now BAE Systems Land and Armaments) and manufactured at the Paladin Production Operation centre at Chambersburg, Pennsylvania.

Chassis The M108 and M109 shared a common chassis (along with the M113 APC), but the M109 was heavier and had a larger gun. The M108 proved unsuccessful, mainly due to its overly light gun.

Crew 4 ea

Displacement Time INA

Emplacement Time According to United Defense, the Paladin can move from road march to firing status in one minute. Response time while in firing position is less than 30 seconds. These reaction times give Paladin a true "shoot-and-scoot" capability. The Paladin's travel lock, a front-mounted bracket that steadies the long barrel during vehicle movement, has been modified to enable remote operation.

Note #1 The Paladin consists of 1,900 parts. Major components include a low-heat rejection engine from Detroit Diesel; Honeywell navigation/positioning system; and an Alliant Techsystems automatic fire-control system (AFCS).

Dimensions

Length, with Rear Box 6.81 m

Length, Gun Forward 9.68 m

Width, with ADMG 3.24 m

Width, over Side Boxes 3.92 m

Height, Overall 3.62 m

Height, Top of MG Mount 3.27 m

Weight 28,848 kg

Ground Pressure 0.95 kg/cm sq

Track, Length on Ground 3.96 m

Automotive

Engine Name 1 x DDC 8V-71T

Engine Type V-8 diesel

Engine Power 440 hp hp

Power-to-Weight Ratio 15.25 hp/metric ton

Transmission Allison ATD-XTG 411-2A (A3) or 411-4 with quick disconnect powershift crossdrive, 4 forward and 2 reverse gears

Fuel Capacity 503 liters

Range 344 km

Speed, Maximum Road 64 km/h

Speed, Average Cross INA

Speed Maximum Swim Not Amphibious

Side Slope 30 %

Gradient 60 %

Vertical Step 0.53 m

Trench 1.83 m

Fording Depth 1.07 m

Suspension Torsion bar, 7 road wheels, front drive, rear idler, no return rollers (all models except PIM). An upgraded suspension has longer torsion bars and hydro pneumatic bump stops to handle the greater vehicle weight.

Note The M109A5 offers upgraded components providing greater durability. It has a higher horsepower low heat rejection (LHR) engine and an improved transmission for increased performance.

Main Gun

Note The elevation/equilibrium cylinder and turret traverse clutch assembly are redesigned to prevent failures.

System

Name 1 x M284

Type Rifled Howitzer

Caliber 155 mm

Length INA

Barrel Length INA

Weight INA

Cannon Groves 48 groves

Rifling Right-hand rifling with constant, 8.93-deg twist

Breech Type Welin-step thread

Recoil System hydropneumatic

Elevation -3/+75 deg (-53/+1,333 mils)

Traverse 360 deg (6,400 mils)

Maximum Firing Range The maximum range of fire is 24 km with standard projectiles and 30 km with rocket-assisted projectiles.

Maximum Rate of Fire 1 rd/min first hour, 4 rd in first 3 min max

Sustained Rate of Fire 2 rpm

Note #1 This self-propelled artillery system is supported by an associated M992 armored ammunition supply vehicle. It is based on the same tracked chassis as the M109.

Note #2 The cab has a rear bustle rack which provides an increased ammunition stowage capacity.

Note #3 The M109A5 share commonality with all of the other M109 family members and fires all NATO-standard 155-mm ammunition.

Ammunition (Option 1)

Name M549A1

Type HERA

Caliber 155 mm

Length 858 mm

Weight 43.54 kg

Basic Load 39 rounds including 2 Copperhead

Ammunition (Option 2)

Name M712

Type Copperhead

Caliber 155 mm

Length 1,372 mm

Weight 63.50 kg

Basic Load 39 rounds including 2 Copperhead

Ammunition (Option 3)

Name M864

Type DPICM

Caliber 155 mm

Length 898 mm

Weight 43.80 kg

Basic Load 39 rounds including 2 Copperhead

Auxiliary Weapon System

System

Name 1 x M2 Browning

Type Heavy Machine Gun

Caliber 12.7mm

Length 1,654 mm

Barrel Length 1,143 mm

Weight 58 kg with tripod and T&E (Traverse and Elevation Mechanism)

Action Short recoil-operated

Rate of Fire 450–600 rounds/min

Muzzle Velocity 890 m/s

Maximum Firing Range 7,400 m

Effective Firing Range 1,800 m

Feed System Belt-fed (M2 or M9 links)

Sights INA

Ammunition

Type Rifle

Caliber 12.7 mm

Cartridge 12.7×99mm NATO

Basic Load 500 Rounds

Fire Control

Name Alliant Techsystems automatic fire-control system (AFCS).

Computerized FCS Yes, The AFCS has a ballistic computer/weapon controller, power conditioner and an inertial reference navigation systems/dynamic reference unit based on the modular azimuth positioning system (MAPS) using ring laser gyro on-board land navigation. The AFCS permits 0.6 mi. (1 km) separation between vehicles, improving gun battery survivability.

Thermal Sight Vehicle Commander INA

Thermal Sight Gunner INA

Main Gun Stabilization Yes

Night Vision Devices Yes

Note It has an all weather ballistic shield mounted over the panoramic telescope; counterbalanced travel lock and provisions for mounting the M140 alignment device.

Protection

Hull Armor 5083 aluminum with composite spall liners and supplemental armor.

Turret Armor The turret is fitted with Kevlar anti-spall lining

Applique Armor DuPont Kevlar armor has been added to the Paladin, forming an inner lining of the cab, roof and crew compartment sides. Rolled homogeneous steel armor is fitted over the driver's compartment and on the rear of the bustle.

Explosive Reactive Armor INA

Active Protection System INA

Mine Clearing INA

Self-Entrenching Blade INA

NBC Protection MCS system

Smoke Equipment No

Fire Suppression Automatic. Improved protection also includes the segmentation of hydraulic lines and the use of a Halon fire-suppression system. The hydraulic system, which is distributed in the A3, has been centralized in the Paladin. The Halon system is intended to snuff out internal fires in less than 0.25 sec. In addition, a microclimate cooling system has been added to improve the working environment and protect against the effects of nuclear, biological and chemical (NBC) warfare. Projectile stowage has been placed lower in the hull to reduce threat of secondary explosions from counter-battery fires.

Image Sources

Notes https://www.dvidshub.net/image/1853828/several-m109a6-paladin-self-propelled-howitzers-conduct-test-fire; https://www.army.mil/article/263588/1_82_field_artillery_test_table_xii_gunnery_readiness; https://asiatimes.com/2019/09/taiwan-aims-to-bulk-up-its-artillery-power/;