|Country of Origin||USA|
|Role||Armored combat fire support vehicle|
|Date Of Introduction
||1963, original M109
||6 (chief of section, driver, two cannoneers, gunner, assistant gunner)
||4 (chief of section, driver, cannoneer, gunner)|
||27.5 tons (24.95 mt)
||31.8 tons (28.849 mt)|
||29.92 ft (9.12 m), M109A5: 30.08 ft (9.17 m)
||32.17 ft (9.8 m)|
||10.33 (3.15 m)
||10.33 ft (3.15 m)|
||10.76 ft (3.28 m)
||10.62 ft (3.24 m)|
||18 in (457 mm)|
||405 or 440 hp (302 or 328 kw) 8V71T turbocharged diesel
||440 hp (328 kw) 8V71T turbocharged diesel|
||217 miles (349 km)
||186 miles (299 km)|
||135 gal (511 l) - diesel
||133 gal (503 l) - diesel|
||35 mph (56 km/h)
||38 mph (61 km/h)|
|Cross Country Speed
||12 mph (20 km/h)
||17 mph (28 km/h)|
||3.5 ft (1.07 m)|
||6 ft (1.83 m) |
|Vertical Wall Climb
||1.75 ft (0.53 m) |
||?||Adds composite spall liners and supplemental armor|
|Explosive Reactive Armor
|Active Protective System
|NBC Protection System
||Typical Ammo Load
||155mm M126 cannon
||Turret - M127 mount; double baffle muzzle brake
||155mm M126E1/M126A1 cannon
||Turret - double baffle muzzle brake
||155mm M185 cannon
||Turret - M178 mount; double baffle muzzle brake
||155mm, 39 caliber barrel length, M284 cannon
||Turret - M182 mount; double baffle muzzle brake
||155mm, 39 caliber barrel length, M284 cannon
||Turret - M182A1 mount; double baffle muzzle brake; advanced bore evacuator
||.50 Cal M2HB machine gun
||Turret top; flexible; belt-feed
The M109-series medium, self-propelled howitzer is a full-tracked, armored combat support, internally loaded, air transportable,
vehicle powered by an eight cylinder, diesel engine. The system is capable of both direct (line of sight) and indirect (out of
the line of sight) firing.
The hull and cab assemblies protect the crew and equipment against small arms fire. The vehicle is divided into three
sections: driver's compartment, engine compartment, and fighting compartment.
The M992 Field Artillery Ammunition Support Vehicle (FAASV)
is the companion vehicle to the M109 howitzer.
It serves as an area from which to service the weapon as well as a storage area for ammunition.
The powerplant can be removed from the vehicle as a complete unit that consists of an
engine Model 7083-7396 or LHR engine Model 7083-7391, transfer assembly, and transmission.
- Engine Model 7083-7396 is a liquid-cooled, two-stroke cycle, diesel-type, model 8V71T equipped with an exhaust-driven
turbocharger (5). The engine develops 405 horsepower at 2300 rpm and delivers power to the transfer assembly (3).
- LHR Engine Model 7083-7391 is a liquid-cooled, two-stroke cycle, low heat rejection, diesel-type, model 8V71T equipped
with an exhaust-driven turbocharger (5). The engine develops 440 horsepower at 2300 rpm, delivers power to the transfer assembly (3),
and uses glow plugs (6).
- The transfer assembly receives power from the engine (1 or 2) and transfers that power to the transmission (4).
- The transmission is oil cooled and mechanically and hydraulically operated. It receives power from the engine (1 or 2)
through a geared power transfer assembly (3). The transmission has seven gears - four forward, one neutral, and two reverse - and
delivers power to the left and right drive sprockets through the output shaft, universal joints, and final drives. It also functions
as the steering and braking mechanism.
The power pack in the M109A6 Paladin incorporates the new Low Heat Rejection (LHR) engine.
The LHR engine is less dependent on the cooling system.
This means that more of the engine's heat is rejected through the exhaust and less through the cooling system.
This is accomplished by insulating the exhaust ports and exhaust manifolds.
The new LHR engine also incorporates a new higher efficient turbocharger.
These changes provide a cooler running and more efficient engine.
Engine horsepower increase is also a by-product of these changes (440 horsepower at 2300 rpm).
Earlier versions of the howitzer have double rear hull doors, later versions have single doors.
- T196, T196E1
- M109 prototypes. Modifications for the T196E1 included diesel-powered engines. The T196E1 was redesignated as the M109.
- M109 (NSN 2350-00-440-8811)
1963. Original production model. Used extensively in the Vietnam war. Replaced the M44 155mm self-propelled howitzer. Armed with 155mm M126 gun mounted in a M127 howitzer mount.
- Distinctive short gun tube with double baffle muzzle brake.
- 7 evenly spaced road wheels with low front sprocket and idler wheel.
- Large boxy turret mounted rear of center.
610x355, 38K, GIF
600x450, 27K, GIF
650x370, 15K, GIF
- M109A1 (NSN 2350-00-485-9662)
1973. Replaced the M109. Used in the Vietnam war. Has a longer gun barrel (M126A1 gun in M127 mount) for increased range.
830x350, 21K, GIF
Manufactured specifically for foreign sales. This model was a new production M109A1 with all recent modifications.
- M109A2 (NSN 2350-01-031-0586)
1979. The M109A2 is a new production weapon which incorporated 27 mid-life improvements to the M109A1. The improvements provide for
increased Reliability, Availability, and Maintainability (RAM) and safety characteristics as well as enhanced operational capabilities.
The M109A2 has the long tube M185 cannon installed in the M178 gun mount. The cab has a rear bustle rack which provides an increased
ammunition stowage capacity. It has an all weather ballistic shield mounted over the panoramic telescope; counterbalanced travel lock
and provisions for mounting the M140 alignment device.
730x350, 30K, GIF
620x400, 37K, GIF
- M109A3 (NSN 2350-01-031-8851)
1979. The M109A3 is a depot converted M109A1 incorporating the 27 mid-life improvements. The operational characteristics of the M109A3 are
virtually identical to the M109A2. Some M109A3s have three contact arm assemblies: all M109A2s have five contact arm assemblies.
585x385, 39K, GIF
- M109A4 (NSN 2350-01-277-5770)
1989. The M109A4 is a M109A2/A3 with modifications which include the addition of Nuclear, Biological, and Chemical/ Reliability, Availability, and
Maintainability (NBC/RAM) product improvement kits. The driver and cannoneer number 2 have an air purifier and two heaters mounted in
the hull. An air purifier and four heaters are mounted in the cab for the rest of the crew. NBC Mission Oriented Protective Posture
(MOPP) gear is stored in the new cannoneer seats and stowage boxes.
The traversing mechanism operates with a hydraulic clutch in the M109A4 instead of using an electric clutch as in the traversing
mechanism of the M109A2/A3 Howitzer. A clutch valve, with a manual override, provides for power traverse in the event of an
electrical failure to the clutch valve solenoid. The M109A4 has two hydraulic filters mounted outside of the power pack.
The M109A2/A3s have one internal hydraulic power pack filter.
The M109A4 has a starter protection circuit with a combat override switch, to allow for emergency starting. The slave start
receptacle has been moved from the battery compartment to the driver's compartment. The M109A2/A3 100 amp alternator has been
replaced by a 180 amp alternator. Crew compartment subfloor drains have been added to provide for the drainage of DS2 used in the
NBC decontamination process and provide for the drainage of excess water.
- M109A5 (NSN 2350-01-281-1719)
1990. The M109A5 is a modified M109A4 with two major improvements: a new M284 Cannon and a new M182 Gun Mount. These improvements provide
the M109A5 with greater range and allow for sustained fire for prolonged periods of time.
- M109A6 Paladin (NSN 2350-01-305-0028)
1993. The M109A6 Paladin howitzer is the latest product improvement to the original M109 155-millimeter self-propelled (SP) howitzer.
The Paladin features improvements in the areas of survivability; reliability, availability, and maintainability (RAM);
responsiveness; and terminal effects. Features include an on-board ballistic computer, secure communications, enhanced position and
navigation system, an integrated muzzle velocity system (MVS), new turret, improved cannon and mount, improved ballistic and nuclear,
chemical, and biological protection, automotive improvements, built-in test equipment (BITE), and driver's night vision capability.
Survivability improvements include:
- Hull and turret structure with composite spall suppression liners and supplemental armor.
- Remote travel lock allows crew to emplace or displace without dismounting from the howitzer.
- Relocated projectiles.
- Segregated hydraulic components.
- Microclimate conditioning system provides filtered and conditioned air to crew's protective masks and vests.
- A fixed carbon dioxide fire suppression system for the engine compartment and portable units for the crew and driver's compartments.
RAM improvements include:
- Engine cooling package.
- Sealed starter and protective circuitry.
- New alternator.
- Final drive quick disconnects.
- Upgraded suspension, hydraulic, and electrical systems.
- Added the prognostic/diagnostic interface unit (PDIU), a maintenance diagnostic and limited prognostic testing unit.
Armament improvements to the cannon include:
- Redesigned interior profile of the gun tube assembly.
- Improved breech and recoil system designed to enhance component life.
- Strengthened muzzle brake.
- An advanced bore evacuator.
The major differences from earlier models, which can be seen, are:
- Stowage baskets.
- Rocket launcher stowage boxes - Provides stowage for three AT4 rocket launchers.
- Bustle extending the entire width of cab.
- Grenade stowage boxes.
- External power receptacle on right rear of hull. NOT TO BE USED FOR ENGINE STARTUP.
- Different BII (tool) stowage.
- Right side escape hatch missing.
- Commander's cupola is higher.
- A bigger travel lock.
- A completely different cab structure with a roof slope.
- M93 Chronograph Antenna with Mount and Terminator.
- Gun mount ballistics shield - Provides protection for variable recoil and recuperator from small arms fire and shrapnel.
- M140 alignment device bracket.
- A large access door on left front side of cab (hydraulic compartment).
- A box shaped compartment on the top where the Microclimate Conditioning System (MSC) is housed.
- Radio antennas.
- PLGR (Precision Lightweight Global Positioning System Receiver) antenna - used to support the Satellite Signals Navigation Set (AN/PSN-11).
More M109 Art - Click on image sample to see full size image.
730x340, 36K, GIF
760x360, 37K, GIF
800x525, 27K, GIF