Aviation & Aerospace - Airpower 2024 - Aircraft by Country - Aircraft Manufacturers Vehicles & Artillery - Armor 2024 - Armor by Country - Armor Manufacturers Infantry Small Arms - Warfighter 2024 - Small Arms by Country - Arms Manufacturers Warships & Submarines - Navies 2024 - Ships by Country - Shipbuilders U.S. Military Pay 2024 Military Ranks Special Forces by Country

M109 (Paladin)

155mm Self-Propelled Artillery (SPA)

United States | 1963

"Still going strong - the M109 Self-Propelled Artillery system debuted in the Vietnam War and has continued a useful service life in the new millennium."

Authored By: Staff Writer | Last Edited: 07/16/2023 | Content ©www.MilitaryFactory.com | The following text is exclusive to this site; No A.I. was used in the generation of this content.
The155mm-armed M109 Self-Propelled Howitzer (SPH) was developed concurrently with the 105mm-armed M108 SPH. Both shared the same hull superstructure and turret design and were differentiated primarily by their choice of armament. The M108 was eventually given up in the long run in favor of the more powerful M109 offering to which the M109 has since enjoyed an exceedingly long operational service life thanks, in part, to a strong design and modernization programs. Its endorsement by the U.S. Army and USMC - and its subsequent combat use during the Vietnam War (1955-1975) - led to its wide acceptance by other global land armies aligned with the United States. Production of both the M108 and M109 systems began in 1962 though manufacture of the M108 ended the following year. The M109 continued in production up until 1969 and was manufactured under several related brand labels: General Motors (Cadillac Motor Car Division), General Motors (Allison), and Chrysler Corporation - interestingly all from the same Cleveland facility. Bowen-McLaughlin-York added additional production in 1974 to meet new demand.

Initial M109 production vehicles were fitted with the T255E4 short-barreled main gun which proved effective but led to excessive wear-and-tear due to the propellant charges in use. This prompted a slight revision of the design which introduced a longer-barreled gun tube in the XM185. The existing M109 fleet was then converted to the new M109A1 standard beginning in 1972 with operational levels reached the following year. During 1974, more M109A1s were built to strengthen existing stocks, these by Bowen-McLaughlin-York, and designated M109A1B.

As completed, the M109 was a conventional SPA form by modern standards. It fitted its powerpack at front-right with the driver at front-left in the forward hull. The turret was placed over the rear section of the vehicle with the large main gun fitted into the forward panel. A cupola was afforded to the commander's position to which a 0.50 or 0.30 caliber machine gun could be installed for air/local defense. The vehicle sat atop a track-and-wheel arrangement which included seven double-tired road wheels to a hull side. The drive sprocket was at front with the track idler at rear while no track return rollers were used. A small door at the rear of the hull allowed for crew entry exit as did side panels, roof hatches and a hatch over the driver's compartment. Main guns featured massive muzzle brakes and were clamped to the hull when traveling. Despite the 155mm caliber, there proved little barrel overhang. The operating crew numbered six - driver, commander, two gunners and two loaders. Turret traversal was a full 360-degrees.

After a period of in-the-field use, more revisions were ordered which included a larger turret bustle which accepted more onboard ammunition storage. New gun mounting hardware was also installed and the floatation equipment seen in original production models was dropped. With these changes in place, the U.S. Army adopted the M109A2 standard and 823 x A2 models followed from 1976 into 1985. Existing M109A1 and M109A1B models were all modified to the A2-standard and these became M109A3.

Article Continues Below Advertisement...
The next major revision of the M109 line occurred during the middle part of the 1980s prior to the end of the Cold War. As the threat of nuclear war had not subsided, it was thought prudent to provide M109 crews with some form of local protection from Nuclear, Biological, and Chemical (NBC) agents and, thusly, an NBC suite was added to the M109. Existing M109A2 and M109A3 marks then graduated in this fashion to become the M109A4. The upcoming M109A5 introduced the M284 series 155mm main gun which replaced the original's M185 model and a 440 horsepower diesel engine was brought along. Expectedly, maximum range of the gun was increased as was performance of the vehicle. M109A5+ signified M109A5s with updated Fire Control Systems (FCSs) and other more subtle internal changes.

After Operation Desert Storm (1991), the M109A6 "Paladin" entered service in 1992 as a wholly improved M109 mark - which many regard as the ultimate evolution of the series. The A6 model improved armor protection for the crew and systems alike and further increased ammunition stocks aboard. An automatic FCS was introduced which assisted in gun laying and improved accuracy. The NBC suite and crew comfort was further addressed while the gun received additional attention. Unassisted engagement ranges now peaked at around 18.6 miles while Rocket-Assisted Projectiles (RAPs) added additional downrange reach. By this time the crew had been reduced to four from six.

M109s were resupplied in the field with additional ammunition and charges through the M992 vehicle. This development was essentially a turret-less M109 though with a fixed superstructure and three crew. The vehicle typically followed M109s into action and supplied the needed munition types on call, the shells being passed through openings at the rear of the M109.

The M109 proved an export success on the global stage, one of the most successful armored vehicles of the Cold War and one of the best American SPG/SPG systems since the close of World War 2 (1939-1945). Operators ranged from Canada to South America, Europe and the Middle East. Chances are those nations fielding an SPG during the Cold War managed a stock of either the Soviet equivalent machine or the American-made M109. Many remain in service today - such has been the effectiveness of the vehicle series in combat.

Combat service has taken the M109 through the Vietnam campaign, the Yom Kippur War (1973), the Iran-Iraq War (1980-1988), the Gulf War (1991), the recent U.S.-led Iraq campaign (2003-2011), and the 2006 Lebanon War. The British Army relied on the M109 for a time until succeeding these units with the locally-designed and developed AS-90 system appearing in 1993.

At one point, the XM2001 "Crusader", detailed elsewhere on this site, was intended as the American successor for the M109 line. This promising program was eventually terminated in May of 1992 - signaling an extended service life for existing M109 vehicles.

Content ©MilitaryFactory.com; No Reproduction Permitted.
Power & Performance
Those special qualities that separate one land system design from another. Performance specifications presented assume optimal operating conditions for the M109A6 155mm Self-Propelled Artillery (SPA).
1 x Detroit Diesel 8V-71T LHR turbocharged, liquid-cooled, 8-cylinder diesel-fueled engine developing 450 horsepower at 2,300rpm and driving a conventional track-and-wheel arrangement.
Installed Power
40 mph
64 kph
Road Speed
214 miles
344 km
The physical qualities of the M109A6 155mm Self-Propelled Artillery (SPA).
31.7 ft
9.67 meters
O/A Length
10.3 ft
3.14 meters
O/A Width
11.9 ft
3.62 meters
O/A Height
63,601 lb
28,849 kg | 31.8 tons
Armament & Ammunition
Available supported armament, ammunition, and special-mission equipment featured in the design of the M109 (Paladin) 155mm Self-Propelled Artillery (SPA).
1 x 155mm M284 howitzer main gun.
1 x 12.7mm M2 Browning Anti-Aircraft heavy machine gun on turret roof.
39 x 155mm projectiles.
500 x 12.7mm ammunition.

Resupply via M992 ammunition support vehicle.
Chemical, Biological, Radiological, Nuclear Protection (CBRN) - YES - OPTIONAL.
Notable series variants as part of the M109 (Paladin) family line.
M109 - Initial Production Model
M109A1 - Longer Main Gun Barrel; Minor Overall Improvements.
M109A2 - Minor Improvements to M109A1 produciton models.
M109A3 - New gun mounting hardware and improved RAM-D.
M109A4 - Improved NBC system; Also covers all updated M109A2 or M109A3 models.
M109A5 - Updated M109A4 production models.
M109A6 - Modernized production model; new turret with automatic fire control system and increased armor protection.
M109A3G (M109G) - German Army export model.
M109L - Italian Army export model.
M109AL "Doher" - Israeli Army export model.
M109L47 - United Arab Emirates and Swiss export model featuring 0.47 caliber main gun tube / barrel.
M992 FAASV - Field Artillery Ammunition Support Vehicle (ammunition carrier); fixed hull superstructure; sans main gun and original turret component.
Global customers who have evaluated and/or operated the M109 (Paladin). Nations are displayed by flag, each linked to their respective national land systems listing.

Total Production: 6,200 Units

Contractor(s): United Defense LP / GM Cadillac / GM Allison / Chrysler Corp / Bowen-McLaughlin-York - USA
National flag of Belgium National flag of Brazil National flag of Canada National flag of Chile National flag of Denmark National flag of Egypt National flag of Ethiopia National flag of modern Germany National flag of Greece National flag of Iraq National flag of Iran National flag of Israel National flag of Italy National flag of Jordan National flag of Kuwait National flag of Morocco National flag of the Netherlands National flag of Norway National flag of Oman National flag of Pakistan National flag of Peru National flag of Portugal National flag of the Kingdom of Saudi Arabia National flag of Spain National flag of Switzerland National flag of Taiwan National flag of Thailand National flag of Tunisia National flag of the United Arab Emirates National flag of the United States

[ Belgium; Brazil; Canada; Chile; Denmark; Germany; Egypt; Ethiopia; Greece; Iran; Iraq; Israel; Italy; Jordan; Kuwait; Morocco; Netherlands; Norway; Oman; Pakistan; Peru; Portugal; Saudi Arabia; Spain; Switzerland; Taiwan; Thailand; Tunisia; United Arab Emirates; United States; West Germany ]
1 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
2 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
3 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
4 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
5 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
6 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
7 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
8 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
9 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense DIVDS imagery database.
10 / 10
Image of the M109 (Paladin)
Image from the United States Department of Defense imagery database.

Design Qualities
Some designs are single-minded in their approach while others offer a more versatile solution to battlefield requirements.
Some designs stand the test of time while others are doomed to never advance beyond the drawing board; let history be their judge.
Developments of similar form-and-function, or related, to the M109 (Paladin) 155mm Self-Propelled Artillery (SPA).
Going Further...
The M109 (Paladin) 155mm Self-Propelled Artillery (SPA) appears in the following collections:
Disclaimer | Privacy Policy | Cookies

2024 Military Pay Scale Military Ranks U.S. DoD Dictionary Conversion Calculators Military Alphabet Code Military Map Symbols US 5-Star Generals WW2 Weapons by Country

The "Military Factory" name and MilitaryFactory.com logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT gmail.com. No A.I. was used in the generation of this content.

Part of a network of sites that includes Global Firepower, WDMMA.org, WDMMW.org, and World War Next.

©2024 www.MilitaryFactory.com • All Rights Reserved • Content ©2003-2024 (21yrs)