In the early spring of 1966, the state-of-the-art 105mm towed M102 Howitzer entered service in Vietnam. However, many experienced artillerymen were initially hesitant to use this new model.
These men are intimately familiar with every detail of the M101A1 howitzer, which has been used in support of U.S. and Allied forces since World War II. As such, they were very wary of new models and did not want their trusty old cannons to be replaced. Their skepticism was quickly put to rest, however, as the M102 howitzer became an important weapon in the arsenal of the U.S. Armed Forces within a few months and was praised for its flexibility, accuracy and lightweight.
Now, after decades of service around the world, the U.S. Navy is about to give this classic American artillery a new chance with an upgrade for the U.S. Air Force.
In 1960, the U.S. Army issued requirements for a lightweight replacement for the 105mm M101 howitzer, which had been the standard weapon of the type since World War II, serving in the European and Pacific theaters and in the Korean War.
In response, the Army’s Rock Island Arsenal engineers created the M102 105mm howitzer. This lightweight weapon is constructed of welded aluminum and is designed to provide direct support fire to light airborne, and air assault forces.
This artillery weapon can fire 33-pound semi-stationary ammunition at a range of up to 7.14 miles. With a muzzle velocity of 1620 feet per second, the M102 can fire 10 rounds per minute for the first three minutes and maintain a sustained rate of 3 rounds per minute.
After manually loading and positioning, the howitzer can be towed by a two-ton truck or a high-mobility utility wheeled vehicle, transported by UH-60 Black Hawk helicopters, or even parachute-dropped by the Airborne Forces.
When placed, its high firepower compensated for the projectile’s lower explosive weight compared to larger 155mm howitzers. Additionally, its considerable range can be increased to 9.38 miles with the help of rocket-assisted rounds. With its low profile and a single-roller tire attached to the wake assembly at launch, the weapon can rotate 360 degrees around a launch platform, acting as its pivot. Howitzers can be raised from minus 5 degrees to a maximum of 75 degrees.
The first prototype of the M102 howitzer was completed at the Rock Island Arsenal in 1962, and the first production models were completed three years later. Once ready for battle, they were introduced to the 1st Battalion, 21st Field Artillery, U.S. Army. Initially, there was some reluctance from the crew, who had grown accustomed to the previous model.
However, they were quickly captivated by the capabilities of the new howitzer. The new model weighs just 3,300 pounds compared to the 4,980-pound howitzer that preceded it, nearly three-quarters of a ton less than the WWII-era howitzer. Over the next four years, older weapons were gradually replaced as the Vietnam War escalated. In a short time, the M102 howitzer became the Army’s standard artillery.
The M102 Howitzer played a significant role in various conflicts, including the Indian Wars and the Vietnam War. Its lightweight design and maneuverability made it a valuable asset on the battlefield. It was widely used by the U.S. Army, South Vietnamese, and Cambodian troops fighting against communism.
The M102’s effectiveness was showcased in the Vietnam War, where it proved superior to its predecessor. Its lightweight construction allowed for easy transport via helicopter, making it ideal for remote fire support bases. The M102, particularly when loaded with the M546 APERS-T ammunition, earned the nickname “The Beehive” for its devastating impact.
The M102 howitzer saw action as recently as the early 2000s when the Arkansas Army National Guard deployed it during the Iraq War. Despite being captured by Iraqi forces during the Iran-Iraq war, the M102 howitzers were recovered and utilized by the 1st Battalion, 206th Field Artillery, providing fire support missions in collaboration with the 29th Infantry Brigade Combat Team.
The Rock Island Arsenal produced over 1,200 M102 howitzers, completing production in 1970. An additional 22 export models were built in 1980. By 1985, the U.S. Army had 526 M102 weapons in its inventory, almost 20 years after their introduction. The BAE Systems’ M119, a 105mm light cannon, later replaced the M102 as the standard frontline howitzer.
Although the M102 is no longer actively used in mounted form within the United States, it still has limited roles in the National Guard and Marine Corps, primarily for launch salutes. The U.S. Air Force tested a modified version of the M102 in 1970 for the AC-130 gunship as part of the Pave the Way Aegis program. This modification allowed the cannon to be fired from the left rear side door of the gunship.
Then, in 1971, the service began integrating these weapons into several AC-130E aircraft, which soon entered service. The combination of the AC-130 gunship and the M102 howitzer has a long history of combat, starting in Vietnam, where the aircraft destroyed more than 10,000 trucks and was credited with several life-saving close air support missions. Then, during Operation Desert Storm, several AC-130s provided close air support and air base defense for ground forces.
Throughout the turn of the century, the AC-130 was actively involved in combat operations in Kosovo, strongly supporting Iraqi Freedom and Operation New Dawn, and was used in many missions in support of Enduring Freedom and Resolute Support.
Gunship helicopters also played a key role in the recent Middle Eastern uprisings, providing armed surveillance, interception and direct support to ground forces engaged with enemy forces. Several U.S. allies and partners around the world still use the weapon to this day, but a new version of the M102 may have just been introduced…
In January 2022, U.S. Naval Surface Warfare Center Dahlgren Division engineers developed an upgraded 105mm cannon unit for the AC-130 gunship. This enhancement enables ground combatants to carry out their missions more effectively and safely, while the AC-130 gunship provides close air support, air intercept, and force protection.
The Dahlgren division collaborated with active-duty AC-130 models at Air Force bases, working closely with experienced gunners and technicians to gather real-time feedback and valuable insights. The upgrade was deemed necessary due to the obsolescence of the M102 howitzer, which is no longer supported.
In September 2022, the updated version of the 105mm cannon was observed on an Air Force AC-130J Ghost Rider gunship during an event in New Mexico with the 17th Special Operations Squadron. While it’s uncertain whether the howitzer is entirely new or incorporates components from the M102, the U.S. Navy’s website refers to it as an upgrade. Photos reveal similarities, such as the top-mounted recoil system found in older Army howitzers from the Cold War era.
The decision to have the Navy develop an improved 105mm gun system for the Air Force’s AC-130 gunship remains unclear, but some speculate that the Navy’s expertise in designing large-caliber guns capable of accurate shooting from moving ships played a role.
Experts believe that this new generation of the 105mm cannon will enable the U.S. Air Force to continue providing close-in support in future military operations, thereby upholding the legacy of the revered M102 weapon.