M110 SPA 203mm Self-Propelled Artillery
Should the Cold War in Europe have gone hot, the M110 would have been a principle performer in the bloody battles to follow.
Authored By Staff Writer; Content ©www.MilitaryFactory.com
By the end of the Korea War (1950-1953), the American Army was in need of modernization to replace many of its weapon systems that dated back to World War 2. One need ultimately became air-portable, tracked artillery systems that could be transported over distances to the awaiting army units. A requirement put forth by the US Army became a self-propelled artillery platform to which the heavy industry-minded Pacific Car and Foundry went to work on developing several pilot vehicles which ultimately produced a range of possibilities, the Army then electing to forge ahead with two promising designs that would become the M107 and M110 self-propelled artillery platforms. Key differences between the two would be the M107's 175mm gun and the M110's 203mm gun though both would utilize the same chassis and gun mounts between them for economical and logistical reasons. The initial batch of M110 vehicles was completed in 1962 and formal acceptance into the US Army and US Marine Corps inventory soon followed.
The M110 was more or less of a conventional design featuring the main gun mount fitted atop a tracked chassis yielding five large rubber-tired road wheels to a side. There was a drive sprocket mounted to the front of the track system though, interestingly, no track return rollers or track idler of any kind was used. The vehicle sat atop a torsion bar suspension system and power was supplied by a single Detroit Diesel / General Motors 8V71T series 8-cylinder, liquid-cooled, supercharged diesel engine developing 405 horsepower at 2,300rpm. Top speed was listed at 34 miles per hour with a 325 mile range. Operational weight was approximately 31 tons. She fielded a running length of 10.8 meters with a width of 3 meters and a height equal to 3 meters as well.
Primary armament of the M110 was its massive 203mm (8") howitzer main gun mounted on the center rear of the hull roof (there was no true superstructure per se). The gun could be elevated between +65 and -2 degrees with 30-degrees traverse to the left or right. 360-degree traversal was only possible by rotating the entire vehicle in a new direction. There were no secondary weapons fitted to the vehicle for the M110 was never intended to fight enemy forces at the frontlines, instead utilizing its powerful cannon to lob shells at targets or areas. Ammunition types afforded to M110 crews included the M14 "Dummy" round, the common M106 High-Explosive round, the M650 High-Explosive rocket-assisted projectile for increased assault ranges, the M404 ICM (Improved Conventional Munition) anti-personnel projectiles intended to explode above the target area with some 180 grenades being launched about, chemical gas projectiles and nuclear-tipped rounds. Only two of the large 203mm projectiles could be carried on the M110 vehicle, the rest of her ammunition supply towed by a support vehicle. A dozer-type spade was fitted to the rear of the hull to counter the 203mm gun's inherently violent recoil when firing - the M110 firing from a stationary position. The powered spade was raised from the ground and stowed when traveling.
Of the thirteen-man crew, only the driver sat in relative protective comfort, his position to the front left side of the hull. The remainder of the - five of which rode with the M110 proper and the other eight in a support vehicle - included a pair of gunners and a pair of loaders. These personnel maintained their respective positions in the open-air rear portion of the vehicle. Categorized as a "self-propelled artillery" system, the M110 was never intended to fight as a direct line-of-sight combat vehicle, hence her open-air gun platform approach and armor protection being no more than 13mm at its thickest. Instead, the crew could utilized the 203mm main gun's excellent range to strike at targets from miles away.
The M110 was fielded with a support vehicle fitting additional crew and the main 203mm ammunition supply. In the US Army inventory, this role was fulfilled by the M548 tracked vehicle while in the British Royal Army inventory, this became the Alvis-produced six-wheeled FV623 "Stalwart". Eight of the thirteen-man M110 crew were transported with these vehicles. In addition to 203mm projectiles, the support vehicles also carried the required charges and fuses for each round.
The M110, with its original M2A2 series 203mmmain gun, was firmly entrenched in the US Army inventory by the mid-1960s. It was not until 1977 that a revised form appeared as the newly-standardized "M110A1". The M110A1 differed from the original production model by implementation of a longer M201 series 203mm gun barrel for increased ranges (no muzzle brake). Within a few years, the M110 was modified yet again to produce the "M110A2" designation standard which was nothing more than the M110A1 with a double muzzle brake and the ability to fire other types of projectiles beyond the standard HE and anti-personnel rounds. Capability to fire the M509 ICM projectile was also introduced with the M110A2 model and some original M110s were also upgraded to strengthen M110A2 numbers.
The M110 proved something of a global success in terms of its usage by America and allied nations. Considering NATO would have gone to war against the Red Army, a military force making heavy use of large-caliber artillery weapons, the M110 was a welcomed addition to the West. Operators beyond the United States included Belgium, Egypt, West Germany/Germany, Greece, Iran, Israel, Japan, Jordan, Morocco, Netherlands, Pakistan, South Korea, Spain, Taiwan, Turkey and the United Kingdom. For some operators, the M110 still remains a viable battlefield piece even to this day despite her 1950s "big gun" pedigree. However, such battlefield guns have fallen by the wayside for many of the modern evolving armies where the digital battlefield has replaced systems such as the M110 with precision-guided munitions in the form of missiles and launched "smart" projectiles.
The M110 saw service in the Vietnam War where the jungle setting generally precluded large-scale use of tanks but made in-direct fire artillery systems valuable. The British Royal Army was another notable operator of the M110 and utilized them as late as the Persian Gulf War of 1991 (as did the Americans in that conflict). By this time, the M110 had been superseded in the American inventory by the Vought/Lockheed Martin M270 MLRS (Multiple Launch Rocket System) and the British soon followed suit shortly after the Gulf War. During the conflict, the Americans relied on the tracked M109 "Paladin" self-propelled series and its 155mm main gun for long-range artillery requirements along with the M110 for heavy duty fire support. As it goes, most armies have given up use of their M110 vehicles today. American use ended in 1991.
As an interesting aside, when the M110s of the American Army faced retirement, their metal gun barrels were reconstituted in the manufacturer of the jackets needed for the first production batch of Texas Instruments / Raytheon GBU-28 "bunker buster" guided penetration bombs. Such "recycling" initiatives allowed for more economical measures to be implemented than outright scrapping of discontinued systems. In essence, the legacy of the American M110s lived on for a time longer. The M110 was never assigned a designation other than "M110", meaning no nickname was associated with the vehicle type during its operational tenure. Its open-air crew area also precluded use of Nuclear, Biological, Chemical (NBC) protection and only the driver was afforded nightvision equipment at his position.
Japan received a manufacturing license to locally-produce their M110s for their Self-Defense Force. For those nations still making use of the M110 today, these have all been upgraded to the "newer" M110A2 standard, noted for its double-baffle muzzle brake.