M1 90MM AA Gun
The display reads:
AAA Gun Battalion
On the morning of December 8th, 1941, the 200th Coast Artillery (AA) commenced firing against Japanese aircraft attacking Clark Field in the Philippines. With the attack on Pearl Harbor just hours old, the gunners of the 200th were anticipating enemy contact. At 1235 hours, local time, a Japanese force of high-altitude bombers with a fighter escort arrived over the field.
The 200th’s twelve M3 guns were unable to reach the high altitude bombers due to fusing limitations on their 3-inch rounds, but by the end of the day their guns had claimed five enemy fighters.
The limitations of the 3-inch round were already known by 1940 and a new gun was slowly coming into service to replace the 1928-vintage M3. The US entry into World War II accelerated the development of the new M1 90mm anti-aircraft gun and units began fielding the new weapon by early 1942.
The M1 90mm anti-aircraft gun was a significant improvement over the M3 and had an effective range to nearly 35,000 feet, nearly 15,000 feet higher than its 3-inch predecessor. However, while a very capable anti-aircraft weapon, unlike most of its foreign counterparts of the day, the 90mm had no dual-role capability. This prompted a redesign of the gun’s mount in late 1942, resulting in the M1A1 90mm gun. This new mount allowed the gun to depress below zero-degrees in elevation and engage ground targets if required.
The gun was redesigned in 1944 and the result M2 90mm gun used a redesigned mount and limber system that would give 90mm gunners the ability to engage ground targets while the gun was still mounted on its two sets of bogey wheels.
AAA gun battalions were on the cutting edge of technology throughout World War II. They were first to incorporate radar into combat operations, and the combination of radars and gun directors led to very accurate fire control that steadily improved throughout the war.
The final major technological advancement of the war was the addition of the Proximity Fuse to 90mm rounds. The VT or Variable Time fuse incorporation a small radar system in the nose of the 90mm projectile that would detonate its explosive when the round came in close proximity to a target. The VT fuse was a significant factor in the success of both the defense of London and Antwerp against German V-1 “buzz bomb” attacks.
With the Japanese invasion of the Luzon towards the end of December, the 200th Coast Artillery fought as infantry and conducted a fighting withdrawal south to the Bataan peninsula.
The 213th Coast Artillery received their first 90mm guns in early 1942 and arrived in North Africa in early 1943. The Regiment was broken up into three separate Gun, Searchlight, and Automatic Weapons Battalions and saw significant combat throughout the Mediterranean theater.
Static emplacement of the 90mm gun allowed for the incorporation of ammunition storage into the walls of the revetment, allowing for a large supply of rounds readily available to the gun crew’s ammo bearers.
Designed specifically for the invasion of Japan, the SCR-784 optimized the larger SCR-584 for amphibious operations and mounted the entire system on an M17 2-ton trailer.
The M7 gun director was an analog computer that collected data from the radar, height finder and tracker and computed a firing solution for all four 90mm guns in the battery.
The M2 90mm gun entered service in mid-1944 and incorporated several improvements over the M1A1 90mm gun, including armor protection for the crew, an automatic loader / rammer and a completely revised limber that used two sets of bogey wheels. These dual bogeys gave the M2 crew the ability to engage ground targets while the gun was still mounted on its wheels. The M2 remained in service alongside the larger M1 120mm anti-aircraft gun through the mid-1950s.
The SCR-584 radar was the “nerve center” of the 90mm anti-aircraft gun battalion. The radar came into service in late 1943 and offered a significant improvement over the earlier SCR-268 gun-laying radar. The radar could detect incoming aircraft at a range of forty miles, giving the battery’s guns ample time to lay on target and enabled them to commence firing as soon as the target came within range.
Taken December 11th, 2013.
M1 90MM AA Gun
The display reads:
AAA Gun Battalion
On the morning of December 8th, 1941, the 200th Coast Artillery (AA) commenced firing against Japanese aircraft attacking Clark Field in the Philippines. With the attack on Pearl Harbor just hours old, the gunners of the 200th were anticipating enemy contact. At 1235 hours, local time, a Japanese force of high-altitude bombers with a fighter escort arrived over the field.
The 200th’s twelve M3 guns were unable to reach the high altitude bombers due to fusing limitations on their 3-inch rounds, but by the end of the day their guns had claimed five enemy fighters.
The limitations of the 3-inch round were already known by 1940 and a new gun was slowly coming into service to replace the 1928-vintage M3. The US entry into World War II accelerated the development of the new M1 90mm anti-aircraft gun and units began fielding the new weapon by early 1942.
The M1 90mm anti-aircraft gun was a significant improvement over the M3 and had an effective range to nearly 35,000 feet, nearly 15,000 feet higher than its 3-inch predecessor. However, while a very capable anti-aircraft weapon, unlike most of its foreign counterparts of the day, the 90mm had no dual-role capability. This prompted a redesign of the gun’s mount in late 1942, resulting in the M1A1 90mm gun. This new mount allowed the gun to depress below zero-degrees in elevation and engage ground targets if required.
The gun was redesigned in 1944 and the result M2 90mm gun used a redesigned mount and limber system that would give 90mm gunners the ability to engage ground targets while the gun was still mounted on its two sets of bogey wheels.
AAA gun battalions were on the cutting edge of technology throughout World War II. They were first to incorporate radar into combat operations, and the combination of radars and gun directors led to very accurate fire control that steadily improved throughout the war.
The final major technological advancement of the war was the addition of the Proximity Fuse to 90mm rounds. The VT or Variable Time fuse incorporation a small radar system in the nose of the 90mm projectile that would detonate its explosive when the round came in close proximity to a target. The VT fuse was a significant factor in the success of both the defense of London and Antwerp against German V-1 “buzz bomb” attacks.
With the Japanese invasion of the Luzon towards the end of December, the 200th Coast Artillery fought as infantry and conducted a fighting withdrawal south to the Bataan peninsula.
The 213th Coast Artillery received their first 90mm guns in early 1942 and arrived in North Africa in early 1943. The Regiment was broken up into three separate Gun, Searchlight, and Automatic Weapons Battalions and saw significant combat throughout the Mediterranean theater.
Static emplacement of the 90mm gun allowed for the incorporation of ammunition storage into the walls of the revetment, allowing for a large supply of rounds readily available to the gun crew’s ammo bearers.
Designed specifically for the invasion of Japan, the SCR-784 optimized the larger SCR-584 for amphibious operations and mounted the entire system on an M17 2-ton trailer.
The M7 gun director was an analog computer that collected data from the radar, height finder and tracker and computed a firing solution for all four 90mm guns in the battery.
The M2 90mm gun entered service in mid-1944 and incorporated several improvements over the M1A1 90mm gun, including armor protection for the crew, an automatic loader / rammer and a completely revised limber that used two sets of bogey wheels. These dual bogeys gave the M2 crew the ability to engage ground targets while the gun was still mounted on its wheels. The M2 remained in service alongside the larger M1 120mm anti-aircraft gun through the mid-1950s.
The SCR-584 radar was the “nerve center” of the 90mm anti-aircraft gun battalion. The radar came into service in late 1943 and offered a significant improvement over the earlier SCR-268 gun-laying radar. The radar could detect incoming aircraft at a range of forty miles, giving the battery’s guns ample time to lay on target and enabled them to commence firing as soon as the target came within range.
Taken December 11th, 2013.