ARMOR-CAVALRY: Part 1; Regular Army and Army Reserve/Post-Korean War


 * The decade following the Korean armistice was marked by two major reorganizations of U.S. Army divisions, both of which influenced the structure of armor units. First to come was the pentomic plan of 1957-59, then the Reorganization Objective Army Divisions (ROAD) plan of 1962-64. Underlying these reorganizations were developments in nuclear weapons that made wide dispersion, high mobility, and great flexibility- without loss of massed firepower- mandatory characteristics for military forces. Combat areas of future nuclear wars were viewed as much broader and deeper than battlefields of the past, requiring small, self-contained, fast-moving units. Speed was imperative not only in the concentration of forces for attack but also in dispersion for defense. On the other hand, the Army had to retain its ability to fight limited or nonnuclear wars, where the requirements for mobility or dispersion were not as important.


 * Tests of new division organizational concepts for atomic warfare, begun in early 1955, culminated in late 1956 in the pentomic organization, and by mid-1958 the new scheme had been applied to all armored divisions. Since combat commands already provided much of the flexibility that was sought, little change was made in the basic structure of the armored division. The greatest change was in firepower, the division artillery being given an atomic capability. The division still had its four tank battalions, and all were authorized 90-mm.-gun tanks (one battalion had previously been authorized 120-mm.gun tanks). Armored infantry and field artillery battalions also remained at four each. A small increase in tanks brought the full-strength total to 360- 306 mounting 90-mm. guns and 54 mounting 76-mm's. Strength of the new division stood at 14,617, only 34 fewer than its former number.


 * From 1951 to 1955 the Regular Army had two active armored divisions- the 1st and the 2d. In 1955 the 3d and 4th were added. Three continued as active divisions for the remainder of the 1953-68 period; the 1st Armored Division was reduced to a single combat command from 1957 to 1962.


 * By late 1955 the Army National Guard armored divisions had been increased from 2 to 6 by converting 4 infantry divisions- the 27th, 30th (that portion in Tennessee), 40th, and 48th. The North Carolina portion of the 30th Infantry Division became a full infantry division and retained "30th" also as its numerical designation. As of mid-1967, Army National Guard had the following armor units: 6 armored divisions, 2 armored brigades (separate), 7 armored cavalry regiments, an armored cavalry squadron, and 16 separate tank battalions. Also, the 17 infantry divisions of the National Guard had 34 tank battalions and 17 cavalry squadrons.


 * The second major reorganization of Army divisions, known as ROAD, was completed in 1964. Under this plan the Army was to have four types of divisions- airborne, infantry, armored, and mechanized- the base upon which each was built, being essentially the same. All had their usual types of organic reconnaissance, artillery, and support units. The main differences came in the maneuver elements- tank and infantry battalions- which varied with mission and other factors. All had three brigade headquarters, which, in the armored division, corresponded to its former combat commands. Thus while the organization of all divisions became more flexible, the change in the armored division was less than in other types.


 * For example, a ROAD armored division with a composition of 6 tank and 5 mechanized infantry battalions would have a full-strength total of 15,966. Since each tank battalion was equipped with 2 light- and 54 medium-gun tanks and each mechanized infantry battalion had 2 light-gun tanks, this combination of maneuver battalions gave an armored division 40 light- and 324 medium-gun tanks, including the 18 light tanks of its armored cavalry squadron.


 * Concurrent with the division reorganizations, another major change having far-reaching effect upon the organization of most combat-type units was the Combat Arms Regimental System, or CARS. Arrival of the atomic era with its new weapons and tactical doctrine had rendered the regiment, the traditional fighting unit of the Army, obsolete- it was too large.


 * Even during World War II armored regiments, except those of the 2d and 3d Armored Divisions, were broken up to form separate battalions, and many old cavalry regiments had been dismembered to form new units. With approval of the CARS plan early in 1957, the old cavalry and armored regiments could be revived, at least in name, to continue their regimental histories.


 * As illustrated in Chart No. 1, the plan provided an average of approximately fifteen battalions that could be organized to perpetuate the lineage and honors of a single regiment. The regimental headquarters was placed under Department of the Army control, and the other regimental elements were used to form separate battalions or squadrons as needed. Within these battalions and squadrons the organic elements were new.


 * Parent regiments for use under CARS were carefully selected. Except for the 2d, 3d, 6th, 11th, and 14th Armored Cavalry regiments, the 1st through the 17th Cavalry regiments were included. Armor parent regiments were the 32d through the 35th, the 37th, 40th, 63d, 64th, the 66th through the 70th, and the 72d, 73d, 77th, and 81st. A subsequent decision by the Department of the Army that CARS cavalry regiments would contain reconnaissance-type units instead of tank battalions caused the redesignation of three cavalry regiments- the 13th, 15th, and 16th- as the 13th, 15th, and 16th Armor. Not affected by this decision were those elements of the 5th, 7th, and 8th Cavalry, assigned to the 1st Cavalry Division, which remained organized as infantry. When the CARS reorganization was completed, cavalry had 9 regiments and armor had 20. Elements of these parent regiments were organized in both the Regular Army and the Army Reserve. Army National Guard parent regiments were selected from National Guard units.


 * The 2d, 3d, 6th, 11th, and 14th Armored Cavalry, which were not reorganized under CARS, retained their regimental structure. Four armored cavalry regiments remained active in the Regular Army, the 6th being inactivated in May 1961 and reactivated in March 1967.