Armoured cavalry
Armoured cavalry are military units using armoured fighting vehicles (AFVs) instead of horses. They began to replace horse cavalry in the heavy shock and the light reconnaissance, skirmishing and exploitation/pursuit roles in most armies commencing after the First World War. In that succeeding capacity, the obsolete name "cavalry" was retained.
Armoured cavalry, or simply armoured units, may be primarily equipped with heavy tanks or lighter and faster light tanks, armoured cars, or even scout cars in the case of what is often known as cavalry scout. Motorised or mechanised infantry may make up a portion of the unit in some countries, supported by either motorised or self-propelled artillery, with possibly airmobile troops on helicopters included.
U.S. Army armoured cavalry had the mission of reconnaissance and security. Unlike armoured and infantry units, U.S. Cavalry is organized into squadrons and troops, which are equivalent to battalions and companies respectively. A regiment of armoured cavalry, such as the 11th Armored Cavalry Regiment (the Black Horse Regiment) in Vietnam, consisted of three full squadrons of armoured cavalry. The squadron normally consisted of a headquarters troop, three cavalry troops, a tank company, a 155-mm self-propelled howitzer battery, and an aviation troop. The three ground troops were a mixture of M48 Patton or M551 Sheridan tanks and M113 ACAVs (Armored Cavalry Assault Vehicles). The aviation troop of the squadron was equipped with helicopters, consisting of UH-1 transports, OH-6 Cayuse scouts, OH-58 Kiowa scout/gunships, and AH-1 Cobra gunships.
Armoured cavalry regiments operated in country for the Corps/Theater Commander, while the squadrons operated as the "eyes and ears" for the US Army Division Commanders. An Army brigade would only be authorized a cavalry troop, and not a whole cavalry squadron.
According to Army doctrine, the cavalry would find the enemy, and hold the enemy in place, until the heavy forces were brought up to deal with the located enemy. This process was known as the battle hand-off. At this point the cavalry is free to disengage and continue with other missions. Security missions could be rear guard, flank guard, or advance guard – the same functions as performed by infantrymen, only with tanks and ACAVs. With the infantry, the advance guard would be called the point man.
During the Vietnam War, it was the mission of armour (tanks) to close with the enemy and defeat them using firepower, manoeuvre, and shock action. With the US Infantry, the mission was the same, minus the shock power. Artillery's mission was to add firepower to the equation. The US Armored Cavalry's mission was to find the enemy and/or provide security for the Army, while having the means to destroy the enemy if becoming decisively engaged. In Vietnam, the US Army deployed 1 Armored Cavalry Regiment (containing 3 squadrons and an aviation squadron), 7 Armored Cavalry Squadrons, and 2 Armored Cavalry Troops:
From about January 1969 until the last mounted unit re-deployed from Vietnam in 1972 (air units remained in country), most armoured cavalry units (except the 11th ACR's tank companies) were equipped with the M551 Sheridan armored airborne reconnaissance assault vehicle (today, known to historians as a light tank).
Current British cavalry regiments in armoured role