Earlier we took a look at the “triangular” infantry division in WWII. Now let’s take a look at the armored division structure. The armored division in the US Army was designed to exploit any breakthroughs in the enemy lines. As such, they were a relatively small division, with all major elements being mounted in either tracked, half-tracked, or wheeled vehicles.
The division headquarters was at the top. Beneath this were three “Combat Commands” which would be roughly equivalent to a modern brigade headquarters. There were three tank battalions (generally equipped with the Sherman tank), three infantry battalions (mounted on half-tracks), and three self-propelled artillery battalions (at this time, most artillery in the Army was towed by trucks).
You can quickly see that this is a much smaller division than an infantry division. Where an infantry division had nine “maneuver” battalions and four artillery battalions, the armored division had only six maneuver battalions and three artillery battalions. But it was still a very “triangular” organization and a very flexible one at that.
The “Combat Commands”, named CCA, CCB, and CCR (for Reserve) didn’t have any set “ownership” of battalions. They were assigned those units the division commander thought they would need for any given mission. Now, typically, you might see each Combat Command organized with one battalion of tanks, infantry and artillery. But this was by no means set in stone. A commander might give CCA two infantry battalions, a tank battalion and two arty battalions with a mission to break through a given position, while CCB would follow through with two tank battalions, the third infantry battalion and the third arty battalion, while CCR was left with no troops, but might be planning the next engagement, when it would receive whatever troops it needed.
There was a ratio of roughly one armored division to five infantry divisions in WWII (well, in Europe. There were no armored divisions deployed to the Pacific Theater). And while they were designed to exploit breakthroughs, that wasn’t the only way they were used. They often spearheaded attacks, led counterattacks against enemy penetrations, and of course, did their fair share of holding the line when on the defense.
You can see the organization of a WWII armored division here.