front-line defense. The tactics prescribed presumed that large tank destroyer forces would swarm to the point of an attack and maneuver to strike at the enemy’s flanks—from ambush if at all possible. Reconnaissance would be key both to finding the enemy and to identifying primary and alternate firing positions. Individual tank destroyers (TDs) would fire several rounds and then displace to another position before firing again. The manual suggested that this activity would take place semi-independently of other combat elements but suggested vaguely that units should call for help if confronted by enemy infantry.35
Put another way, a tank destroyer officer described the doctrine this way: “The idea is that if [boxing great] Joe Lewis is sitting in the corner with his back turned, you hit him behind the ear with brass knuckles. Then you get the hell out before all Harlem breaks loose.”36
Bruce selected as the motto for the new force: “Seek, Strike, Destroy.”37
With 20-20 hindsight, many observers have sharply criticized this doctrine. Indeed, combat would reveal major shortcomings. The doctrine utterly missed the realities of combined-arms warfare. It suggested no role for TDs during advances by friendly forces. And it presumed German use of tanks on a large scale that proved very much the exception rather than the rule. Several factors are worth keeping in mind, however, as one follows the story:
• The U.S. Army had never fought a mechanized war before. It was starting from scratch in almost every regard. One of the few “facts” available to the drafters was that on all fields of battle to date, neither tanks nor static antitank defenses had stopped the German war machine.
• Tank destroyer thinkers were not, for once, trying to refight the last war. The program would nevertheless become mired in a cycle of re-fighting the last campaign as critics weighed in.
• The psychological environment was one of fending off further German advances, for the Nazi high-water mark had yet to come. Thinking naturally gravitated to the seemingly most pressing problem; failure to solve it might make worrying about tank busting under other circumstances an academic exercise.
Moreover, tank killers and their comrades in the units with which they would fight were a pragmatic lot, and the problems embedded in the official TD doctrine do not appear to have had much effect on the war effort. The doctrine would gradually shift to reflect battlefield lessons, but these twists were of little direct concern to the battalions in battle. In the words of the Army’s post-war General Board report on tank destroyers: “Suffice it to say that the self-propelled tank destroyer proved to be a most versatile weapon on the battlefield, and although its use did not follow pre-combat doctrines, it did fill a need and became a very highly respected part of the successful infantry-armor-artillery team.”38
Building an Organization
Bruce concluded that self-propelled (SP) battalions were the best way to implement the new doctrine. The Louisiana and Tennessee maneuvers had suggested that it would be impossible to save emplaced towed guns if the infantry was forced to retreat. American observers in Africa had reported that emplaced British antitank guns often survived only long enough to fire four to eight rounds.39 The SP formation became standard on 5 June 1942.40
The standardized tank destroyer battalion initially comprised 35 officers and 807 enlisted men organized into:
• A headquarters company with communications, transportation, and motor-maintenance platoons included.
• A reconnaissance company consisting of three reconnaissance platoons and a pioneer (engineer) platoon.
• Three tank destroyer companies, each consisting of two 75mm gun platoons and one 37mm platoon, a two-gun antiaircraft section, and a twelve-man security section.41 The TD platoons inherited the four-gun configuration of their forebears, the field artillery batteries, rather than the five-vehicle formation standard in Western armored units.
Interestingly, McNair objected to the choice of SP guns, arguing that they would be too difficult to conceal on the battlefield. He pushed the use of towed antitank guns. Marshall, however, favored pursuing the SP option.42 The Army would swing wildly back and forth on this question once it began to gather battle experience.
The Army wanted TDs that would be fast and light, and not only to permit them to maneuver rapidly from one firing position to another. The light vehicles also would be able to cross bridges, ford streams, and skim through swamps that tanks could not manage. There were some skeptics. George Patton Jr., for one, argued that the tank destroyer was destined to become nothing but another tank.43
The new battalions received the ad hoc equipment immediately available while Bruce set about convincing Ordnance to procure modern, fully tracked SP gun carriages for the new force. During the summers of 1940 and 1941, the Army had begun experimenting with improvised self-propelled antitank guns. In late 1941, fifty of the new halftracks were fitted with the venerable 75mm field gun (also mounted in the General Lee and Sherman medium tanks) and shipped to the Philippines in time for the Japanese invasion. With the 75mm mounted, the vehicle was at or above its load-carrying capacity. The gun bore was almost seven feet off the ground, and the gun could safely traverse at most 21 degrees to the side. Swinging the gun any further could lift a track off the ground, and firing under such conditions risked flipping the vehicle.44 This was a far cry from McNair’s vision of a “stable shore gun” with which to fight tanks.
Standardized as the M3 gun motor carriage, this vehicle was issued to the tank destroyer battalions to equip their heavy platoons. The halftrack had just enough armor—one-quarter inch of face-hardened plate—to ward off small arms fire. A gun shield for the 75mm cannon was five-eighths inches thick and rated enough to stop .30-caliber rounds at two hundred fifty yards. The M3 was completely open on top. TD crews found that it was hard to turn, which could prove a major problem in battle.45 The vehicle could move at 45 miles per hour on level terrain—much faster than even a light tank—but it had less than one foot of ground clearance. There were five men in the crew.46
The M3s were the good news. The light platoons were first issued Ford “swamp buggies” mounting a 37mm gun. These were replaced in early 1942 by the M6, a 3/4-ton four-wheel-drive Dodge weapons carrier with a 37mm gun mounted on a 360-degree swivel in the bed.47 In practice, the gun was viewed as facing to the rear, because firing it forward would shatter the windshield and injure the driver and front crewman.48 Other than a quarter-inch splash shield on the gun, the four-man crew was completely exposed to enemy fire. The Army said that the vehicle would allow crews to move quickly to points of vantage—the M6 could travel at 55 miles per hour—and pack enough firepower to destroy a light tank.49 In truth, it was well aware that the 37mm gun had proved to be a poor antitank weapon in British hands long before American forces drove the M6 into combat.50
AGF in May 1942 ordered production of yet another expedient, the M10 motor gun carriage. The M10 was constructed on the proven M4 Sherman tank chassis and had a crew of five. The first model was powered by twin diesel engines, while the M10A1 used a Ford gasoline engine. The vehicle had between one-half inch and two inches of frontal armor and between three-quarters and one inch on the sides, as compared with two inches and one and a half to two inches, respectively, on the early model Sherman tank. Oddly, since doctrine drove the selection of thin armor to retain speed, the vehicle was pre-equipped with bosses for mounting auxiliary armor on the hull. A 3-inch (76mm) converted antiaircraft gun was mounted in an open-topped turret, which also had a .50 -caliber antiaircraft machine gun mounted toward the rear.51 A large number of 3-inch guns were available because they were being replaced on submarines with 5-inch models and in antiaircraft units with 90mm guns.52 The turret had a manual traverse mechanism instead of the powered system used on the M4 Sherman.53 The Army designed the M10 to be able to outmaneuver and outshoot the then-
