The American Roots of Blitzkrieg

What the Germans Learned in Visits to Fort Knox Before World War II Broke Out in Europe

During the early 1930s, long before Germany’s panzer divisions rolled into Poland and introduced the world to blitzkrieg, or lightning war, the German Army had been studying how other nations were approaching mechanization, the employment of tanks, and the theoretical promise of maneuver warfare. In developing their doctrine, Reichswehr and Wehrmacht staff officers visited other nations that were wrestling with these same problems, including England, France, the Soviet Union, and the United States. These intelligence-gathering missions brought them to Fort Knox, Fort Benning, Fort Eustis, and Fort Meade where they observed how the American Army was applying the potential of the internal combustion engine to future warfare. In the fall of 1930, as Major Heinz Guderian was working on the problem of troop motorization at the German Defense Ministry, one of his colleagues, Captain Adolf von Schell, was attending the Infantry School’s advanced course at Fort Benning. As a student, von Schell materially contributed to the school by sharing his experiences in World War I.1 In addition, he was very adept at discussing modern concepts of mobile warfare, then a major area of investigation for the German Army. Exploring these interests, von Schell requested a two-week attachment to the U. S. Tank School, then at Fort Meade, where he wanted to observe the 34th Infantry (Motorized). This unit had detached a machine gun company to Fort Eustis, Virginia, to join the Mechanized Force, an experiment that lasted only about a year. Although von Schell’s visit was approved, it was later cancelled because the 34th Infantry was in the process of changing station. The Mechanized Force was experimental in the sense that it was composed of combined arms capable of independent operations as a mobile force that went far beyond traditional infantry and cavalry formations. This futuristic vision, similar to a British experiment in the late 1920s, was short-lived. The experiment ended in the fall of 1931, partly a casualty of inter-branch rivalry, partly a casualty of the Depression that had gripped the nation. The vision was deferred until July 1940, when the combined arms Armored Force was created over the objections of the chiefs of the Infantry and Cavalry branches. In the meantime, each branch was directed to pursue mechanization on its own. Following this guidance later in the 1930s, the Cavalry branch created a mechanized force at Fort Knox, which also drew German interest and led to additional staff visits. Colonel Daniel Van Voorhis, the commander of the 1st Cavalry (Mechanized) and his S3, Major Robert W. Grow, recalled German visits to Fort Knox in 1933, including one by a Major Phillips, a German general staff officer. Phillips, an ordnance tank expert, expressed ideas on mechanization that agreed with the developments at Fort Knox, where Colonel Van Voorhis was developing a self-Colonel Van Voorhis, foreground, stands in formation with his troops at Fort Knox in the 1930s. Note the wide range of equipment, including tanks and armored cars, as America attempted to forge its first mechanized force. ARMOR — 7 contained mobile force capable of deep operations and fighting mounted. A few months later, Major Phillips was back at Knox, this time with Major Hans von Greiffenberg, another general staff officer. The visitors took rides in the 1st Cavalry’s armored cars, observed demonstrations of new radio equipment, and after hours, retired to the Doe Run Inn for dinner and discussions with their hosts. Colonel Van Voorhis recalled that the Germans were not particularly interested in the Americans’ equipment, but on their views about the proper tactical and strategic employment of mechanized forces. Major Grow, who accompanied Van Voorhis, agreed, and added that the thinking at Fort Knox regarding the employment of self-contained units was ahead of the Germans. It was Grow’s opinion, however, that the German Army was more advanced in the development of vehicular equipment. In addition, Grow wrote in his diary that the German military was “going all out in anticipation of a European war.”2 At the time of the Germans’ visit, the 1st Cavalry (Mechanized) included the Armored Car Troop for long distance reconnaissance; the Scout Troop for close-in reconnaissance and security; the assaulting or striking squadron of combat cars; and their holding unit, the Machine Gun Troop. Communications were carried out largely by a simple code system over voice radio supplemented by motorcycles, automobiles, and hand signals.3 The following year, at the beginning of the important Fort Riley maneuvers in spring 1934, the 1st Cavalry (Mechanized) commanded by Colonel Adna R. Chaffee, Jr., demonstrated its operational mobility by traveling overland from Fort Knox. The maneuvers were designed to determine how far the cavalry had progressed with mechanization, motorization, and new weapons development for deep operations with a self-contained force. Before the maneuvers, Army Ordnance developed anew combat car for the mechanized Cavalry, the 9.5-ton convertible Combat Car T4. The design was based on the Christie Combat Car T1. By mid 1932, four CCT1s had arrived at Fort Knox and became the nucleus for the striking squadron. Like the CCT1, the CCT4 employed the convertible wheel-and-track and helical spring suspension system, and was briefly tested at Fort Knox before the Fort Riley maneuvers. The test committee recommended the vehicle, with modifications, be declared standard. It was a decision Chaffee strongly supported based on his earlier experience observing the Christie tank acceptance tests and comparing those with the CCT4’s operational mobility and speed. During service tests following the maneuvers, the CCT4 outperformed the Ordnance-designed 7-ton CCT5, which displayed a double “Mae West” turret and anew rigid suspension system. The CCT5 was a radical departure from the Christie design. The vehicle was full tracked and non-convertible, employing a volute spring or bogey suspension system with a divided power train. During the tests, the Christie type suspension system provided a more stable gun platform with better ditch-crossing capabilities, while the Ordnance-designed vehicle was more maneuverable but so choppy in cross-country performance that accurate marching fire was impossible.4 Understandably, observers at Fort Riley did not favorably view the “Mae West” profile.5 At year’send, Chaffee was overruled. The decision was made to acquire a modified CCT5 (minus the “Mae West”) for the cavalry. Generally, combat car proponents at user level favored the CCT4. At the staff level, however, the War Department favored the 7-ton weight and lower cost of the CCT5, thus taking advantage of the opportunity to produce a less expensive vehicle manufactured at Rock Island Arsenal. In addition, the CCT5 avoided the engineering dilemma imposed by the wheel-track convertible design. Captain H. H. D. Heiberg, who served with the mechanized cavalry since 1932, recalled that the decision to adopt the CCT5 was made in the War Department “by officers [who had] probably never ridden in a tank, much less fired from one.”6 More so, the decision was driven by a War Department directive to impose a weight limit of seven tons. The CCT5 was standardized for production as the Combat Car M1. The vehicle reflected certain features, such as the Ordnance-designed volute suspension system, which remained characteristic of all U. S. tanks until late in World War II.7 In November 1936, a reported German tank expert wrote in the military weekly, Militar Wochenblatt, that in spite of its high speed, the CCT5 was a “perfect example of bad construction.” The Americans had repeated all the mistakes European tank and armored car builders had made, he noted. Furthermore, American tank armor was too light to resist modern weapons.8 Heinz Guderian, who was emerging as a key German practitioner of armored warfare, noted that the Christie tank developed by the Red Army since the early 1930s was also too light; however, it was a well-designed and tested machine with great speed.9 The War Department, however, defended its mechanized equipment, claiming it compared favorably with that of any nation.10 (The German observation soon proved correct. When U. S. Army tanks were first employed in Tunisia in February 1943, they lacked sufficient armor and armaments to engage German tanks. This disparity was never corrected until

Captain Adolf von Schell, far left, visited Fort Knox to observe the U. S. approach to mechanization as his superior, General Heinz Guderian, at left, planned Germany’s mechanized force. Leading the U. S. effort at the time was Colonel Daniel Van Voorhis, at right, who was testing new weapons and new theories of mobile warfare at the Kentucky post. 8 ARMOR — after the Battle of the Bulge, according to General Omar N. Bradley, the commander of the Twelfth Army Group during its assault on Fortress Europe.)11 Meanwhile, the Wehrmacht’s interest in military developments in the U. S. continued. Writing in the Militar Wis-senschaftliche Rundschau in January 1936, Colonel Guderian — now considered by the U. S. Army attaché in Berlin as one of the foremost experts on motorization and tanks — noted that the United States occupied the first position among all countries in the world regarding the technical production of its automobiles. Its army, however, has not yet participated in this economic development, he wrote. Guderian criticized the U. S. Army for not giving special attention to Christie tanks, which were given their greatest fulfillment in the Red Army rather than the country of their origin. He was also critical of the autonomy of the U. S. Army branch system that gave control of tanks to the infantry and the cavalry reference of tanks as combat cars. Concluding, he noted that a consolidated authority was lacking.12 In November, Guderian published another article in the Militar Wissen-schaftliche Rundschau, which reflected his strong interest in mechanized warfare as expressed in the United States, England, France, and the Soviet Union. This article represented the official doctrine regarding the employment of tanks in mechanized warfare. He emphasized that the striking power of armored troops must rely on fire, speed, and armor protection. Though the tank was the main maneuver weapon, it must also rely on the cooperation of other combat arms, he argued. Guderian quoted the famous British tank proponent, J. F. C. Fuller, who stated that tanks tied to the infantry decreased the value of that weapon, a problem he found in American and French armies. The mission of the motorized infantry and motorized artillery or the new self-propelled mount was to utilize the effect of amass tank attack. Regarding air power, Guderian saw the necessity of providing support for the ground attack. Concluding, he stressed opposition to infantry accompanying tanks, the significance of speed, mass, and surprise, and the importance of auxiliary combat arms as organic to tank forces.13 Attempts were also made in the U. S. Army to deal with the issue of a mechanized division. Between 1936 and 1937, the Command and General Staff School at Fort Leavenworth published an instructional text describing the organization and tactical employment of a mechanized division. In the text, the mechanized force was described as “all arms,” self-contained, and capable of deep independent operations, leading to pursuit and exploitation of success. This doctrine was similar to what the mechanized cavalry was working out for years at Fort Knox. Adding to force mobility, the text saw the use of aviation for command control, reconnaissance, and tactical ground support.14 In June 1937, now-Lieutenant Colonel von Schell returned to the United States to visit a number of military bases to again assess the degree of army mechanization. This visit was a result of the courtesies extended by the German government to the U. S. Army Attaché in Berlin to visit their military establishments and inspect mechanized ve-THE MACHINES: 1930s State of the Art Above, the unusual Christie convertible wheel/track suspension is seen in the wheeled configuration with its tracks stowed above and below the fenders on each side. Called “combat cars” (the cavalry was prohibited from owning “tanks”), the T4 was armed with machine guns. Above, the Ordnance-sponsored T5 Combat Car descends a slope during testing. Its vertical volute spring suspension was later a common feature of U. S. light and medium tanks, but the idea of twin turrets was abandoned for tactical reasons. The first German efforts, like this Pzkpw I destroyed by afield gun in Poland, at right, also proved to be too light for combat and were soon relegated to scouting and command missions. The Pzkpw I was also limited to machine gun armament. ARMOR — 9