by the 7th Armored Division in March. McNair recommended for one division in five to be an armored division, which meant up to 50 armored divisions by the end of 1943. Pressure increased on Devers, who was promoted to lieutenant general (equal in rank to McNair) on 6 September 1942, to push more armored units through the pipeline even more quickly. Training was sometimes neglected because of the pressing need to get units ready for overseas deployment. Initially, the Armored Force trained all of the components of the armored division, but after March 1942, it became restricted to tank personnel, with other personnel coming from their own branch training centers. Devers sent Patton, now commander of I Armored Corps, to set up the Desert Training Center (DTC) in the California-Arizona Mojave Desert, where soldiers could train for desert warfare. When it closed in 1944, 20 infantry and armored divisions had trained there; although none fought in the desert, and five of them were sent to the Pacific. Devers was an articulate proponent of the Army's now-emerging tactical doctrine of combined arms: infantry-artillery-armor-close air support. He carried a translation of a German manual on the components of the Panzer division. Devers was neither the first nor the only general to embrace combined arms as the doctrinal solution to the problem of how best to employ tanks, but he was well-placed to act upon it. At his direction, an updated comprehensive (460 pages) Armed Force Field Manual: Tactics and Technique FM 17–10 was written, published, and distributed in March 1942. A German manual on tank platoon tactics, with a foreword by Heinz Guderian, was translated into English and issued as an Armored Force publication. March 1942 saw a reorganization of the armored divisions in the wake of the 1941 maneuvers. Devers added an artillery headquarters to the armored division and reorganized the artillery component into three battalions, each of three batteries of six M7 Priest self-propelled guns. A division trains headquarters was added to coordinate logistical activities. In a first, at Devers' insistence, a flight of light aircraft to be used for artillery spotting and reconnaissance were included in the new Table of Organization and Equipment (TO&E) for each division. He was a strong and early supporter of the development of the DUKW, an amphibious truck. Vannevar Bush later recalled that in the early stages of its development, Devers was the only