This concentration of creative talent was not incidental to the unit’s mission. The work of making rubber tanks look like real ones, of constructing fake headquarters that would be visible to German aerial reconnaissance, of staging the entire physical environment of a division-sized force with the resources of a 1,100-man unit, required a kind of spatial and visual intelligence that the Army was correct to associate with training in art and design.
The sonic deception element, the 3132nd Signal Service Company, required a different set of skills: audio engineering, sound recording, and the technical capacity to operate large and specialized playback equipment in field conditions. The radio deception element required men who could imitate the distinctive individual qualities of other operators’ Morse code — something experienced telegraphers could identify even when the message itself was legitimate.
## The Four Elements
The 23rd Headquarters Special Troops was organized into four main elements, each responsible for a different layer of the deception.
The 603rd Engineer Camouflage Battalion, with 379 men, was the largest component and handled visual deception. Its equipment included inflatable rubber replicas of M4 Sherman tanks, artillery pieces, trucks, jeeps, and other military vehicles. The Sherman replicas were impressive pieces of engineering: neoprene-coated fabric shells that weighed approximately 93 pounds when deflated but could be inflated to their full scale — a vehicle 20 feet long, 8 feet wide, and over 9 feet tall — in less than twenty minutes using a gasoline-powered compressor. From the air or at distance, they were difficult to distinguish from the real thing.