The deception was not meant to be perfect under close inspection. The 603rd positioned their dummies under imperfect camouflage, in ways that allowed German aerial reconnaissance to “discover” them. Too-perfect concealment would defeat the purpose; the goal was to be found, in the right place, suggesting the presence of units that were not actually there.
The 603rd also used other methods to suggest a larger presence: they lit campfires, hung laundry on lines, ran vehicles back and forth to create tire tracks and exhaust evidence, and generally created the environmental signs that a large military formation would leave. The 406th Engineer Combat Company, with 168 men, used bulldozers to simulate the kind of track marks that real armored vehicles leave in soft ground.
The Signal Company Special — formerly the 244th Signal Company — had 296 men and handled radio deception. Its operators built fake traffic networks that mimicked real units’ communication patterns and volume. This was technically demanding work. Military radio operators of the period communicated in Morse code, and experienced operators developed individual “fists” — the distinctive rhythms and characteristics of their sending style that other telegraphers could recognize. The 23rd’s radio operators trained to imitate these individual styles, so that a German intelligence analyst monitoring the radio traffic could not only see the right call signs in the right locations but could recognize the apparent operators as the same individuals who had been transmitting from those units for weeks.
The 3132nd Signal Service Company, with 145 men, handled sonic deception. This element had been trained at the Army Experimental Station at Pine Camp, New York — the facility that is now Fort Drum. The company operated large speakers, reportedly weighing around 500 pounds each, that were mounted on halftracks. The speakers played recordings made at Fort Knox, Kentucky, that captured the specific sounds of an armored and infantry force: the clanking and grinding of tank treads, the rumble of truck convoys, the shouting of sergeants at formation, the mechanical noise of bridge-construction equipment. Under the right atmospheric conditions, these recordings could be heard up to fifteen miles away.