The site was designed in January and February 1943 by engineers from the Peenemünde research facility and the Organisation Todt. On 25 March 1943 the construction plans were presented to Hitler, who immediately gave the go-ahead for the project to begin. The construction firm Holzman & Polanski was awarded the contract and 6,000 workers from Building Battalion 434 started construction that same month using plans by Franz Xaver Dorsch, Construction Director at the Organisation Todt. It was envisaged that the structure would be ready by the end of July 1943, though not its wiring and plant, and it was intended that it would be fully operational by 1 November 1943.