Shortly after the Wizernes site had been captured in September 1944, Duncan Sandys, the head of the British "Crossbow Committee" investigating the V-weapons programme, ordered the constitution of a Technical Inter-Services Mission under Colonel T. R. B. Sanders. It was given the task of investigating the sites at Mimoyecques, Siracourt, Watten, and Wizernes, collectively known to the Allies as the "Heavy Crossbow" sites. Sanders' report was submitted to the War Cabinet on 19 March 1945.
