La Coupole ( English: The Dome ) was a Nazi Germany bunker constructed in a former limestone quarry and planned for V-2 rocket assembly and launches. The site was bombed as a " Heavy Crossbow" target and the rockets were launched from mobile firing batteries, instead.
Prior to 1942, the Bauer and Nebel consulting firm was contracted to design the intricate erector to transport checked-out Wizernes V-2s from underground to the surface launcher. For launches, the rockets would be hauled from the service chamber through concrete tunnels Gretchen and Gustav past the planned 5feet (1.5 m) thick solid steel bomb-proof doors. On July 8, 1943, Hitler viewed a colour V-2 rocket film and scale models of the Watten bunker and mobile launching-troop vehicles. Instead of the "shoot-and-run" mobile launching Walter Dornberger advocated (and eventually used), Hitler reaffirmed that there should be more than one fixed bunker. By September 1943, construction at Watten (despite Allied bombings), Wizernes, and the 'special' V-2 site at Sottevast was on schedule. Work on La Coupole was begun after the nearby Le Blockhaus had been damaged by Operation Crossbow bombing. On November 5, 1943, the Allied Central Interpretation Unit (CIU) reported photographs of Wizernes construction. In January 1944 a concrete dome 71 m in diameter, 5 m thick and weighing an estimated 55 000 tonnes was built over the top of the facility. Similar to the Verbunkerung method, the Wizernes plan was to build a bomb-proof dome on the ground on the edge of the 30 m / 100-foot-deep quarry, then excavate a facility beneath. Directly beneath the dome, a 35 m / 117 ft diameter by-21 m high hexagonal room was planned to house the rocket production facility. After final assembly and fueling, the rockets were to be moved outside and fired. In May 1944, the "953 (Semi-Mobile) Artillery Detachment", started Abteilungen ( English: firing detachment ) training at Blizna for operations at Wizerne. The detachment consisted of one technical and two operational batteries to launch up to 50 rockets daily from Wizernes. On July 3, 1944, the Oberkommando West gave permission to stop construction at the heavily damaged Watten and Wizernes sites, and on July 18, 1944, Hitler ruled that plans for launching V-2s from bunkers no longer need be pursued. In late August 1944 the site was captured by the Allies, and the Allies recovered the uninstalled Wizernes doors from storage at Le Blockhaus when it was captured.
Instead of excavating underneath a constructed roof as at Wizernes, the Verbunkerung method first built a roof for a new facility (provided bombing protection), then jacked the roof up enough for a portion of the walls to be constructed—walls upon which the jacks would be used to further raise the roof and successively heighten the walls to the design height.