Test Stand VII (, P-7) was the principal V-2 rocket testing facility at Peenemünde Airfield and was capable of static firing rocket motors with up to 200 tons of thrust. Notable events at the site include the first successful V-2 launch on 3 October 1942, visits by German military leaders, and Allied reconnaissance overflights and bombing.
Description
Two distinguishing features of P-7 were the 670-yard-long elliptical high-sloped sand wall and the wide concrete-lined trench (flame pit) with a large symmetrical water-cooled flame deflector of molybdenum-steel pipes. The concrete trench, nearly wide with concrete walls, sloped gradually away from each side of the flame deflector to a depth of , rising again symmetrically toward the side of the arena. Beside the flame pit was a long underground room where diameter delivery pipes were housed to route cooling water at 120 gallon per second from three huge pumps in the pumphouse to the flame deflector in the pit.
While the elliptical sand wall was for blocking high sea winds and blown sand, concrete structures were integrated into the wall and under the ground to protect equipment and personnel from rocket explosions and enemy bombing (a sand-filled dummy warhead, called "the elephant", was normally used). A large gap in the wall allowed easy entry by vehicles (particularly railcars with propellants), and an open tunnel through the ellipse wall at the narrower southern end also allowed entry. Integrated into the ellipse wall next to the tunnel was a massive observation and measuring blockhouse containing the control center. The control center had a double door with a bulletproof glass window from which an observer maintained telephone communication with the Telemetering Building at a remote location from P-7. A receiver in a lighthouse near Koserow provided telemetry from rockets with the Wolman System for Doppler tracking. For rockets that used radio control for V-2 engine cutoff, the Brennschluss equipment included a transmitter on the bank of the Peene about from P-7 and the Doppler radar at Lubmin (a motorized Würzburg radar, the "rhinoceros"). assembly and preparation hall/hangar (), which had been designed to be able to handle a larger A9/A10 multi-stage rocket that was planned, but never built. The roof of the hangar had camera stations for filming events.
Allied reconnaissance and bombing
On 15 May 1942 after photographing German destroyers berthed at the port of Kiel, Spitfire pilot Flight Lieutenant D. W. Stevenson photographed 'heavy construction work' near the Peenemünde aerodrome. Later in the month Constance Babington Smith decided the scale was too small ... then something unusual caught my eye ... some extraordinary circular embankments ... I then dismissed the whole thing from my mind. Then a year later on 22 April 1943, Bill White and Ron Prescott in RAF de Havilland Mosquito DZ473 were sent from Leuchars to photograph damage from Allied bombing at the Stettin railyards: "On leaving Stettin, we left our cameras running all down the north coast of Germany, and when the film was developed, it was found to contain pictures of Peenemünde." The Medmenham interpreters studied the elliptical earthworks (originally photographed in May 1942) and noticed an "object" long projecting from what was thought to be a service building, although it had mysteriously disappeared on the next frame.
On 22 April 1943 a large cloud of steam was photographed near the embankments, which was later identified as coming from a rocket engine being test fired.
After Operation Hydra bombed other areas of Peenemünde in 1943, the P-7 blockhouse roof was reinforced, and in a 1944 raid, the blockhouse occupants suffered one injury when a periscope fell. A former adjutant at Peenemünde, Oberstleutnant Richard Rumschöttel, and his wife were killed during the attack,