At the end of July 1917, the then long-range gun "Wilhelm", better known as the "Paris Gun" of the Krupp company, was tested and fired in Altenwalde. The bedding was aligned so that the projectiles flew over the East Frisian Islands to the Dutch Wadden Sea and detonated there, the distance being between 130 and 150 kilometers. The 106 kilogram projectiles flew at a launch angle of about 55 degrees, mostly in the airless space of the stratosphere (about 38 - 40 kilometers altitude), at a speed of about 1645 meters per second. After firing, the projectile took about three minutes to reach its target.