Radio sonde, operated suspended from a barrage balloon. Early vacuum bags were made from war surplus barrage balloon fabric. Do 217 collided with the cable of a barrage balloon over the River Tees. The park was home to a barrage balloon anchorage and an ackack emplacement. The H-20 also was equipped with barrage balloon cable-cutters. A war-surplus barrage balloon winch was used for launches. The character was named after the barrage balloon, which was known as a blimp. A WWII barrage balloon mooring anchor was located on the island. During World War II the No.11 Balloon Centre, a barrage balloon depot, was built here.