At the occasion of the documenta IV in 1968, in Kassel, Germany, Christo and Jeanne-Claude created the largest ever inflated structure without a skeleton. After three unsuccessful attempts, it was erected on August 3, 1968, with the assistance of five cranes, two of which were 230 feet (70 meters) high and weighed 200 tons each.
The pair of giant cranes, the tallest Europe had to offer, had been operating separately in northern France and in Hamburg, Germany. It took two weeks just to make arrangements for both cranes to arrive simultaneously in Kassel, to elevate the inflated air package from its horizontal position on the ground to its vertical position.
The 7 ton air package consisted of an envelope made of 21,528 square feet (2,000 square meters) of Trevira fabric coated with PVC and tied with ropes. The heat-sealed fabric envelope was restrained by a net made of 11,482 feet (3,500 meters) of rope specially prepared by professional riggers and secured by 1,200 knots.
The elevation took 9 hours. Once elevated, the 5,600 Cubicmeter Package stood 280 feet (85 meters) tall, with a diameter of 32.8 feet (10 meters). Chief engineer Dimiter Zagoroff designed a three-and-a-half ton, 36-foot (11-meter) diameter steel cradle-like base to support the air package 36 feet (11 meters) above the ground. The steel cradle was hinged on a central steel column anchored in a one-ton concrete foundation.
Air pressure was maintained by a centrifugal blower run by a variable-speed electric motor. A gasoline generator stood by in case of power failure. To keep the air package in its vertical position, steel guy wires were anchored to 12 embedded concrete foundations, six 10-ton and six 18-ton, which were completely removed when the air package was taken down three months later.
All expenses of the project were borne by Christo and Jeanne-Claude through the sale of original drawings, collages and early works of the fifties and sixties.
The land was restored to its original condition.