If the wind speeds are excessive, sensitive crane assembly work may be delayed for weeks rendering detailed plans absolutely useless. Waiting for days to assemble wind turbines, for example, is hardly a rarity. To stay with this example, crane work at wind farms must be stopped if the wind reaches a speed of more than six to nine meters per second depending on the hoist height and type of load. Here at Liebherr, we calculate these limits for tricky hoisting work for our partners precisely. Last autumn an assembly job took place in southern Germany, which was extremely susceptible to wind and for which the limit was actually reduced to just two meters per second.

To recap briefly, a deep storm low with the pretty name of “Bianca” passed over large parts of southern Germany in February 2020. In some places, weather stations recorded wind speeds of over 160 kilometers per hour. The region to the south of Lake Ammer in Bavaria did not escape the ravages of the storm. Since 1963, the spherical protective cover on “Antenna 1” at Raisting Earth Station has projected up into the sky like a giant puffball, visible for miles around. This industrial monument is known by the name “Radome”, an abbreviation of the words “radar” and “dome”. Its white air dome, a threequarter sphere with a surface area of 5,300 square meters, held in shape permanently by a fan generating a low pressure in it, fell victim to the winter storm. Since then the luminous red directional antenna has been exposed to the elements. Recording the damage, issuing a tender, planning and production of a new spherical membrane – all this takes time.

Johann Würz also sent an LTM 1230- 5.1 to Raisting as a second crane for working with a personnel cage and for setting up the larger crane. This modern five-axle model arrived at the site a few days earlier. It helped to hoist the membrane, which had been manufactured in Turkey, off the truck, unpack it and unfold it on a prepared surface. The new cover weighed a good ten tonnes and without the powerful boom on the mobile crane, it would not have been possible to move it. Before the new cover could be hoisted into position, an air hose, a tube with a diameter of one meter had to be installed along its opening. The idea behind this was that when it was hoisted over the parabolic antenna, it would be possible to push the opening on the underside apart. Additional hoses filled with air pressure were installed all around the antenna by rope access technicians and the crane. To protect both the fabric cover and the technical systems on the industrial monument.

It was in fact the gusty weather that then blew the site schedule completely out of the window. On the day scheduled for the installation work, the anemometer on the luffing jib of the LTM 1650-8.1 showed in the crane operator's cab that the wind speeds were permanently too high. Everything and everyone was ready when, as the breeze increased, the crane operator finally issued his considered but determined decision to call a halt to work for the day after discussing the situation with everybody concerned. They decided to try again the next morning. The meteorologists had forecast the prospect of a brief period of no wind. They decided to start work well before sunrise.

Until it was decommissioned in 1985, the satellite ground station played an important role in radio and telecommunications systems on a global level. The most important use of the radome was certainly the transmission of the first moon landing by the Apollo 11 mission in June 1969. The television signal was transmitted from the NASA Centre in Houston, Texas by satellite to the parabolic antenna in Raisting, from where it was broadcast to large parts of Europe. The Summer Olympic Games in 1972 held in Munich were also broadcast around the world by the radome. Furthermore, the American forces stationed in West Germany used the ground station to acquire a particularly secure connection to the USA during the Cold War.

This article was published in the UpLoad magazine 01 | 2022.