November 8th, 1990. Germany's third largest builder of public works BILFINGER BERGER, specialist in making foundations for major structural complexes. They are seen here working on the base of the Tower, which contains the underground anchorage piles that are in each Tower base. To make these Tower bases, shet metal pile cells were driven into the bed of the river up to 54 meters in depth, hundreds of steel sheets some 2 meters in diameter, and then filled with concrete. This German worker is supervising the concrete filling of the piles.