Buckminster Fuller was able to create his largest geodesic dome in the shape of the US pavilion. As early as the fifties, the visionary and eloquent architect had experimented with space-frame structures which were to ensure trussless and at the same time climatically-protected spaces in huge dimensions. The dome for Montreal was supported on steel bases that had been embedded in the 60 centimeter thick annular foundation made of reinforced concrete. The supporting framework consisted of a lightweight assembly of bars that was welded together at nodes. The bars had to be connected to a total of 5,900 nodes, of which there were 82 different types. The space frame was composed on the outside of triangles and on the inside of hexagons. On the inner framework, 1,900 arched acrylic glass segments were fitted into the hexagons.
Over a construction period of five months, this reticular, filigree structure built up into a 61 meter high three-quarter sphere with a diameter of 76.25 meters. The complex structure was calculated by computer; these calculations had to take into account bearing loads and the loading from wind and snow, as well the openings for entrances and passages for the monorail, which drove right through the middle of the dome. The result was an interior space of 190,000 cubic meters in volume which was flooded with light and in which somewhat coarse, multi-story fixtures made of concrete supports and slabs with escalators were built. These exhibition platforms stood freely in the room like a large sculpture, without touching the dome, which had an almost weightless effect. To control the sunlight and heat, the panes were tinted green and bronze. In addition, some segments in the zenith of the dome were fitted with awnings made of aluminum-coated fabric which a motor made unfold, depending on the position of the sun. The pavilion looked particularly attractive at night, when the sphere glittered from the inside like cut crystal.
|Year: 1967||City: Montreal||Country: Canada|
|Duration: 28th April - 27th October 1967|