nium and steel, with a blue aluminium deck cladding, is an uncluttered area of 35,000 sq. ft. (3,251 sq. metres). No interior bracing structures or poles are needed. Heights are also impres sive. The centre of the dome is 40 ft. (12 metres) high, the cantilevered cor- ners dip to 20 ft. (six metres), and the entrance porches are 10 ft. (three metres) high.
The pavilion consists of four sec- tions, each with about 200 different components. Each triangular section is different in dimension or angle and in the pavilion there are only four iden- tical components of any given type. Despite this, costs are not high, as is so often the case with non-standard parts.
The triodetic system is by no means new, but this is believed to be the largest building for which it has been used. The system originated in Canada but the British engineering firm, Vickers Ltd., in association with British Aluminium Co., have the ex- clusive manufacturing and marketing rights in the United Kingdom, Western Europe, and marketing rights for the rest of the world, excluding North America.
The range of cladding materials which can be used with the triodetic system is almost as wide as the struc- ture's uses. In Tehran the infill panels are in plastics. The same material
A space frame formed of tubular structural members fitted with the new form of connector.
could just as easily be used for the trough decking, but obviously site conditions and the availability of local materials would determine the choice.
Since lightness is the main feature, the use of claddings similar to those in the British pavilion would keep costs to a minimum. The speed of erection too, keeps labour and site costs at bottom.
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47 metres) the cylinder hubs are fairly thick. For the same reason, the pavilion is supported underground by reinforced concrete footings under the eight steel columns which slant up to the centre dome. Each pair of steel columns stands at an entrance, one on either side. For the rest, the structure
is cantilevered. The edging trim is steel, the rest, aluminium. The alumi- nium weighs in all only 13 tons and is relatively inexpensive.
Earthquake give
Tehran is in earthquake territory. So the pavilion required additional ground ties which added to its cost. But these would not be necessary for something smaller, or a similar sized structure in a less vulnerable area. The total cost of the Tehran pavilion was about £60,000 (US$144,000).
British pavilion at the Second Asian Inter- national Trade Fair, Tehran. It provides 35,000 sq. ft. (3252 sq. metres) of un- interrupted exhibition space
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Far East BUILDER, November 1969
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