IDA-3 is constructed mostly from spare parts to speed construction. Floating bridges were historically constructed using wood. Buildings and lots can now be constructed on slopes. Steel framework can be easily constructed of electrical conduit. It was originally constructed of wood and spanned . Sewers are often constructed as circular pipes. The old terminal was originally constructed in 1927. Individual components cannot be constructed in isolation. The elevators were also constructed from plywood. Twelve refers to the number of pitches on which the scales can be constructed. The hull must therefore be constructed with high precision. They were carefully constructed by his imagination. Several ring roads have also been constructed. Around the same time, pandiagonal squares were being constructed. Eventually an underground city can be constructed.