Cardboard Tube Bridge
We have all seen the Popsicle stick bridges that can hold some heavy weights. This cardboard tube bridge takes bridge building to the next level! “Weighing 7.5 tonnes, the bridge is made from 281 cardboard tubes, each 11.5 centimetres (four inches) across and 11.9 millimetres thick. The steps are recycled paper and plastic and the foundations wooden boxes packed with sand. Balloons filled with 1.5 tonnes of water were used