Sydney Harbour Bridge weighs 52,800 tonnes and it is the first iconic structure which we see, lit up with fireworks on NY Eve/Day. At 134 metres,she is the world's tallest steel arch bridge, it's deck spanning 1149 metres. And she is 86 years young! To maintain the'old matriarch of Sydney harbour'; Roads and Maritime Services(RMS) is deploying a computing network of 2,400 sensors to measure the vibrations in metal. They then apply machine learning algorithms to sensor data, so that the crew is alerted, even before the cracks and faults appear.