how many bolts are in the sydney harbour bridge
Sydney Harbour Bridge The bridge is held together by six million Australian-made hand-driven rivets supplied by the McPherson company of Melbourne,[14][15] the last being driven through the deck on 21 January 1932.[13][16] The rivets were heated red-hot and inserted into the plates; the headless end was immediately rounded over with a large pneumatic rivet gun.[17] The largest of the rivets used weighed 3.5 kg (8 lb) and was 39.5 cm (15.6 in) long.[12][18] The practice of riveting large steel structures, rather than welding, was, at the time, a proven and understood construction technique, whilst structural welding had not at that stage been adequately developed for use on the bridge.[17]
Sydney Sydney is a coastal basin with the Tasman Sea to the east, the Blue Mountains to the west, the Hawkesbury River to the north, and the Woronora Plateau to the south. The inner city measures 25 square kilometres (10 square miles), the Greater Sydney region covers 12,367 square kilometres (4,775 square miles), and the city's urban area is 1,687 square kilometres (651 square miles) in size.[69][70][71]