Construction of the Sydney Harbour Bridge took 1400 men eight years to complete. They joined 53000 tonnes of steel with six million rivets. The opening ceremony brought together the largest group of people ever seen in Sydney, estimated at 'over a million'. Although the number is questionable, the suburbs of Sydney were certainly deserted as spectators swarmed to the Bridge approaches. After the official ceremony and procession, the Bridge was open to pedestrians until midnight.