One of the little known facts about the Sydney Harbour Bridge construction. It was built from the buttress' at each end to a central point where the 2 halves were to be joined. The halves were cantilevered from cables, which during the process of joining the 2 halves were slowly slackened to allow the bridge to droop down and make the connection. However as this process was started in the afternoon the contraction of the cooling cables and bridge steelwork was faster than the cable tension could be released. Work was stopped once the engineers realised they were chasing their tails, and recommenced the following morning to make use of the heat expansion.