The House on the Bridge Essay

Submitted By N1teCrawler
Words: 326
Pages: 2

The arch is composed of two 28-panel arch trusses; their heights vary from 18 m (59 ft) at the centre of the arch to 57 m (187 ft) at the ends next to the pylons. The arch has a span of 503 m and its summit is 134 m (440 ft) above mean sea level; however, expansion of the steel structure on hot days can increase the height of the arch by as much as 18 cm (7.1 in).[9] Large steel pins support each end of the arch, allowing it to rotate to accommodate expansion and contraction caused by changes of temperature, and avoiding stresses that would otherwise cause damage. The total weight of the steelwork of the bridge, including the arch and approach spans, is 52,800 tonnes, with the arch itself weighing 39,000 tonnes.[10] About 79% of the steel was imported from England, with the rest being sourced from Australia.[11] On site, the contractors set up two workshops at Milsons Point, at the site of the present day Luna Park, and fabricated the steel into the girders and other required parts.[11] The bridge is held together by six million Australian-made hand-driven rivets supplied by the McPherson company of Melbourne,[12][13] the last being driven through the deck on 21 January 1932.[11][14] The rivets were heated red-hot and inserted into the plates; the headless end was immediately rounded over with a large pneumatic rivet gun.[15] The largest of the rivets used weighed 3.5 kg (8 lb) and was 39.5 cm (15.6 in) long.[10][16] The practice of riveting large steel…