Science

= What I know about Bridges cars go over it =

= What I want to learn to about Bridges how do they make it stable. =

= What I have learnt about Bridges 1 bridge fell down =

=__Sydney Harbour Bridge__= **Location: Sydney Harbour, Australia** Architects: Dr J.J.C Bradfield Date Completed: 19 March 1932 Height: 134 metres Length: 1149 metres The Sydney Harbour Bridge was opened on March 19th 1932 after six years of construction. Made of steel the bridge contains 6 million hand driven rivets. The surface area that requires painting is equal to about the surface area of 60 sports fields. The Bridge has huge hinges to absorb the expansion caused by the hot Sydney sun. You will see them on either side of the bridge at the footings of the Pylons. Sydney Harbour Bridge is the world's largest (but not longest) steel arch bridge, and, in its beautiful harbour location, has become a renowned international symbol of Australia.

=__Humber Bridge__= **Location: Humberside, England.** Architects: Not Known Date Completed: 1981 Height: 155.5 metres Length: 2220 metres The Humber Bridge is a suspension bridge with the north tower sited on the high water line and the south tower founded in shallow water 500m from the shore. On the north bank, a hard well-jointed bed of chalk comes close to the surface and is covered by a tough layer of glacially deposited chalky boulder clay. The chalk has provided good foundations for both the anchorage and tower on this bank, on the south side, soft alluvium is underlain by beds of boulder clay, sand and gravel. Below these beds, at a depth of 30m, there is a deep bed of stiff, heavily fissured kimmeridge clay, on which the tower and anchorage have been founded. Designed to cross the last major unbridged estuary in Britain, the bridge comprises reinforced concrete towers aerial-spun catenary cables and a continuously-welded, closed – box road deck