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Iron Bridge - arch bridge.
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Arches
are used in bridges in different ways, depending on whether
they are made of steel, brick or stone. The arch takes (transmits)
the load from the deck of the bridge to the land on both sides.
Stone was used in many Roman bridges.
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The Pont du Gard is an aqueduct
built 2000 years ago to carry water across a valley and is
still standing today. Arch bridges can form wider spans than
an unsupported beam.
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Pont du Garde.
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Yarm
Viaduct. |
Victorian
stone arch railway viaduct at Yarm. Built with tall pillars
and many arches.
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The
first metal bridge was an arch made from iron in Shropshire.
This was so famous that the place was named Iron
bridge, it was opened in 1781 and still stands
today. The designer was unsure of the best way of joining
the iron parts.
It had not been done before.
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Ironbridge, Shropshire. |
Ironbridge model. |
A
wooden model was made using dovetail
and mortice & tenon
joints usually used in furniture making. |
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The
iron bridge was then constructed according to the wooden model.
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Ironbridge
detail. |
Ironbridge
detail. |
Ironbridge
detail. |
Brick
arch bridge. |
With
brick arches set below the deck of this bridge there is little
space underneath them for boats to pass through, especially
if the water level is high. |
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Aberfeldy
stone arch bridge
in Scotland.
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Aberfeldy Bridge, Scotland. |
Sydney Harbour Bridge. |
Arches
can also be set above the deck as on the Sydney harbour bridge
in Australia. This allows much more space beneath for ships
to pass under. |
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Tyne
bridge in Newcastle.
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Tynebridge,
Newcastle. |
Canal tunnel bridge - Edam.
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Dutch
tunnel bridge over a canal.
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See
how the deck follows the shape of the arch beneath it.
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Tunnel arch bridge - Edam. |
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