Page 48 - DK Children's Encyclopedia

Bridges SEE ALSO

▸ ▸ Cars p.52
▸ ▸ Engineering p.91
Bridges are structures that carry people and vehicles ▸ ▸ Materials p.157
over obstacles. They are usually built over rivers, ▸ ▸ Rivers p.211
valleys, and roads. Bridges are designed to hold ▸ ▸ Storms p.243

heavy loads and survive bad weather. ▸ ▸ Transportation
pp.258–259

Bridge types
Engineers design different types of bridges
depending on the size of the gap to be
crossed, the type of land around it, and
the weight of the crossing traffic. The wires used
for the cables on
the Golden Gate
Suspension bridges Bridge could go
A suspension bridge can carry around the Earth
heavy loads. Steel cables are
anchored to strong supportive three times.
towers, spreading the weight.

Cables provide
support from above. Tall towers at each
end of the bridge
are anchored deep
in the ground.

Road or
walkway made
Golden Gate Bridge, from strong
San Francisco, CA
concrete.

Arch Truss Beam
Arch bridges are usually made of stones A truss bridge is built from triangles called A beam bridge is the most simple design.
cut into exactly the right wedge shapes trusses. Triangles are the strongest shapes, All the weight is placed directly on top.
to form an arch. so this bridge can carry heavy weights. It is built to be stiff and not bend.
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