Facts on engineering - Part 2 Bridges - Information and tasks for kids

In order for people, animals and vehicles to cross over roads or rivers, it is necessary to build a bridge.  It must be planned properly because it must be able to carry the weight and not fall, it must be sturdy and even look nice.  This planning and designing is done by an engineer.

There are many bridges across the world and some are a bit more famous than others.

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There are different types of bridges and certain things like the function and money available is taken in consideration when an engineer designs a bridge.  The most common types of bridges are beam-, arch-, suspended-, cantilever- and truss bridges.

• Find pictures of different types of bridges.

Bridges must be build to last and be safe.  In certain countries you will find bridges that are very old.

The Zhaozhou Bridge is the oldest standing bridge in China and the world’s oldest stone segmental arch bridge. Built in 605 AD, it is still standing strong today, over 1400 years later. 

The Inca civilization that lived in the Andes Mountain, had to find ways in which they can cross rivers or between parts of the mountain and for this they used bridges made out of rope.  These bridges were strong, but sometimes they had to be repaired which was dangerous and a few people died in the process.

When the Industrial Revolution started, a lot of wrought iron were used in the frame of bridges but this was later replaced with steel because it can take more resistance before breaking.

Steel shrinks or expands in heat and cold and this must also be taken in consideration when building a bridge.  The Sydney Harbour Bridge can go lower or higher by about 18 cm because of this fact.

The Brooklyn Bridge that connects New York and Manhattan, was build in 1883 and it carries about 145 000 vehicles every day.  Not an easy task to maintain.

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 The Golden Gate Bridge in San Francisco, USA is a well known suspension bridge that was completed in 1937. It has a total length of 8981 feet (2737 metres) and features 80000 miles (129000 kilometres) of wire in its two main cables. 

Maybe interested in becoming an engineer that will build buildings or bridges?  You are going to build your own bridge by using recycled material. Use your imagination and build something 'spectacular'.  You can use which ever material you want, but it has to be strong enough to carry at least 10 kilograms.

Have fun.  You can find videos to give you ideas or just use your own.

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