Unit D Lesson D7 Bridges
Completion requirements
Lesson D7: A World of Bridges
Video Lesson
Bridges are essential transportation structures for humans, both in the past and today. Bridges make possible travel across barriers that otherwise would involve long distances and much time. Bridges make possible the efficient transport of resources
such as oil, wood, and food. Watch this video to learn more about various types of bridges.
Lesson D7: A World of Bridges
London Bridge in the USA?
Figure D.2.7.1 – In medieval times, some Londoners built houses on the deck of London Bridge.
Figure D.2.7.2 – In 1831, engineers redesigned and rebuilt London Bridge.
A well-known nursery rhyme and game for little children is
London Bridge is Falling Down. London Bridge crosses the Thames River in London, England. It never fell down suddenly, but various versions of the bridge have been torn down and replaced during its 2000-year history.
The 1831 version of London Bridge started sinking slowly into the river by the 1920s. In the 1960s, the London city government decided to replace London Bridge again. They came up with the idea to sell the old bridge, and their idea worked!
London Bridge was sold to an American businessman in 1968. Workers took apart the bridge, numbered all the pieces, and shipped it to the USA. London Bridge was reassembled in Lake Havasu City, Arizona, where it still stands.
The 1831 version of London Bridge started sinking slowly into the river by the 1920s. In the 1960s, the London city government decided to replace London Bridge again. They came up with the idea to sell the old bridge, and their idea worked!
London Bridge was sold to an American businessman in 1968. Workers took apart the bridge, numbered all the pieces, and shipped it to the USA. London Bridge was reassembled in Lake Havasu City, Arizona, where it still stands.
Reading and Materials for This Lesson
Science in Action 7
Materials:
Science in Action 7
Reading: Pages 290-295
Materials:
No other materials are required for this lesson.
Figure D.2.7.3 – This bridge is Tower Bridge; it is not London Bridge.
Figure D.2.7.4 – The current modern version of London Bridge.
Connections
Connections: Environment
>> Wildlife Bridges
To find food, to find shelter, and to escape predators, animals cross roads that pass through their habitats. Each year, many collisions occur between vehicles and animals along busy highways.
National parks were established to protect wildlife and the environment, not put them in danger. On the Trans-Canada Highway in Banff National Park, many vehicles used to hit and kill or injure animals. Parks Canada designed an effective solution to such vehicle-wildlife collisions. They built bridges over the Trans-Canada highway specifically for animals. Animals use these overpasses with the help of fences along the highway to direct them to safe crossing.
>> Wildlife Bridges
To find food, to find shelter, and to escape predators, animals cross roads that pass through their habitats. Each year, many collisions occur between vehicles and animals along busy highways.
National parks were established to protect wildlife and the environment, not put them in danger. On the Trans-Canada Highway in Banff National Park, many vehicles used to hit and kill or injure animals. Parks Canada designed an effective solution to such vehicle-wildlife collisions. They built bridges over the Trans-Canada highway specifically for animals. Animals use these overpasses with the help of fences along the highway to direct them to safe crossing.
Figure D.2.7.6 – In Alberta, wildlife often are near roadways.
Figure D.2.7.7 – An animal overpass in Banff National Park.
Watch More
Wildlife Bridges
Watch this video to see a close-up view of a wildlife bridge in Banff National Park.
Watch this video to see a close-up view of a wildlife bridge in Banff National Park.
Watch this video to see some examples of wildlife bridges for other animals around the world. Check for other sites including a crab crossing in Christmas Island National Park, Australia.
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Building and Rebuilding Bridges
In June 2013, the worst flood in Alberta's history affected southern Alberta. Several bridges were damaged or destroyed by the force of flooding rivers. In Calgary, three narrow pedestrian and bicycle suspension bridges over the Elbow River were destroyed completely. These bridges had wooden decks, which washed away in the flood.
Watch the following video to see these damaged bridges.
In June 2013, the worst flood in Alberta's history affected southern Alberta. Several bridges were damaged or destroyed by the force of flooding rivers. In Calgary, three narrow pedestrian and bicycle suspension bridges over the Elbow River were destroyed completely. These bridges had wooden decks, which washed away in the flood.
Watch the following video to see these damaged bridges.
Extreme Bridges
Humans have built some enormous bridges!
The longest bridge in the world is a rail bridge in China, which is 165 km long. That's the distance between Edmonton and Red Deer!
The tallest bridge in the world is called the Millau Viaduct (Figure D.2.7.8.) It is a vehicle bridge with one pier that is 343 metres tall, which is taller than the Eiffel Tower!
Many people think that walking or driving over bridges is fascinating, thrilling, and sometimes scary. Do you like crossing bridges?
Humans have built some enormous bridges!
The longest bridge in the world is a rail bridge in China, which is 165 km long. That's the distance between Edmonton and Red Deer!
The tallest bridge in the world is called the Millau Viaduct (Figure D.2.7.8.) It is a vehicle bridge with one pier that is 343 metres tall, which is taller than the Eiffel Tower!
Many people think that walking or driving over bridges is fascinating, thrilling, and sometimes scary. Do you like crossing bridges?
Figure D.2.7.8 – The Millau Viaduct located in Southern France.
Watch More
Bridge Climbers
Watch this video to see people climbing the Sydney Harbour Bridge, in Australia.
Watch this video to see people climbing the Sydney Harbour Bridge, in Australia.
There is no Self-Check for this lesson. Please continue to the next lesson.