1. Rope bridge
Rope Bridge Bridge Designs
Episode 2:
Bridge designs

2. Objectives: Rope Bridge Bridge Designs
To Map the forces acting on a rope bridge.
To investigate the effects of tower height and number of rope supports on bridge strength.
To choose a design for a rope bridge.
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3. Rope Bridge Bridge Designs
Welcome back! Now that you understand how forces act on a bridge I’d like you to map the forces acting through the ropes that hold bridges up.
Engage
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4. Rope Bridge Bridge Designs
two tall towers?
Engage
two short towers?
Rope Bridge Bridge Designs
We have a number of designs for the bridge. These are some of the sketches our engineers have come up with. Which do you think will be best for our bridge?
just one tower? 4

5. Rope Bridge Bridge Designs
Taller towers must be better surely?
Explore
Why? And remember taller towers will cost more. How about having more ropes?
But if you only need one surely it will be easier to build with just one? You’re making the design too complicated!
Rope Bridge Bridge Designs
Maybe we could use cheaper ropes if each one carried a bit of the weight?
I’m just not sure. I think we need to do some investigations to find out which design is best. 5

6. Rope Bridge Bridge Designs
Explore
OK team, time for some real scientific investigations then! I’ll need your answers soon - and remember, I need to be sure your methods are good and the data you produce is reliable. Good luck!
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7. Rope Bridge Bridge Designs
Explain
Time to explain what you have found. I think a poster with your experimental methods and the data you have collected is the best way. I need one from each team and then I can compare them all.
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8. Rope Bridge Bridge Designs
Elaborate
Look at these two bridges from around Kazakhstan. Can you explain why the designers have chosen to build them in the way they have? What are the advantages of each design?
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9. Rope Bridge Bridge Designs
Elaborate
The beautiful Atyrau bridge over the Yessil river in Astana. If you look at the bridge from above, its cover resembles the shape of a fish, which is a symbol of Atyrau region. The bridge is metres long and 10.5 metres wide and includes a six-metre pedestrian lane and a three-metre bicycle lane!
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10. Rope Bridge Bridge Designs
Elaborate
Rope Bridge Bridge Designs
This rope bridge is much simpler and carries no lorries! Why did the designers use this method of holding up the walkway? 10

11. Rope Bridge Bridge Designs
Evaluate
OK, time to make a choice! Draw a sketch of the bridge you plan to build and explain why you have chosen this design. Use the results from your investigation to explain how the bridge will deal with the forces produced by people going across it every day.
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