Investigate granny margaret thabang’s problem (60 minutes)
In your team, read through the following story.
Rivers provide much-needed water for communities, but sometimes they can also make life difficult for people. For example, during the rainy season, people from villages on one side of a river struggle to get to the other side of the river,if there is no bridge.
Many of the people in the KwaNogawu village next to the uThukela River in KwaZulu-Natal work on the other side of the river. The doctors, banks and shops that they need to visit are also on the other side.
School children cross this river to get to their schools, and the elderly have to walk through it once a month to collect their government grants from the offices on the other side.
Usually, the villagers cross the river on foot, because the nearest bridge is very far away. But during the rainy season, when the river is in flood, it becomes very dangerous. The water levels are so high that it is difficult to get through it safely, and the villagers have also seen crocodiles in the river. Everyone is scared of drowning or getting attacked by the crocodiles, but they don’t have a choice and have to go through the river to get to the other side.
Write a few sentences to explain the problem the villagers have.
Can you suggest a few ways to help Granny Margaret Thabang cross the river?
A tender is a bid for work from a company. It gives details of how much the company would charge to complete a project.
The Thukela Municipality placed a tender request in the newspaper asking contractors to submit tenders for a structure to help people safely cross the river at KwaNogawu village.
Municipalities are not allowed to choose a contractor without giving as many contractors as possible a chance to apply. This is to stop anyone from being favoured over others, and to prevent corruption. Each contractor writes a tender document, which is a description of their plan for the project and shows how much they will charge to complete the work. The job is given to the contractor who presents the best plan at the lowest price.
You are going to build a structure to help the community. Read the story again and then investigate the different bridges below to decide which structure will be the best solution for the problem.
Investigate structures to solve the problem (60 minutes)
On this page and the next there are drawings of different types of bridges. You learnt about these bridges in Grade 8. Do you remember what the names mean? If you cannot remember, look at your Grade 8 book or ask your teacher to help you.
Different types of bridges use different materials and construction methods, but they all have a similar function.
In your group, discuss some of the advantages and disadvantages of each of the bridges for the community. Think about which parts will help the community, and which parts will not help.
If the bridge is meant to carry cars, it might be too expensive for your tender. Remember that the bridge has to solve the community’s problem. In technology, we call this fit-for-purpose. In this case, it means that your bridge has to be strong and high enough to carry people and not cars. However, your bridge has to be strong enough to withstand floods, which are common in KwaZulu-Natal. Your bridge must also be stable, so that it does not sway and cause old people and children to fall when they walk across. It should have a structure that can span a wide river.
Use the following list to help you to investigate each of the bridges in Figure 5on the previous page. Also bring pictures of bridges to school. You can find photographs of bridges in old newspapers and magazines.
Checklist for investigating bridges
Is the bridge for cars?
Is the bridge for people?
Is the bridge too expensive for the tender?
Can the bridge be built strong and high enough so that it is not washed away by floods?
Can the bridge be built so that it is stable and does not sway?
Can the bridge be built long enough so that it can reach or span across the river?
Is the bridge strong enough so that the villagers can walk safely across?