Things to consider
design issues. Design issues are things to think of when something like a cellphone tower, bridge, building or power station is designed. They include the purposes of the object or structure, the cost, and how people and the environment will be affected.
Why do you think tower A was designed to look like a tree?
Why does tower C have cables, but tower D has no cables?
Why will tower A not topple over and fall, even when the wind is strong?
Why does tower D have a large concrete block at the bottom, but tower E hasno foundation?
When an ugly object stands in a beautiful environment, people say the object causes visual pollution.
When an object falls over easily, people say it is unstable.
The lower part of an object like a tower, on which it stands, is called the base.
Which of the towers on the previous page has the widest base? Why was it designed to have such a wide base?
Which of the towers do you think is most unstable? Why do you think so?
Try to make the tube stand upright on one end. Try this at both ends. What do you notice?
When most of the weight of an object is in its lower part, engineers say it has a low centre of gravity.
When most of the weight of an object is in its upper part, engineers say it has a high centre of gravity.
What is more stable: an object with a low centre ofgravity or an object with a high centre of gravity?
Which tower on page 146 has the highest centre of gravity?
The following are different ways to prevent towers from falling over easily:
- Make the centre of gravity low. One way of doing this is to connect the tower to a heavy object at its bottom.
- Fasten the tower to the ground with cables.
- Plant the tower deep in the ground.
- Give the tower a wide base.
Look at the sketches of the six towers again. For each tower, say which method or combination of methods was used to make it stable.
Strong foundations help to keep towers from falling over. Which towers have foundations under ground level to keep them stable?
How do the underground foundations differ from each other?
Some of the towers are built from solid concrete or fibre glass. Other towers are metal structures. Why do you think the metal towers have triangles in them?
Now examine your desk and think about how you want the new desks to be made. Write notes in the space below, and make a few free-hand sketches too.
Write the document that will be sent to the factory manager on a loose sheet of paper. Your document should include one or more drawings. State the dimensions of the school desk.
Make a 3D oblique drawing in the space below of the desk you want to be made.
Does your document say if the legs of the desk should be made of wood, metal or plastic?
Instead of evaluating your own document, you can evaluate someone else's document. Your teacher could arrange this.
Does your document say how wide the desk top should be?
Does your document say how high above the ground the desk top should be?
Does your document say how smooth or rough the surface of the desk top should be?
Rewrite your design brief with specifications in the space below and on the following page. Include a single vanishing point perspective drawing.
