What it shows
A lock raises or lowers boats by letting water in or out of a chamber between gates. The model shows how water finds its own level and moves a boat with no engine lift.
The science
Water always flows until its levels match on both sides of an opening, as in connected vessels. In a lock, the chamber is first made level with the lower canal and then filled from the upper canal, lifting the boat. The gates are opened only when levels are equal so there is no strong flow.
Materials
Cost: under Rs 200. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- A long plastic box or tray
- Three card dividers with waterproof tape
- Two small gates made from plastic sheet
- A foil or plastic toy boat
- Water and a jug
- A ruler and food colour
Safety
For this project: Work over a tray and keep floors dry. An adult must cut thick plastic. Do not use electric items near water.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Divide the box into a high section, a middle lock chamber and a low section using two gate dividers.
Fill the high section with water to about 10 cm and the low section to 4 cm.
Place the boat in the low section next to the lock gate.
Open the low gate so the boat enters the lock chamber and close it again.
Slowly open a small gap in the high gate to let water in.
Watch the boat rise as the chamber fills until it matches the high level.
Open the high gate fully and let the boat move out.
Reverse the process to lower the boat and note how the water levels change.
What you should see
The boat rises with the water in the chamber and moves to the higher section with no lifting by hand, showing how real canal locks work.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1Why do water levels match?
Water flows from high to low until pressure is equal.
2Why not open both gates at once?
A sudden rush of water would wash the boat and damage the gates.
3What is a lock used for?
To move boats between different levels in a canal.
4Where is water saved?
In modern locks with side ponds.
Take it further
Add a side tank that stores some lock water to save it.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
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