← Investigators EngineeringTriangulation30 minutesStd 6–8

Newspaper Tower Load Test

✨ Rolled newspaper and a few triangles hold a full bottle of water half a metre in the air.

Two paper tube towers under the same bottle of water: the square framed tower on the left racks over into a parallelogram and folds, while the tower on the right with a diagonal taped across every face stays square and carries the load down to the ground. — How it works

🧰 You need

old newspaper
sticky tape
scissors
a measuring tape
books or a filled water bottle as the load

⚠️ Ask an adult about the scissors and keep the load low so nothing heavy can fall on your feet.

👀 What you will see

The square-framed tower leans sideways and folds long before the paper itself breaks. The triangulated tower carries much more and usually fails by one tube buckling. Tightly rolled tubes are far stronger than loosely rolled ones.

🧪 Do it

Roll sheets of newspaper into tight thin tubes and tape each one so it cannot unroll.
Build a square-sided frame tower about fifty centimetres tall and measure its height.
Add the load slowly on a flat card on top and note what happens.
Rebuild the same height, but tape a diagonal across every square face.
Load this tower the same way, adding weight step by step, and record what it holds.
Write down which member failed first in each tower.

💡 Why it happens

A square frame can change shape into a parallelogram without any side changing length, so it collapses sideways under load. A triangle cannot change shape unless a side actually stretches or shortens, so adding diagonals makes the frame stiff, and engineers call this triangulation. Rolling paper into a tube also puts the material far from the tube's centre line, which resists both squashing and bending. The load must find a continuous path of members down to the ground, and the weakest link on that path decides the strength of the whole tower.

🔁 Now try this

Build two towers of equal height and equal newspaper, one with squares and one with triangles, and record the mass each carries before failing.

🤔 Think about it

Look at a pylon or a crane and count the triangles; why is there hardly a square to be found?

🧘 Ask the Acharya

“Look at a pylon or a crane and count the triangles; why is there hardly a square to be found?” — ask him and he will explain it from your own chapters.

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