Reach for the sky – the 3.5km lego tower

No, there isn’t really a tower of Lego bricks to rival a mountain – but theoretically there could be. Often these days when you have a question, you check Google and find the answer. Just occasionally though you’ll find a question that nobody has asked before – like how many Lego bricks could you stack on top of each other before the weight of the tower is enough to crush the bottom brick. In essence, what’s the tallest Lego tower you could possibly build?

After realising that nobody knew, BBC show More or Less asked Dr Ian Johnson, lecturer at the Open University, to help them find out. What they found surprised everyone. Testing Lego blocks using equipment usually reserved for stress-testing engineering supplies they discovered that the familiar 2×2 ordinary Lego could withstand a force of nearly 4,240 Newtons – the equivalent of six well built men – bearing down on the brick before it lost structural stability. Imagine that, standing six men on top of one Lego brick to crush it. When you work the maths out from the force of weight it can uphold against the weight of an individual block, factor in the size of a block and scale up… a single Lego piece can support about 375,000 other Legos on top of it. That tower would be 3.5km tall!

Back to the start though, there’s some bad news; it would be impossible to build a tower of lego that tall as the slight deviations in positioning over the sheer number of bricks involved would topple the tower long before 375,000 could be stacked together.

For more on the science behind the question, check out this piece on the BBC’s website.

If you could build a model out of Lego, would would you build?


Lifelong geek, and now admin at Worlds Beyond.