Catenary Arch

Build the catenary arch.

Push down on the arch from above. Does the arch feel stable?

What other arches can you see in the centre? Are they catenary arches?

A good arch should not collapse under its own weight.

A catenary is a type of curve that redirect an arch’s weight along the curve, so the arch itself does not bend. This makes the catenary the best shape for a strong freestanding arch.

A catenary arch is just the shape of a free hanging chain turned upside-down.

Although circular arches, triangle arches and flat arches are easier to construct, they do not have the same structural properties as the catenary arch.

The catenary is the best shape for an arch that only needs to support its own weight. However, if the arch needs to support a weight equally spread along its span, such as a bridge, then the best shape is a parabolic curve.