Starling (architecture)

This article is about the architectural term. For the bird species, see Starling.

The starlings of Tower Bridge are clearly seen beneath the roadway.

In architecture, a starling (or sterling) or, more commonly, cutwater is a defensive bulwark, usually built with pilings or bricks, surrounding the supports (or piers) of a bridge or similar construction. Starlings are shaped to ease the flow of the water around the bridge, reducing the damage caused by erosion or collisions with flood-borne debris, and may also form an important part of the structure of the bridge, spreading the weight of the piers. So the cutwaters make the current of water less forceful.

One problem caused by starlings is the accumulation of river debris, mud and other objects against the starlings, potentially hindering the flow.