noun
swing bridge; swivel bridge
A bridge that rotates horizontally to allow water traffic to pass.
この運河には古い旋回橋が架かっている。
An old swing bridge spans this canal.
可動橋 is a broader term for any movable bridge, while 旋回橋 specifically refers to a swing bridge that pivots horizontally.
Compound of 旋回 (rotation) + 橋 (bridge), describing a bridge that swings open.