A
transporter bridge, also known as a
ferry bridge or
aerial transfer bridge, is a type of
movable bridge that carries a segment of roadway across a river. The
gondola is slung from a tall span by
wires or a metal frame. The design has been used to cross navigable
rivers or other bodies of water, where there is a requirement for ship traffic to be able to pass. This has been a rare type of bridge, with fewer than two dozen built. There are just twelve that continue to be used today,
including one converted into a
lift bridge and one designed as, but not yet operating as, a transporter bridge.