Transporter bridges are very rare, with only eight remaining in use out of a total of twenty built worldwide. They work by carrying a gondola suspended above the water, but well below the level of the rails that carry the bogie that supports the car on long wires.
The Newport Transporter Bridge crosses the River Usk in Newport, Wales. Built in 1906, it is the oldest and largest of the three historic ferry bridges that remain in Britain, and also the largest of the eight that remain worldwide.
The transporter design was chosen for this bridge because the river banks are very low at the desired crossing point. An ordinary bridge would have required very long approach ramps to gain sufficient height to allow tall-masted sailing ships to pass under it. A ferry was not an option because the river is not navigable at low tide.
The wire between the towers spans a length of 645 feet. Power to propel the gondola is provided by two 35 hp electric motors, which power a winch situated in an elevated winding house at the eastern end of the bridge. The gondola travels total span at just under 10 feet per second.
The engineering of this bridge is outstanding. When compared with somewhat better known (thanks to the 1980s British TV series, Auf Wiedersehen, Pet) Middlesbrough Transporter Bridge, this larger bridge required much less steel to construct, since it made better use of cables for support. The visitors center is on the west bank of the river and features exhibits on the history of the bridge, its construction and other transporter bridges around the world. You can make the crossing either on the gondola, or walk up the steps and cross the main truss on foot.
The 1959 movie Tiger Bay was filmed partly on the Newport bridge (though in the film it had miraculously moved to the Cardiff docks!). Its child star, Hayley Mills, is now the Honorary Life Vice President of the Friends of Newport Transporter Bridge, an organization dedicated to protecting this important historic structure.