Bridges That Move

How would you design a bridge to cross a river in a busy industrial port?   You can not use a conventional bridge because you must keep open the shipping channel. 

One solution would be to build an aerial ferry or a transporter bridge. A movable roadway, or gondola is slung beneath a gantry which carries a high level walkway. These bridges avoid the need for long approach ramps and are applicable were ferries would be impractical.  At Newport this was because the river has such a large tidal range. At Duluth it was because the canal froze over in winter.  In total, less than twenty were completed. The design fell from favour with the rise of the motor car.  I have found nine that are either still in use or still standing.

Aesthetically these bridges remain as imposing symbols of an industrial age.

Those that remain are:

1. The Vizkaya Bridge in Spain.   

This spans the mouth of the Nervion River near Bilbao.  Built in 1893 by Alberto Palaci with industrial support from Ferdinand Arnodin, this is the world’s oldest transporter bridge. It is 164 metres long and can transport six cars and several dozens of passengers in 90 seconds. It was declared a World Heritage Site in 2006.

2. Newport Transporter Bridge, Wales. 

This spans the River Usk at Newport.  It opened in 1906 and is the oldest remaining transporter bridge in Britain and is the largest such bridge left in the world.  The Runcorn transporter bridge which had been built one year early was demolished in 1961.  The walkway is 177 feet (54m) above the river and the towers rise to 242 feet (74m).  The gondola can traverse the river in just over a minute.

This bridge was designed by Ferdinand Arnodin. Arnodin is regarded as the father of the transporter bridge. He patented the idea in 1887. He was directly responsible for 18 such bridges, including six in France.   Arnodin incorporated suspension bridge and cable stay technologies in his designs. His factory at Châteauneuf-sur-Loire specialised in producing prefabricated metal substructures. Although the French were world leaders in this technology many of the French bridges were destroyed during the Second Wrodl War. Worldwide three of the Arnodin bridges are still standing.