Saint-Nazaire Bridge

Saint-Nazaire Bridge
Coordinates	47°16′43″N 2°09′57″W
Carries	Cars, pedestrians and cycles
Crosses	Loire river
Locale	Saint-Nazaire
Official name	Pont de Saint-Nazaire
Maintained by	Conseil général de la Loire-Atlantique
Characteristics
Design	Cable-stayed bridge
Total length	3,356 m
Longest span	404 m
History
Opened	1975 (built in 1974)
Statistics
Toll	Free
Location

The Saint-Nazaire Bridge (Template:Lang-fr) is a cable-stayed bridge spanning the Loire River and linking Saint-Nazaire on the north bank and Saint-Brevin-les-Pins on the south bank, in the department of Loire-Atlantique, Brittany, France. The bridge is crossed by the "Route bleue" (RD213).

The cable-stayed metallic structure measures 720 m and, including the access viaducts, represents a total length of 3 356 m.

History

The Saint-Nazaire Bridge was commissioned on October 18, 1975 after three years of construction. With its 404-meter central span, the 720-meter metal structure held, at the time of its construction, the world record length for a cable-stayed metallic bridge.

In 1992, the Loire-Atlantique general council took over the Saint-Nazaire SAEM, the contractor for the creation and operation of the bridge. Access to the bridge became toll-free on October 1, 1994.

The building was remitted to the Loire-Atlantique’s general council road heritage organization, which is responsible for its management and maintenance since August 1, 1995. Since its creation, trading between the north and south shores of the estuary have improved considerably.

At the time of its construction in 1975, the Saint-Nazaire bridge was the longest one ever built in France. Moreover, it held the world record for the longest cable-stayed bridge for eight years.

Construction and specifications

The bridge consists of two access viaducts made out of prestressed concrete: the northern viaduct is 1 115 m long, and the southern one is 1521 m long. The main structure is composed of a 720 m long cable-stayed metallic frame. It is crossed by the department road RD 2132.

The construction of the bridge was entrusted to a consortium of companies:

• Metallic construction: Compagnie Française d’Entreprises Métalliques (CFEM) ;
• Concrete structures: Société Générale d’Entreprises (SGE) (the foundations were subcontracted to Morillon-Corvol, Courbot and Dodin).

Traffic rules and regulations

The speed limit is 70 km/h. Certain or even all vehicles may restricted during strong winds (starting at 80 km/h for cyclists).

The general council has implemented a lane management system for the bridge. The reversible lanes allow, during the day or special events, for a second lane to be dedicated to the busier way. The system has folding barriers, with illuminated red studs that are embedded in the asphalt, and road sign frames that allow for illuminated road signs (green arrow/orange or red cross) to indicate the way that is assigned to each of the three lanes.

Unique in France, the system went live on August 25, 2010 and is regarded as "experimental". In fact, it is a requirement from the state since the traffic code mandates white markings on the ground. The Loire-Atlantique general council has, therefore, received a one-year permit that has renewed every year since then.

However, the illuminated beacons have become too fragile because of the LEDs.

Also, the increased traffic during the summer causes numerous traffic jams despite the system.

To offer an alternative way of crossing the river for pedestrians and cyclists during the summer (May to September), in June 2010 the general council considered a river shuttle service between Saint-Nazaire and Mindin. Because of its prohibitive cost, the idea was abandoned in December 2011.

The only regular coach lines using the bridge and providing intercity connections between Saint-Nazaire and the Pays de Retz region are those of the Lila network (routes 15, 16 and 17). Route 17 vehicles are fitted with eight bicycle-only spaces.

External links

• structurae website