Yesterday, the department of the Seine-maritime which begins a little before Rouen and ends in Le Havre had only two bridges over the Seine : the bridge "William the Conqueror" (commissioned in 1970) which connects the right bank to the left bank inside the city of Rouen and the bridge of Tancarville (commissioned in 1959)which connects the Marais-Vernier with Tancarville in the first cove of the Seine when one leaves the bay of Seine.
The Seine-Maritime (76) is a department bordering the English Channel stretching from Cap de la Hève over the Seine to Le Tréport (Bresle Valley) on the Alabaster Coast. It ends after Rouen towards Paris, at Gournay-en-Bray. Before 1955, it was called Seine-Inferieure.
Today Seine-Maritime is home to more than a third of the population of the new Normandy region, or more than one million two hundred and fifty thousand inhabitants in 2013.
This position lying above the Seine naturally cuts the department of Seine-Maritime from any land relationship with neighboring territories south of the Seine. This department had only two bridges over the Seine: the Guillaume le Conquérant bridge (1970) which connects the right bank to the left bank inside the city of Rouen and the Tancarville bridge (1959) which connects the Marais-Vernier with Tancarville in the first cove of the Seine when one leaves the bay of Seine. In fact, the plateau Cauchois which constitutes half of the area of the department of Seine-Maritime was without a reliable and constant communication route to the south. The ferries do not run at night and have a limited load, even if they were present every 30/40 kilometers in the past.
French agriculture, a European flagship to protect
It was therefore vital for the region's economic boom to break this isolation. But not to interfere at the same time with the maritime traffic of the port of Rouen, first exporter of French cereals but especially European. Indeed, the port of Rouen is fed, via the three terrestrial modes (rail, road and fluvial), by the main French cereal regions at the crossroads of which it is located and which alone represent half of the national production.
This imperative of not harming maritime traffic has given rise to the term "sea bridge", which is a common shorthand for the common name "deck in maritime format / standard" throughout the world. Standards evolving naturally, it was vital for each bridge construction to permanently push back the known limits so as not to be "handicapped" in the future. In fact, all the bridges built over the Seine entered during their construction in the book of records. The three bridges have a 50-foot air gap * in the middle. But the records being made to be beaten, they remained there more or less as the time goes by ... So we will return successively on the construction of Bridges Tancarville (1959), Brotonne ( 1977) and Normandy (1995).
Bridge of Tancarville : 3,5 years (42 months) - Bridge of Brotonne : 3 years (41 months) - Bridge of Normandy : 7 years (82 months)
Air draught : free space between the river / sea level at high tide and the underside of the central span of the bridge.
The Bridge of Tancarville, the precursor of the maritime bridges
The Tancarville Bridge was commissioned on July 2, 1959 and signed the death of the ferry Seine, war damage, linking Berville-sur-Mer, south of the Seine (Eure) to Hode (in Seine-Maritime).
When commissioned, the Tancarville Bridge, with a central span of 608 meters, was the longest in Europe. Today, it remains a national record. The set weighs 7,500 tons.
Its two pylons have a height of 123 meters and support about 6,000 tons of work. The left bank (south) pylon has a depth of 28 meters because of the marshy nature of the soil (near the marsh-vernier). That of the right bank has "only" a depth of 18 meters .
The Tancarville Bridge is a suspended cable-stayed bridge whose model has been tested in the wind tunnel to test its resistance to ocean storms since we see the sea, beyond Le Havre, from its central span. The cables are connected at the ends to anchor blocks, the largest of which is similar in size to the Arc de Triomphe (Place de l'Etoile in Paris) and weighs 36,000 tons.
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