The Pont du Gard

Hi friends (or strangers) !
Today it's all about that bass... Sorry all about the that bridge!

The "Pont du Gard" (those damned French, it's unpronounceable!) is an ancient bridge in France that was part of an aqueduct which provided water to the gallo-roman city of Nemausus (current Nîmes).
In the 1st century AD, Nemausus was an important coastal city of 20,000 inhabitants. This impressive (by this time) number of habitants and the opulence of the Roman lifestyle required huge amount of water to fill the fountains, the baths and villas.

Aqueduc of Nemausus

Consequently Romans started to build a 50km (why are they using meters? It's 30 miles!) long aqueduct. However the source was only 15m (50ft) higher than Nemausus! Therefore Roman engineers proved a great accuracy by doing this feat of sustaining a steady flow of water all along the aqueduc with a small gradient (average gradient of 1m high for 3km long).

Representation of the main points of the aqueduct, their altitudes and the inclination

The second big problem met during the construction of the aqueduct was the crossing of the Gardon river and its valley. To achieve this crossing Romans built the highest of all aqueducts bridge! It is 275m long (900ft) for 49m high (160ft). As you can see below, the Pont du Gard is an arch bridge of three tiers of arches, the water flowed on the top of it. To span the river, they built arches with a maximal span of 24m (82ft) and maximal height of 22m (72ft) only with simple materials (stone, wood...), equipment and mathematics.

Pont du Gard in 2014

Romans employed wooden made scaffolding and falsework to support the bridge and the arches during the construction. To lift off the stones, they used human powered treadwheel crane: workers had to spin the wheel like hamsters! "They are crazy, those Romans!"

Reconstitution of an antic roman treadwheel crane

This Bridge also shows that the Roman art and architecture was very developed and refined. Their culture was all about the excessiveness: tall bridge, tall statues, tall tale, tall tall...
The technical prowess they achieved by building this high bridge with equipments from their time is absolutely impressive and demonstrates the ingenuity and the accuracy displayed by Romans.
I introduced you to this marvelous bridge, to show you that Roman are not only good at conquests and destruction but also at construction. Romans didn't conquer territories just for their glory. They brought this glory into the conquered nations and shared knowledge with them. I think this is why Rome succeed to keep a waste Empire for a long time. The relationship they had with most of their provinciae was interdependent, instead of a one way relationship based on domination.


Citations:

images from
http://fr.wikipedia.org/wiki/Pont_du_Gard
http://en.wikipedia.org/wiki/Treadwheel_crane
homemade sketch
informations took from the vidéo "Le Pont du Gard et Arènes de Nîmes" of C'est pas sorcier