English: Just as the mist clears.

The Viaur Viaduct in the Aveyron department of France, along with the Eiffel Tower and the Gabarit Viaduct, stands as one of the ?Big Three? of French metalic structures. The first stone was laid on 3rd May 1895 and the bridge opened on 5th October 1902.

The factoid essentials are a central span of 220 metres, a total span of 410 metres over a gorge 116 metres deep. A million hand driven rivets hold together 3734 tonnes ( say around half an Eiffel Tower) of steel.

The gestation of the project was prolonged; original plans called for a conventional masonary structure but the science of bridge engineering was changing fast following the acclamation of Gustaf Eiffel?s Paris tower. In 1878 in Portugal the river Drouro had been spanned at Porto with a metallic design and so the Societe de Construction Batignolles under the supervision of the Engineer Paul Joseph Boden ( 1848- 1926) was charged with design and construction.

Site preparation and foundation stonework took some two years to complete during which time the steelwork was prefabricated at Batignolles? Paris workshops and at other French steelmaking centres. As was normal at this period the scaffolding was essentialy all made of wood.

A pleasing feature of the bridge is the elegence of the point where the two cantelivered arms touch ? the articulated central key providing some vertical and horizontal elasticity and deformation under extremes of wind pressure

The bridge made a substantial impact on the socio-economic development of this region. Linking Rodez with Carmaux and thence to Albi, Toulouse and beyond it permitted the exploitation of heavy and voluminious goods of the quarries and mines of the region such as limestone while phosphate fertilisers could now be run into the region to transform the rural economy. A measure of the success of the railway connection was that the price of lime quickly halved.