Usually, the light barely passes through the bridge of sovereigns, located Boulevard Berthier, in the Batignolles district (Paris, XVIIth). In this long weekend in May, dozens of SNCF network technicians and workers take advantage of a lesser crowds to replace the aprons of the book, where circulates The RER Cand which serves as support for the 20 lanes leading to Saint-Lazare.
To carry out this XXL project, until Sunday, May 11, no RER C is rolling between Champ-de-Mars, in Paris, Montigny-Beauchamp and Pontoise (Val-d’Oise). The Bridge of Sovereigns is a work built in 1868, which supports the tracks on which the 1,600 daily trains of Paris Saint-Lazare train station.
“The replacement of the apron is an essential operation to maintain the reliability of the circulation of the Transilian L, J, and trains of the Nomad network operated by SNCF travelers circulating on the bridge, as well as those of the RER C which pass below”, summarizes SNCF Réseau.
“Léonard”, a compact tool to replace the aprons
This vast project, started during the May 1 bridge, will be finalized between August 1 and 12. Time to replace the 25 aprons each weighing between 25 and 60 tonnes. For this delicate operation, in an extremely dense urban and rail sector, SNCF Network and Bouygues have designed a new tool, called Léonard.
Rather than bringing in a huge crane to lift the old blocks of the bridge and replace them, this “lifting table” on rail moves on the track using six motor carts. Léonard’s overpowered cylinders remove the brick and steel blocks from the old bridge, from below. Then he comes to place the new aprons of the book (built in Thieux, in Seine-et-Marne) thanks to his swivel arms.
This innovative, “compact and powerful” tool has several advantages. “It is expensive than a crane, it is less risky and it is less bulky,” sums up Gilles Gautrin, modernization and development director at SNCF Network Île-de-France.
Thanks to the discretion and efficiency of Leonardo, there is no need to cut many paths on the surface. Less than 10 % of lines in lines L and J and Norman TERs are deleted during work weekends. The complete replacement of the Pont des Sovereigns will still request several weekends in June, July and August. The new work will be completely finalized in November. Cost of the operation: 34 million euros.
