The Colbert Bridge in Dieppe, one of the last swing bridges in Europe, is being restored. The Sarens teams were mobilised to dismantle this 840-tonne, 70-metre-long structure.
Dating back to the 19th century, this bridge connects the port of Dieppe to downtown. Classified as a Historic Monument, it is currently undergoing a complete restoration and renovation with a view to its automation in 2025. 12,000 vehicles pass through it every day and 1400 manoeuvres per year are carried out, allowing 2300 ships to enter and leave the commercial basin.
Its dismantling was entrusted to Eiffage Metal, which called on the Sarens group for the lifting and transfer operations, from the work over a period of 15 months until the reinstallation of the bridge, a stage in which Sarens will again be involved.
The aim was to lay the 840-tonne, 70-metre-long bridge on a barge, which then sailed to the port, where the bridge was delivered to another quay, rotated 180° and crossed a road before reaching the restoration site. The bridge was raised about 4 meters high. Sarens installed underdeck supports and ramps for the SPMTs, which are essential for loading the deck in and out of the barge.
A complex installation, difficult to access, in a context constrained by the geographical location of the site, in the heart of the city center, while trucks and cranes had to circulate without interrupting traffic. The water level rose by 8 meters in less than 6 hours, making the operation very critical. In addition, the dock could not support the weight of the SPMTs, so a support beam had to be installed.
The equipment included 8 CS250 jacking lathes, 4 SPMTs with 8 axle lines, load carriers and distributions, 12 5800 mm and 2750 mm axles, 4 hydraulic winches and 24 ballast pumps. Almost all of the equipment arrived from Wolvertem (Belgium) by truck, with a total of 40 trucks.
The installation of the equipment took place in several phases: one week of preparations, two weeks of execution and another week for demobilization. Given the tides, and therefore the fluctuating water levels, all calculations and preparations had to be made for a specific day, with no margin for error since this would have postponed the operation for several weeks...
