The overall cost of the operation is 19.6 million of which 4.4 million is financed by the French government.
This bridge started its service back in 1889 and it’s the last major swing bridge in Europe to operate in its original configuration.
Sarens has been responsible for the dismantling of the bridge, with a weight of 840 tons and 70 meters length.
The Colbert Bridge, a late 19th-century iron hydraulic swing bridge in the port of Dieppe, in the north-west of France, is currently undergoing a complete restoration and renewal. This swing bridge allows ships to enter and leave the commercial dock and provides an essential road link between Dieppe and Neuville with over 12,000 vehicles crossing it daily. It is maneuvered 1,400 times per year for 2,300 ship movements.
The Colbert Bridge was brought into service in 1889 and it’s the last major swing bridge in Europe to operate in its original configuration, which led to it being listed as a historic monument in 2017. The Dieppe Port, the owner of the bridge, planned to dismantle the structure to completely renovate it and automate its operation from 2025 onwards.
The dismantling was carried out by the Eiffage Metal Group and Sarens was its partner in the maneuvers, marking the beginning of a period of fifteen months of work on the commercial port, until the reinstallation of the bridge, scheduled for May 2025, where Sarens will participate again.
Sarens, world leader in heavy lifting, engineering transport and crane rental services, began its intervention in mid-January with its technical solutions and engineering project. The project site was in the middle of the city where trucks and cranes needed to stand on the streets but during the works, traffic remained ongoing.
Jacking equipment had to be installed under the bridge in a pit with very difficult access. The water level rose 8 meters in less than 6 hours, which made the operation very critical. On top of that the quay side was not strong enough to support the weight of the Self Propelled Modular Transporters (SPMTs) so a long heavy beam had to be installed.
The equipment that was used included 8 jacking tower CS250, 4 SPMTs of 8 axle lines, various supports and load spreading, 12 bridges of 5800mm and 2750mm, 4 hydraulic winches and 24 ballast pumps. Almost all equipment came from Wolvertem (Belgium) by truck, for a total of 40 trucks. The equipment set-up was done in different phases. One week for the preparations, 2 weeks for execution and another week for demobilization were needed.
As the tides and water levels changed every day, all the calculations and preparations had to be done for one specific day. If that window had been lost, the operation would have been postponed for weeks, causing important delays in the overall progress and important economic losses. However the international experience acquired in similar projects by Sarens’ engineered team eased the choice of the necessary equipment and enabled the operation to succeed.
The ongoing operation also consists of the restoration of the shunting cabin and remodelling of the powerhouse façade, as well as the renovation of its roadway, the widening of its pavements to make them accessible to people with reduced mobility and the restoration of the staircase, which will offer significant benefits to the community.
The mechanism that turns the bridge is hydraulic and simply uses water from the canal, which on a normal day requires only the presence of two technicians. In winter, to avoid the risk of frost blocking the mechanism, wooden formwork is installed around the tubes and jacks and filled with about 20 tons of horse manure. The heat generated by the manure can protect the bridge down to -10°C for several months. These exhausting operations, which keep about ten people busy two nights a year, should disappear by 2025 thanks to the insulation of the hydraulic circuits.
Over the past few years, Sarens has established itself as a strategic player in similar projects. Recently the company has completed several major projects, including the installation of the OA14 bridge, weighing 5,850 tons, in Bettembourg (Luxembourg). Sarens has installed a new pedestrian bridge between the Hazebrouck railway station (France) and its car park and an 8,400 ton railway bridge on the A1 motorway in Amsterdam (Netherlands). The company also replaced a railway bridge in Stockholm ‘s (Sweden) city center using the "floatover" method.
About Sarens
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With more than 100 entities in 65 countries operating without borders, Sarens is an ideal partner for small to large-scale projects. Sarens currently employs 5,000 highly qualified professionals who are ready to serve the needs of any client worldwide and in all market sectors. https://www.sarens.com/