For the complex rehabilitation of the historic Barrage de Lavalette in the Haute-Loire region of southern France, the construction consortium led by Legendre Génie Civil has deployed a tailored lifting solution from Wolffkran to address extreme space and logistical constraints.

A WOLFF 7534.16 Clear flat-top tower crane, mounted on a WOLFF City Portal 520, has been operational at the site since March 2025. The crane plays a central role in replacing three original floodgates dating back to the 1950s and modernising a fourth gate installed in the 1990s, all of which have experienced significant wear after decades of service.

With a hook height of 20.4 m, a jib length of 40 m and a maximum lifting capacity of 16 tonnes, the crane is being used to install temporary structures and to remove and position both old and new floodgates. The project is particularly challenging as the dam crest measures just 6.7 m in width, significantly restricting crane erection and delivery operations.

According to Wolffkran, wind gusts exceeding 45 km/h further complicated installation works, extending the crane assembly period from the planned two days to around three and a half days.

A key requirement of the project was to keep traffic moving, as a public road runs across the dam and could not be closed for the full construction duration. To address this, the crane was installed on a City Portal solution, allowing vehicles to pass underneath. Load distribution beams were first positioned to spread crane loads evenly across the dam crest, followed by erection of the portal structure and crane using heavy mobile cranes.

While the City Portal enables continued access, road closures are required on weekdays between 9 am and 2 pm, as safety regulations do not permit loads to be slewed over live traffic. All lifting operations are therefore carried out within this restricted window.

One of the most demanding tasks involved removing a floodgate counterweight weighing approximately 51 tonnes. As the concrete block could not be lifted in a single piece, it was cut into sections on site, with individual segments of up to 16 tonnes lifted using the WOLFF crane.

Legendre Génie Civil noted that Wolffkran was the only supplier able to provide a complete package under the site’s constraints, including the crane, portal solution, assembly, operation, service and maintenance. Wolffkran has been involved from the early planning stages and will continue supporting the project throughout the approximately 24-month construction period.

The Lavalette Dam project highlights the role of specialised crane solutions in enabling complex infrastructure rehabilitation works under highly constrained site conditions.