LAYHER takes the helicopter to an exceptional construction site

An exceptional site...

The Baous penstock is located at the end of the Pont de l'Arn near Mazamet in the Tarn department (81). It originates 130 meters above the EDF power plant and descends for a length of 160 meters, crossing the Arn River, which is 40 meters wide, to reach the plant on the opposite bank. There, water from the upper levels is collected and then converted into energy.

Located in the heart of the Haut-Languedoc regional natural park, the site was therefore subject to major constraints to respect this exceptional environment.

...Exceptional means!

The work of removing asbestos from the existing paintwork was already an environmental challenge.

To carry out these works, EDF and the DONELLI company, in charge of asbestos removal and painting, entrusted SERVICE ECHAFAUDAGE 31 with the task of creating a scaffold allowing access at all points and total containment of the pipe.

With extensive experience in challenging construction sites, acquired over several years with its supplier LAYHER Echafaudage Toulouse, SERVICE ECHAFAUDAGE 31 has therefore implemented a precise operating process because this mission required the combination of several talents, for the technical aspect as well as for the coordination of the different trades.

LAYHER provided the study, technical assistance, and 120 tons of UNIVERSAL® scaffolding equipment, chosen for its adaptability, versatility, and scalability. Furthermore, these components are protected by an 80-micron thick hot-dip galvanizing coating, guaranteeing their reliability in inclement weather conditions, as was the case at the start of the project.

These 120 tons were delivered bundled in 800 kg packs for helicopter transport, which was the only feasible supply solution given the difficult access to the pipeline. The helicopter transport was carried out by FAF, a company located in Argelès (66).

To organize these deliveries and receive the crane trucks from the company THURIES (Toulouse), SERVICE ECHAFAUDAGE 31 prepared a site a few kilometers from the construction site by carrying out earthworks and fencing work to store the equipment while awaiting its removal by helicopter.

This project began in the snow and cold with the watchwords of safety, respect for the environment and deadlines.

Speakers

EDF : project owner

LAYHER : study, delivery, technical monitoring of the construction site, coordination of stakeholders

SE31 : Scaffolding rental/erector

DONELLI : Asbestos removal / painting

FAF : Helicopter transport

Technical scaffolding and synchronization

The scaffolding installed on the upper pipeline located in the mountain was received in several 50 m phases, before moving on to the construction of the 40 m pipeline bridge.

To install the suspended scaffolding, a temporary installation on concrete blocks positioned in the river was necessary.

This highly technical structure required a detailed study by LAYHER's design office, as well as rigorous monitoring of assembly compliance with the plans and synchronization of the interventions of the various stakeholders.

Indeed, it was essential that everything be precisely orchestrated, particularly for the assembly of the suspended scaffolding. The calculations had been carried out on the basis of a completely empty pipe in order to be able to resume the suspended scaffolding, so it was imperative that the team responsible for purging it be synchronized on the day.

The river, meanwhile, had to be at its lowest point upstream so that the temporary scaffolding installed in the riverbed would not be swept away by it.

The water cut-off at the dam therefore also had to be timed correctly. 

Once the scaffolding was in place, SERVICE ECHAFAUDAGE 31 removed the temporary installation structures.

Since the suspended scaffolding could not be anchored in the traditional way, it was secured by ties and buttressing against the wall of the pipe, protected by wedges. The whole thing was surrounded by tubes and clamps.

With this suspended scaffolding in place, the DONELLI company was able to complete its work and, thanks to the professionalism of all these companies, the pipeline has regained its original splendor and this exceptional site has been preserved.

Established in France since 1980, the LAYHER company has revolutionized the world of scaffolding with innovative and safe solutions.

It provides its customers with a rental stock of 35 tonnes of equipment spread across its 000 depots, as well as a design office made up of experts, consulted for the most technical projects (Maison de la Radio, Total La Mède, the Eiffel Tower, the Grand Palais, etc.)

www.layher.fr

Contact: Aurélia Jourdain

aj@tara-communication

+01 49 30 10 70