Reducing pollution and disturbance with the evacuation of debris by cable
Using urban cable cars to transport rubble or earth from construction sites, for example. The aim? To generate less dust, less noise and less pollution than with a road transport solution
The example of Clichy
This 45,000 sqm property development led by the company Redman, in the eco-neighbourhood of Bac in Clichy-la-Garenne (Hauts-de-Seine), involves the demolition of the existing buildings, as well as the excavation of two hectares of land to a height of eight metres. It’s a massive challenge for our teams, who – on behalf of the planner Citallios, in a consortium with AD Ingé (agent) and S’PACE Architecture & Environnement – are responsible for EPCM of the earthworks, and management of the debris, much of which is contaminated. In total, some 250,000 tons of earth and rubble have to be evacuated, in an area already saturated with construction sites.
After studying various options, our consortium integrated the cable car solution into the design of the works, in line with the community’s strong desire to reduce the impact of the site. This is the only system of its kind in France: a cable car solution carrying excavated earth leading to river barges via the Seine.
The cable car, a worksite innovation
An overground cable car system now connects the construction site with barges moored about 400m away, along the Clichy dock on the banks of the Seine, for a period of 7 months.
This solution is a first in France for an urban site. Designed exclusively for this project by the company Mecamont Hydro, the cable car is 490m long and consists of two lines that operate independently of one another. Each of the four suspended skips transports up to 20 tons of rubble to the river, moving about 200 tons of earth per hour and 1500 tons per day.
Avoiding 80 lorryloads every day
For our work in this consortium, our teams had to take into account various constraints linked to the scale of these earthworks in a dense urban environment, and make sure the innovative cable car project was in line with technical requirements regarding the management of contaminated waste and the existence of adequate outlets accessible by water.
Concerned about the well-being of his constituency, Rémy Muzeau, Mayor of Clichy, has welcomed this particularly innovative solution. By prioritising fluvial evacuation, it avoids evacuation by land which would have required a rotation of nearly 80 trucks a day, leading to the equivalent of 2 tons of CO2 emissions, and generating significant noise, dust and road congestion in the area.
An environmentally friendly construction site
- The use of river transport for the disposal of excavated material, an alternative method that reduces disturbance for residents and the environment (traffic congestion, air pollution, noise, etc.)
- A minimum of trucks required to remove the debris resulting from demolitions in particular, for the installation of the cable car platform.
- Combating construction dust: washing truck wheels, misting and manual watering of deconstruction areas with consideration of wind, stopping work in strong winds
- Noise reduction: sound level monitoring to verify that regulatory thresholds are met.
- Rehabilitation of neighbouring roads