The normal underwater laying of cables / ducts involves the opening of a trench with a bucket excavation, the installation and subsequent closure of the excavation, all delimiting the operating area with temporary fixed anti-turbidity structures. Overcoming this laying system is essential to operate without compromising the delicate balance of sensitive ecosystems such as the Venice lagoon (SIN site of national interest).
While laying a 132kW underwater power line in the Venetian lagoon we used the hydraulically controlled trencher cable sinker "MAC 1” equipped with a self-propelled anti-turbidity floating structure. This system has been the subject of an extensive environmental investigation which has resulted in two measurement campaigns: the turbidity of the water with the CDT multi-parameter probe and the acoustic climate induced by the construction site on the surrounding landscape.
The investigation confirmed the effectiveness of our installation system and of the environmental aids that mitigate the effects on the environment: the turbidity levels are lower than the traditional installation (the material suspensions decrease during the excavation / burial and the diffusion of the material resuspended from the seabed) and the monitoring of the acoustic climate has detected 4 dBA at a distance of 150 m from the construction site (corresponding to the daytime emission limit value of the areas included in class 1).