6. Cable laying and repair

6.1 Tracing the route

The aim of this phase is to determine the route the cable will take, and to analyze the underwater terrain, water depth and soil characteristics. All this data is then used to define the different types of cable that will make up the link, and to plan the appropriate installation equipment. In addition, knowledge of the relief is necessary to determine the exact length of cable to be manufactured, taking into account the gradients covered by the cable resting on the seabed.

Water depth and seafloor relief are measured using MBES (Multi-Beam Echo Sonar) equipment fitted to survey boats. Although this technique has been around since the early 1990s, analysis of the data provided by these MBES has progressed considerably in recent years,...