L3 Technologies
Installation Planning and Cable Route Engineering

Adequate planning is the cornerstone to every successful marine installation. L3 MariPro engineers plan every project with the goal of minimizing risk and maximizing success. This goal is accomplished by involving engineers from the installation team in the design, manufacture and test phases of the system. This practice insures that each system is designed and built to ensure a successful installation.

Dockside Sensor Node Deployment Rehearsal Sample of MakaiPlan program for cable route planning

 

Planning tools such as desktop studies, bathymetric surveys, sub-bottom profiles, cable route engineering programs, cable ship dynamic simulations and modeling, field trials and real-time cable lay monitoring are utilized to plan and monitor every meter of the cable lay. Trained and capable personnel coupled with proper and well maintained equipment, vessels and crews that meet rigid operational and safety specifications are included in each installation plan. Every deployment is successfully performed in accordance to detailed installation and safety plans developed specifically for that type of system. If necessary, deployment tests, field trials and rehearsals are scheduled to insure success.

As the project progresses and more detailed data from a Cable Route Survey becomes available, the cable route is engineered, refined and verified. The Cable Route Survey typically provides multibeam bathymetric mapping, side scan sonar and sub-bottom profiling that identifies seabed features and hazards, and defines the seafloor sediment layers and structure. Cone Penetrometer Testing data may also be used in conjunction with sediment core samples to provide ground-truthing of the initial geologic interpretation for cable burial assessment.

Makai bathymetric view
with cable route overlay
Sample of MakaiPlanPro showing cable lay vessel track (yellow & red) to accurately position cable (blue) on seafloor as planned per the Route Position List

 

A Cable Lay Plan is then developed utilizing data from the desktop and route surveys. This plan contains minute-by-minute details of the proposed installation vessel's speed, course and position, and the cable payout speed and tension that will accurately position the cable and sensor nodes as closely as possible to the desired Route Position List (RPL) coordinates on the seafloor. The Cable Lay Plan is critical to insuring that the cable is on the seafloor along the correct route positions to avoid suspensions over irregular terrain. The Cable Lay Plan is simulated and refined as necessary to obtain realistic maneuvers that the installation vessel is capable of performing.

The Cable Lay Plan is then downloaded into the installation vessel's Dynamic Positioning computers. L3 MariPro's Installation Directors and Navigators coordinate with the installation vessel's Captain and Deck Officers to test, refine and rehearse the vessel's movements (maneuvers) before the actual cable deployment.