Power source management and electrical fault mitigation in seafloor networks

Initially deployed in 2010, the CSnet Offshore Communication Backbone (OCB) located in the Mediterranean Sea approximately 100km off the south coast of Cyprus contains oceanographic sensors and an array of seismometers providing scientists with valuable real time data for analysis. Recently, it was decided to transition the power and communications feed to the OCB seafloor network from a buoy located directly above the network to a shore-based supply utilizing two telecommunication cables (known as Poseidon, owned and operated by Radius Oceanic Communications, Inc.) connected to shore. To maintain redundancy after a potential electrical shunt fault occurs on one of the telecommunication cables, resulting in a power short to seawater, the OCB requires load-sharing diodes between the power feeding cables and the nodes. The seafloor network nodes, designed and built by OceanWorks, can be expensive to recover, so an alternative approach to adding load-sharing diodes had to be developed. This paper discusses the migration of a seafloor network to a redundant power feed architecture without the recovery of the seafloor network nodes and successful mitigation of a potential electrical shunt fault.