Anchor line load monitoring system.

Strainstall installs an anchor line load monitoring system for the FPSO Cidade de Anchieta.

The turret moored FPSO, previously named the Espadarte, underwent a fast-track upgrade at a shipyard in Singapore in readiness for its new mission in the Baleia Azul Field in Brazil. Operating in a water depth of 1221m with a daily throughput of up to 100,000 barrels of oil, safety is paramount.

The stand-alone Chain Tension Monitoring System™ is a key safety aid, measuring and displaying the anchor mooring loads in the nine legs of the vessel using sub-sea strain rings designed and manufactured by Strainstall.


Four strain rings were installed on each of the nine hawsepipe chain support tubes and fitted with a sub-sea cable for connection to a local junction box on the chain stopper deck. The junction boxes include amplifiers to convert the low level signals from the strain rings to a 4-20A signal for onward transmission to a master control unit located in the turret equipment room.

System Benefits:

The system provides a real-time display of the mooring line tension in each anchor leg, along with necessary data acquisition, processing, and storage. Alarms, triggered when tensions approach safe operational limits, enable operators to take remedial action. The system has a 25+ year design life and can be upgraded to include monitoring of metocean conditions, vessel draft and ballast.