Cranemaster-PHC-at-record-depths-resonance-subsea-landing

We are proud to announce that a world record was recently set in the Gulf of Mexico. Never before has a Passive Heave Compensator (PHC) reached 2960 meter!

The challenge received from the customer was to overcome resonance during lowering of a subsea module and ensure the manufacturer’s required landing speed.

To demonstrate the feasibility of the operation, the engineering department at Cranemaster Headquarters in Norway ran Orcaflex analysis at “worst case” conditions according to DNG-GL Recommended Practice.

Splash zone crossing, resonance check by calculating the natural period of the system with and without a Cranemaster PHC and safe landing of the structure where all analyzed.

Operations in such deep waters put strong demand on the equipment to be used, and the Cranemaster PHC met all the requirements from the customer, including certification for operations at 3000 meter (9800 ft) depth.

The Cranemaster unit worked as expected from the analysis during the whole lowering process. The dynamic motion of the subsea module was dampened by the PHC through all phases, from safely deployed through the splash zone, lowering through ultra-deep water and installation on the seabed. No snap loads, no lowering resonance and controlled landing contributed to the success.