ABERDEEN, UK – Red Marine has delivered two shock absorber systems to Subsea 7 for installation later this year on the dive support vessel Osprey.
Each comprises a shock absorber and winch line tensioning system to protect the dive bell and handling system during launch and recovery operations.
The shock absorbers are designed to reduce shock loading on the lift winch wire caused by the differential motions of the vessel and the diving bell.
In operation, a maximum acceptable line tension is set. Once this value is attained, a shock absorbing cylinder extends, releasing extra wire length - up to 3.2 m (10 ft) - into the system.
This reduces line tension in a controlled manner down to an acceptable level, Red Marine claims.
A slack management capability ensures wire tension stays above a minimum acceptable level if the vessel and bell move toward each other, reducing the risk of snatch loadings on the system.
Each shock absorber system weighs 4.3 metric tons (4.74 tons).