For the Compliant Cylinder Project, the hydraulic locking equipment - pistons, cylinders, brackets and clamp - was produced from Ferralium® 255 (UNS S32550, Alloy 255, DIN 1.4507, ASTM F61), chosen for its proven resistance to sea water combined with high strength.
The Compliant Cylinder Project, run by BMT at Hythe, Southampton, studies the behaviour of flexible offshore structures under the action of waves and tides. It is jointly sponsored by Government and the oil and gas industry.
To let the stiffness and natural frequency be varied, the cylinder is made in six segments controlled by a hydraulically operated locking system. The locking equipment sits between adjacent cylinders, as shown in the photograph.
The cylinder has been tested on the Christchurch Bay tower since last winter, where wave heights up to seven metres have already been experienced.
