Henderson Hoops: A New System for Marine Growth Inhibition on Offshore Tubulars

Abstract

Polypropylene hoops encircling the tubulars of offshore structures are used to inhibit marine growth through their rotation which is induced by the action of current on flaps with a hinged connection to the hoop. Axial motion occurs naturally for inclined and horizontal tubulars in tidal flow and requires an extra vane attachment for vertical tubulars. Controlled tests in the marine environment suggest that the concept is nearly completely effective. The final design for the device which is being mass-produced is described.