METHOD OF MANUFACTURING A STEPPED RISER, AN ELEMENT FOR FORMING INTO A STEPPED RISER AND A STEPPED RISER AND A MEMBER FOR CHANGING THE MECHANICAL DYNAMIC PERFORMANCE OF A STEPPED RISER

摘要

A method of manufacturing a stepped riser comprising providing a first sheet of metal (10) with a layer (50) of plastics or polymer material bonded to the metal with at least one indentation (45,48) formed in the layer of plastics or polymer material thereby to allow bending of the sheet of metal along pre-determined lines substantially without inducing compression or tension through the thickness of the layer (50) of plastics or polymer material.