Abstract: An electrically insulating cross-arm for a tower for high-voltage power networks. The cross-arm includes an insulating structural member for attachment to the tower body and to support a conductor cable. The insulating structural member comprises a solid rigid spine extending along a long axis having cross sectional profile, normal to the long axis, having a second moment of area of its cross sectional profile about every axis normal to the long axis and dissecting its centroid has a value of A2/2? or more, where A is the area of the cross sectional profile. The structural member provides resistance to bending and compressive buckling and allows conductors to be safely supported at reduced tower height. T and Y shaped cross sections provide water run-off and inhibition of organic growth. The structural members are also generally useful as insulator members in high voltage power networks.

Abstract: An electrically insulating cross-arm for a tower for high-voltage power networks. The cross-arm includes an insulating structural member for attachment to the tower body and to support a conductor cable. The insulating structural member comprises a solid rigid spine extending along a long axis having cross sectional profile, normal to the long axis, having a second moment of area of its cross sectional profile about every axis normal to the long axis and dissecting its centroid has a value of A2/2? or more, where A is the area of the cross sectional profile. The structural member provides resistance to bending and compressive buckling and allows conductors to be safely supported at reduced tower height. T and Y shaped cross sections provide water run-off and inhibition of organic growth. The structural members are also generally useful as insulator members in high voltage power networks.