Patent ID: 8895861

Claim:
An electrically insulating cross-arm for a tower arranged to carry power conductors spaced from a body of said tower, the cross-arm comprising at least one first insulating structural member having a proximal end adapted for attachment to the tower body and a distal end adapted for attachment to a conductor support means, wherein the first insulating structural member comprises a solid rigid spine extending along a long axis between the distal and proximal ends and wherein the spine has a cross sectional profile, normal to the long axis, having a centroid and wherein the second moment of area of the cross sectional profile about every axis normal to the long axis and dissecting the centroid has a value of A 2 /2π or more, where A is the area of the cross sectional profile, and wherein the rigid spine comprises three rib-like protrusions extending along the axis, arranged to form at least two substantially concave faces therebetween and wherein the cross-sectional profile of the rigid spine is substantially T or Y shaped, the rib-like protrusions providing the arms of the T or Y shape.