Transmission cable with helical support elements of curvilinear profile

In a strain cable comprising a core which includes at least one transmission element;

• a structure which includes a tubular layer of interlocking metallic support members which are helically spun so as to form a single central passage accommodating the core;
• and at least one layer of metallic load-carrying elements helically spun around the structure, the improvement wherein the interlocking support members are wires of curvilinear profile having a helical pitch of 10.degree. to 30.degree. , the interlocking wires being at most twelve in number and the width, radial height and cross-sectional shape of the wires being such that the structure formed by the wires is radially and longitudinally self-supporting and sufficiently strong to resist reduction of the cross-section of the central passage when tension is applied to the cable in normal use and to protect the core against transverse stress.