high tensile strength to diameter ratio characteristics even though the core 15 comprising the transmission element could not be subjected to a compacting force without damage thus it is seen in fig5 that the cable 1 has high tensile strength properties which are imparted by the main strands 3 4 and 5 while also having a transmission element 17 by which signals may be transmitted along the length of the cable as for example between a towing target and a towing vehicle referring to fig4 there is illustrated a cross sectional view of the cable 2 where the main strands 3 4 and 5 are not compacted to the same extent as that shown in fig3 such that a space remains between adjacent strands this space is necessary to accommodate a core 20 as shown in fig6 and 7 where the core comprises an electrically non conductive material for example a non conductive plastic material and which is in the form of a ribbon extending along the length of a cable the core 20 includes therein ribs or arms 21 which as shown in fig7 extend between adjacent main strands 3 4 and 5 so as to insulate adjacent strands from one another the resulting cable construction has a plastic sheath 22 surrounding the main strands 3 4 and 5 so that the strands are encased within the sheath and so that the main strands are insulated from one another in this form of the invention the main strands themselves may comprise electrically conductive elements whereby the strands.