Method of impregnating a cable

A method of impregnating a cable with water impenetrable and water repellant sealing material, the cable comprising a plurality of conductors having a band thereon which permits inward passage of said sealing material under pressure in flowable form said method comprising passing the cable axially through a pipe having open ends, the pipe and cable forming an annular gap along the length of the pipe which gap is between 1 and 3 mm in thickness and is relatively thin compared to the diameter of the cable, said gap being formed uniformly along the length of the pipe, said gap extending to the open ends of the pipe, heating the sealing material to a temperature to render the same flowable, injecting the heated sealing material under pressure into said pipe at an intermediate position between the open ends thereof to cause part of said sealing material to flow inwardly into said cable while the remainder of the sealing material travels axially along the cable in said gap in opposite directions and freely flows axially outwards from the gap at the ends of the pipe, said sealing material undergoing cooling in the cable to form a barrier against penetration of water.