The bers, 250m，are positioned in a loose tube made of a high modulus plastic. The tubes are lled with a water-resistant lling compound.The tube is wrapped with a layer of PSP longitudinally. Between the PSP and the loose tube water-blocking material is applied to keep the cable compact and watertight. Two parallel steel wires are placed at the two sides of the steel tape. The parallel steel wires are placed at the two sides tape. Then，the cable core is covered with a thin PE inner sheath.After the PSP is longitudinally applied over the inner sheath，the cable is completed with a PE outer sheath.
