The design and manufacture of direct burial wire

Outside the high-density service areas in the central parts of cities, telephone operating companies in this country have, until recent years, found it economically necessary to use aerial distribution facilities. Open-wire construction in particular, with its high initial cost, high maintenance cost, and frequent service interruptions, offered a desirable area for development of a direct burial facility. Various efforts using rubber insulated wire with no outer protection failed, which led to the development of rubber insulated wires with neoprene jackets. Experience in certain areas indicated the need for additional mechanical and electrical protection so a light, flat ribbon steel armor is provided under the jacket in certain types of this wire.