345-kY Underground Transmission on the Consolidated Edison Company of New York System

In 1953, it was foreseen by electric utilities that, in approximately 10 years, underground 345-kV transmission would be required in some areas. In the 1960s, it became desirable to extend 345-kV transmission circuits underground into the New York City metropolitan area. On the basis of information obtained from the Cornell research project, it was possible to plan and install a large commercial installation; approximately 60 circuit miles are now in service. The capability of one circuit is over 500 MVA, and with capabilities of this order there is a decided economic advantage over presently used lower transmission voltages.