EEI-Manufacturers 500/550 KV Cable Research Project. Cable C-High Pressure Oil Paper Pipe Type

Background for development of EHV underground transmission is traced, introducing pertinent details of one manufacturer's research and development on 500 kV pipe cable. Highlights of cable design and manufacture are summarized. The continuing search by the industry for a synthetic alternate to oil-paper insulation is discussed in relation to future cable designs. Advantages of forced cooling for EHV underground transmission systems are recognized.