Cable impregnated with high-viscosity oil

DURING 1941, a 7-mile circuit of 120-kv high-pressure gas-filled pipe-type cable known as the SMD-type cable was installed by The Detroit Edison Company, and has been in satisfactory operation since it was energized on December 31, 1941. An impregnating compound of much higher viscosity than that normally used in the mass-impregnation of cables was employed, and, at the time, preimpregnation of the tapes seemed to be the only method of assuring satisfactory impregnation throughout the wall of insulation.