whereas under the same circumstances failures have occurred in the 12,000-volt cables. Several of these 12,000-volt failures assigned to external damage have occurred in cables which, upon being withdrawn for repairs after failure occurred, showed marks on the lead sheaths, indicating damage at the time of installation. A number of cases of damage to the lead sheath of 9000-volt cables have been found when the cables were being withdrawn for reinstallation at another location, and experience appears to indicate that had these cables been operated at 12,000 instead of 9000 volts, cable failures would have resulted.