Problems of operation and maintenance of underground cables

The scarcity and high cost of transmission materials demands that the transmission capacity of electric underground cables be increased to a maximum. The causes of failures of cables are analyzed and the conclusion drawn that overheating is the most important for consideration. Methods of removal of heat from the cables are considered, and recommendations made for flooding the conduit with water, in order that the copper in underground lead-covered cables may approach the transmitting capacity of aerial cables.