Development of a new installation method along bridge for a 275 kV HPOF cable

A novel method was developed for installing a 275 kV high-pressure oil-filled (HPOF) cable along the 100 m long Yotsugibashi Bridge (Japan). Because of the length of the bridge there was not enough space to absorb the thermal expansion of the steel pipes. A splice and expansion joint were developed which could absorb the thermal expansion of pipes and the relative movement of the internal cable core. The system also permits an exchange of gasket in the event of an oil leak, without decreasing the oil pressure. The splice and joint are described, and test results are reported. Installation has shown the method to be practically applicable.<>