Koolau-Pukele structures replacement project

摘要

One of the key substations on Hawaiian Electric Co.'s (HECO) grid in Oahu is the Pukele Substation. This substation services approximately 18 percent of the total load on the island, including the key business and vacation area of Waikiki and the densely populated area of east Oahu. The Pukele Substation is serviced by two parallel 138kV transmission lines*the Koolau-Pukele 138kV #1 line and the Koolau-Pukele 138kV #2 line. The two most critical structures on these lines are located on the top of the ridge: structure #9 on the Koolau-Pukele 138kV #1 line and structure #2 on the Koolau-Pukele 138kV line #2. The cumulative effects of both normal and severe weather in their 40-plus years of service caused some deterioration of the strength carrying capabilities of these aluminum lattice towers. An inspection of structures #2 and #9 in 1998 revealed that both were showing signs of distress. As a result of this inspection, and because of the importance of these two lines, a tower replacement program was quickly initiated. Since these two lines are the only two lines servicing the Pukele substation, one line would have to remain in service at all times.