Originally constructed in the early 1900s to supply power to Southern California, Powerhouse 2-2A was due for an upgrade that would help enhance the reliability of the 12 kV and 33 kV power distribution systems at Big Creek.
Construction under this contract included the installation of a new 12 kV Substation with a 7.2/12kV transformer bank, 12 kV switchracks with four new vacuum circuit breakers and a Mechanical Electrical Equipment Room. Before construction could begin on the new Substation, crews had to clear the existing foundations and facilities from the former housing area located above the Powerhouse and complete improvements to grading and drainage. In addition, crews installed new underground getaways that included precast concrete vaults, duct banks and conduits that would connect the existing Powerhouse to the new Substation.
One final component necessary to connect the new Substation to the existing Powerhouse, approximately 900 feet across the canyon, was the installation of an 11,000-pound steel A-frame on the roof of Powerhouse 2. The A-frame would support overhead powerlines coming from the fourth floor of Powerhouse 2 and over to the new Substation. Because of its weight and size, the A-frame had to be set on the roof with the assistance of an S-64 Sikorsky Sky-Crane from Siller Helicopters, Inc. When construction was complete for the new Substation, crews demolished the old Substation, taking special care to transport and dispose of equipment containing high levels of oil so as to not disrupt or harm the surrounding environment. Once clear, the site was paved and striped for a new parking area for SCE employees.