The project included the removal of two existing station service transformers, design and fabrication of two replacement transformers, and installation of two station service transformers and ancillary equipment at the Ice Harbor Lock and Dam. Replacement transformers were 5000/6250kVA, mineral oil-immersed transformers with On-Load Tap Changers on the secondary side. Transformer TJO was a Class I air-cooled, 15kV/4160V transformer that utilized the existing 5kV and 15kV bus duct. Transformer Two was a Class II air-cooled, 115kV/4160 that utilized the existing 5kV bus duct.