Three transformers at the power relay station at Boulder Dam, [s.d.]

Photograph of three transformers at the power relay station at Boulder Dam, [s.d.]. The three tall cylindrical structures can be seen at center. Wires extend out from the tops of the transformers. Several tall metal towers can be seen in the background, while a large spool of wire is visible in the foreground at left. A sign on the transformers reads "Transformer Bank B Bus No 2".

博尔德大坝（Boulder Dam）电力中继站内三台变压器的照片，[无具体拍摄日期]。画面中央可见三台高大的圆柱形变压器，其顶部延伸出多条输电线路。背景中矗立着多座高耸的金属铁塔，画面左侧的前景处摆放着一个大型线轴。变压器上的标识牌标注有“变压器组B 2号母线”。