From the Morgan Sweeney Photograph Collection (PH-00228). Rim tower C11T1x during erection June 22, 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). Hoover Powerplant showing reinforcing steel workers tying and placing steel rod. Carpenters installing forms preparatory to placing concrete August 31, 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). General activity in generator foundation forming for the Hoover powerplant, note generator foundation bolts around circle on October 4, 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). A-9 turbine pit the form work completed for concrete lift to elevation 673ft in 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). Concrete placement in progress for Unit A-9 in August 24, 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). Unit A-4 turbine at the Hoover Dam, the boring mill in operation boring for lower stationary seal on September 17, 1951.

From the Morgan Sweeney Photograph Collection (PH-00228). Interior view of A-8-9 penstock. Dark spots at 45 degree from vertical and horizontal mark the location of lower set of piezometer taps. Taps locations have been cleaned and repainted. Note wire projecting into penstock, upper right, locating tap hole. Pool of water visible at bottom, tire hoist inside 30-foot penstock at top of raise.