Five albumen prints of a Buttress Dam/Ambursen Dam, 1876-1953

Five albumen prints of a Buttress Dam/Ambursen Dam (All five measure 12.75 x 18 cm in cardstock frame 20 x 25 cm). The buttress dam also called the Ambursen dam was named after a Norwegian American inventor and engineer named Nils Frederick Ambursen (1876-1953) who invented the design in the early 20th century. He held many patents on concrete forms applied to dam building. His first patent is dated 1903. He formed the Ambursen Engineering Company to build his type of dam. At one time he lived in Swissdale, Pennsylvania and designed several dams in Pennsylvania. The buttress dam is especially used in wide valleys where there is insufficient rock to support the weight and size of other types of dams. It is usually made of reinforced concrete. Based on landscape topography, the dam construction ongoing in these five photos, is possibly the Warrior Ridge Dam spanning the Frankstown Branch of the Juniata River, near Petersburg, PA. which was in operation in 1928, however, there are many other possibilities as this type of dam was useful in many areas needing to retain water for hydroelectricity, irrigation or mining.