Nils F. Ambursen Explained

Nils F. Ambursen (February 6, 1876 – January 17, 1953) was a Norwegian-American civil engineer and inventor. He was the founder of Ambursen Hydraulic Construction Company and was known for his influential dam designs in the early 20th century.^[1]

Early life and education

Ambursen was born at Fredrikstad in Østfold, Norway and was educated at the Telemark Civil Engineering College (Telemark ingeniørhøgskolein) in Skien, Telemark. Ambursen came to the United States by the age of 21.^[2]

Career

Working for the B. F. Sturtevant Company in Hyde Park, Boston, Massachusetts, in 1903, Ambursen developed an innovative concrete slab and buttress dam for an industrial client in Theresa, New York.^{[3] [4]} Ambursen's design was for a buttress dam requiring minimal buttress thickness in which the upstream part is a relatively thin flat slab typically made of reinforced concrete. Ambursen's concrete-slab-and-buttress design used far less material than a traditional gravity dam making it both a significant engineering advance and cost effective for clients.^[5]

Ambursen promptly filed a patent on his own behalf and organized the Ambursen Hydraulic Construction Company, based in Boston. From 1903 through 1917, the company used the technique to construct more than one hundred dams in North America, most in New England. The record-breaking 41m (135feet) La Prele Dam in Converse County, Wyoming used 43 percent less concrete than an equivalent concrete gravity dam.^[6] The structure allowed an interior hollow under the spillway; the 1907 Bloede's Dam on the Patapsco River in Maryland housed its hydroelectric power plant inside that hollow and therefore "under water". The company sued to preserve its patents fairly aggressively but with mixed success.^[7] In some cases, the Ambursen dam became a more generic "Ambursen type", for instance at the 1911 Lock and Dam No. 1 on the Upper Mississippi River between Minneapolis and Saint Paul, Minnesota. Civil engineer George Freeman received his own November 1912 patent on a modified version of the concrete buttress dam used there.^[8]

In 1917, Ambursen left his company, which has continued to bear his name for over a hundred years.^[9] Today perhaps fifty Ambursen-type dams from the post-World War II era stand outside the United States. The tallest example, 83m (272feet), is the 1948 Escaba Dam (Dique Escaba) in Tucumán, Argentina.^[10]

Work

Ambursen's designs include:

(all dams listed located in the United States)

• Warrior Ridge Dam (1906) in Huntingdon County, Pennsylvania; "the focus of widespread attention in the engineering press"^[11]
• Ellsworth Dam (1907) in Ellsworth, Maine^[12]
• Bloede's Dam (1907) in Ilchester, Maryland^[13]
• Ashley Dam (1907-1908; undermined 1909) on the Housatonic River near Pittsfield, Massachusetts^[14]
• La Prele Dam (1908–1909; refurbished in 1977) near Douglas, Wyoming
• Rapidan Dam (1908 - 1910) on the Blue Earth River, Rapidan Township, Minnesota^[15]
• River Mill Dam (1911) in Estacada, Oregon; on the National Register of Historic Places^[16]
• Powersite Dam (1911–1913) in Forsyth, Missouri^[17]
• Overholser Dam (1917–1918) in Oklahoma City, Oklahoma; on the National Register of Historic Places^[18]
• Remmel Dam (1924) impounding Lake Catherine, Jones Mill, Arkansas; on the National Register of Historic Places^[19]
• Stony Gorge Dam (1926-1928) in Glenn County, California.^[20]

See also

• List of civil engineers
• List of inventors
• List of Norwegians
• List of people from Boston

External links

• Introduction to Buttress Dams

Related reading

• Lyon, William K.; George W Petersen (1921) Comparative designs of Gravity and Ambursen dams (Armour Institute of Technology)
• Hager, Willi H. (2015) Hydraulicians in the USA 1800-2000: A biographical dictionary of leaders in hydraulic engineering and fluid mechanics (Boca Raton, FL: CRC Press)

Notes and References

1. Web site: Key Developments in the History of Buttress Dams -Flat Slab Buttress . simscience.org . March 1, 2016 . dead . https://web.archive.org/web/20080603152748/http://simscience.org/cracks/advanced/butt_hist1.html . June 3, 2008 .
2. Web site: Telemark ingeniørhøgskole. Norsk samfunnsvitenskapelig datatjeneste AS. March 1, 2016.
3. Web site: B.F.Sturtevant History. Sturtevant Division of Westinghouse . August 1, 2017.
4. (National Register of Historic Places)
5. Web site: Ambursen buttress dam. United States Society on Dams. March 1, 2016.
6. http://uwdigital.uwyo.edu/islandora/object/wyu:4023 La Prele Dam
7. Jackson, Donald Conrad. Building the Ultimate Dam: John S. Eastwood and the Control of Water in the West. p. 295.
8. http://lcweb2.loc.gov/pnp/habshaer/mn/mn0300/mn0384/data/mn0384data.pdf Mississippi River 9-Foot Channel
9. http://www.nycompaniesindex.com/ambursen-company-f9/ Ambursen Company
10. http://www.orsep.gob.ar/presa-7.html Escaba
11. https://www.loc.gov/pictures/collection/hh/item/pa3237/Warrior Ridge Dam, Spanning Frankstown Branch of Juniata River, Petersburg, Huntingdon County, PA (Historic American Buildings Survey)
12. Jackson, Donald C. Great American Bridges and Dams. p. 88.
13. http://www.dnr.state.md.us/fisheries/bloededam/image/HistoricDocumentation.pdf Bloede Dam
14. Engineering News-Record. Volume 62. April 1, 1909. p. 345.
15. Blue Earth County, Minnesota. Blue Earth County Historical Society. p. 86
16. Web site: River Mill Hydroelectric Project. National Register of Historic Places Registration Form . August 1, 2017.
17. Web site: Powersite Dam. White River Valley Historical Quarterly . Kathleen VanBuskirk . June 10, 1984. August 1, 2017.
18. https://npgallery.nps.gov/pdfhost/docs/NRHP/Text/07000518.pdf Lake Qverholser Dam
19. http://encyclopediaofarkansas.net/encyclopedia/entry-detail.aspx?entryID=2319 Remmel Dam on the Ouachita River at Jones Mills (Hot Spring County, AR
20. Web site: Stony Gorge Dam. structurae.net. August 1, 2017.