10/31/2022
On this day in engineering: Mount Rushmore National Memorial opens October 31, 1941.
DYK?
Park area 1,278.45 acres
Visitors 2,525,868 (2021)
Designated as a National Memorial - October 1, 1925
Each day carvers climbed 700 stairs to the top of the mountain
90% of the mountain was carved using dynamite
During the 14 years of construction, not one fatality occurred
Timeline:
1923. December 28 - South Dakota State Historian Doane Robinson suggests a sculpture in the Black Hills.
1925. March 3 and 5 - Federal Government and South Dakota authorize a carving in the Harney National Forest.
1927. August 10 - First ceremonial drilling takes place at Mount Rushmore after President Coolidge hands Borglum a set of drill bits.
1941. March 6 - Gutzon Borglum dies in Chicago.
1941. October 31 - Final drilling takes place under the direction of Lincoln Borglum, the son of Gutzon Borglum. Mount Rushmore National Memorial was declared a completed project.
Images:
3 Gutzon Borglum inspecting work on nose of Washington.
4 Lincoln figure under construction. The face of Abraham Lincoln under construction on Mount Rushmore in 1936 with Gutzon Borglum monitoring the work.
5 Gutzon Borglum observes two workers carving Jeffersons eye
6 A driller uses a jackhammer drill to honeycomb the granite while carving Mount Rushmore. This was one of the final stages in removing the excess rock during the carving process.
7 Inside a winch house. Winch houses were built on top of Mount Rushmore during the construction. Workers in Bosun's chairs attached to steel cables would be raised and lowered by the winches while they worked on the carving.
8 A blacksmith sharpens drill steel in a shop located at Mount Rushmore. A blacksmith would sharpen as many as 400 drill bits in one day.
Learn more:
Jenny Jones. A Symbol of Democracy: The Mount Rushmore National Memorial
Civil Engineering Magazine, Vol 81, Issue 2 (2/2011)
https://doi.org/10.1061/ciegag.0000547
Mount Rushmore. History & Culture. The National Park Service (2022) https://www.nps.gov/moru/learn/historyculture/index.htm
đź“· LoC, NPS, Carol Highsmith. Public domain.