CLEVELAND — The Coast Guard announced, Wednesday, a proposal to remove the Fresnel Classical Lenses from two lighthouses in Duluth, Minnesota, this fall in partnership with the Minnesota State Historic Preservation Office.
The two lighthouses affected are the Duluth Harbor South Breakwater Outer Light and Duluth Harbor North Pier Light. The Fresnel Classical lenses would be replaced with modern light emitting diode lanterns which are more dependable and energy efficient.
Replacing the lenses will reduce the range of the lights slightly. The Duluth Harbor South Breakwater Outer Light would be reduced from about 16 nautical miles to 13 nautical miles, and the Duluth Harbor North Pier Light would be reduced from 14 nautical miles to 10.5 nautical miles.
The lenses would be removed in order to preserve them. Due to the harsh environmental conditions, including temperature fluctuations and ultraviolet rays, the lenses slowly deteriorate. Once removed, the lenses would be loaned to a local museum so they can be displayed to the public and maintained in a controlled environment.