Duluth South Breakwater Outer Light

The appropriation which paid for the initial construction of this light was made in 1870, with the intent to build a structure at the end of the Northern Pacific Railroad docks.[5] Storm damage, however, delayed construction until 1872, by which point the canal had been dug.[5] A wooden pyramidal tower was erected, initially equipped with a fifth-order Fresnel lens.[4] An elevated walkway led back down the pier; a frame dwelling for the head keeper was constructed nearby, with the assistants required to look for lodging elsewhere in the city. This tower was first lit in 1874.[4][5]

The area is notoriously foggy, and an automated bell taken from the South Manitou Island Light—the first in a long series of fog signals—was installed in 1880.[5] This was replaced by a pair of steam-powered whistles in 1885, housed in a newly constructed shelter on the breakwater.[4] The noise from these whistles brought complaints from city residents, so a parabolic reflector mounted in a sawdust-filled box was installed in a successful effort to direct the sound out towards the lake.[4] Fog signal operation, it may be noted, averaged 472 hours a year for the first ten years of operation; in 1895 the whistles blew for 1,048 hours, an average of over four hours a day over the eight-month season.[4][5]

In 1886 the lens was upgraded to a fourth-order Fresnel lens, and the characteristic changed from a red and white flash to a fixed red signal.[5]

The late 1890s reconstruction of the ship canal resulted in the replacement of this tower and the fog signal house with a single brick lighthouse containing both signals.[5] This house, constructed of Cream City brick, was completed in 1901, and the new tower was first lit on September 1 of that year.[4] This tower stood on the southeast corner of the rectangular building, and housed the lens retained from the old light; the fog whistles and their reflector were also moved from the old structure to the new.[4][5] The latter were replaced in 1915 with locomotive whistles,[4] and in 1921 with Type F diaphones, setting off another round of noise complaints, which led to the installation of a new sound reflector. The diaphones were replaced in 1968 with an electronic horn,[4] but in 1976 a group styling itself TOOT (for "reTurn Our Old Tone") began a campaign to restore the fog signal.[5] Horns from the Kewaunee Pierhead Light were obtained,[4] and in 1995 the diaphones were put back in service, eliciting, of course, a new round of noise complaints, which led to restriction of the signal to daytime operation.[5] The signal required a three-phase current supply for operation, and when this failed in 2005, the Coast Guard refused to pay for repairs; legal concerns led the city to refuse to pick up the tab, and the signal was dismantled the following year.[5] The light, however, continues in service, displaying a fixed green light.[2]

The South Breakwater Outer Light was listed on the National Register of Historic Places in 2016 for its local significance in the themes of engineering, maritime history, and transportation.[6] It was nominated for its association with federal efforts to establish nationwide navigational aids, and for being characteristic of early-20th-century harbor breakwater lights built around the Great Lakes.[7]

• List of lighthouses in Minnesota
• National Register of Historic Places listings in St. Louis County, Minnesota

• Media related to Duluth South Breakwater Outer Light at Wikimedia Commons