In 1872, the U. S. Corps of Engineers advertised for proposals to build a navigational beacon on the outer end of the Duluth Ship Canal’s south pier. Contractors built a wooden pyramidal tower and capped it with an octagonal cast-iron lantern housing a fifth order Fresnel Lens. The light, which cast a red beacon visible 12.5 miles away, was lit for the first time on June 2, 1874. In 1877 the light was upgraded with a fixed red fourth order Fresnel lens.
The western tip of Lake Superior was notorious for its extremely thick fog. In 1880 engineers installed an automated fog bell inside the light’s wooden tower, but it proved inadequate. Five years later it was replaced with twin steam-powered fog whistles housed in a small structure near the light. Duluth experienced one of the foggiest seasons on record in 1895, and the fog-signal whistle screamed for over one thousand hours, gobbling up forty-five tons of coal in the effort. The whistles not only sent a warning to mariners on the lake, they also bounced off Duluth’s rocky hillside, creating a cacophony most residents couldn’t bear. To remedy the problem, the signal’s horns were relocated to the roof and covered with a parabolic reflector. The reflector directed sound away from the city and nearly doubled the signal’s reach. The fog signal would be upgraded several times over the years.Building new concrete piers in 1900 meant tearing down their shaky old wooden counterparts—and everything on top of them. In June 1900 contractors began constructing the new lighthouse, a single-story Romanesque Revival-influence building forty-five feet long and twenty-two feet wide made of buff-colored Cream City brick. Capped with a red roof and featuring Roman arch windows, the structure contained a new fog signal outfitted with a steel parabolic reflector to keep the hillside quiet—yet like its predecessor the signal came to be both loved and despised by Duluthians. A tower sprouted thirty-five feet in the air from its east end; here workers installed a gallery deck and the old tower’s lens inside a new circular cast-iron lantern that gave it a range of twelve miles. On September 1, 1901, the new light guided mariners to the canal for the first time.
When the ship canal’s North Pier Light was constructed in 1910 it originally cast a white beam. Later both lights were changed to be navigationally appropriate: the south pier was fitted with a green light, and the north with a red. In 1915 the fog signal’s steam-powered twin whistles installed in 1901 were replaced by locomotive whistles, which in turn were replaced in 1923 by electrically powered twin Type F diaphone horns whose deep “Bee-Oh” tone could be heard for twenty miles. Almost immediately Duluthians complained. The horn was much too loud and rattled windows, disrupted conversation, and woke the sleeping. In 1968 the Coast Guard installed a much quieter single-tone horn. While some Duluthians rejoiced, others dearly missed the old horn’s deep toot and felt the City had lost part of its identity. They called the new signal a “peanut whistle.”
A nonprofit organization called TOOT (ReTurn Our Old Tone) worked to bring the deep-voiced signal back. They purchased another antique diaphone, renovated it, and installed it in the south breakwater light. TOOT maintained the horn using city funds and fired up the signal in June 1995. For the next ten years city councilors were besieged by letters both for and against the horn. Further, TOOT’s failure to both keep the horn operating and communicate with the city caused friction. In 2005 the city took over operation, but that fall the Coast Guard asked Duluth to stop using the horn as it interfered with fog detection equipment and confused mariners. On September 26, 2006, members of TOOT dismantled the horn. The Coast Guard’s peanut whistle still blows in foggy conditions: While most ships have radar and GPS navigation, many smaller craft do not.