01/16/2026
This picture from the 1920s shows the Sault’s Union Carbide plant. The hydro-electric powerplant, whose primary customer was the “Carbide,” is peeking out from behind. The Carbide plant began producing calcium carbide here in 1903 and purchased the powerhouse and power canal ten years later. Together, the powerhouse and carbide plant employed about 600 people at peak.
Calcium carbide is made from heating a mixture of slaked lime (calcium hydroxide) and coke. When water is added to calcium carbide, acetylene gas is produced. Acetylene was used in lamps before electricity was widely available and is still used in welding and many chemical processes. The lime came on ships upriver from Rogers City; some coal and coke came by rail from across the river, and some came by ship from several ports.
The calcium carbide produced was shipped in 100-pound drums, by ship in the early days, and by rail in the later years of operation. The waste material was piled to the south of the plant, at Easterday and Shunk. (This site is listed at epa.gov as Superfund Site MID980992457. Remediation seems to have been limited to a fence, soil cover, and a “vegetative cap,” in the early 2000s.)
We can see three different tracks in this picture. The ground-level track that crosses Portage Avenue is for the trains that bring the coal and coke we see piled all around. The higher track on the trestle that loops around the piles is for the trolley moving lime from ships in the harbor we see in the lower right corner of the picture. Finally, the track running down Portage Avenue is for the streetcar we can see, which transported many a worker to and from work.
The Union Carbide plant closed in 1963, after 60 years of operation. This closing hit the Sault hard, at about the same time as the closings of four other major employers: the Northwestern Leather Company (“the tannery), Cadillac-Soo Lumber Company, Soo Woolen Mills, and Lock City Machine & Marine.
The Carbide Dock Project is to revitalize the former dock and manufacturing site. The dock is now a deep-water port, enabling Sault Ste. Marie to host cruise ships. The site is supposed to feature a new seawall, boardwalk, and park.
Materna Collection neg. #208. Post by Collette Coullard
