Duluth’s City Engineers
After reading about Ferdinand Arnodin’s aerial transfer bridge in Rouen, France, Duluth City Engineer Thomas McGilvray at once recognized the potential of a similar bridge over the Duluth Ship Canal. In 1899, the same year the French bridge was completed, McGilvray sat down at his drawing table and began adapting Arnodin’s plans for the Duluth Ship Canal. City officials loved it.
Born in 1863 in Aberdeen, Scotland, McGilvray attended private schools and earned an engineering degree at the University of Edinburgh. In 1884 McGilvray emigrated to North America, where he began his career as a surveyor for the Canadian Pacific Railroad in Calgary, which eventually lead to a job with the St. Paul & Duluth Railroad. Working for the StP&D, McGilvray laid the foundation of the1892 Duluth Union Depot and designed the street layout for Smithville and portions of West Duluth owned by the railroad.
McGilvray moved to Duluth in 1890, employed with the firm of Patton & Frank, which was owned in part by former city engineer William B. Patton. When Patton again became Duluth’s City Engineer in 1893, McGilvray began a private practice. In 1897 McGilvray replaced Patton as Duluth’s City Engineer. The move came not because McGilvray was necessarily a better engineer than Patton, but that he was a Democrat. At the time, Duluth’s mayor appointed most city officials, and from 1890 to 1908 whenever a Democrat was in office, McGilvray held the job; when a Republican became mayor, Patton took over as city engineer. During this time the pair also joined forces, creating the Duluth Engineering Company.
Patton took over the bridge project in 1900 when Republican Trevanion Hugo became mayor. Born in Philadelphia in 1860, Patton was living in Duluth by 1885. Prior to his work on the bridge, his most public engineering accomplishment was designing the Lakewood Pump House, which still provides Duluth with its clean drinking water. Patton was also a noted Mason, one of four charter members of the King Solomon Temple of England; the other three were former presidents Teddy Roosevelt and William Howard Taft and General Thomas J. Shryock, one-time treasurer of Maryland. Patton had served as the grand master of the Minnesota Grand Lodge, and at his death in 1923 he was considered “one of the leading Masons in the world.”
McGilvray lived to see the bridge converted and again served as city engineer from 1933 to 1941, living in retirement until his death in 1957. A year before McGilvray died, a Duluth Herald reporter asked the old engineer about both his transfer bridge and “that up-and-down gadget” that replaced it. “It’s been a good bridge,” he told the reporter, “But some day it will have to go. Every bridge runs itself out of business.” He was referring to the fact that bridges eventually become obsolete due to changes in use: Either the bridge is no longer required or can no longer handle the loads, whether it be increased traffic or increased weight. “I knew that when I built the aerial bridge,” he said. “So I can’t say I’m sorry to see it reaching the end of its usefulness. I’m pleased that it served as long as it has but you can’t allow sentiment to stand in the way of progress.” The newspaper’s headline was a bit dramatic: “Says Its Builder: City’s Famed Bridge Doomed.”
Aerial Bridge Designer “CAP” Turner
Before Duluth city engineer Thomas McGilvray presented his idea for an aerial transporter bridge to Duluth city officials, he needed to know if such a bridge would work in Duluth’s cold climate. And McGilvray was a road engineer, not a bridge engineer. Fortunately, in 1899 bridge engineer Claude Allen Porter was working in Minneapolis at the time. Turner, born in Rhode Island in 1869, graduated from Lehigh University’s School of Engineering in Bethlehem, Pennsylvania, in 1890. After working for several companies in the eastern U.S., Turner moved to Minneapolis in 1897 to take a job with the American Bridge Company (ABC).
McGilvray reached out to Porter, asking whether he thought the idea would work. Porter replied yes—with some alterations. Duluth’s canal was often windy and its waters icy in the winter. Porter’s idea was to not build a suspension bridge, but rather a stiff-girded bridge that held up to wind. Its gondola car would not be suspended by cables, which would allow the car to swerve in the wind, but also by stiff steel girders. Finally, there would be no submerged chain, which could easily ice over and interfere with shipping traffic. Instead Turner would devise an overhead “traveling pulley.” Porter’s design would make the Duluth bridge unique: The first transfer bridge built in the western hemisphere and the first stiff-girded transfer bridge ever constructed.
In 1901, while working on Duluth’s aerial bridge, Turner formed his own firm after ABC became a subsidiary of United States Steel. During his career Porter received over thirty patents for using reinforced concrete, including “mushroom cap” columns, first used in St. Paul’s 1911 Lindeke-Warner Building. His other notable designs include the Mendota Bridge between Fort Snelling and Mendota Minnesota (once the longest continuous concrete-arch bridge on the planet), the 2,730-foot Arcola High Bridge (aka the “Soo Line High Bridge”) spanning the St. Croix River north of Stillwater, Minnesota, and the the Liberty Memorial Bridge between Bismarck and Mandan, North Dakota.