Duluth is a port city in the U.S. state of Minnesota and the county seat of St. Louis County. Located on Lake Superior in Minnesota's Arrowhead Region, the city is a hub for cargo shipping. The population was 86,697 at the 2020 census, making it Minnesota's fifth-largest city. Duluth forms a metropolitan area with neighboring Superior, Wisconsin, called the Twin Ports. It is south of the Iron Range and the Boundary Waters Canoe Area Wilderness. It is named after Daniel Greysolon, Sieur du Lhut, the area's first known European explorer.
A transporter bridge, also known as a ferry bridge or aerial transfer bridge, is a type of movable bridge that carries a segment of roadway across a river. The gondola is slung from a tall span by wires or a metal frame. The design has been used to cross navigable rivers or other bodies of water, where there is a requirement for ship traffic to be able to pass. This has been a rare type of bridge, with fewer than two dozen built. There are just twelve that continue to be used today, including one converted into a lift bridge and one designed as, but not yet operating as, a transporter bridge.
The Duluth MN–WI Metropolitan Area, commonly called the Twin Ports, is a small metropolitan area centered around the cities of Duluth, Minnesota and Superior, Wisconsin. The Twin Ports are located at the western part of Lake Superior and together are considered one of the larger cargo ports in the United States. The Twin Ports are close to many natural attractions such as the North Shore, the Apostle Islands, and the Superior National Forest.
The Montlake Bridge is a double-leaf bascule bridge that carries State Route 513 over Seattle's Montlake Cut—part of the Lake Washington Ship Canal—connecting Montlake and the University District.
Dr. John Alexander Low Waddell was a Canadian-American civil engineer and prolific bridge designer, with more than a thousand structures to his credit in the United States, Canada, as well as Mexico, Russia, China, Japan, and New Zealand. Waddell’s work set standards for elevated railroad systems and helped develop materials suitable for large span bridges. His most important contribution was the development of the steam-powered high-lift bridge. Waddell was a widely respected writer on bridge design and engineering theory, as well as an advocate for quality in higher education engineering programs. The company he founded in 1887, 'J.A.L. Waddell, Consulting Engineer,' would eventually become the modern day Hardesty & Hanover, a leading moveable bridge engineering firm. Many of Waddell's surviving bridges are now considered historic landmarks.
Split Rock Lighthouse is a lighthouse located southwest of Silver Bay, Minnesota, US on the North Shore of Lake Superior. The structure was designed by lighthouse engineer Ralph Russell Tinkham and was completed in 1910 by the United States Lighthouse Service for $75,000, including the buildings and the land. It is considered one of the most picturesque lighthouses in the United States.
The Stillwater Bridge is a vertical-lift bridge crossing the St. Croix River between Stillwater, Minnesota, and Houlton, Wisconsin. It formerly connected Minnesota State Highway 36 and Wisconsin Highway 64. Around 18,000 vehicles crossed the bridge daily. The new St. Croix Crossing bridge crossing the St. Croix river valley to the south of Stillwater replaced its purpose, having opened to highway traffic on August 2, 2017, leaving the Stillwater Lift Bridge to be preserved and to be converted to bicycle/pedestrian use.
The Sky Ride was an attraction built for the Century of Progress 1933 World's Fair in Chicago, Illinois. It was a transporter bridge designed by the bridge engineering firm Robinson & Steinman that ferried people across the lagoon, Burnham Harbor, in the center of the fair. It was located near Northerly Island, but was demolished after the Fair, having carried 4.5 million passengers. The Sky Ride had a 1,850-foot (560 m) span and two 628-foot (191 m) tall towers, making it the most prominent structure at the fair. Suspended from the span, 215 feet (66 m) above the ground, were rocket-shaped cars, each carrying 36 passengers.
The Prescott Drawbridge, also called the Point Douglas Drawbridge, is a steel girder bridge with a double-leaf bascule drawbridge section. The roadbed of the drawbridge span is a steel grate. The bridge carries U.S. 10 across the St. Croix River and connects Prescott, Wisconsin, with the Point Douglas park area of Denmark Township, Minnesota. This is the only highway drawbridge in the Minneapolis–Saint Paul area with active traffic. It was completed in 1990 and replaced a rare regional example of a Waddell & Harrington vertical-lift bridge completed in 1922 that operated as a toll bridge from 1923 to 1946. The environmental impact statement, published in 1979, considered a higher level fixed bridge at this location.
The Historic Caddo Lake Drawbridge, also known as the Mooringsport Bridge, is a vertical-lift bridge that is listed on the U.S. National Register of Historic Places. It was built in 1914, to replace a ferry, by the Midland Bridge Company of Kansas City, Missouri, under authority of the Caddo Parish Police Jury. The lift span has been inoperable since the 1940s.
Claude Allen Porter Turner was an American structural engineer who designed a number of buildings and bridges, particularly in the midwestern U.S. states of Iowa, Minnesota, and Wisconsin.
Minnesota Point, also known as the Park Point neighborhood of Duluth, Minnesota, United States; is a long, narrow sand spit that extends out from the Canal Park tourist recreation-oriented district of the city of Duluth. The Point separates Lake Superior from Superior Bay and the Duluth Harbor Basin.
The St. Paul Union Pacific Vertical-lift Rail Bridge is a vertical-lift bridge that spans the Mississippi River in downtown St. Paul, Minnesota, United States. It is one of only three vertical-lift bridges along the Mississippi River, along with the Hastings Rail Bridge in Hastings, Minnesota, and the Wabash Bridge in Hannibal, Missouri. It was designed by Waddell & Harrington and built in 1913. In 1925, the north end of the bridge was raised about 16 feet (4.9 m) to tie in with tracks that served the St. Paul Union Depot yard. The vertical-lift span has 105-foot-high (32 m) towers, and the electrical lift system was built with a possible 45-foot (14 m) elevation. However, by 1973, the amount of lift was reduced to 37 feet (11 m) because of aging of the equipment.
The Armour-Swift-Burlington (ASB) Bridge, also known as the North Kansas City Bridge and the LRC Bridge, is a rail crossing over the Missouri River in Kansas City, Missouri, that formerly also had an upper deck for automobile traffic.
The Lake Superior Maritime Visitor Center is a museum in Duluth, Minnesota, operated by the United States Army Corps of Engineers.
The Canal Street railroad bridge is a vertical-lift bridge across the south branch of the Chicago River in Chicago, Illinois. It was designated a Chicago Landmark on December 12, 2007.
Snowden Bridge is a high-clearance, vertical-lift railroad bridge, built in 1913, that spans the Missouri River between Roosevelt and Richland Counties in Montana, USA, between Bainville and Fairview, Montana, and near Fort Union Trading Post National Historic Site and the ghost town of Mondak near Montana's eastern border with North Dakota. Snowden Bridge is a near twin of the Fairview Bridge, which crosses the Yellowstone River in North Dakota, both bridges having been built by Montana Eastern Railway within 10 miles (16 km) of each other over different rivers in different states.
The Duluth Ship Canal is an artificial canal cut through Minnesota Point, providing direct access to Duluth harbor from Lake Superior. Begun privately in 1871, it was put under federal supervision and maintenance several years later. It is still an important component of the harbor facilities.
