International Dredging Review

International Dredging Review

In 2016 the U.S. Army Corps of Engineers St. Paul District celebrates its sesquicentennial (150th) anniversary. The district held a ball on February 13 at the Lost Spur Banquet and Conference Center in Eagan Minnesota. The district is also hosting a number of open houses around the district over the year to celebrate with the public and all regular events (summer awards party retirees’ reunion history day and annual open houses) will be 150th anniversary themed.

The St. Paul District also unveiled a new website celebrating the history of the district. It included a look at some of the districts oldest dredges.

In 1930 a nine-foot draft channel was legislated by Congress to increase commerce on the Mississippi River. The U.S. Army Corps of Engineers began construction of the series of 29 locks and dams between St. Louis and Minneapolis creating a stairway of water for river traffic which would need regular dredging.

The St. Paul District operated three hydraulic dredges in the 1920s and 1930s. The Vesuvius Peelee and Cahaba were responsible originally for the majority of the dredging done to maintain the channel. Other dredges used in the early days were the Dundee Taal and St. Croix. Many million cubic yards of sand and silt had to be dredged to establish the nine-foot channel and the old steam dredges were slow with the capability to move only 500000 cubic yards of material during a season. A new dredge with a far larger capability and modern equipment was needed to meet the challenge on the rivers.

Plans and specifications for a new more efficient hydraulic dredge began in 1935. It was to be named after William A. Thompson (b. Dec. 16 1854). He graduated from the University of Vermont with a degree in civil engineering in 1878 and entered federal service that same year with the Corps of Engineers. In 1896 he was appointed to the position of Assistant Engineer responsible for the improvements on the Upper Mississippi River. 

Built by Dravo Corporation in Pittsburgh Pennsylvania the dredge William A. Thompson was christened there in March 1937. A grand-daughter of William Thompson broke the traditional bottle on the hull. Construction cost was $846130. The new vessel arrived at the Corps Fountain City Wisconsin Service Base in 14 days arriving on May 22 1937.

hydraulic dredge Thompson was capable of extracting 1800 cubic yards per hour. The hydraulic pump was driven by a 1800 horsepower diesel engine; two 850 horsepower diesel engines generate electrical power to run the two 500 horsepower motors used for propelling the vessel. 

The Thompson was the biggest single piece of equipment used by the St. Paul District. It is 267 feet long from the tip of the cutterhead to its stern. It was 48 feet wide and had a minimum bridge-clearing elevation of 52 feet nine inches. It had a 22-inch intake and 20-inch discharge. The vessel could dredge to a depth of 26 feet and cut a channel 350 feet wide from one mooring.

In order to maintain a three-shift operation the 1370-ton dredge can carry up to 66 people for a four-crew complement to work 24 hours a day seven days a week. The Thompson normally dredged 1.5 to 2 million cubic yards each year. During the dredge’s first 50 years of service 102951300 cubic yards of material passed through its pump. 

The Dredge Thompson was replaced by the Dredge William L. Goetz which was christened on June 24 2005 at the Winona Levee Park in Winona Minnesota. The Thompson continued to serve as a quarters boat until 2008. In 2012 the Thompson was sold to Community Development Alternatives in Prairie Du Chien Wisconsin. It departed on its last voyage on June 12 2012 arriving at its new home the following day. CDA is working to preserve the Thompson and its rich history of service on the Upper Mississippi River. CDA is currently developing plans to convert the Dredge Thompson into a Museum of River Transportation.