team visited the Lock and Dam 5A warehouse in Fountain City, Wis., Nov. 15,
2013, to inventory a large pile of wooden patterns used for the Dredge William A.
Thompson, which served the district from 1937 to 2006.
Thompson, eligible for listing on the National Register of Historic Places, was
recently acquired by the Prairie du Chien Community Development Alternatives,
Inc. This group plans to convert the vessel into a museum of river
transportation highlighting the dredging machine itself, social aspects, the
national impact and its role in transforming the nation’s transportation system
and the river. A key part to this history is the patterns uniquely built for
are currently stored in wooden crates and stacked about two stories high in the
warehouse. They were previously stored in the ‘pattern’ building in Fountain
City until the building was demolished because of safety issues,” said Brad
patterns range in size from large to small. Some of them measure 12 feet in
length or diameter, while others are the size of a shoe box.
Spading, engineering and construction, said the patterns were used to make
replacement parts for the large machinery on the vessel. Inventory sheets
showed that some patterns were frequently shipped off to be cast, while others
were not used at all. “When a replacement part was needed for the Dredge
Thompson, another vessel, or one of the lock and dams, the pattern was shipped
to a foundry,” he said. “The foundry made a mold by placing the wooden pattern
into a mixture of sand and clay for casting. The mold was then filled with
molten metal, left to cool, and the metal part was extracted, finished and
readied for return shipment.”
plans to finish cataloging all of the patterns before shipping to Prairie du
Chien, Wis., to reunite with the vessel.