Ship Propellers

© Photographed May 28, 2015
Erected by Interstate Steamship Company, Bay Shipbuilding Corporation,
the Door County Maritime Museum, and the U.S. Coast Guard
Sturgeon Bay, Door County, Wisconsin

Ship Propellers
Much of the history of the city of sturgeon bay has been shaped by the comings and goings of all manner of ships and boats. The marine propeller played an important role as these vessels transitioned from sale to steam as their primary means of propulsion. Propellers continue to be an essential component in the propulsion system of most ships and boats plying in the Great Lakes today.

A propeller is essentially a type of fan that transmits power by converting rotational motion into thrust. A pressure difference between the forward and rear surfaces of the plane create thrust as water is accelerated behind the propeller. A marine propeller is commonly referred to as a screw propeller or screw.

Components of two very different size marine screw propellers are exhibited here. A single blade from the enormous propeller that once move the massive lake freighter Hon. James L. Obesrtar towers on your left. Launched on November 2, 1958 the Oberstar [sic] is 106 feet long and can carry over 32,000 times of cargo. Template you see here was one of five that bolted to a central hub to create a propeller over 19 feet in diameter. It was donated by the Interlake Steamship Company, owner and operator of the Oberstar [sic].

The smaller propeller to your right is cast in bronze as a single piece. This propeller is from the health master of US Coast Guard barge CGB-12002. A “thruster” is a small propulsion propeller specifically designed to push a vessel from side to side. Rather than being at the rear of the vessel, these smaller propellers are typically located in a tube-like structure built into the hull facing the side of the vessel.

The small propeller was donated by the US Coast Guard Cutter Mobile Bay. This powerful 140-foot icebreaking tug boat is configured to fit into a notch at the stern of CGB-12002 to form one of the Coast Guard’s largest bouy tenders.

The generosity of Interstate Steamship Company, Bay Shipbuilding Corporation, the Door County Maritime Museum, and the U.S. Coast Guard helped to create this exhibit.
The propellers and marker are located at Sawyer Park on South Neenah Avenue, south of its intersection with Oregon Street, Sturgeon Bay, Wisconsin 54235.

Click here to view all markers at Sawyer Park.

The marker and the propellers.

The marker is located at the Sawyer Park Boat Launch.

The marker is located at Sawyer Park in Sturgeon Bay, Wisconsin.

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