Voith Tug

A Voith-Schneider tractor tug. These vessels use an ingenious drive system invented by Austrian engineer Ernst Schneider, and were first installed on a boat in 1928. The vertical blades revolve in a circle like a merry-go-round, and twist to push water when they reach the right point in the circle. The driver can adjust the angle of thrust almost instantly using a wheel and levers in the wheelhouse.

Tractor tugs like this one can push and pull like a conventional tug, but also have the ability to slow or turn a fast moving ship by pulling at sharp angles while attached to the stern of the ship. This method uses the large fin under the tug, called a skeg, as a rudder or brake.

The model for this drawing is the Lindsey Foss, which along with its sister ship, the Garth Foss, works as an escort tug in the north Puget Sound, particularly in Rosario Strait near the San Juan islands, and in the Strait of Juan de Fuca.

I will be outlining the function and design of these tugs in my upcoming book Working Boats: Safety, Salvage, and Rescue.

There will be 500 signed, numbered prints in this limited edition.

Artist: Tom Crestodina