The W.T. Preston's steam-powered engines were first installed on the Swinomish in 1914, then transferred with most of the machinery to the new wood-hulled W.T. Preston in 1929, and to her steel-hulled replacement in 1939.
Originally fired with cordwood, the steam boiler was later converted to burn heavy fuel oil. Modern burners, installed in 1967, used lighter diesel fuel, greatly improving combustion and reducing air pollution.
Typical operating speed in smooth water was 6 to 7 knots and, in mildly rough water, 3 to 5 knots. The paddlewheel churned at 16 revolutions per minute in normal cruising.
W.T. Preston Snagboat
The U.S. Army Corps of Engineers operated steam-powered sternwheeler "snagboats" in rivers from Blaine to Olympia, to keep the region's tributaries clear of navigational hazards. The W.T. Preston was the last of the sternwheelers.
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At right, the W.T. Preston is seen steaming across Puget Sound. The flat bottom and shallow draft of sternwheelers such as the Preston let them go far upriver but made them unsuited to the choppier waters of the open sound.
Photo courtesy of the Anacortes Museum, Wallie Funk Collection.
The diagram at far right shows the basics of sternwheel operations. It is by Ronald R. Burke from his book "Heritage of a Snagboat: Story of the W.T. Preston."
The photo below at far right shows a crewman watching the main boiler of the W.T. Preston. The boiler provided steam to power the Preston's stern paddlewheel.
Photo courtesy of the Anacortes Museum