Old Tacoma Marine, Inc.

tugboat Arthur Foss

tugboat Arthur Foss's antique Washington Iron Works diesel engine, installed in 1934.  The tug is now owned by Northwest Seaport, a non-profit maritime museum.
Model #: 6-24 Engine #: 7347
Bore & Stroke: 18" x 24" Cylinders: six
Horsepower: 700 RPM: 200
Current Owner: Northwest Seaport link
Current Location: Seattle, Washington map
Condition: Operational

Engine History

Five years after the Foss Launch and Tug Company purchased the steam tug Wallowa, they rebuilt her from the hull up into a modern diesel tug. Renamed the Arthur Foss after the 1934 conversion, the rebuilt tug was powered by one of the largest Washington Iron Works diesel engines ever built. With six 18" x 24" cylinders that generated between 700 and 900 horsepower, the engine made the Arthur one of the most powerful tugs on the West Coast.

More about the Arthur Foss's antique engine

Recent news

December 2007: the Arthur Foss's throw-out bearing was repaired during the 2007 Diesel Engine Theory Workshop, hosted by Northwest Seaport in partnership with the Center for Wooden Boats and Old Tacoma Marine Inc. Everett Engineering Inc. rebabbitted the bearing, returning it to operational condition and allowing the Arthur's propeller to be engaged for the first time since 2001. Read more about this project at Northwest Seaport's website here.

Engine Modifications

  • uses an Atlas-Imperial fuel pressure regulator
  • has new-style heads on cylinders two through six, with two studs and a collar instead of one big castellated nut to hold the valve cages
  • has a zerk fitting or 1/8-inch pipe tapped hole in each new tappet guide
  • External Links

    Northwest Seaport's Arthur Foss page
    National Historic Landmark Nomination for the Arthur Foss
    Engine Workshops on the Arthur Foss
    Videos of the Arthur Foss's engine on YouTube
    Photos of the Arthur Foss's engine on Flickr
    Blog entries about the Arthur Foss on WordPress