Steam boating in the Otter

• Approximate weight empty 1100 lb.
• 19' LOA, 5' beam, draws 18".
• Carries 4, 5 in a pinch
• top speed 6.0 knots, cruises at 5 knots @ 100 psi.
• fuel capacity 6 gallons, makeup water 10 gallons
• Hull built by Bill Gruenwald of Aeolus Boats, Davenport, CA.
• Hull is fantail skip jack.
• built of Douglas fir plywood and mahogany, copper & bronze fastened
• decks are painted canvas
• Barbie and I built the engine, boiler & canopy.
• We've used the Otter in lots of beautiful places, including
• Sacramento River Delta, CA
• Donner Lake, CA.
• Lake Tahoe, CA.
• Devils Lake, OR.
• UpperKlamath Lake, OR.
• Nehalam River, OR.
• Victoria, BC
• Lopez Island, WA.
• Boiler is my impression of a Lune Valley design, including:
• 54 coils of 1/2" copper tubing, silver soldered into
• 108 3/8" pipe nipples welded into
• central pressure drum welded from 7" pipe with
• 7" pipe cap on the bottom and
• reducer to 4" pipe on top for a steam dome.
• The boiler has a 180 psi safety and was hydrotested to 400 psi.
• Boiler receives yearly hydrotest to 300 psi.
• Fueled with diesel in a steam atomizing burner.
• boiler is started using propane to atomize diesel until 10 psi is reached.
• Burns 1 to 1.5 gallons/hour of diesel at 5 knots.
• Here's more info on the Otter's boiler.
• Engine is a converted industrial GE refrigeration compressor.
• bore and stroke 2" x 2.5", twin cylinder single acting
• D-valve, 80% cut-off, ball bearing slip eccentric for reverse.
• Crankcase runs flooded with water; I do add a small amount of 600W steam cylinder oil to keep the bearings happy.
• Engine pictures are HERE.
• Various smaller components are interesting as well:
• Here's a sketch and some description of the steam pressure regulator I made following Allan Gregg's design.

Steamboat information

•  Northwest Steam Society
•  www.steamboating.org
•  The Steam Boat Association of Great Britain (SBA)
•  Rainer Radow's Steam Boat Page, Since 1994