This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This odd steam-powered three-wheeler was successfully titled as a motorcycle upon completion by its builder, Huntington Beach, California-based aviation mechanic Fred Hensel. The seller believes it was built in the late 40’s or early 50’s, and included expired California registration documents date from as late as 1966. Bodied from riveted aluminum in aircraft style, the seller says that the level of craftsmanship and engineering quality on display is very impressive, and though it’s been driven around on compressed air, the ad includes a disclaimer that no one should attempt to build pressure in the system as it exists–fair enough considering no one seems to know when it last ran under its own steam. Find it here on eBay in Rockaway Park, New York with reserve not met.
Reads the ad: “This is a fascinating, completely hand made, one of a kind steam motorcycle. I believe it was built in the 40’s by an aviation mechanic in California named Fred Hensel. It is not getting the attention it deserves in my small collection, and it has to be seen to fully understand what a mechanical work of art it is. It has rack and pinion steering, a two-part fold-up steering column, which folds up, and away, for entry into the vehicle. You could write a book on all of the insane engineering that went into it. The detail and craftsmanship that this man put into this vehicle is mind boggling. Anything that could me made by hand, was.”
Here’s a look at the rear, which appears to incorporate a second, similarly narrow rectangular door as the front left corner. Reportedly there’s a sunroof as well.
The seller’s steam knowledgeable friends have looked over the vehicle, and it’s believed to run on solid fuel–i.e. wood, coal and the like rather than propane or other gasses. More of their assessment is quoted in the ad: “The four pedals on the floor are, from left to right, parking brake, clutch, service brake (not connect to the master cylinder) and steam valve. Water is supplied to to the boiler by electromechanical injector pump. It is believed to be timed by an electrically driven cam operating a switch. Stepping on the right pedal will open the valve to the engine. To start the engine the piston must be in the middle of it’s stroke. To achieve that goal a lever has been built in on the chain sprocket. Moving the lever from side to side will bar the engine to starting position. It is an induced down draft with the chimney at the bottom. The blower is regulated by a rheostat. A damper controls airflow on both exhaust and intake.”
The inside is a mess of levers, pedals (four of them!), petcocks, taps, dials, hoses, and other improvised fittings. We’re not sure how it’d be driven, but engineering and construction were undoubtedly a labor of love for Mr. Hensel, and it’s simply cool to see that his contraption has survived.