50 HP Fairbanks Morse, II

This 50HP Fairbanks-Morse engine, built in 1911 and installed at historic Mt. Wilson Observatory in 1912, was for many years the only source of power at the Observatory campus. It's "a twin cylinder gasoline fueled engine, directly coupled to a generator capable of producing 40 kilowatts of power at 125 volts DC." There's more about the engine here and here.

 

We got our tour courtesy of Ken (L) and Larry (R) Evans, who've been keeping the engine running for more than 15 years.

Ready, set...let's see what this baby can do.

A brief view from the other side.

Not everyone gets excited about it. But a lot of us do.

The Fairbanks Morse engine is in a restricted area of the Observatory campus, but the Observatory itself is open to the public every day, 10am-5pm, as long as the roads are open. The Cosmic Cafe is open on weekends from April through November. Guided tours of the Observatory are available on weekends, or by reservation. You can even reserve one of the telescopes for a star gazing party! Or a photo shoot! Or an anniversary party! Or a wedding! I'm pretty sure there's not a more unique location, at least not within driving distance of my house.

11/23/15 update from Ken Evans (left, above): 

"If that lizard got onto the running flywheel, it would have to go 60 miles per hour to stay in one spot. Just a little trivia I once figured out.

"I am draining the water out of it tomorrow, Tuesday Nov 24 for the winter. Freezing nights are predicted for several days and we don't want to damage anything on such a treasure.  So the show season is over. Of course it can be looked at, just not run."

11/26/15 Here's another update from Ken Evans, and let's all thank him and Larry; they've been so helpful and informative and that's what makes this fun.

"Electricity Now and Then -  The AC electricity for Mt Wilson is supplied by SoCal Edison. In the Power House where the Fairbanks-Morse engine is located the DC is provided by solid state rectifiers and distributed from there. Originally DC was provided by various sizes of internal combustion engines. The F-M being the last. It was really a battery charger. There was a room with glass jar wet batteries and were charged during the day. At night the batteries were used which provided non polluting quiet power that astronomers liked. When AC power came to the Observatory in 1917, an AC motor driving a DC generator was installed and the F-M was a back-up. We are not sure if the AC-DC motor set was used to charge the batteries or ran all the time.

Fuel Oil -  A fuel oil called California Distillate was used as the source of heat. It is lighter than kerosene maybe like paint thinner. A large storage tank was set on a high spot and distributed to Day Tanks at various facilities by gravity. The Fairbanks-Morse engine was run on it. However, we use gasoline now for the demonstration runs. They had to start it on gasoline and then switch over to the distillate. It had to be delivered up the Toll Road but no reference has been found about delivery.

A lot of propane is now used at Mt. Wilson for heating and cooking.

Engine Running -  The engine had to be run during winter because it was the main power source. So freezing was not an issue. The combustion air intake can come from three sources. First is outside air, then room air and last, a shroud around the exhaust manifold would provide warmed air. We only use outside air. We only run the engine for demonstration during the summer. We have another volunteer that has figured out the generating system and we have generated electricity to run a light bulb and a motor for compressed air for starting. We have a modern air compressor for starting now. One cylinder of the two is converted to run on air to start the second cylinder and then converted to produce power from both.

Water -  Water for Mt. Wilson is obtained from wells near by. But because of the drought, they have gone dry and water is trucked in."