On 2010-06-14, Jon Elson wrote:
I was at the local ice cream place that is adjacent to one of the local
train tracks.
The Amtrak pulled up to exchange passengers at the nearby station. A
bit after it stopped, I heard a very familiar and unexpected sound.
It was a large air compressor driven by a 60 Hz 3-phase motor. I'd
guess from the sound it very well could be a Quincy, and I'd guess maybe
15-25 Hp 4-cyl 2-stage, with pneumatic unloaders.

Anyway, it struck me as just a tiny bit odd they'd use an electric
compressor, as they have mechanical power available off the Diesel engine.
I also noticed the Diesel didn't seem to change speed when the train
accelerated, so I'm guessing they run a single engine at 60-Hz
synchronous speed all the time, so they can distribute 60-Hz power for
air conditioning, etc. to the coaches. So, no aux engine for the
non-traction power.

Anybody know anything about this?

I personally think that it is very smart to run the train's compressor
from an electric motor. After all, the compressor needs to run only
very intermittently, to charge the braking system and such.

No idea on constant 60 Hz from the main motors, but if this is done, I
would think that it is fantastic for a passenger train that needs a
lot of auxiliary power.

i

i