[BC] Radio engineers become steam engineers

[David Reaves]

Hi, Dave!
The physics behind a steam locomotive isn't entirely foreign to those
with RF or AC knowledge.

The typical steam engine's left and right side wheelsets are driven
in quadrature (90 degrees out of phase) to each other, with the each
side's piston alternately providing positive and negative force every
cycle. Just like sines and cosines. (But no, they do not designate
one side's wheels as 'real' and the other 'imaginary.')  :-)

The locomotive designers refer to this as 'quartering' the wheels
(because one set of wheels is rotated a quarter-turn, 90 degrees,
from the other set). Getting even a few degrees 'out of quarter'
would be a serious problem as the locomotive could get in a position
where the wheels are locked and won't move in either direction.

By carefully applying the proper amount of force (steam) synchronized
at exactly the right phase, the locomotive can be worked at its
highest efficiency for a given torque requirement. Not totally unlike
a Class C amp working at "cutoff" (coincidentally or not, the same
term 'cutoff' is used for locomotives to designate at what point in
the rotational phase and for how long the power should be applied).

Mr. Foti, being the owner of a real live, fire-breathing steam
locomotive might have something to say here...

On Sun, 25 Mar 2007 08:18:09 EDT, Hultsman5 at aol.com wrote:

>FYI  FROM BIRMINGHAM, AL
>
>Gentlemen,  Claude Gray is still alive and kicking.  I last saw
>him at a
>Birmingham Hamfest Flea market.  About five years ago I ran into
>him at the
>Birmingham Zoo.  He was operating the steam engine of the Zoo
>Railroad there.  He
>actually had a license to operate a steam engine.   The Zoo has since
>replaced the steam engine with a gasoline model and he  declined
>the engineers job.
>The steam train was moved to the Heart  of Dixie Railroad Club with
>lots of
>track in Calera, AL.  They were having  alot of trouble getting it
>timed
>correctly.  Claude came in and tuned it  right up.
>
><snip>