Hello, Steven,

Today they are--sort of. There are actually three different "grids" that
free-wheel in respect to each other. There is power transfer across these
boundaries by using DC transmission lines (large AC-->DC and then DC-->AC

In the interim report on the Aug 14, 2003 blackout, there is a good
overview of this

I'm not sure how accurately this was done system-wise in 1963. I do recall
in that era two clocks in power control rooms. One running off NBS time,
the other running off the grid. They needed to agree once a day.

There have been various reports about how much the power drifts and what is
the power company commitment to average it out to precisely 60.000... Hz.



At 03:05 PM 3/5/2004 -0500, you wrote:
>----- Original Message -----
>From: Richard L. Hess
> >I guess, at least that day, the 60Hz in St. Louis was pretty much spot on!
>Aren't all the electrical systems in North America synchonized at an exact
>60Hz, in order to avoid various spectacular results when they are
>(which is often the case)? I have ni idea how this is done, but I think I've
>been told it was/is done...
>Steven C. Barr