I've just acquired a book published in 1959 which states that some West Coast areas use 50Hz supplies and that parts of upstate New York have 25Hz power.

Now I know from discussions here in the past that the Los Angeles area once had 50Hz power but switched to 60Hz in the 1930s, but just how many other areas used something other than 60Hz?

And were 50 and even 25-Hz systems really still in use as recently as the late fifties?

Paul, not for certain, but I do not think it is possible for anything other than 60. Reason being is the interconnected grids throughout the country.

I wired up a factory that made equipment for export.

Had two 50 hz generators. They were actually 60 hz electric motors belt driving 50 hz generators.

Also had single pole double throw type switches so they could switch between power sources at the same test station. Each test station was 400 amp using camlocks.

I recall no differences in wiring size or wiring methods or anything like that.

Not a whole lot of information here, I just wanted to make you aware that 50 hz is used in house for testing purposes.

And lots of facilities that work with aircraft or military electronics have 400 Hz power available, usually via a motor-generator set.

Pensylvania Railroad used 11000VAC @ 25Hz for electric traction with the GG-1 electric locomotives. Don't know if this is still the case today

Some West Virginia coal mines used power around 25 Hz as late as 1952 when my grandfather was a mine electrician. He later described his work to me. Some of the small towns next to the mines were powered the same. He said the flicker in the incandescent lights was visible.

There are Two main HIGH voltage distribution systems in the USA. Direct Current and 60 HZ.
As was mentioned by dereckbc, the USA is on two Grid systems, East and West, and MUST be 60 HZ. If a given generation plant starts to deveate from the 60 HZ, the others pull it back. Individual Facilities may have converters to different frequancies for their operation, but the UTILIT grid is always 60 HZ. Outside the USA, I have found only 50 and 60 HZ from Utilities, with some countries having both.

Grids having to be synchronized is a good point, but could it be that back in the 1950s there were still some small areas which were not connected into statewide and national grids but just had a few power stations running a local network?

In England at this time, there were some cities in which the older, downtown districts were still running on their original DC distribution systems fed from a local power plant, even though outer, newer areas had been interconnected to the grid to get AC power.

That sounds very much like a local power plant along the lines I'm thinking about. Didn't many of the small mining places in WV start out as company towns? It seems quite probable in such a case that the mining company might have installed local generators to their own standards for the whole town.

25Hz was also used on some railroad lines in Britain in the past. The 25kV AC power supplied for all the main electrified lines these days is 50Hz though, with substations providing power from the main national grid.

AFAIK, there are more separate grids.

I know for a fact the Quebec and Southern Ontario grids are separate, and I heard Texas is practically on their own grid.

On the whole, I think the separte grids may be:
Quebec/eastern Canada.
South Ontario/Northeast US
South East US
Texas
Midwest US
Western Canada
Western Seaboard (including BC).
Alaska is probably a whole separate grid, and of course Hawaii will be too.

Here a link you may find interesting:
http://services3.ieee.org/organizations/pes/public/2003/sep/peshistory.html

That's an interesting article. It confirms that the Buffalo/Niagara region of NY did have 25Hz generators, but I wonder how late regular residential loads were actually being supplied at that frequency, and not at 60Hz via converters?

By the way, the book I mentioned at the start is actually on model railroad wiring. This is the third edition, with the first out in 1950, so it's possible that things had changed in those few years as grids were expanded and developed.

I guess there's also the possibility that the generators were only feeding into the 60Hz converters by that time but somebody just got the wrong end of the stick.

I worked on a railroad in Duluth MN and we had 25 cycle power into mid 1980's. Both 25 and 60 cycle were supplied by the utility. I was on the crew that had to eliminate the need for 25 cycle as the utility was discontinuing it. I don't know how they generated it on their end but we had two 13.8kv loops on our property.

Paul, there some states that are not connected to the US grids. This is a result of the New York blackouts back in the 60's. Howevewr it does not mean they are intercconected.

When I worked for a utility in Oklahoma we interfacerd with Texas utilities via DC. We entered the yard at 138KV AC, rectified to DC, had a bus to the the Texas utility, they inverted back to 138KV AC all in the same substation.