TELECOM Digest OnLine - Sorted: Re: 25 Hz railroad power--book recommendation

Re: 25 Hz railroad power--book recommendation

T (
Tue, 14 Mar 2006 17:54:05 -0500

In article <>,

> I see there was a lot of interest in power distribution. There's an
> excellent book that covers the history of electric propulsion on steam
> railroads, "When the Steam Railroads Electrified" by William
> Middleton. It is now in its second edition which contains added
> information. There's a chapter on motor technology.

> Railroads electrified to (1) increase track capacity since electric
> trains were faster and more flexible, and (2) avoid smoke in tunnels.

> A big innovation was the "multiple unit" (MU) passenger train. These
> are trains, usually commuter trains or subways, that have no
> locomotive. The motors are part of the carriage with the wheels and
> the engineer sits in a vestibule at the front of the train. These
> have the advantage of being very flexible in size--one car or 16 cars
> as needed, and easy to turn around since they are bi-direction. MU
> cars also accelerate faster.

> With the advent of diesel engines and improved ventilation, some
> tunnel electrifications were shutdown. Some commuter electrifications
> were shut down as well.

> The Pennsylvania Railroad had a massive electrified network for its
> passenger and freight trains. While started in 1915, it reached its
> peak in the 1930s. Most of the passenger network remains in place run
> by commuter agencies or Amtrak, but the freight network was shutdown
> after Conrail inherited the Pennsy.

> Diesel locomotives are actually electric, with the generator carried
> above. As such, they have many of the advantages of an electric
> engine without the expense of maintaining a power distribution network
> (substations and overhead wires).

> Street railways and subway-elevated lines used 600 V DC and most still
> do (somewhat higher voltage) to this day. The relatively low voltage
> requires frequent substations.

> Railroad trains used a variety of voltages and AC frequencies. As
> mentioned, 11000V 25Hz was common and still in use to this day.

> Opinion follows...

> I am a strong proponent of electric propulsion. A modern electric
> powerhouse is far more efficient due to economy of scale than an
> on-board power plant could ever be. The plant could run on coal, oil,
> or gas, and many can be switched from one source to another. The
> exhaust can be economically cleaned up by scrubbers. Since the plant
> is more efficient in the first place, more of the fuel is burned up
> and less left over to go up the stack. Also, nuclear plants which do
> not release air pollutants or use scarce oil can be used.

> Rail is the most efficient means of travel for short distances.
> Unfortunately, this country has chosen to massively invest in air and
> highway and despite that investment, those modes remain overcrowded
> and unable to accomodate all demand. Fast trains -- which are not
> that costly to build -- should be used for regional transport needs
> and would be far more efficient in terms of fuel, safety, and
> pollution. We don't have the land to build more airports and roads,
> and trains fit in anywhere. Planes are better for coast to coast
> trips.

Interestingly a few years back when they re-built PVD airport they
decided to put a rail station in on Jefferson Blvd, about 1500 feet
from the terminal. They'd then get people to the airport via very
light rail.

They're building the station as I type. They've also announced that
they're going to build a station in the Wickford section of North
Kinstown, RI. Also announced is that a stations will be built in
Cranston, Pawtucket and Westerly RI and the MBTA has said they'll be
willling to run commuter rail through RI. Finally!

My guess is that it will take about five years to complete all this
work. But the other thing they let on about was that MBTA will run
into CT where you can pickup their transit trains and ride right into

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