Passenger Trains > DC Streetcars

Will the planned DC streetcars get their power from overhead wires or from a slot in the pavement between the rails as they did years ago?

Probably overhead wire. I don't know of any rail system on the planet that uses hidden slot-access "third rail" power. On top of that, I seriously doubt any such design would meet current safety requirements!

The tramway in Bordeaux, France is slot powered in certain visually sensitive areas where overhead wires are undesirable.

On the DC front, I think the National Capital Planning Commission is still opposed to overhead wires in certain areas, but 2 segments currently under construction will have overhead wires since they are outside of the sensitive view corridors. I know the planners are considering battery powered streetcars as a way to enter the historic areas without upsetting the NCPC.

Jarrett

Theres a line that has a Lionel like 3rd rail that is powered only when the tram is over top of it.

mario_puzo Wrote:
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> The tramway in Bordeaux, France is slot powered in
> certain visually sensitive areas where overhead
> wires are undesirable.
>
> >
> Jarrett

I rode the tram in Bordeaux a few years ago and there was no actual slot third rail. It seemed more like an induction system for both street and Pvt. Rt. of way operation. Thee was one exception for a few blocks in front of and near the downtown SNCF rail station where genuine overhead trolley wire WAS used.

SNCF= Society Nationale Chemin de Fer for those of you who watched passing trolley cars during your high school French classes!!

NSDTK Wrote:
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> Theres a line that has a Lionel like 3rd rail that
> is powered only when the tram is over top of it.

I'm certainly no expert on this, but I thought I remember reading that the old DC system also powered up the rail in the slot somehow only when a car was above it. I'm sure fears of kids poking sticks or other items into the slot have existed for many years.

The old slot streetcar power system (which I think was in NYC, but I'm probably wrong on that) had a slot an inch or so wide between two grounded metal plates. The 3rd rail was several inches off to the side, and a T head or cobra head was on the bottom of the slot follower, so that it could reach off to the side to get to the power rail.

It was a fairly high maintenance system, and had problems in heavy rains and in freezing conditions, but was used because the city fathers didn't like looking at all the ugly overhead wire. I can't recall if the system was retired and replaced with overhead before the streetcars themselves were retired.

These days a Wampfler induction system could probably be made for not much more than the cost of doing a live rail. Not that it would be cheap, but both would be fairly obscenely expensive.

The DC "conduit" power system only applied in the "old Federal city", which meant Georgetown, downtown, and around the Capitol and Union Station. Outside of those areas, conventional trolley wire was used.

Wisconsin Avenue trolleys changed to conduit at P Street, at the top of the hill down into Georgetown.

To answer the original question, AFAIK as I know (and have seen) the DC trolley lines under construction will use conventional trolley wire or catenary (not sure which). The line on Firth Stirling Street has catenary poles already erected. There are poles at various places on Benning Road and H Street as well. The line on H Street ends just short of Union Station at present. I believe they're still deciding on how to bring it into the station. Track construction on both lines is largely complete, wire installation has not started. Construction progress is very slow.