Comments on: Boundaries of Tram Operation Extended Beyond the Catenary

By: EngineerScotty

EngineerScotty — Wed, 30 Dec 2009 02:10:22 +0000

One other place where a dedicated conductor is used for ground return is with trolleybusses, where the rubber tires prevent current from being conducted to the ground.

By: Ocean Railroader

Ocean Railroader — Wed, 30 Dec 2009 01:30:48 +0000

Catenary is good in that it is cheap to intill and take care of it. It can be good looking if the poles around it have good types of glass and clay insulators around it. It is still very rare or uncommon to see catenary along railroad tracks most of the time in the US.

By: Max Wyss

Max Wyss — Tue, 29 Dec 2009 19:02:46 +0000

Actually, that system kind of reminds me of the Gyrobus concept from the fifties of the last century, where buses were equipped with flywheels, and got “recharged” at the station stops.

An alternative to batteries are supercapacitors, which can be charged way faster than batteries, and may also be lighter, although the capacity may be lower.

It depends on the underground, but in most cases, the rails can act as ground return. There are places, where a dedicated conductor is used for the ground return (such as some lines of the London Underground). This conductor may also be a “simple” cable.

I don’t really see the problem with catenary; there are many cities having it, and even in places which are “historically sensitive”.

By: EngineerScotty

EngineerScotty — Tue, 29 Dec 2009 16:43:49 +0000

Streetcars conduct power to ground through their wheels, and don’t need utilities to be moved, just tracks in the pavement.

I’m with OR; it’s the size and weight of the vehicles that inhibit utilities under the roadbed.

By: Ocean Railroader

Ocean Railroader — Tue, 29 Dec 2009 16:02:14 +0000

I remeber hearing that the Richmond streetcars did have to have ground wires put in near the tracks. The reason why most utilities are moved is the size and load of the train and it’s tracks uselly.

I could see this system being tried out in Washingtion DC no wire zone but I think catenary will still be around in that it’s not that bad to build wires and the trains get power 100% of the time vs have to watch a battery that could run out. I wonder though could a streetcar take on power under a catenary section and then use the power in the areas that don’t have catenary or are not aloud to have ait.

By: Christopher

Christopher — Tue, 29 Dec 2009 14:04:54 +0000

I’ve got a question so hopefully someone knows the answer.

I was under the impression that one of the reason light rail lines are so expensive to construct at grade is that they require utilities to be diverted so that the rails can act as an ‘earth’ line (I have no gret knowledge of electrics so bear with me if I murder the terminology). If LRVs are storing their power in batteries do they need to be earthed and if not, do utilities need to be moved?

By: Alon Levy

Alon Levy — Thu, 09 Jul 2009 19:19:01 +0000

In passenger cars, the majority of energy, I believe about 80%+, is spent on driving; air conditioning, radio, etc., count for only a small percentage of energy consumption.

By: Daniel M. Laenker

Daniel M. Laenker — Thu, 09 Jul 2009 15:29:12 +0000

Even better for STEEM in Washington is that WMATA has done a great deal of business with ALSTOM before. So it shouldn’t be too much of a stretch.

That said… no air conditioning? Surely you must know what DC is like in the (humid subtropical) summer. Ugh!

By: Dave in KY

Dave in KY — Thu, 09 Jul 2009 05:10:42 +0000

The benefits for rail are big,
but the huge winner in this technology could be trolleybuses, which might be able to out-compete hybrid buses at their own game. Futhermore, it would be a natural for TBRT (TrolleyBusRapidTransit). You peg the buses to stations with at-floor level loading, where the bus is charging, then the bus can use the entire street grid to get to the next stop.

By: Andrew

Andrew — Thu, 09 Jul 2009 01:00:32 +0000

This is awesome!