Would this be AC or DC current?
Most modern electrical plants for RRs are AC. The DC electrical systems will probably go the way of the DoDo bird before to long.
The PRR used 10,000 volts 50 cycle AC and stepped it down in the engine. Reason for the 50 cycle is they were afraid people along the right ofway would try to tap in to the power source and 50 cycle is a visible flicker when used for lighting.
11000 volts, 25 cycle, he meant to say. The motors they used then needed lower freq than 60 Hz-- maybe they still do?
Wouldn’t the fact that it was 10,000 VAC be a much bigger impediment? Considering that it takes a lot less voltage to kill, worrying about flickering lights just seems odd to me.
The higher the voltage the easier it is to “push” it through the wires minimizing power losses. Even the power companies do it this way as far as they can before stepping it down to120 to a house.
I realize that, but what I’m saying is why worry about frequency as a means of discouraging would-be consumers when tapping the line to feed a transformer could be a hazardous endeavor for a potential thief?
Perhaps some folks tried and somehow succeeded.
Here in Europe, it seems that each country has its own standard. For freight traffic originating in Rotterdam and travelling to the Ukraine you either have to change motive power about 4 times, or use one of the newer “multisystem” electrics now on the market. Bombardier manufactures the TRAXX class 189 which can run under caternary throughout Europe using the following 4 systems:
15kV/16.7Hz
25kV/50Hz
1.5kV and 3kV DC
DC is alive and well in some countries such as the Czech Republic and the Netherlands. I know of no plans to convert these systems.
As for tapping into a railroad’s grid, standard household current in Europe is 220-240V/50Hz, so I doubt that anybody would or could go to the trouble of trying to transform the high voltages to something they could feasably use.
While learning electronics, a bit of power stuff was talked about. Electric companies would get ‘upset’ with a property owner that strung a wire parallel to the overhead wires, and - through induction, transformer style - end up with enough electricity to run a few low wattage devices, like electric lights. Never tried it so don’t know if the tale is apocraphyl.
Living under a transmission line might have payoffs. But 25 cycle electricity was not good for lights, and how close is close enough for transformer action to be successful?
Art
http://www.northeast.railfan.net/classic/MILWdata5.html
Doing some more digging I found that page. Why are there two pantographs atop the locos? Did one not give enough ‘juice’?
Some misconceptions in this thread. Older locomotives used low frequency AC because you can run it through a Universal Motor which is designed just like a DC Motor. The limiting factor is arcing at the brushes, there is no absolute limit, it’s just that as the frequency goes up brush life goes down. Americans used 25Hz power, while the Europeans used 16.67 Hz. Modern Solid-state Recifiers and then 3-phase drives have pretty much eliminated the need for low frequency in AC electrifications, but the cost of change means that they will live on, especially in Europe with their extensive electrification networks. The big disadvantage of low frequency AC is the cost to convert from commercial frequency, and the need for heavier transformers and smoothing chokes on the locomotives.
For CNW 6000 there are two pantographs for several reasons
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you have a spare if the first becomes damaged without bringing down the overhead wires.
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In winter the first will clear ice off the contact wire allowing the second to make better electrical contact.
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With the relatively low voltage of DC locomotives you may need two pantographs up to give enough surface area against the wire at maximum power and low-speeds( the motors draw lots of Amps at low speeds)
For Lee Koch, the German Class 189 is a Siemens built Eurosprinter, The Traxx Multisystem electrics are German Class 186.
Your question about two pantographs has to do with the type of internal propulsion in the engine. A diesel is a diesel electric in that the diesel turns a generator or alternator that sends electricity to the electric motors on the axles to turn the wheels. Some electric engine used an AC motor to turn a generator that sent power to the wheels. My limited understanding is that type of engine needs to remain in contact with the catenary at all times because if the pantograph was not in contact with the wire for some period of time and the engine was under power, when it came back in contact with the wire it could be out of phase causing a short circuit and shutting everything down or worse. So if you picture the wire from each pantograph joining together at some point and then a common lead to one side of the motor you have an idea of what is happening
Thanks for straightening things out. The reason I started this thread (don’t laugh!) is because I wanted to model a hypothetical loco and use overhead power along with onboard power. Thus I’m going to equip an AC4400 with a pantograph. Plus the more I’m reading about electrified lines the more I think they’re “cool”.
There was a Washington based railroad the Yakima Valley that had steeplecab electric engines and a 44ton Ge. The 44 ton Ge had a trolley pole becasue the signals all had trips in the catenary not the rail so there is some precedence for what you want to do.
That’s the YVT, which dropped the wires in the late 1980’s. Power was 600 volts DC, i.e. standard voltage for trolley lines and most interurbans. The line provided passenger service in the early days.
Pacific Electric had a similar situation. All of the trips for signals, grade crossings, etc. were set up through the overhead wire so several diesels and some cabooses were equipped with trolley poles to actuate the signal system.
Quite a few countries use 50-cycle current, as seen in this chart:
While they don’t use pantagraphs, much (if not all) of the Diesel fleet running into GCT and Penn Station is dual-mode, using third rail as the power source…