Ive heard of some Electrics running in the Alps that are quite the brutes; I could be wrong.
CSSHEGEWISCH wrote: wjstix wrote:I suspect if we compare apples and apples - 1930's electric engines vs. 1930's diesels, the electrics would come out far ahead. It would be interesting to see what could be built today as far as a straight electric freight engine.The most recent straight electric freight designs that we have were the GM6C and GM10B demos of the late 1970's and the GF6C's in British Columbia of the 1990's. The GM10B seemed to be the design that was pushing the limits of the envelope.
wjstix wrote:I suspect if we compare apples and apples - 1930's electric engines vs. 1930's diesels, the electrics would come out far ahead. It would be interesting to see what could be built today as far as a straight electric freight engine.
The most recent straight electric freight designs that we have were the GM6C and GM10B demos of the late 1970's and the GF6C's in British Columbia of the 1990's. The GM10B seemed to be the design that was pushing the limits of the envelope.
I am no engineer(of either stripe) but my understanding of the difference in design between High Horsepower European and North American locomotives are all about high speed versus tractive effort. There are a number of European electrics with impressive ratings (10,000 HP or greater!) but they do not have the pulling power in heavy freight service of the average North American unit (4400 HP GE or 4300 HP EMD). They are designed to pull passenger and short freigth trains at 100 MPH plus speeds.
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
But energy production isn't the biggest limitation AT ALL. Transferring the energy into locomotion is.
As for the GG-1 comparison, I made the comment because others in the thread had brought it up, not because I felt it was the best comparison to make. Gearing however is not a big deal in this discussion. Traction motor enhancement, AC traction motors, wheel slip controls, steerable trucks. All these things have helped to make the modern 3rd gen (or are we at 4th gen) significantly more powerful then anything to come before it.
Milwaukee Boxcabs suffer the same issues as the GG-1 old technology.
A better question of whose most powerful would be ACe vs. GEVO or perhaps 90MAC-H vs. AC6000 though I think the ACe and GEVO would probably outperform.
Another factor to consider is the source of the energy. Any self-contained locomotive (diesel, steam, or gas turbine) is constrained by the amount of energy that can be produced by its prime mover (diesel engine, steam boiler, or gas turbine). A straight electric is not self-contained since it draws its energy from an outside source (the power plant) and is constrained more by the capacity of the catenary and feeders to carry that energy than by the capacity of the power plant to produce that energy.
I agree! Generally when a source says "maximum" tractive effort or just "tractive effort" they have selected the number that shines the best possible light on the locomotive. Usually that number is starting tractive effort, which includes undisclosed limiting caveats such as a percentage adhesion that requires dry, nongreasy rail, good rail and wheel profile, straight level track, etc. And of course 1 minute later in the real world the locomotive slips and tractive effort goes to 0.0, or 5 minutes later the traction motors overheat and short out ...
The meaningful number is maximum continuous tractive effort.
RWM
chefjavier wrote: YoHo1975 wrote: Who cares how much power you can generate if all it does is spin the wheels? It's not the engine size or traction motor size that dictates how much power is actually applied to the rails, it's the physics of a round steel wheel on a flat steel rail. I'd say your average SD70ACe could out pull any 3 GG1s, because it can translate the power to moving the train better. I suggest check your information.
YoHo1975 wrote: Who cares how much power you can generate if all it does is spin the wheels? It's not the engine size or traction motor size that dictates how much power is actually applied to the rails, it's the physics of a round steel wheel on a flat steel rail. I'd say your average SD70ACe could out pull any 3 GG1s, because it can translate the power to moving the train better.
Who cares how much power you can generate if all it does is spin the wheels?
It's not the engine size or traction motor size that dictates how much power is actually applied to the rails, it's the physics of a round steel wheel on a flat steel rail. I'd say your average SD70ACe could out pull any 3 GG1s, because it can translate the power to moving the train better.
I suggest check your information.
Here http://www.spikesys.com/GG1/specs.html we find that the Maximum Tractive Effort for a GG1 is 77,500 lbs. And here http://www.emdiesels.com/lms/en/locomotive/na_freight/sd70ace/index.htm we find that the Continuous Tractive Effort for a single SD70ACe is 157,000 lbs. But there's no way the GG1 with its primitive adhesion systems and electrical transmission is going to exert maximum tractive effort except under the very best conditions, and for only a few minutes, whereas the SD70ACe can exert its CTE under poor conditions until it runs out of diesel fuel a few days later. So maybe the SD70ACe on paper can only outpull two not three GG1s, but in the real world the SD70ACe probably could.
As speed rises eventually the GG1 is able to draw more amperes from the catenary than the SD70ACe can from its main generator, but it's a spurious capability because railroading isn't done that way. It's so rare it's statistically invisible the number of times that a train is (or was) dispatched with a locomotive that can't start it on level track without assistance from a helper locomotive.
Sure thing Champ,
the GG1 can produce 70,700 lbs TE unspecified via DC (unspecified is always assumed to mean starting TE.)
The SD70ACe can produce
191,000 lbs starting TE
157,000 continuous TE
So, I apologise, I mispoke. It can ALMOST produce as much as 3 GG1s. 3 gg1s producing 213,000 lbs TE
Berk765 wrote: Were the electric locomotives that operated by an overhead wire more powerful than the diesal electric locomotives?
Were the electric locomotives that operated by an overhead wire more powerful than the diesal electric locomotives?
Keep in mind the mechanical aspect of a Diesel Engine. It's the production of electricity that produce traction to the wheels. Electric like GG-1 would produce faster because it goes straight to traction.
It comes down to how much amp can you feed a traction motor between the wheels for how long?
My vote is with the electric, Ive heard stories of three GG1's on the same wire. It is my understanding they could not feed em all.
Dont forget the Turbine. Those things rule.
Give me steam locomotives or give me DEATH!
Berkshire Junction, bringing fourth the cry of the Iron Horse since 1900.
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