Germany and Sweden both use 15kv 16 2/3Hz, but Denmark wich lies in between thse two countrys with no other rail route around, recently electrified with 25kv. What gives with that? Now they only have one type of loco that can travel through, the class EG.
To me this made no sense.
martin.knoepfel wrote:Italy's mainlines, except High-Speed-ROW, are 3kv DC. Some years ago, they considered going to 6kV, but they stopped the project. Several countries which started mainline electrication from scratch like the PRC or Denmark chose 25 kV AC. Same story for the UK, although they have a vaste network of DC third-rail in the Southeast and had suburban lines with 1,5 kV DC in several regions of the country.
A few years ago, upon the completion of the Transiberian AC electrification project, I did a survey of existing rail electrification mileage in Europe (including Russia). Summarized as follows:
AC
15 kV, 16 Hz .. 42,400 miles
6.6 kV 25 Hz .. 91 miles
25kV, 50Hz ... 74,373 miles
11 kv50Hz .. 482 miles
DC
1500 vDC.. 15,746 miles
3 kVDC .. 65,044 miles
1000-1200 vDC .. 572 miles
1800 vDC ... 21 miles
600-900 vDC ... 5,252 miles
3 kVDC mileage:
Russia .. 18,800 miles
Poland .. 11,967 miles
Italy ... 10,688 miles
Ukraine .. 9,000 miles
Spain .. 6,416 miles
The 3 kVDC is virtually all "Milwaukee" type -- patterned directly after the Milwaukee Road's installation.
As to the merits or perceived disadvantages of various Voltages and AC vs. DC, I suggest you guys just look at Europe, where we have a whole plethora of differing systems. The best selling electrics here nowadays are multi-system locos, able to operate under AC, DC, and a number of different voltages (please see the Siemens EuroRunner or the Bombardier TRAXX family). There is plenty of experience as well as tried and true equipment for almost any electrical system imaginable. It's all doable in North America, but the COSTS... And don't forget the difficulty of reliable contact to caternary which is high enough to give clearance for double stacks!
Speaking of Fuel cell technology, I believe that it would be most practicable as a source of power for the substations, not as a mobile source of power in locomotives.
You are correct about Hydrogen being a tankable carrier of energy. Problem, is, for hydrogen to be pure enough for fuel cell operation (not just a additive to regular petroleum fuels) you need four times the energy you will get from the Hydrogen to convert it from some other source, using a projection of the most effiicent processes possible. This may be possibly someday be a technology useful for light duty machines like personal autos (although hybrids will be the way to go, for safety as well as other reasons, and electrics should have been the way to go with swappable batteries at filling stations, but the auto industry hasn't shown any willingness to buy this) but anyone who really understands the physics of the situation concludes quickly that railways are possibly the last place for this technology, even after aircraft. The conversion processes in use today give an energy output of about one-tenth the total energy applied to make the Hydrogen. This is the complete chain, from the power input to the conversion process to the output of the fuel cell to the electric motor drive.
Concerning the reduction of weight and size of the added equipment to make a diesel elctric into dual service with high-voltage catenary pickup capability, both for conversions of designs and for conversion of existing modern locomotives, the 60 Hz and combination 60Hz-25Hz transformers on modern electrics are a very major portion of the weight and real-estate on the locomotive. I had proposed twin locomotive pairs, one straight electric and one diesel-electric, which can be twinned or operated separately. When twinned, (with five heafty jumper electric power cables connecting the two) all eight or twelve axles can have state-of-the-art motors that draw power from the equipment on the straight electric when under catenary and from the diesel-electric when not under catenary. But for one unit to do the job, existing 60Hz equipment would just about increase the weight and bulk by 50% or more, and this is too much. But 400Hz would bring it down to reasonable size or whatever freqeuency Boeing does use. Again, the power electronics could pick up dc or any frequency the power company wishes to provide.
CrazyDiamond wrote: Eventually many lines in North America will have no choice but to go to electrics. As the world runs out of 'easy to get' fuel, fuel costs will continue to rise. As the world develops lower cost solar, wind, hydro, tidal generation, the RRs will financially forced to convert from diesel to electric grid. The risk is, since we are so short-term focused, and do not believe in long term investment we risk waiting too long, then it will be too late in the sense that the costs to convert will be even more expensive, and our overseas competitors will already be enjoying an electric system that has already paid for itself many times over. When my son starts school it won't be French langauge he will be learning as a second language, I will be getting him taught Chinese....because 20 years from now China will rule the world and or economy will be broken. They will be driving the energy efficient hybrids and we will be riding the bicycles. Our cheap energy ride is over and the 'harsh reality' is just starting to begin. This is why USA and Canada are resisiting Kyoto Protocol. We believe it will cost us too much money money to convert from a fossil fuel driven economy to one that uses less fossil fuel. Other nations aroudn the world have already completed their obligations becase they were already less dependant on fossil fuels then we are.
Eventually many lines in North America will have no choice but to go to electrics. As the world runs out of 'easy to get' fuel, fuel costs will continue to rise. As the world develops lower cost solar, wind, hydro, tidal generation, the RRs will financially forced to convert from diesel to electric grid. The risk is, since we are so short-term focused, and do not believe in long term investment we risk waiting too long, then it will be too late in the sense that the costs to convert will be even more expensive, and our overseas competitors will already be enjoying an electric system that has already paid for itself many times over. When my son starts school it won't be French langauge he will be learning as a second language, I will be getting him taught Chinese....because 20 years from now China will rule the world and or economy will be broken. They will be driving the energy efficient hybrids and we will be riding the bicycles. Our cheap energy ride is over and the 'harsh reality' is just starting to begin. This is why USA and Canada are resisiting Kyoto Protocol. We believe it will cost us too much money money to convert from a fossil fuel driven economy to one that uses less fossil fuel. Other nations aroudn the world have already completed their obligations becase they were already less dependant on fossil fuels then we are.
That's why I throw hydrogen into this discussion. With fuel cell technology, hydrogen is basically a "tankable" electricity. Thus, hydrogen is the carrier of the energy from an electrical source to an electrical use - without the complexity of a wired distribution system. It is a much better fit for the railroad business model. Hence the heavy research in Japan - who already has world class experience in electrical RR.
dd
PS: I am an electrical engineer by training and as much as I would like to see a US electrical RR infrastructure, I am still leaning toward hydrogen.
erikem wrote: MichaelSol wrote:The Milwaukee's choice of 3k vDC was an economic decision. GE had tested 5k and 6k systems. Railway electrification at 5K vDC was perfectly feasible. The 6k was rejected. The only reasoning or explanation I can find in contemporaneous accounts is that 6k required "freakish mechanisms" in the locomotives. Apparently some sort of engineering term I am unfamiliar with.3 KV DC was probably the economic limit at the time the Milwaukee electrified and probably was close to the economic limit until very recently. What's changed is the availability of high voltage power electronics (e.g. Powerex has had a GTO that would hold off 4KV and rated at carrying 4,000 amps) and things may get even more interesting when SiC devices become more widely available.While regenerative braking is possible with single phase AC (done by the N&W, VGN and GN), it is still a lot easier with DC.
MichaelSol wrote:The Milwaukee's choice of 3k vDC was an economic decision. GE had tested 5k and 6k systems. Railway electrification at 5K vDC was perfectly feasible. The 6k was rejected. The only reasoning or explanation I can find in contemporaneous accounts is that 6k required "freakish mechanisms" in the locomotives. Apparently some sort of engineering term I am unfamiliar with.
The Milwaukee's choice of 3k vDC was an economic decision. GE had tested 5k and 6k systems. Railway electrification at 5K vDC was perfectly feasible. The 6k was rejected. The only reasoning or explanation I can find in contemporaneous accounts is that 6k required "freakish mechanisms" in the locomotives. Apparently some sort of engineering term I am unfamiliar with.
3 KV DC was probably the economic limit at the time the Milwaukee electrified and probably was close to the economic limit until very recently. What's changed is the availability of high voltage power electronics (e.g. Powerex has had a GTO that would hold off 4KV and rated at carrying 4,000 amps) and things may get even more interesting when SiC devices become more widely available.
While regenerative braking is possible with single phase AC (done by the N&W, VGN and GN), it is still a lot easier with DC.
The newest E-Locos from the Big 3 European manufacturers all have IGBTs rated at 6.2 - 6.5kV so the DC link is now at that rating. Of course with IGBTs at that rating you can build Choppers to lift the DC voltage to the Link voltage. But no matter what, if the locomotive is going to produce 6MW then you need OHE that can provide that much. With modern microprocessor controls and 4-quadrant power convertors, regeneration isn't too difficult with single phase 60Hz AC either.
MichaelSol wrote: The only reasoning or explanation I can find in contemporaneous accounts is that 6k required "freakish mechanisms" in the locomotives. Apparently some sort of engineering term I am unfamiliar with.
erikem wrote: 3 KV DC is too low of a voltage for a new electrification, 10 to 15KV would be more like it. Higher voltages would run a higher risk of a fault that won't clear until the line is shut off for a second or so (which argues for some energy storage on the locomotive).
3 KV DC is too low of a voltage for a new electrification, 10 to 15KV would be more like it. Higher voltages would run a higher risk of a fault that won't clear until the line is shut off for a second or so (which argues for some energy storage on the locomotive).
But, ultimately, it was simply a cost decision. The higher voltages required more expensive locomotives and cheaper overhead, the lower voltages required heavier overhead, but less expensive locomotives. The Milwaukee's particular conditions of distance, grade and tonnage -- and numbers of locomotives relative to the size of the installation -- put the decision squarely at 3,000 volts DC; just as the contemporaneous BA&P design was cost effective at 2,400 volts.
I am sure that the cost considerations have changed considerably, particularly in regard to using off-the-shelf, rather than custom built, locomotives. However, this note is a reminder that the decision at the time was not technology limited, but rather cost driven.
L.W. Wylie, with whom I spoke at some length regarding his 1968 study, and who was a consultant on various DC and AC electrifications throughout the world -- including the advanced AC Shinkasen high speed railway -- was adamant that the 3,600 volt DC system was superior for a regular freight, mountain railroad. I wish I had known better, 37 years ago, to take copious notes on his specific reasoning.
beaulieu wrote:Yes, I realize that DC practice is to feed from both ends. Do you think that is an advantage? Or is it a work-around to overcome a limitation of the system? The low voltage means heavier contact wire, which means heavier supports and probably more of them, stronger anchorages for the tensioning system, the dual-feeding means more substations, and all of that is almost certainly going to cost more.
Yes, I realize that DC practice is to feed from both ends. Do you think that is an advantage? Or is it a work-around to overcome a limitation of the system? The low voltage means heavier contact wire, which means heavier supports and probably more of them, stronger anchorages for the tensioning system, the dual-feeding means more substations, and all of that is almost certainly going to cost more.
I would think it has several advantages. One is inherent redundancy in that you will still have power if one substation dies (though it will be greatly reduced). Another is that the substations can be set up to current share by letting the output voltage drop when the current draw reaches the limit for that substation. Yet another advantage is lack of phase breaks.
wallyworld wrote: MichaelSol wrote: The Electrification was just about studied to death between 1968 and 1972. Several proposals were made.1) The L.W. Wylie study of 1968. Proposed upgrades, electrifying the Gap, proposed a new electric locomotive design to be ordered up. A detailed engineering study that showed compelling cost operating advantages, but left it to the railroad to determine the best means of financing the upgrade. This study generated a great deal of internal review and, in turn, stimulated suppliers to propose equipment and actual costs to supplement the study.2) The three largest PNW electric utilities -- Puget Power & Light, Washington Water Power, and Montana Power Company -- put together a joint study and made a joint proposal. 1970 if I recall correctly. They favored continued DC operation based on their own study which showed that the DC was superior to AC for the Milwaukee's mountain operations, closing the gap, and purchasing new locomotives from GE, upgrading the system overall with silicon diode rectifiers, and raising the voltage to 3,900 vDC.Financing was a combination of salvage sales (replacing copper with aluminum on feeder), loans, and wheelage fees on the Milwaukee high voltage line; possibly from sales revenue generated from sales of the lines to the power companies.3) An updated Power Company study was submitted to the Milwaukee in 1971, based on GE and EMD actual price quotes for motive power.4) GE made a detailed proposal in 1972 to upgrade the entire system. It was instigated by the power company study. GE agreed with most elements of the power company study, including recognition that the existing DC system would be superior in operation to any alternative AC system. GE's proposal was more detailed than any prior study and, at least from a presentation standpoint, made a clear and detailed presentation based on GE's "Econometric Computer Program" and took the analysis clear through to a "before tax" and an "after tax" scenario.5) The MILW legal department's proposal to re-electrify using a high voltage, state-of-the-art AC system, financed almost entirely by a $250 million grant from the FRA as a demonstrator project for railroad electrification. FRA had approved it; all that remained was MILW board approval.6) MILW internal studies, ongoing. An interesting one was done by VP Management Services Gaye Kellow when he pointed out in 1970 that the most economically efficient system was a combined electric/diesel system like the Milwaukee was currently operating, rather than going either all-electric or all-diesel. The GE analysis showed that upon full operation in 1974, the system would have generated a net pretax savings at a 2.7% growth rate in traffic of $30,000. By 1980, the savings would have been just under $1 million annually at 2.7% or $1.4 million annually at a 5% growth rate, assuming diesel fuel at 16 cents per gallon by 1980. Total accumulated savings in each case by 1980 was $3.2 million and $4.8 million. By 1985, the savings would have been $8.9 million and $16 million respectively. In the all cases, the underlying assumptions of rate of growth and rate of diesel fuel cost increases were far too conservative, and actual savings would have been much greater.Over the estimated life of the system, by 2003 the respective total savings would have $221.6 million and $403 million. In that year, the annual savings would have reached $24 million and $49 milllion respectively.As it turned out, with substantially greater growth in traffic in the electrified zones, and substantially greater increases in diesel fuel costs than projected in the study, Milwaukee would have saved closer to $20 million by 1980 in annual operating savings.Fascinating insight into this topic from an historical viewpoint....
MichaelSol wrote: The Electrification was just about studied to death between 1968 and 1972. Several proposals were made.1) The L.W. Wylie study of 1968. Proposed upgrades, electrifying the Gap, proposed a new electric locomotive design to be ordered up. A detailed engineering study that showed compelling cost operating advantages, but left it to the railroad to determine the best means of financing the upgrade. This study generated a great deal of internal review and, in turn, stimulated suppliers to propose equipment and actual costs to supplement the study.2) The three largest PNW electric utilities -- Puget Power & Light, Washington Water Power, and Montana Power Company -- put together a joint study and made a joint proposal. 1970 if I recall correctly. They favored continued DC operation based on their own study which showed that the DC was superior to AC for the Milwaukee's mountain operations, closing the gap, and purchasing new locomotives from GE, upgrading the system overall with silicon diode rectifiers, and raising the voltage to 3,900 vDC.Financing was a combination of salvage sales (replacing copper with aluminum on feeder), loans, and wheelage fees on the Milwaukee high voltage line; possibly from sales revenue generated from sales of the lines to the power companies.3) An updated Power Company study was submitted to the Milwaukee in 1971, based on GE and EMD actual price quotes for motive power.4) GE made a detailed proposal in 1972 to upgrade the entire system. It was instigated by the power company study. GE agreed with most elements of the power company study, including recognition that the existing DC system would be superior in operation to any alternative AC system. GE's proposal was more detailed than any prior study and, at least from a presentation standpoint, made a clear and detailed presentation based on GE's "Econometric Computer Program" and took the analysis clear through to a "before tax" and an "after tax" scenario.5) The MILW legal department's proposal to re-electrify using a high voltage, state-of-the-art AC system, financed almost entirely by a $250 million grant from the FRA as a demonstrator project for railroad electrification. FRA had approved it; all that remained was MILW board approval.6) MILW internal studies, ongoing. An interesting one was done by VP Management Services Gaye Kellow when he pointed out in 1970 that the most economically efficient system was a combined electric/diesel system like the Milwaukee was currently operating, rather than going either all-electric or all-diesel. The GE analysis showed that upon full operation in 1974, the system would have generated a net pretax savings at a 2.7% growth rate in traffic of $30,000. By 1980, the savings would have been just under $1 million annually at 2.7% or $1.4 million annually at a 5% growth rate, assuming diesel fuel at 16 cents per gallon by 1980. Total accumulated savings in each case by 1980 was $3.2 million and $4.8 million. By 1985, the savings would have been $8.9 million and $16 million respectively. In the all cases, the underlying assumptions of rate of growth and rate of diesel fuel cost increases were far too conservative, and actual savings would have been much greater.Over the estimated life of the system, by 2003 the respective total savings would have $221.6 million and $403 million. In that year, the annual savings would have reached $24 million and $49 milllion respectively.As it turned out, with substantially greater growth in traffic in the electrified zones, and substantially greater increases in diesel fuel costs than projected in the study, Milwaukee would have saved closer to $20 million by 1980 in annual operating savings.
The Electrification was just about studied to death between 1968 and 1972. Several proposals were made.
1) The L.W. Wylie study of 1968. Proposed upgrades, electrifying the Gap, proposed a new electric locomotive design to be ordered up. A detailed engineering study that showed compelling cost operating advantages, but left it to the railroad to determine the best means of financing the upgrade. This study generated a great deal of internal review and, in turn, stimulated suppliers to propose equipment and actual costs to supplement the study.
2) The three largest PNW electric utilities -- Puget Power & Light, Washington Water Power, and Montana Power Company -- put together a joint study and made a joint proposal. 1970 if I recall correctly.
They favored continued DC operation based on their own study which showed that the DC was superior to AC for the Milwaukee's mountain operations, closing the gap, and purchasing new locomotives from GE, upgrading the system overall with silicon diode rectifiers, and raising the voltage to 3,900 vDC.
Financing was a combination of salvage sales (replacing copper with aluminum on feeder), loans, and wheelage fees on the Milwaukee high voltage line; possibly from sales revenue generated from sales of the lines to the power companies.
3) An updated Power Company study was submitted to the Milwaukee in 1971, based on GE and EMD actual price quotes for motive power.
4) GE made a detailed proposal in 1972 to upgrade the entire system. It was instigated by the power company study. GE agreed with most elements of the power company study, including recognition that the existing DC system would be superior in operation to any alternative AC system. GE's proposal was more detailed than any prior study and, at least from a presentation standpoint, made a clear and detailed presentation based on GE's "Econometric Computer Program" and took the analysis clear through to a "before tax" and an "after tax" scenario.
5) The MILW legal department's proposal to re-electrify using a high voltage, state-of-the-art AC system, financed almost entirely by a $250 million grant from the FRA as a demonstrator project for railroad electrification. FRA had approved it; all that remained was MILW board approval.
6) MILW internal studies, ongoing. An interesting one was done by VP Management Services Gaye Kellow when he pointed out in 1970 that the most economically efficient system was a combined electric/diesel system like the Milwaukee was currently operating, rather than going either all-electric or all-diesel.
The GE analysis showed that upon full operation in 1974, the system would have generated a net pretax savings at a 2.7% growth rate in traffic of $30,000. By 1980, the savings would have been just under $1 million annually at 2.7% or $1.4 million annually at a 5% growth rate, assuming diesel fuel at 16 cents per gallon by 1980. Total accumulated savings in each case by 1980 was $3.2 million and $4.8 million. By 1985, the savings would have been $8.9 million and $16 million respectively.
In the all cases, the underlying assumptions of rate of growth and rate of diesel fuel cost increases were far too conservative, and actual savings would have been much greater.
Over the estimated life of the system, by 2003 the respective total savings would have $221.6 million and $403 million. In that year, the annual savings would have reached $24 million and $49 milllion respectively.
As it turned out, with substantially greater growth in traffic in the electrified zones, and substantially greater increases in diesel fuel costs than projected in the study, Milwaukee would have saved closer to $20 million by 1980 in annual operating savings.
Fascinating insight into this topic from an historical viewpoint....
So close, so soon before the oil embargo. It's enough to make one cry!
daveklepper wrote:But conversion from 60Hz to 400Hz with power solid state electronics on the locomotive may be possible as developments in semiconductors progress. And that should drastically reduce the size, weight, and cost of transformers, which are one huge ticket item in ac 60 Hz 25000volt electrics.Michael, we have to stick with 60Hz AC because it is what the power companies provide and transmit. To go to high voltage dc would make sense, but you would then need power conversion at the substations in addition to doing again on the locomitve. The added costs would greatly outway the economies.I had not thought of frequency conversion right before the transformers to 400Hz until reading this thread. I wonder if GE or EMD have thought of it?
But conversion from 60Hz to 400Hz with power solid state electronics on the locomotive may be possible as developments in semiconductors progress. And that should drastically reduce the size, weight, and cost of transformers, which are one huge ticket item in ac 60 Hz 25000volt electrics.
Michael, we have to stick with 60Hz AC because it is what the power companies provide and transmit. To go to high voltage dc would make sense, but you would then need power conversion at the substations in addition to doing again on the locomitve. The added costs would greatly outway the economies.
I had not thought of frequency conversion right before the transformers to 400Hz until reading this thread. I wonder if GE or EMD have thought of it?
AC equipped diesel locomotives first rectify the output of the traction alternator to provide a DC bus for the inverters - current practice is to use IGBT's for switching - the output of the inverters is a variable voltage variable frequency AC. It would seem to me that an electric locomotive could be made by *cough* simply *cough* replacing the prime mover and alternator with the appropriate power conversion gear (whether it be converting from 60 Hz at 50KV or 25 Hz at 11KV or DC at 3.3KV) to provide the appropriate bus voltage. GE has been working on adding a battery pack to the internal bus on their future locomotives and such a battery pack could be very useful for an electric locomotive.
The ratings on IGBT's have progressed to the point where it would be practical to run the inverter off of a 2.4 to 3.3 KV DC bus - would have made for lighter cars on the old Lackawana and CN suburban electrifications than what they're using now after converting to AC catenary.
Back to 400 Hz - the real pain with 400 Hz is that circuit breakers won't work as well due to the very short zero crossing time - one of the advantages of 25 Hz over 60 Hz was the lower frequency was better in allowing arcs to quench due to the longer time at near zero current.
beaulieu wrote: MichaelSol wrote: In contrast to AC practice, a DC "section" consists of two substations.Yes, I realize that DC practice is to feed from both ends.
MichaelSol wrote: In contrast to AC practice, a DC "section" consists of two substations.
In contrast to AC practice, a DC "section" consists of two substations.
Yes, I realize that DC practice is to feed from both ends.
Well, my point was, it doubles the amps available.
Yes, there is a different argument about other aspects, and that too would be an interesting discussion.
MichaelSol wrote:In contrast to AC practice, a DC "section" consists of two substations.
beaulieu wrote: One other question not much discussed, Michael mentions 3900V DC, if you are going to have reasonably powerful locomotive consists you are going to have to have large current flows, and hence a pretty good cross-section on the contact wire. If you assume a locomotive consist of say 14 MW yielding a current draw of 3580A. 6000A is a common load limit for a substation, this would not be enough for two trains to be drawing full power in any section.
One other question not much discussed, Michael mentions 3900V DC, if you are going to have reasonably powerful locomotive consists you are going to have to have large current flows, and hence a pretty good cross-section on the contact wire. If you assume a locomotive consist of say 14 MW yielding a current draw of 3580A. 6000A is a common load limit for a substation, this would not be enough for two trains to be drawing full power in any section.
dldance wrote:<snipped> ddps re: weight savings -- concrete is a lot cheaper than copper.
<snipped>
ps re: weight savings -- concrete is a lot cheaper than copper.
But is anything saved in removing a smaller amount of copper from the locomotive only to hang more of it from cantenary supports? Also, the savings in transformer weight are from the iron core, not the copper windings.
Jetliners use 400Hz electrical power.
IIRC the electrical systems in Boeing jets uses a frequency higher than 60hz but I can't remember what it is. The stated reason was to save weight. If it is 400hz then there is a catalog of transportation/reliability certified electrical components to draw from.
daveklepper wrote:I owe Michael an apology: An old issue of Technology Review, the MIT Alumni magazine, showed the advantages of high-voltage dc transmission, as high as 100,000 volts, 100kV. The new power line partly under water (under rock and sand under the water) helping to resolve power shortage on Long Island, is dc. Using the latest technology, and converting to 400Hz directly following the pantograph to minimize size, weight, and cost of transformers, would allow the locomotive to operate equally well off dc, 60Hz ac, or the 25Hz ac that remains on the southern portion of the NEC (Sunnyside, Queens, NY - Washington). The electrification would be more logical if the railroad right-of-way was also used by a new modern power transmission line, and it would be the power company's decision whether 60Hz ac or direct current were used, and the locomotives could accept either.Why 400Hz? It is a frequency that allows efficient transformer design. (At MIT, I helped fund my expenses by designing transformers for Mystic Transformers in Winchester. My commute was on the B&M, and I had the engine pass given me by Ernie Bloss, in connection with my part-time work on the B&M, following a summer as student engineer at EMD in La Grange, where I had some input to the design of the GP-9 in 1952.) Lower frequencies require more mass in the magnetic structure to avoid saturation, while higher frequencies involve capacitor coupling losses across coil windings and across insulation between core and wire plus additional hysterisus losses in the core. Hsyterisus: The energy-change in the core lags slightly behind the change in core current, not a problem at 400 Hz, but a problem as frequencies climb. Also, if goes much above 1000Hz, radio interference and inteference with signal systems can be a problem unless shielding is well designed and maintained.
I owe Michael an apology: An old issue of Technology Review, the MIT Alumni magazine, showed the advantages of high-voltage dc transmission, as high as 100,000 volts, 100kV. The new power line partly under water (under rock and sand under the water) helping to resolve power shortage on Long Island, is dc. Using the latest technology, and converting to 400Hz directly following the pantograph to minimize size, weight, and cost of transformers, would allow the locomotive to operate equally well off dc, 60Hz ac, or the 25Hz ac that remains on the southern portion of the NEC (Sunnyside, Queens, NY - Washington). The electrification would be more logical if the railroad right-of-way was also used by a new modern power transmission line, and it would be the power company's decision whether 60Hz ac or direct current were used, and the locomotives could accept either.
Why 400Hz? It is a frequency that allows efficient transformer design. (At MIT, I helped fund my expenses by designing transformers for Mystic Transformers in Winchester. My commute was on the B&M, and I had the engine pass given me by Ernie Bloss, in connection with my part-time work on the B&M, following a summer as student engineer at EMD in La Grange, where I had some input to the design of the GP-9 in 1952.) Lower frequencies require more mass in the magnetic structure to avoid saturation, while higher frequencies involve capacitor coupling losses across coil windings and across insulation between core and wire plus additional hysterisus losses in the core. Hsyterisus: The energy-change in the core lags slightly behind the change in core current, not a problem at 400 Hz, but a problem as frequencies climb. Also, if goes much above 1000Hz, radio interference and inteference with signal systems can be a problem unless shielding is well designed and maintained.
One question I have about your point of less weight, what is the advantage if you are going to have to add concrete and steel to the locomotive to bring the weight up for adhesion purposes. I realize the cores of the transformers are special iron alloys, but weight savings when you have eliminated the diesel and the fuel, is not of prime importance, for passenger service yes, for freight no. One other question not much discussed, Michael mentions 3900V DC, if you are going to have reasonably powerful locomotive consists you are going to have to have large current flows, and hence a pretty good cross-section on the contact wire. If you assume a locomotive consist of say 14 MW yielding a current draw of 3580A. 6000A is a common load limit for a substation, this would not be enough for two trains to be drawing full power in any section.
MichaelSol wrote: 5) The MILW legal department's proposal to re-electrify using a high voltage, state-of-the-art AC system, financed almost entirely by a $250 million grant from the FRA as a demonstrator project for railroad electrification. FRA had approved it; all that remained was MILW board approval.Over the estimated life of the system, by 2003 the respective total savings would have $221.6 million and $403 million. In that year, the annual savings would have reached $24 million and $49 milllion respectively.As it turned out, with substantially greater growth in traffic in the electrified zones, and substantially greater increases in diesel fuel costs than projected in the study, Milwaukee would have saved closer to $20 million by 1980 in annual operating savings.
Thanks to Chris / CopCarSS for my avatar.
Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.
beaulieu wrote: JT22CW wrote: Lee Koch wrote:Since privatization, German Railway refurbished the substations and caternary of a former East-German branch line, but the lines are dead now, because a private competitor was able to provide less expensive service with diesel-electricsNot likely that the service is less expensive. Electric service is still cheaper than diesel service. (Which railway are you citing, incidentally?—with all due respect, I must ask for the name, otherwise I'm going to assume this to be hearsay.)He is obviously talking about the Rubelandbahn. John Beaulieu
JT22CW wrote: Lee Koch wrote:Since privatization, German Railway refurbished the substations and caternary of a former East-German branch line, but the lines are dead now, because a private competitor was able to provide less expensive service with diesel-electricsNot likely that the service is less expensive. Electric service is still cheaper than diesel service. (Which railway are you citing, incidentally?—with all due respect, I must ask for the name, otherwise I'm going to assume this to be hearsay.)
Lee Koch wrote:Since privatization, German Railway refurbished the substations and caternary of a former East-German branch line, but the lines are dead now, because a private competitor was able to provide less expensive service with diesel-electrics
He is obviously talking about the Rubelandbahn. John Beaulieu
Exactly! And I might add, as I've mentioned on another thread, that open access has led to a plethora of private rail freight haulers turing to the newest generation of diesel-electrics, although most of Germany's main lines are electrified, albeit at 15kV/25Hz. I don't really know to what extent their use of diesels is dependent on overpriced power rates charged by the Deutsche Bahn/German Railway, which, despite open access, still manages the ROW.
As to JT's mention of the Trans-Siberian, well, the railroad and the power company are both State monopolies, so you can't really compare that with North America. Sure, electrification would be possible, but it's not just the initial capital investment in putting up the caternary; you also have to maintain it, even in remote areas!
No contemporary heavy (western) electrification? I forgot this one..link to photos
http://www.drgw.ws/gallery/gallery.asp?on=20060926
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Michael S., I hate to send you digging through your papers again...but I believe you have mentioned in the past a 1970's proposal by some PNW electric utilities to finance renovations of the MILW's PCE electrification. What was the payback mechanism? Just an added price to the electricity sold? Did the proposal cover the entire electrification system (transmission lines, catenary, poles, substations)? What about locomotives? Would it have filled in the "gap"? What was the payback time for their investment?
Anyone know if utility financing has been looked at for electrification schemes since then?
If dual-mode heavy-duty electrics-diesel electrics were available, electrification could come gradually without the need for frequent engine changes. This would remove one of the obsticacles. Again, perhaps in some cases the power companies could make the investment. It is their coal that is burned to make the electricity, and they pay for the transport of the coal.
Regarding the New Haven at the time of the purchase of the ex-Virginian N&W electrics: They did have to put new wire up from the east end of the New Haven Railroad Station to Ceder Hill Yaard and some of the yard tracks. plus most of the wire on the LIRR Bay Ridge Branch, and at Oak Point Yard in the Bronx, a good 15% of their electrification. Then Conrail took this wire down again! And Amtrak has put some of it back up as part of the electrification to Boston. The posts were still in place.
spikejones52002 wrote:it would be a lot cheeper and effecient if they went to 400hz instead of 60 hz. All the controls would be smaller and more effecient. Once they standarized 400 hz the cost would drop considerably.
it would be a lot cheeper and effecient if they went to 400hz instead of 60 hz. All the controls would be smaller and more effecient.
Once they standarized 400 hz the cost would drop considerably.
Not really.
The problem with 400 Hz is that it isn't suited for long distance transmission - inductive voltage drop is almost 7 times worse than at 60 Hz and skin effect starts raising resistive losses. I suspect it would be quite a challenge to design an MVA class transformer to operate as efficiently at 400 Hz as currently available transformers do at 60 Hz.
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