Main Line Electrifications

[MichaelSol]

QUOTE: by greyhounds:Whether the man is(was) "Curator of Transportation" or "Curator of Transporation History" at the Smithsonian has absolutely nothing to do with anything significant.

This is typical. You brought it up -- ""Historian?".

Yes, I answered.

That's about as far as the discussion needed to go.

Best regards, Michael Sol

[greyhounds]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by bobwilcox

Bill's current title is Curator, Division of Work and Industry, National Museum of American History. You can see his cv at: http://americanhistory.si.edu/about/staff.cfm?key=12&staffkey=706

Greyhounds would characterize this as an insignificant detail.

The Smthsonian's staff page is at the following:

http://www.si.edu/ofg/Staffhp/withuhnw.htm

That page contains the following text:

William L. Withuhn
Curator of Transportation History

National Museum of American History
Smithsonian Institution
PO Box 37012
MRC 628
Washington, D.C. 20013-7012
--------------------------------------------------------------------------------
Research Interests
writing book, "The American Steam Locomotive: An Engineering History, 1880-1960."
--------------------------------------------------------------------------------
Current Research Projects
"Woody Guthrie" (SITES); Smithsonian Presidio Trust Partnership Exhibits Proposal (San Francisco); Urban Transportatation Museum, Lowell National Historical Park (National Park Service, Lowell, Mass); "America On The Move," opening at NMAH 2004, a major Smithsonian reinstallation/exhibition of the social history of American transportation, 1876-2000.
--------------------------------------------------------------------------------
Recent Publications
"Rails Across America: A History of Railroads in North America," Smithmark Publishers (N.Y.), 1995.

Best regards, Michael Sol

Well, we agree. I do characterize this as an insignificant detail. Whether the man is(was) "Curator of Transportation" or "Curator of Transporation History" at the Smithsonian has absolutely nothing to do with anything significant.

Discussion of his writing on why studies of establishing main line freight electrification in the US came up negative would be relavent and interesting - but you're stuck on his title. (There were such studies on the BN, ATSF, ICG, Conrail, and the UP, maybe more.) They produced no electrification. And what main line freight electrification that did exist, Conrail, Milwaukee, Virginian, etc. -- was shut down in favor of diesel operation.

Now understanding why would be interesting. And maybe things have changed.

But you want to argue about one word in a title.

[MichaelSol]

QUOTE: Originally posted by bobwilcox

Bill's current title is Curator, Division of Work and Industry, National Museum of American History. You can see his cv at: http://americanhistory.si.edu/about/staff.cfm?key=12&staffkey=706

Greyhounds would characterize this as an insignificant detail.

The Smthsonian's staff page is at the following:

http://www.si.edu/ofg/Staffhp/withuhnw.htm

That page contains the following text:

William L. Withuhn
Curator of Transportation History

National Museum of American History
Smithsonian Institution
PO Box 37012
MRC 628
Washington, D.C. 20013-7012
--------------------------------------------------------------------------------
Research Interests
writing book, "The American Steam Locomotive: An Engineering History, 1880-1960."
--------------------------------------------------------------------------------
Current Research Projects
"Woody Guthrie" (SITES); Smithsonian Presidio Trust Partnership Exhibits Proposal (San Francisco); Urban Transportatation Museum, Lowell National Historical Park (National Park Service, Lowell, Mass); "America On The Move," opening at NMAH 2004, a major Smithsonian reinstallation/exhibition of the social history of American transportation, 1876-2000.
--------------------------------------------------------------------------------
Recent Publications
"Rails Across America: A History of Railroads in North America," Smithmark Publishers (N.Y.), 1995.

Best regards, Michael Sol

[bobwilcox]

Bill's current title is Curator, Division of Work and Industry, National Museum of American History. You can see his cv at: http://americanhistory.si.edu/about/staff.cfm?key=12&staffkey=706

[MichaelSol]

QUOTE: Originally posted by greyhounds

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by greyhounds
"One is a historian?" He was curator of transportation at the Smithsonian when the article was written. (Maybe he still is.)

He is Curator of Transportation History at the Smithsonian.

Best regards, Michael Sol

Well the book I cited says he is "curator of transportatiion", not Curator of Transportation History. See page 80 of "Railroad History", autumn 1999, #181.

It's best if you don't pick at insignificant details.

Railroad History apparently had a typo. I did not question you, you questioned my characterization of him as a historian. If you thought it important enough to question my characterization, don't be offended when you get an answer.

Best regards, Michael Sol

[greyhounds]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by greyhounds
"One is a historian?" He was curator of transportation at the Smithsonian when the article was written. (Maybe he still is.)

He is Curator of Transportation History at the Smithsonian.

Best regards, Michael Sol

Well the publication I cited says he is "curator of transportatiion", not "Curator of Transportation History". See page 80 of "Railroad History", autumn 1999, #181.

It's best if you don't pick at insignificant details.

[MichaelSol]

QUOTE: Originally posted by jchnhtfd

Quote from Michael Sol: 'It does however underscore the fact that railway engineering is often guided by conventional wisdoms rather than ongoing analysis.' regarding the tendency of railway engineers to be, in his view, somewhat conservative.

I think somewhere along the line, my point got missed.

I am speaking to the economic viability of an 80 year old system of railway electrification. I think that qualifies, by any analysis, as advocating a quite conservative view of railway electrification engineering. And this is particularly true from the standpoint of tens of thousands of miles of that system still existing and operating. Nothing is more conservative than well-engineered systems that continue to generate after nearly a century of operation a superb rate of return, for which modern propulsion systems still cannot match in terms of economic efficiency.

The problem is that in the discussion, many people are guided by conventional wisdoms. See the quote cited above: "3 phase AC is the cheapest form of moving energy. Period." Very emphatic. Very wrong. Yet, people seem to feel that this perception of AC power transmission is relevant to evaluating DC railway electrifications. That is found throughout this thread even though long distance transmission and locomotive power supply aren't quite the same things. Yet, that perception colors the debate.

Technology continues to change, in some cases requiring a reassessment of these conventional wisdoms that, in this case, makes assumptions that AC is just simply superior to DC. Since this is the startng place for many people -- see this thread -- the discussion doesn't go very far when the bias interferes with the discussion.

The first place that people, even engineers, start to fall flat on their face is this uninformed assumption: "AC is the cheapest form of moving energy. Period." To have a rational discussion, these mythologies have to be dispensed with. Once readers get the idea that these "inherent" advantages do not, in fact, exist at all, then the discussion can proceed to discuss genuine merits not simply obsolete ideas which not only distort the discussion, but are in fact wrong.

However, from the standpoint of future electrification, the steady, and remarkably rapid progress of HvDC suggests a trend to show that the very conventional reasons for AC railway electrification -- access to and ease of use of existing AC delivery installations -- will most likely become obsolete within our lifetimes. This is probable, not just possible. What is remarkable is that while much of the electrical engineering community is looking at this rapid evolution, this very thread, and indeed your post, shows the evidence that for this particular application -- railway electrification -- there is a stubborn resistance to even considering the operating and economic implications.

Something that good engineering, and in particular conservative engineering, always takes into account.

If there is a profound example of the advantages of conservative engineering, it is found in the 47,000 miles of existing 3kvDC railway electrification still operating around the world, nearly a century after the first wires for it were strung on the Milwaukee Road.

Hence, my point.

Best regards, Michael Sol

[jchnhtfd]

Quote from Michael Sol: 'It does however underscore the fact that railway engineering is often guided by conventional wisdoms rather than ongoing analysis.' regarding the tendency of railway engineers to be, in his view, somewhat conservative. Quite true. It is part of the nature of the beast: railway engineers are trained to think in terms of what is going to work, and keep working, for anywhere from 50 years to a century, and it does sometimes give the impression of being rather conservative. There are, however, examples to the contrary, and instances of innovative thinking. Unfortunately, the corpses of the relevant advocates litter the landscape, and tend to deter the rest of us from being too radical.

The remarks regarding high voltage DC transmission for bulk power transfer are quite well taken, and I, for one, have no problem with them. They are all true. They are also almost irrelevant to the ostensible topic of this thread, which is main line electrification.

As is true of so many things in capitalist societies, the question of main line electrification, never mind the details of how it is to be implemented, is primarily an economic question; engineering, and engineering choices, are an important part of the equation, and are gone over with great care to determine the best return on investment. There is no room for ideology there. The fundamental question, which the railway and the engineer must solve, is 'what is the best way (in terms of return on capital) to move the expected traffic from point X to point Y'. If it turns out that a wheelbarrow is the best approach, so be it. If it involves electrifying -- by whatever means -- a given line, so be it. In most cases, it doesn't involve electrification.

If it does involve electrification, then the engineer is -- again -- faced with the task of determining the best way to do it.

Yes, railway engineers tend to be conservative. Frequently, railway equipment and fixed assets appear to be (to the uninitiated) overbuilt. But, as I said above, I would still like to think that railway engineers produce a product with exceptional reliability and safety, at a reasonable cost.

[MichaelSol]

QUOTE: Originally posted by greyhounds
"One is a historian?" He was curator of transportation at the Smithsonian when the article was written. (Maybe he still is.)

He is Curator of Transportation History at the Smithsonian.

Best regards, Michael Sol

[greyhounds]

QUOTE: Originally posted by MichaelSol

QUOTE: Originally posted by greyhounds

I'd reccomend a back copy of "Railroad History #181" - autumn 1999 from the Railway & Locomotive Historical Society. It has two good articles on the subject.

1) "Risk and the Real Cost of Electrification" by William L Withuhn
2) "Why the Santa Fe Isn't Under Wires" by Wallace W. Abbey

Good writing on why the decision was made not to electrify.

I know one of the gentlemen quite well, and have an immense personal regard for him, but, with all due respect, of these two gentlemen one is an historian and the other a retired public relations executive. and neither has a management or engineering background. Railroad History, while I enjoy the journal, is usually not thought of as a serious journal of engineering analysis. What, exactly, did they discuss?

Best regards, Michael Sol

"One is a historian?" He was curator of transportation at the Smithsonian when the article was written. (Maybe he still is.) I don't think he'd put his name, or the Smithsonian's, on a poorly researched paper.

Anyway, the main point was that the financial risks of electrification are too great. The projected ROI was fantastic, on the order of 32% for the UP. But, the costs were all up front and the payback was years in the future. The company would have a negative cash flow for 9-10 years. Sensativity analysis showed great risks if everything didn't go as planned.

They were projecting diesel fuel and electricity costs 10 years plus out. There was no certainty. In the end it was a "bet the company" proposition. If everything went right there would be tremendous benifits, but if everything didn't go right the corporation would be destroyed financially. There is no way everthing was going to go right. The risk was too great.

Now they did note that the major expense was the new locomotives. If existing diesel electrics can be modified to operate as straight electrics that may reduce the risks.

[MichaelSol]

QUOTE: Originally posted by uzurpator

QUOTE: [i]from Michael Sol/[i]However, future planning does not seem to account for the fact that 100kv, 200 kv, 350 kv and 500 kv AC supply sources will not be available in the not-so-distant future, as these lines are converted to DC for its inherent long distance transmission efficiency and environmental advantages.

3 phase AC is the cheapest form of moving energy. Period. HVDC is used where it is impossible to string typical high tension line - usually to connect an island to a mainland or to connect two off-phase systems. Cost of a high power converter is astronomical.

This is pretty outdated. And more words like "astronomical."

AC was preferred as recently as the 1970s but that view began to change in that decade as engineers looked at the overwhelming success of the John Day Dam HVDC line to California.

It does however underscore the fact that railway engineering is often guided by conventional wisdoms rather than ongoing analysis.

This is the current view on HvDC.

With sources.

According to Siemens Power Engineering Guide, Transmission & Distribution, 2004, p. 36, the primary advantage of DC for high voltage transmission is "economic transmission of bulk power over long distances." They also note that it is used "for connection of asynchronous power grid systems," and for "connection of synchronous but weak power grid systems," as well as for "increasing the transmission capacity of existing rights-of-way." 1/36, p. 1.

Siemens notes that HVDC systems can "stabilize weak AC links or supply even more active power, where the AC system reaches the short-circuit capability," but that, in cases where bulk power is transmitted over long distances, which they see as 1,000 km or more, the HVDC is economically superior to HVAC as it can transmit more power, more efficiently.

A paper entitled "High Voltage Direct Current (HVDC) Transmission Systems Technology Review Paper" by Rudervall, Carpentier, and Sharma, prepared for the World Bank, listed the advantages of HVDC over HVAC in the following order: environmental advantages, the most economical to build and operate, facilitates asynchronous connections, power flow control, and the stability and power quality of the transmission.

According to these gentlemen, the cost of HVAC systems begins to exceed the cost of construction of a comparable HVDC system when the transmission distance exceeds 670 km which is only 419 miles. At 1000 miles, the cost of a comparable HVDC system is 75% the cost of an HVAC system, and the differential increases as distance increases, that is, the cost of the HVAC systems increases more rapidly than the cost of the HVDC with increasing distance. [p. 6].

They specifically note: "The investment cost for for HVDC converter stations are higher than for high voltage AC substations. On the other hand, the costs of transmission medium (overhead lines and cables), land acquisition/right of way costs are lower in the HVDC case. Moreover, the operation and maintenance costs are lower in the HVDC case. Initial loss levels are high in the HVDC system, but they do not vary with distance. In contrast, loss levels increase with distance in a high voltage AC system." [p. 7].

Interestingly, "technological developments have tended to push HVDC system costs downward, while environmental considerations have resulted in pushing up the high voltage AC system costs."

The largest project on earth is in Brazil, and dwarfs our Bonneville Power project lines, carries 1,440 MW. It operates at 600 kVDC with a rated power of 6300 MW, transmitting over 490 miles, and was gradually phased in to current capacity in the mid to late 1980s. "HVDC was chosen basically for two reasons: partly to be able to supply power from the 50 Hz generators to the 60 Hz system, and partly because an HVDC link was economically preferable for the long distance involved." In 1990, an HVDC project in India brought on line a 500 k VDC system carrying 1500 MW over 500 miles, and the "most important reasons" for using the DC system were "better economics, halved right of way requirements, lower transmission losses, and better stability and control."

As I remarked when I suggested that DC utilizes the cross section of the conductor more efficiently than AC, "HVDC can carry more power for a given size of conductor." [p. 14].

The World Bank study states that the general convention for choosing HVDC over HVAC is when "large amounts of power (>500 MW) needed to be transmitted over long distances (>500 km, 310 miles). Transmitting under water was the next most commonly considered reason, and connecting asynchronous AC systems the third most common reason for using HVDC.

The paper points out, however, that technological advances are continuing to bring the costs of HVDC installations down compared to HVAC, and that the economic feasibility point in favor of HVDC systems as a transmission medium -- as opposed to a purpose relating to stability or effectuating trans-grid power transfer -- may now be as low as 200 MW and only 40 miles. This is very significant, not only because of the rapidity with which this transmission frontier was reached -- this was fantasy just ten years ago -- but how close this is, relatively speaking, to requirements of heavy DC railway electrification, particularly in the context of auxilliary use of railway corridors for electric power transmission.

Indeed, Siemens reports that 10 of 17 recent HVDC installations that it has made around the world were for long distance transmission purposes, rather than for other -- stability or AC system integration purposes. What is also interesting is that of the remaining seven systems which Siemens has constructed, so called back-to-back, several have been built in the US to facilitate AC grid connections. There are now a number of DC systems which are now being constructed simply to buffer AC systems. The "ease of conversion" which long justified AC technology has been found to have serious defects and Edison would probably be gratified that engineers now must turn to DC to permit AC to AC systems transmission. Interestingly, I can find no cost analysis that adds the cost of these HVDC back-to-back systems to any "true" cost of the associated HVAC systems that require them. The HVDC systems have no such hidden but necessary costs.

A U.S. Department of Energy Symposium held August 3, 2001, "Analysis and Concepts to Address Electric Infrastructure Needs", strongly suggested expanding general use of HVDC lines in the United States, arguing that conversion of existing HVAC lines to DC would double the capacity of such systems and that fact alone justified a review of existing HVAC systems as a way of meeting demand which has exceeded current transmission capacity in the United States. A prophetic paper given the recent AC power grid fiasco in the Northeast. Engineers at the symposium pointed out that not only could HVDC move substantially more power than a similar HVAC system, but that "for an AC line with the same conductor and insulators per phase, losses were 50% higher" than for the HVDC systems and the efficiency of HVDC systems meant power savings. This was the basis for my statement that, the longer the system, the greater the DC advantage. "A simple rule of thumb may be applied in that the cost of a DC transmission line may be 80 to 100% of the cost of an AC line whose rated line voltage is the same as the rated pole to ground voltage of the DC line ... [however] the cost advantage of DC transmission for traversing long distances is that it may be rated at twice the power flow capacity of an AC line of the same voltage." "HVDC Transmission,"Dennis Woodford, Manitoba HVDC Research Centre, 3/18/98.

An IEEE paper suggests the same: "Challenging Opportunities for Incoming Engineers in HVDC Transmission Technology," Katancevic, IEEE Paper, 2002
Winter Meeting: "Cost of transmission losses caused with HVDC are far and away lower than costs of HVAC transmission losses." ... "For very long distance transmission links, ... decisive [also] are the construction costs [in favor of HVDC]."

The point of all of this is that conventional wisdoms can create compelling orthodoxies even among professionals. Even the history books write, as a form of drama, the "battle" between Tesla and Edison over AC vs DC and that "AC won." This became a conventional wisdom that somehow DC was just a electrical stepchild, an obsolete approach to mass electrification that never could go very far for a variety of technical reasons. However, as current trends indicate, DC is now, ironically, the medium that enjoys cutting edge technological advances which demonstrate decisive economic superiority over AC in precisely those areas which the general misconception believed DC was most inferior, high voltage transmission.

This is why DC railway electrification papers are once again as common as AC papers at international conferences.

Best regards, Michael Sol

[arbfbe]

Moving the electricity and powering the locomotives are two completely different engineering problems. The MILW solved them by using high voltage AC in pretty thin wires to get the power from the dams in Montana to the substations along the line. There the conversion to DC was made to power the locomotives. The locomotives were supplied directly by the trolley wire which was supplemented the entire route byt a substantial copper feeder. The feeder wires were 8 or 10 times the size of the catenary wire or the HVAC lines. These heavy copper cables would have been prohibitively expensive to use to move DC from the dams to the mainline. Poles would have had to have been really close together to support the weight realtive to the length. I would suggest any future railroad electrification would use the same technology. Solid state electronics, computer automation and technological advances make the cost of a substation less of a capital constraint than when the MILW electrified their lines in the early 1900s.

[Anonymous]

MichaelSol:

Amount of substations per sections does not matter really - the thing is that you cannot really go above ~2kA continuus without some major engineering in place. To lower currents you need to increase voltage. 6 kV DC - feasible, but anything more then this... I dunno. There might be problems with extinguishing arc with DC voltages so high and possible tight clearances.

On 3kV DC a typical 8000 hp universal loco may go as high as 4 kA. Getting more of them on a single section - bad thing... But not a problem with 25 kV AC (or 15 kV AC - for that matter).

I suspect that the 5 kV loco costs are not an issue now :)

QUOTE: This was something we noted: AC locomotives appeared to have shorter economic service lives than standard DC equipment.

With many AC locos reaching 50 year time frame... Besides - noone builds straight DC locos anymore.

QUOTE: This no doubt remains true for electric locomotives as well. And, as Alan points out, anything placing voltages on the order of 20k, 25k or 50k directly into the confines of a locomotive body shell that is then converting that power to DC and back to AC again, represents a lot of high voltage activity in a very small space.

Oh come on - you know it is not true. In a comparsion to a straight DC loco an interior of a modern AC loco is just a set of boxes. No 3kV relay boxes, switches etc. ANd the HIgh voltage goes as far as the transformer. Usually all connections are made on the roof of the loco. There is no live 25kV in the vehicle.

QUOTE: Russian Railways reports 56 empoyee deaths per year related to electrification -- as opposed to other railway related causes -- apparently most of them occuring on AC sections.

Sources?

Anyhoo - SZD employs about 1,5-2 million people. Stellar safety record...

QUOTE: However, future planning does not seem to account for the fact that 100kv, 200 kv, 350 kv and 500 kv AC supply sources will not be available in the not-so-distant future, as these lines are converted to DC for its inherent long distance transmission efficiency and environmental advantages.

3 phase AC is the cheapest form of moving energy. Period. HVDC is used where it is impossible to string typical high tension line - usually to connect an island to a mainland or to connect two off-phase systems. Cost of a high power converter is astronomical.

QUOTE: Well, 3600 vDC costs about $45,000 per mile to electrify, heavy conductor and all. This $1 mi per mile figure sounds inordinately high.

Omg - check current prices.

Recently, to upgrade an existing catenery to 200 kmh polish railways paid ~$250.000/km. That works out to $400k per mile (2 tracks) - that is sans substations, connection ot the power grid and masts. 1mil/mile is usual cost.

$45k will not buy you the necessary wire, let alone the whole catenary ;)

Townsend:

Except for a few rare circumstances (like arc furnaces) noone uses 100+ kV for anything else then transmission.

In this part of the world 3kV DC stations are fed from 6 to 20 kV 50hz, stepped down to 3,6 kV/50 hz then rectified, and smoothed.

To get from 110 kV the voltage usually goes down 110 -> 40 -> 20 -> 10/6 kV.

[MichaelSol]

QUOTE: Originally posted by jchnhtfd

The AC traction motor is far simpler than a DC traction motor, and has almost overwhelming advantages. If this were not true, there would never be such a thing as AC diesels with their higher price tag. Railroad equipment purchasers and maintenance personnel are not fools...

Unless things have changed, the traction motor was not the high cost maintenance item on diesel-electric locomotives. On our cost per hp maintenance curves for the Milwaukee Road diesel fleet as of 1974, road diesel hp maintenance costs remained fairly constant for approximately the first three years after purchase, then began a steep rise. By the eighth year, the cost per hp of maintenance exceeded the costs of acquisition of new power. This drove purchasing decisions for the diesel-electric fleet. However, the traction motors were not a significant part of that cost, at any point in the curve. The weak spot was not the DC traction motors, the weak spot was the diesel engine.

By comparison, the electric fleet's cost per hp maintenance curves were essentially flat. They were, in nearly all instances, approximately one-third the cost per rated hp of the maintenance of a road diesel-electric at year four, even though the newest units were already a quarter century old, some of the electrics in the fleet were nearly 60 years old and for the period of the study, still in mainline service.

I do not recall traction motor cost or failure being a significant driver of the existing cost of maintaining the electric fleet. An AC motor may be a superior motor to the DC motor, but in economic terms, under most conditions the DC motor delivers the necessary performance without a significant overall maintenance cost difference.

Is it more difficult to maintain? Apparently so.

Is that a significant economic argument in favor of the AC traction motor? If that's all there was to it, sure. But without seeing some current comparable data, the low actual cost of DC traction motors in heavy mainline service, many of them quite old, suggests to me that excepting unusual service demands, there isn't an economic justification for the substantially higher locomotive purchase price, particularly since the design simplicity of the AC motor itself is accompanied by a significant increase in the complexity and cost of the "locomotive" that is able to use the AC motor.

And, the adoption of an AC traction motor does nothing to primary source of increasing maintenance costs: the diesel engine. I guess they've solved a problem that wasn't really a problem, and done nothing for the component that is the cause of 90% of the maintenance costs. This justifies .... what?

The question raised to me is whether the benefits meet or exceed the opportunity cost of the higher cost of acquisition, but also whether or not the more complex machine will ultimately have the same economic service life. A rule of thumb is well tested that more complex machines fail more often than less complex machines. I guess time will tell for the AC diesel-electric and whether that rule has finally been turned on its head.

However, Alan makes a good point. Any characteristic that is genuinely favorable for the AC traction motor is perhaps most efficiently utilized in a DC traction context in order to maximize its economic benefits.

Best regards, Michael Sol

[arbfbe]

All of the power fed to the electric locomotives was 3000, 3300 and then 3600 vDC. Speed control was by means of series, series-parallel and parallel connections between the traction motors. Threre were also resistance grids, shunt connections between the motor fields and other things I am only aware of and have no real understanding. Then the MILW wanted to change AC voltages they used transformers and when they wanted to change AC to DC they used an AC motor to run a DC generator to create the voltage they wanted to power the locomotives. Today there are alternatives available for the same purposes but the majority of AC to AC conversions still use transformers.

Modern AC diesels use an alternator to generate AC power. That power is then fed into a set of rectifiers where it is converted into smooth DC current. That DC current is then converted back into AC at the frequency need to give the speed of the locomotive desired. Thus a pure DC feed to the locomotives could be used to power either DC or AC traction motors in one of a new generation of locomotives based on current technology. AC traction motors on electric locomotives used in mountain territory have a number of attractive advantages. Regeneration using the AC traction motors should be much simpler on a DC line since the current would just need to be changed to DC to feed the trolley and would not have to be phase matched to the supply voltages.

[Anonymous]

I am still a bit hazzy on the mechanichs of DC electricity. I know DC cannot be stepped up and stepped down like AC can, so how is power in a high voltage transmission line, say 132kv, stepped down to 3000 volts for use in a locomotive? I do know that in many railway applications, when high voltage DC is used, the motors in a 6 motor engine will be connected all 6 in serise, 2 groups of 3 in serise and finally 3 groups of 2 in serise, so the maximum voltage across each motor is never more than 1500 volts. I admire the robustness of high voltage DC applications, but I feel i have to run with the PACK and go for 25kv AC.

[MichaelSol]

QUOTE: Originally posted by uzurpator

Wires cost ~1mil/mile. So to electrify you'd need to spend $315 million. That money will cover switching in that yard for several hundread years ;)

Well, 3600 vDC costs about $45,000 per mile to electrify, heavy conductor and all. This $1 mi per mile figure sounds inordinately high.

Best regards, Michael Sol

[MichaelSol]

QUOTE: Originally posted by greyhounds

I'd reccomend a back copy of "Railroad History #181" - autumn 1999 from the Railway & Locomotive Historical Society. It has two good articles on the subject.

1) "Risk and the Real Cost of Electrification" by William L Withuhn
2) "Why the Santa Fe Isn't Under Wires" by Wallace W. Abbey

Good writing on why the decision was made not to electrify.

I know one of the gentlemen quite well, and have an immense personal regard for him, but, with all due respect, of these two gentlemen one is an historian and the other a retired public relations executive. and neither has a management or engineering background. Railroad History, while I enjoy the journal, is usually not thought of as a serious journal of engineering analysis. What, exactly, did they discuss?

Best regards, Michael Sol

[greyhounds]

I'd reccomend a back copy of "Railroad History #181" - autumn 1999 from the Railway & Locomotive Historical Society. It has two good articles on the subject.

1) "Risk and the Real Cost of Electrification" by William L Withuhn
2) "Why the Santa Fe Isn't Under Wires" by Wallace W. Abbey

Good writing on why the decision was made not to electrify.

[jchnhtfd]

Just a few little comments here...

The AC traction motor is far simpler than a DC traction motor, and has almost overwhelming advantages. If this were not true, there would never be such a thing as AC diesels with their higher price tag. Railroad equipment purchasers and maintenance personnel are not fools...

Multi-phase AC was NOT invented to solve the 'problem' of 'no push' twice each cycle. Multi-phase -- most usually three phase -- power was developed to address the problem of starting an AC motor; a single phase AC motor will not, without auxiliary devices, start on its own (although it will keep running very nicely, thank you). Without getting all Steinmetz here, suffice it to say that with three phase power, you can get a very nice rotating magnetic field, which will drag a rotor (which can be unbelievably simple) along with it, with about as much torque (and power) as you want -- and if you can control the frequency, at any speed you want. This is what modern variable speed drives, such as are used on AC diesels and electric motors, do: you control the torque by the current in the field, and the speed by the frequency supplied to the motor. Wheel slipping? No problem, my friend -- reduce the current slightly. Want to go faster? No problem -- increase the frequency (and current). There is nothing complex about any of it, and maintenance is dead simple -- something fries, pull the board and slip in a new one.

I am sorry that Michael feels that those of us in railway engineering are planning for the past, rather than the future; I'd very much rather not think so... and, in terms of on-board equipment, I'll stick with my alternators, static converters, and AC motors for the time being -- if I never see another commutator again, it's going to be way too soon!

[MichaelSol]

QUOTE: Originally posted by uzurpator

Spacing on the polish system ( 3kV dc) is between 5 and 20 miles - depending on the traffic density. Typical substation is about 4,5 MW continuus and currents may reach 2,6 kA when ET42 (6600 hp) class loco is working hard.

Considering that a single Little Joe was 5500 hp - that is about the same - buuut - with longer substation spacing (28 miles - as yau claim) the loss of voltage might be higher. I suspect that currents could go up to 3 kA then... impressive to say the least.

Milwaukee voltage drop could drop as low as 2400 volts between substations. A Little Joe might be pulling as much as 1800 amps IF it was working hard. The locations of substations was such that usually at that distance, Joes would be working on flat ground, with a couple of exceptions. But, naturally, the substations tended to be located on Mountain grades, with slightly closer spacing.

Two Joes could pull 3600 amps if the voltage dropped to 2400 volts. DC systems, however, generally pair substations, whereas AC splits the power sources so phase is not a problem. Indeed, with the DC system, three or more power supplies can be fed to one train if necessary.

On DC then, a typical power pair, Drexel and East Portal substations on the Rocky Mountain Division, have a combined capacity of 12 MW, to feed an energized section. At one hour overload on this 28 mile section, the capacity is 24 MW. For two Joes using 3600 amps, they have available to them 5000 amps, with an overload capacity of 10,000 amps. Big power, but it is carried on that section by 1,000,000 cm of direct contact wire, 500,000 cm of copper feeder cable, and 750,000 cm of aluminum feeder, for a total of 2.25 million cm of capacity.

It was routine to have as many as four Little Joes drawing from an energized section of track. Of course, if one set was going uphill and one downhill, the downhill set was generating power of its own into the trolley system, and represented an additional source of power for the uphill train.

The ability to raise and lower trolley voltage at the substations enabled more efficient movement of heavy trains, sometimes it was useful to deliver less than 3600 vDC to the engines.

The DC design was simply rugged. The fact that 80 year old 3000 vDCsystems continue to operate on more railway mileage than just about any other form of electric traction it testimony to both their economy and reliability.

GE had tested a 5000 vDC design for the Milwaukee. The only reason it was not used was economic. The cost savings of copper cable permitted by the higher voltage was more than offset by the hgher costs of manufacturing the locomotives to operate at that voltage. The 3,000 vDC resulted from the intersection of two cost curves, nothing more.

The DC traction motor was, at that time, far superior to anything else. The use of relatively low voltqges DC, compared to AC, was primarily a historical artifact that no longer exists: the difficulty of converting DC voltages from one to another, compared to the ease of converting AC voltgages. That problem no longer exists. For any benefits of any particular voltage insofar as distance of transmission is concerned, AC and DC now compete on relatively equal terms.

The modern AC motor ostensibly changes the equation a bit, but the bottom line is that an AC "locomotive" is now a substantially more complex machine than its DC counterparts, and regeneration remains an expensiive option with AC, whereas it is an inherent design benefit of the DC systems. This was something we noted: AC locomotives appeared to have shorter economic service lives than standard DC equipment.

Note that DC diesel-electric locomotives sell at asubstantial price advantage to AC locomotives, notwithstanding that the AC design is not "new". This no doubt remains true for electric locomotives as well. And, as Alan points out, anything placing voltages on the order of 20k, 25k or 50k directly into the confines of a locomotive body shell that is then converting that power to DC and back to AC again, represents a lot of high voltage activity in a very small space.

Russian Railways reports 56 empoyee deaths per year related to electrification -- as opposed to other railway related causes -- apparently most of them occuring on AC sections.

However, future planning does not seem to account for the fact that 100kv, 200 kv, 350 kv and 500 kv AC supply sources will not be available in the not-so-distant future, as these lines are converted to DC for its inherent long distance transmission efficiency and environmental advantages. The advantages that the Transformer gave to AC systems will be gone entirely, as AC rail electrification will almost certainly have to incur the expense of rectifier substations rather than transformer substations, and the additional cost of inverters if they care to regenerate back into the power grid.

Once again, rail planners may be preparing for the past, rather than for the future.

Best regards, Michael Sol

[Anonymous]

No one has touched on one of the biggest impedements to the economies of electrification in the US, namely property taxes. Electrification significanly raises the real property value and thereby the taxes. For anything less than very heavily used lines any reduced operating costs resulting from the use of electricity will be spent on local property taxes. And this is totally ignoring the interest needed on the loans to pay for the infrastructure, which in a few areas of the US invokes another set of taxes.

There are two notable exceptions to the above. The electrified railroad can be a government or quasi government agency, as Amtrak , SEPTA, NJDOT, and the like. They are generally immune from taxes. This was the case in much of Europe until recently and is still the case in places. The other exception has been utilities who could until recently automatically pass on their costs to the consumers and thus had no real incentive to find the true lowest cost solution.

[Anonymous]

ungern: i used a hyperbole for the fact that fuel used by switching is insignificant to the cost of electrification... ;)

Think about it - UPRR Bailey Yard has 315 miles of track. Wires cost ~1mil/mile. So to electrify you'd need to spend $315 million. That money will cover switching in that yard for several hundread years ;)

[Tulyar15]

QUOTE: Originally posted by ungern

Actually, I won't ever suggest 3rd rail in a switching yard.

When the Southern Railway in England embarked on its big electrification programme in the 1920's and 1930's, it used 3rd rail and only passenger trains were electric (all worked by EMUs). When WW2 broke out, shortage of good quality coal prompted the Southern to build some electric locos for freight trains. Because it would be impractical to have 3rd rail in switching yards, the yards concerned were equipped with simple trolley wire. When the lines from London to the Kent Coast ports were electrified on 3rd rail in the 1950's more yards were wired and more locos built with both pick up shoes and pantographs. But in the 1960's a class of locos called "Electro Diesels" which were basically electric locos with a small (600hp) diesel engine on board were built. These proved to be much more useful than the straight electric locos which were then scrapped and the yards de-wired. But now Brush are fitting an old Class 86 electric loco with batteries to provide a more eco-friendly alternative to the Elector-Diesels, a few of which are still running.

[arbfbe]

futuremodal,

While the FL9 concept was a nice idea you end up with expensive units that spend a lot of their time outside the electric zone where all the high priced dual mode equipment goes to waste. That is not a great way to utilize capital. It worked on the NH account the units were into the electrified trackage every day. Now think about the MILW. The dual use units leaves Tacoma and works over the Cascades and in your secnario only on the short sections of mountain grade. Full diesel through Idaho to St Paul Pass where the dual use pantographs are raised. Then out of trolley from Haugen to Butte where the pans go up again for the mountain. Then no pan use all the way to St Paul or KC. So you might as well cut them off in Harlo and turn them back. So they become restricted use units in which case you might as well buy straight electrics for the lines west of Harlo.

The NH was an ac railroad while the MILW was dc. None of the equipment would have been interchangable. The FL9s worked since the third rail was compatible with the diesel traction motors. They were not compatible with the catenary with it's ac voltages.

The measure of work for electricity is Watts. You get watts from multiplying the volts times the amps. Volts is the pressure of the electricity through the system and amps is the volume of the electrons through the system. Now you can get 100 watts of power in any number of ways so long as volts x amps = 100w. P=IxE if you remember your high school physics. If you have 100 volts you only need to shove 1 amp through the iwres to have 100 watts. Or you can use 1 volt to move 100 amps. That 1 volt does not move too much through wires though since the wire has resistance. The 100 v option is better for over coming the resistance of the wire. Since you are only trying to move 1 amp the wire does not have to be very big, you are not trying to move a lot of volume.

On the users side, high voltages are a problem. With all that power they need a lot of insulation to keep Readdy Kilowatt coralled where you want him. There it makes to use bigger wires for a shorter distance to get the work done. The MILW AC supply to the substations was pretty small wire compared to the copper feeder on the trolley poles that brought power from the substation to the catenary. The dual catenary was about 4' or wire to make a pound of copper while the dc feeder at the same 3600 v DC was about 4# of copper for every foot of wire. So it took about 4.25 lb of copper for every foot of railroad to feed a couple of trains at a time. On the other hand, the AC commercial lines fed substations, small towns and other rural areas.

Another argument AC proponents hand out is since the AC cycle goes positive to negative with each cycle change the line system will break an arc while the continuous nature of the DC will hold the arc until something burns through or a breaker kicks out. The DC proponents will say how that same factor means you have a period at each cycle change where there is not any pu***o make work. The AC people developed multi phase AC to counter that short coming.

At one time the AC vs DC arguments were just as strongly argued as the standard gauge vs narrow gauge battles. With today's technology i doubt there is all that much difference with a newly designed system in either mode. The big battle is to get someone to make the investment. The saying goes ithat electrification is the program every one wants to be the second company to take the plunge.

[Anonymous]

QUOTE: Originally posted by CSSHEGEWISCH

Although dual-mode (FL9-type) locomotives to cover a tunnel-type electrification sound like a good idea to improve utilization, they still have their limitations. Amtrak generally does not allow its P32's to stray beyond Albany, which pretty much restricts their range to not a whole lot too far beyond the end of third rail. Dual-mode locomotives on a tunnel electrification could not be allowed to stray too far from the mainline that has the tunnel, which would restrict their utilization to some extent. They would also be more expensive than conventional diesel-electrics, which would make it hard to justify their purchase when their operating range would still be restricted.

That was one of the things that pops to mind. However, there are two different subjects I want to broach regarding the FL9 concept: (1)Why the Milwaukee did not consider an FL9 type locomotive, and (2)if an FL9 type solution would work to allow more capacity through the Cascade Tunnel.

1. My thought regarding the Milwaukee circa 1970 was that they were faced with an electrical physical plant that needed to be upgraded (and possibly expanded) or eliminated. With a bi-modal locomotive such as the FL9, they could have eliminated much of the catenary over the more water level grades such as the Clark Fork segments without having to establish new crew districts and locomotive transfer areas. This way they could have focused on upgrading only the mountainous segments of the electrification at a fraction of the cost of upgrading or expanding the entire electrical physical plant.

2. For the current Cascade Tunnel, one would have to balance the cost of rostering FL9-type locomotives that are limited to a small geographic area against the benefits of increasing capacity, perhaps doubling capacity over Stevens Pass (aka no time delays to ventilate the tunnel). I also wonder about clearances in the Cascade Tunnel, whether one can even restring catenary without interfering with double stacks, or whether the third rail option might work (at least in the tunnel).

[ungern]

Actually, I won't ever suggest 3rd rail in a switching yard.

Also hi voltage transmission lines running alongside the mainlines could allow the railroads another income source. Amtrak actually makes money by allowing open access of its transmission lines that power the NEC in the wholesale electricity market.

Uzurpator, where did you get the 0.00000005% number for amount of fuel used while switching?

Ungern

[TH&B]

Ungern;
I think that's a very good question, I've never realy thought of that. I think the fuel used by railroad switching is actualy alot and wastefull and in fact CPRail recently quoted that their switchers are killing them in fuel. Railroads are always using older downgraded diesels and "double switching". If switching costs could be reduced railroads could maybe compete better with shorter hauls.

Just electrify the yards with DC I suppose and use very simple switchers with pantographs.

But please don't suggest to use 3rd rail hehehe, for the swicthmens sake.

[Anonymous]

Switching - about 0.00000005% of fuel used by railroads

[ungern]

This makes me ask a question.

How about the railroads electrifying their yards? This minimize the expense with much of the benifits because isn't yard switching a big use of diesel fuel. Already railroads are beginning to buy "green goats" for yard switching because they're more effecient why not take it a step further and just electrify the yards and leave the line for the diesel-electrics?

Ungern
BNSF fan