Main Line Electrifications

[arbfbe]

The a.c. vs d.c. argument is really sort of a bugabo anyway. AC current travels long distances better than DC but DC has always been easier to control at the locomotive. All of those MILW substations were there to convert AC to DC and DC to AC as needed. So the MILW used commercial AC to get the power to the rail lines and then DC to feed the trains. I have no doubt any modern system would do the same thing. They would take commercial AC power from the grid and feed lower voltage AC to the locomotives or feed DC to them. Note all the nice new AC diesels from EMD and GE have AC alternators in them but the output is converted to a very smooth DC voltage before computer controlled circuitry converts the DC back to very specific frequency AC to feed the traction motors. It would be plausable that feeding pure DC through the catenary to the locos would be the best solution to regulating the speed of the locomotives.

Lawrence Wylie was not convinced in the benefits of AC line voltages and ac locomotives when designing an upgrade to the MILW system in the early 1970s and wa pushing for an upgrade to the DC system in place with increased capacity to run longer and more frequent trains.

Lets face it , 12K, 25K or 50K voltages in a locomotive is a lot of electrons looking really hard for a way to get out of there. The 600v systems in modern diesels have shown they can generate 1000 hp per axle and that seems to be a limit to adhesion with out implementing more sophisticated wheel slip and power control systems.

[MichaelSol]

QUOTE: Originally posted by futuremodal
[In the Milwaukee thread, you had mentioned the MU'ing of electrics and diesels by the Milwaukee. Was this strictly one man control from the cab of the electric, or was there ever a situation where the diesels could draw current from the "mother" electric?

The engineer of the Electric could, through the diesel synchronous controller (Wylie throttle), control any diesels operating behind the electrics directly through the electric controls. The diesels could not, however, obtain operating power through the electrics. The only dual source equipment on the Milwaukee were special rotary snowplows designed to either accept overhead 3600 vDC power through a pantograph, or 600 vDC power from a diesel locomotive.

Best regards, Michael Sol

[MichaelSol]

QUOTE: Originally posted by 440cuin

DC is out dated for heavy main line electric trains. The modern heavy ore trains and high speed trains around the world use 50,000 volts AC. This has the capacity to give more power then the biggest diesel lashups ever used in USA.

50kvAC remains pretty unusual.

DC systems of all types, from 600 v to 3000 v, constitute 58,000 miles of European rail line, of which 3 kV DC is 77% of the total mileage. AC mileage of all types amounts to 74,000 miles, of which the 25 vAC, 50 mHz systems are approximately 64% of the total AC mileage, or 47,000 miles. It is interesting to note that, nearly 50 years after its introduction, the AC "standard" that was adopted in many cases on political grounds is, in spite of the strong political and economic backing of the French government, still only slightly ahead of the the 45,000 miles of 3 kVDC systems based on the Milwaukee Road design which are still hauling freight and passengers to this day and which never enjoyed a government support or export subsidy. If the recent trans-Siberian construction is not included, 3 kV DC would still be the predominant railway electrification type in Eurasia.

An interesting thing about the current AC "standard" is its history. The primary European AC standard prior to WWII was a 15 kVAC16Hz system. It was developed by Czech and German engineers. This remains the primary electrification standard of Germany, Austria, Norway, Sweden and Switzerland. There remains nearly 27,000 miles of this old AC "standard." Germany and the other named countries have shown little inclination to adopt 25kv50Hz "standard" AC systems.

Modern planning toward the new AC system is primarily a result of European "integrationist" policies, propelled by French economic interests, rather than technical economic justification.

Indeed, at the commencement of WWII, DC was the overwhelming standard of Europe. Spain had adopted 3kvDC in 1922, Italy in 1928, USSR, Belgium and Poland in 1926. France, Holland and England had adopted 1500 vDC systems. This was in spite of Westinghouse and German companies offering AC systems resembling today's technology. Indeed, Milwaukee Road itself had turned down a 14,000 v AC system proposed in 1914 by Westinghouse on both technical and economic grounds.

During WWII, the impetus for widespread AC electrification was primarily a Nazi initiative, after Germany overran most of Europe and began implementing AC railway electrification planning and design. So, AC electrification has an interesting political heritage.

After WWII, AC railroad electrification became almost entirely a political consideration. France was looking to exploit export markets and build its industry. In several areas of endeavor -- aircraft, armaments, engines -- France developed standards which were specifically designed to offer an alternative to conventional [i.e American or German] industrial technology, and pushed political alliances to facilitate markets for these alternatives.

In the electric locomotive development division of SNCF, engineers were specifically directed to escape the "dependence path." [Bouley, Japan Railway & Transport Review, 3:49-51]. The French chose the 25 vAC 50 mHZ standard because it was specifically different, but also marketable because it was cheaper to build. It was not until 1955 that the 25 vAC 50 MHz standard was, through French political pressure, accepted as a "standard" at European conferences.

What is interesting is the failure of that standard to become much of a standard, or at least how slowly it became one. While it is the cheapest to construct, and therefore virtually all recent construction by the fiscally shaky Russian government has been at this standard, the primary adopters of that standard were France, Great Britain and the Soviet Union.

A review of current electrification shows considerable 3 kV DC mileage throughout Europe, and that it is being extended in countries such as Italy and Poland. A 1999 European electrification conference showed several papers presented on improvements in DC railway electrification and I was surprised to see that research is continuing in this type of system; indeed, at that conference there were nearly as many DC papers as AC related papers.

Milwaukee was interesting from the standpoint that as it aged, it was not derated in capacity, but was increased at minimal cost.

A review of current electrification practice shows the durability of this 80 year old DC design standing up extraordinarily well against a subsidized and heavily promoted AC system.

Recent technological innovations in high voltage technology have favored DC considerably from a transmission efficiency standpoint, and so we may soon be at a point where DC will again be the preferred railroad electrification technology.

Best regards, Michael Sol

[mvlandsw]

QUOTE: Originally posted by futuremodal

QUOTE: Originally posted by MichaelSol

AC would probably be used, but regarding DC, Milwaukee Road used a 3600 vDC system. It's 5,500 hp Little Joes used approximately 1200 amps, or 1400 if the Joe went to its overload capacity of 7000 hp. The catenary used two 500,000 cm copper wires, with auxilliary feeder cable augmenting the catenary through either a 500,000 cm copper feeder, or a 750,000 cm aluminum feeder cable, with 4,000 or 6,000 kW substations located at approximately 28 mile intervals. The system could typically handle two 5,500 hp Little Joes and a four unit Boxcab helper, 7000 hp, without overheating the catenary.

It routinely paid for itself, even with relatively light usage, every 8-10 years.

Best regards, Michael Sol

Michael,

In the Milwaukee thread, you had mentioned the MU'ing of electrics and diesels by the Milwaukee. Was this strictly one man control from the cab of the electric, or was there ever a situation where the diesels could draw current from the "mother" electric?

The diesels produced their own power. They did not drawany power from the electric locomotive or the overhead wire.

[Randy Stahl]

Michael,
since you are in the Pacific NW perhaps you can find a way to save an old friend. Milw super dome #58 needs a friend badly. It's at the AOE facility and they have no plans for it . Breaks my heart to see it die.
Randy

[Anonymous]

QUOTE: Originally posted by MichaelSol

AC would probably be used, but regarding DC, Milwaukee Road used a 3600 vDC system. It's 5,500 hp Little Joes used approximately 1200 amps, or 1400 if the Joe went to its overload capacity of 7000 hp. The catenary used two 500,000 cm copper wires, with auxilliary feeder cable augmenting the catenary through either a 500,000 cm copper feeder, or a 750,000 cm aluminum feeder cable, with 4,000 or 6,000 kW substations located at approximately 28 mile intervals. The system could typically handle two 5,500 hp Little Joes and a four unit Boxcab helper, 7000 hp, without overheating the catenary.

It routinely paid for itself, even with relatively light usage, every 8-10 years.

Best regards, Michael Sol

Michael,

In the Milwaukee thread, you had mentioned the MU'ing of electrics and diesels by the Milwaukee. Was this strictly one man control from the cab of the electric, or was there ever a situation where the diesels could draw current from the "mother" electric?

[TH&B]

DC is out dated for heavy main line electric trains. The modern heavy ore trains and high speed trains around the world use 50,000 volts AC. This has the capacity to give more power then the biggest diesel lashups ever used in USA.

Mark in Utah;
A double set TGV high speed train has 4 x 6000hp units to accelatate a 1000 ton train to 188mph. The wires hold up fine.

[Randy Stahl]

The bottom line is that electricity is in great demand and the price of electricity is on the rise too. Until electricity becomes VERY cheap it's not worth the big expense of installing wires.
Randy

[MichaelSol]

AC would probably be used, but regarding DC, Milwaukee Road used a 3600 vDC system. It's 5,500 hp Little Joes used approximately 1200 amps, or 1400 if the Joe went to its overload capacity of 7000 hp. The catenary used two 500,000 cm copper wires, with auxilliary feeder cable augmenting the catenary through either a 500,000 cm copper feeder, or a 750,000 cm aluminum feeder cable, with 4,000 or 6,000 kW substations located at approximately 28 mile intervals. These substations had a one-hour overload capacity of 200% of rated capacity. By isolating sections to permit two or three substations per block, the system could easily provide as much as 36,000 KW or more to a train.The system could typically handle two 5,500 hp Little Joes and a four unit Boxcab helper, 7000 hp, without overheating the catenary.

It routinely paid for itself, even with relatively light usage, every 8-10 years.

Best regards, Michael Sol

[martin.knoepfel]

Main line electrification in mountain region would be with high-tension AC.

Low tension DC on the other side is the best solution for streetcars, LRT and subways

[Anonymous]

I'm not an expert on electricfication, but it appears to be used the most where you have lightly loaded trains running on a frequent basis, such as commuter rail and light rail systems. This is probably due to the limitations of an overhead catenary.

The light rail system in Salt Lkae uses a 700 VDC optimum voltage. This of course floats around due to a wide assortment of things. If we assume 700 VDC, we get a few numbers that can be scary:

A 4400 hp locomotive will consume roughly 750 watts X 4400 hp = 3.3 megawatts, or 3,300,000 / 700 volts = 4700 amps!!!!!! Even if by chance the system voltage is kicked up to 2800 volts, you're still looking at close to 1200 amps.

Not many wires can carry this current. Imagine if you have multiple engines pulling a coal drag..... Get the idea? You also have a substantial voltage drop along the wire, so you have to space the substations (DC power supplies) fairly close along the route.

You'd have to run a LOT of freight to pay for such a system.

Mark in Utah

[nanaimo73]

I think electrification was put back 30 years when BN placed that order for 370 SD70MACs. I am sure they must have given a lot of thought to electification at that time.

[Anonymous]

1. With the price of petroleum fuels and products going up, am wondering if anyone has heard any rumblings from any railroad corporate HQs about considering electrifying main lines?
2. I know freight traffic levels have been up in the past year, but based on the cyclical nature of the business, would this traffic increase be enough to initially sustain and eventually recover the costs of any such project.?
3. Which road(s) would benefit the most?
4. Where would potential electrifications be most likely?

My own observations and opinions on the subject are:
- This is probably a subject kept on the back burner in all Class 1 HQ's, and is dusted off in times such as these. However, I have not seen or heard of any accounts that any RR is considering such topics at this time.
- It would make sense to electrify mainly in mountainous regiions where railroads now expend more fuel to move the same tonnage of freight than across the plains or flatlands. Thus all North American Class 1's could benefit. to some degree, and stem initial installation costs by electrifying only the sections which now cost the greatest amounts to transit. To me this would include any main lines spanning the Appalachan's in the east and the Rockies in the west..