Electric freight locomotives

[Lyon_Wonder]

In the early part of the 20th century and up to the 1970s, several railroads used pure electric locomotives on electrified lines, which were by the 1970s abandoned or replaced with diesel electrics.  Two of railroads that had electrified lines which weren’t located in the northeast were Milwaukee and Great Northern.  Milwaukee in particular operated the Little Joe, an electric locomotive built by GE, originally built for the USSR back in the late 1940s and sequestered by the US government for use by domestic railroads.  If either GN (part of BN after 1970) or Milwaukee didn’t abandon their electrified lines and the continued to use electrified wires, I wonder what types electric engines they would have purchased to replace their aging 1940's vintage units?  In the mid 1970s BN consider the idea of electrifying some of their routes as a response to the rising price of oil during the oil crisis.  Did EMD or GE, at one time or another in the 1960s and later, toy with or propose designs for electric freight engines?  If such a need arose they could have leveraged the components of their existing diesel designs, minus the prime mover, to run off electrified wire.            

[Lyon_Wonder]

 

 

 

 

[tutaenui]

An interesting question and I think the answer is probably not. I suspect one of the reasons Milwaukee abandoned electrification was not so much that it was cheaper to run an all diesel operation but that the infrastructure was just plain worn out and even if the Milwaukee was rich enough to replace it, it wouldn't do it like for like but would replace it with a modern 25Kv or 50Kv system. However that is not to say that a modern electric would not look like latest EMD or GE diesel with pantographs! However it would be more likely some sort of double cab unit would emerge.

[cprted]

Perhaps something like this?

[MStLfan]

Or like those Amtrak E60's. IIRC several coal roads out west have electric loco's similar to those Amtrak E60's as well as second hand units from Mexico (build circa 1990?).

greetings,

Marc Immeker

[spikejones52002]

Now this is drawing on old memories (20+).

I watched a documentry about Canada building a new 50KV. point to point electric line in western Canada. I think it was to haul coal.

[CSSHEGEWISCH]

Now this is drawing on old memories (20+).

I watched a documentry about Canada building a new 50KV. point to point electric line in western Canada. I think it was to haul coal.

That was BCR's Tumbler Ridge line.  Seven GF6C's were built by GMD to work that line.  The mine has since closed, the catenary de-energized, and the locomotives scrapped.

[beaulieu]

Here is another possible electric freight locomotive design that might have been used;

 

EMD GM10B Demonstrator 

 

This locomotive was tested on Conrail, but when Conrail decided to end electric operations to take as much freight off the NEC. Their interest ended. 

[wallyworld]

The Milwaukee Road's transition to the UP passenger scheme makes for an interesting what if...

[steinmike]

If either GN (part of BN after 1970) or Milwaukee didn’t abandon their electrified lines and the continued to use electrified wires, I wonder what types electric engines they would have purchased to replace their aging 1940's vintage units?

One clue might be to look at the PRR.  In 1959, they leased 66 E-44 from GE.  As originally delivered the units used water-cooled ignitron rectifiers to convert the overhead AC into DC for the traction motors but the later units (E44a's) had silicon rectifiers that were much more reliable.  They might have looked at something that was an interim step between the E-44's and the E-60's.

While it's likely that the GN and Milwaukee might have considered similar directions, I'd have to agree that the age of their infrastructures and the costs to maintain and upgrade them were probably a big part of the decision to go with diesels.

[cprted]

Now this is drawing on old memories (20+).

I watched a documentry about Canada building a new 50KV. point to point electric line in western Canada. I think it was to haul coal.

That was BCR's Tumbler Ridge line.  Seven GF6C's were built by GMD to work that line.  The mine has since closed, the catenary de-energized, and the locomotives scrapped.

Actually the mine is open again, but trains are being pulled by diesels. At least one of the locomotives was saved, it is in the Prince George Railway and Forestry Museum.

[samfp1943]

Here is another possible electric freight locomotive design that might have been used;

 

EMD GM10B Demonstrator 

 

This locomotive was tested on Conrail, but when Conrail decided to end electric operations to take as much freight off the NEC. Their interest ended. 

I may be mistaken, but I am thinking that this particular model of electric was actually built, and was exported to Sweden. It was on trucks provided by the Swedish Railway. It was actually shown in a TRAINS magazine, which I am unable to find at this time.. I am sure if I am mistaken, someone can provide correct info. Thanks!

[Erie Lackawanna]

Here is another possible electric freight locomotive design that might have been used;

 

EMD GM10B Demonstrator 

 

This locomotive was tested on Conrail, but when Conrail decided to end electric operations to take as much freight off the NEC. Their interest ended. 

I may be mistaken, but I am thinking that this particular model of electric was actually built, and was exported to Sweden. It was on trucks provided by the Swedish Railway. It was actually shown in a TRAINS magazine, which I am unable to find at this time.. I am sure if I am mistaken, someone can provide correct info. Thanks!

I'm not an expert on the GM10B or GM6C (built at the same time, on C-C trucks), but I think you may have reversed what happened.  They were both built (I photographed them both running in NJ in the late 1970s), but I dont think they went to Sweden.  I think there were both scrapped here.  They did have Swedish elements to them (at least that sounds familiar to me), and maybe even had parts built there.

[MichaelSol]

 ... I'd have to agree that the age of their infrastructures and the costs to maintain and upgrade them were probably a big part of the decision to go with diesels.

They weren't.

[PBenham]

The problem for Conrail was that PRR's old electrification didn't go far enough for it to make sense to invest hard to get capital in straight electrics. The failure of PRR to continue it's electrification to at least Pittsburgh, or more realistically Conway did not help the cause one iota! In today's economic world the electrics wouldn't make sense unless they could run coast to coast over two or more of the big seven. (Such as NS Oak Island-Chicago/Kansas City, BNSF Chicago/ Kansas City-Los Angeles/Long Beach, for example.)

Another problem we are facing a shortage of generating capacity since it is almost impossible to build an electric generating facility. Never mind trying to build an atomic plant, it cannot be done any more. Coal fired plants are much too expensive to build and are obsolete before they open! The EPA has no policy in place to permit such facilities to be built free of the litigation threat from environmentalists, or other NIMBYs. Damming a river that isn't already dammed somewhere else? fuhgetaboutit!

[MichaelSol]

Another problem we are facing a shortage of generating capacity since it is almost impossible to build an electric generating facility.

The problem isn't supply, it's transmission capacity.

The electric power grid tends to lose significant power over distance. It is highly inefficient. Currently, generating capacity is far in excess of needs, but the system loses so much in transmission losses, and the grid is "full up." Utilities confronted "congestion" and dispatching problems long before the railroads did.

The culprit?

High voltage AC power transmission.

A U.S. Department of Energy Symposium held August 3, 2001, "Analysis and Concepts to Address Electric Infrastructure Needs", recommended general use of HVDC [High Voltage Direct Current] lines in the United States, as the conversion of existing HVAC [High Voltage Alternating Current] lines to DC would double the capacity of such systems in terms of use of existing ROW and reduced cross-section 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. 

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 and a substantial reduction in current transmission losses.

[PBenham]

Another problem we are facing a shortage of generating capacity since it is almost impossible to build an electric generating facility.

The problem isn't supply, it's transmission capacity.

The electric power grid tends to lose significant power over distance. It is highly inefficient. Currently, generating capacity is far in excess of needs, but the system loses so much in transmission losses, and the grid is "full up." Utilities confronted "congestion" and dispatching problems long before the railroads did.

The culprit?

High voltage AC power transmission.

A U.S. Department of Energy Symposium held August 3, 2001, "Analysis and Concepts to Address Electric Infrastructure Needs", recommended general use of HVDC [High Voltage Direct Current] lines in the United States, as the conversion of existing HVAC [High Voltage Alternating Current] lines to DC would double the capacity of such systems in terms of use of existing ROW and reduced cross-section 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. 

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 and a substantial reduction in current transmission losses.

But, what will this change over cost the consumer at the end of the line?

[ndbprr]

There were two GM experimental engines tested.  Both were white.  I think the other was numbered 1977 or 1978 and had CC trucks.  Neither was adequate for CR to pursue which doesn;t really surprise me since GM had never built anything like that before.  GE was the master of motors as the PRRR called them.

[Kevin C. Smith]

The problem isn't supply, it's transmission capacity.

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 and a substantial reduction in current transmission losses.

Interesting-I always thought that DC was prone to losses that AC wasn't (hence the Edison/Westinghouse battles of the currents 100 or so years ago). Any idea at what voltages the HVAC losses become greater then HVDC?

[Paul Milenkovic]

Back in the Edison-Westinghouse days, DC meant low-voltage DC, the voltage you got straight from the generator without step-up transformers.

High-voltage DC (HVDC) means you use transformers and electronic switches and rectifiers to step up the voltage and turn it into DC.  HVDC has losses associated with those electronic switches.  AC has losses associated with the voltage switching back and forth at the line frequency.  Apart from those effects, the low loss is from the high voltage which means low current for a given amount of power.

I thought HVDC was lower loss because you could operate it at higher voltage given the technical restrictions on AC voltage.

[MichaelSol]

I thought HVDC was lower loss because you could operate it at higher voltage given the technical restrictions on AC voltage.

"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.

This is because DC utilizes the full cross-section of a conductor for transmission, whereas in AC, the higher the frequency the more the current concentrates on the surface of a round conductor. This is called the skin effect.

 

[MichaelSol]

But, what will this change over cost the consumer at the end of the line?

You are probably already using power that has been DC rectified and inverted at high voltages. Siemens has installed several HVDC conversion facilities between ansynchronous power grid systems in the United States.

Part of the Bonneville Power Administration's Columbia River power load to California is carried on a 1440 MW HVDC line -- the Celilo-Sylmar, 800-kV d-c Transmission Line.
This line runs about 845 miles from the Celilo Converter Station, the northern d-c terminal of the NW-SW Intertie on the Columbia River near The Dalles, Oregon, via Nevada to the Sylmar Station. This bipolar overhead transmission line, with an operating voltage of 800 kV (±400 kV) and a power rating of 1,440 megawatts (MW), was constructed and placed in service in 1970.

Hyrdo-Quebec transmits 2,000 MW of 900kV HVDC to Massachusetts, (completed in 1992) and (will be) to Ontario, 2009.

According to ABB, "the latest groundbreaking innovation in power transmission is ABB's HVDC Light^TM, a unique technology that extends the economical power range of HVDC transmission down to a few tens of megawatts. It is particularly suitable for small-scale generation and transmission applications. ... Following the first commercial installation in Sweden in 1999, HVDC Light has been chosen for several transmission projects of between 3 and 200 MW in the United States, Australia and Europe."

 

 

[erikem]

The problem isn't supply, it's transmission capacity.

The electric power grid tends to lose significant power over distance. It is highly inefficient. Currently, generating capacity is far in excess of needs, but the system loses so much in transmission losses, and the grid is "full up." Utilities confronted "congestion" and dispatching problems long before the railroads did.

The transmission efficiency figures quoted in my power systems classes (1975) were 90 to 94%. One of the side effects of 'skin effect' was that the inductive reactance for a typical transmission line was much larger than the resistance.

 

The culprit?

High voltage AC power transmission.

A U.S. Department of Energy Symposium held August 3, 2001, "Analysis and Concepts to Address Electric Infrastructure Needs", recommended general use of HVDC [High Voltage Direct Current] lines in the United States, as the conversion of existing HVAC [High Voltage Alternating Current] lines to DC would double the capacity of such systems in terms of use of existing ROW and reduced cross-section 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. 

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 and a substantial reduction in current transmission losses.

The downside of inductive reactance is that it is what typically limits the capacity of an AC transmission line (which is one reason why 400 Hz is not used by electric utilities (highest frequency used was 133 Hz). In addition, overcoming the inductive reactance requires supplying reactive power - now done with a combination of generator excitation and capacitors, formerly done with synchronous condensers (which are essentially generators with no prime movers). Poviding the reactive power also increases system losses.

HVDC does have the advantage of using most of the conductor area (the current tends to get squeezed towards the center of the conductor). In addition, the peak voltage is the same as the average voltage with DC which significantly reduces corona losses.

One other advantage of HVDC is not needing to maintain the ends in synchronism - useful for tying the western and eastern US together. In fact there are several asynchronous connections in a line roughly tending south of Miles City. 

[erikem]

If either GN (part of BN after 1970) or Milwaukee didn’t abandon their electrified lines and the continued to use electrified wires, I wonder what types electric engines they would have purchased to replace their aging 1940's vintage units?

  Did EMD or GE, at one time or another in the 1960s and later, toy with or propose designs for electric freight engines? 

 The BA&P bought a couple of 2400VDC B-B's from GE in 1957 and I suspect that new (meaning early 1960's) locomotives for the Milwaukee might have looked like the BA&P units ofr B-B's or the E-44's if the Milwaukee wanted C-C's.

GN de-electrified the Cascade tunnel in 1956.

My 1980 copy of the Car and Locomotive Cyclopedia shows a 2500HP B-B from GE with a boxcab like front and a hood unit like rear, so GE was still very interested in the electric locomotive market at that time.

As I mentioned in another thread, GE's AC drive system relies on an internal DC bus to feed the traction inverters, so it should be fairly easy to replace the output of the traction alternator with the appropriate power conversion package - at least for the electrical design. Mechanical design would be a different matter, but shouldn't be that difficult.