tdmidget https://wwwstadlerrailcom-live-01e96f7.s3-eu-central-1.amazonaws.com/filer_public_thumbnails/filer_public/9f/04/9f043579-4036-4851-8ce6-a4665c18fe1f/20_eurodual_cam2_grey_1530px_srgb.jpg__1020x680_q90_crop_subsampling-2_upscale.jpg I can't speak for others but I have trouble keeping a straight face at the thought of a locomotive with 9000 straight electric hp and 4000 diesel electric that doesn't even have automatic couplers. They have much more to worry about than horsepower.
https://wwwstadlerrailcom-live-01e96f7.s3-eu-central-1.amazonaws.com/filer_public_thumbnails/filer_public/9f/04/9f043579-4036-4851-8ce6-a4665c18fe1f/20_eurodual_cam2_grey_1530px_srgb.jpg__1020x680_q90_crop_subsampling-2_upscale.jpg
I can't speak for others but I have trouble keeping a straight face at the thought of a locomotive with 9000 straight electric hp and 4000 diesel electric that doesn't even have automatic couplers. They have much more to worry about than horsepower.
The lack of an automatic coupler is a sad story, thanks to the French who refused its installation in the sixties. But high horsepower is always useful (note that we rarely operate more than two locomotives in Europe, thanks to coupler and siding limitations). Europe railroads are mostly passenger-oriented, and here high horserpower is extremely useful (especially in electric mode, which costs 1/3rd of the diesel). You get higher acceleration after the 'critical speed' (which is dictated by weight), and you get fast freight trains which can run along 100 mph stopping passenger trains.
N.F.
owlsroost RME A more interesting version would incorporate something like a C175-16 (with accordingly higher diesel horsepower) to better match the capability under wire with the capability otherwise. That is basically what the 'AFRODual' at the bottom of this page is - rated at 3000kW in electric mode and 2800kW in diesel mode (from a CAT C175-16 engine). I assume space and weight constraints (and expected use patterns) limited the UK duals to 950hp diesel power.
RME A more interesting version would incorporate something like a C175-16 (with accordingly higher diesel horsepower) to better match the capability under wire with the capability otherwise.
That is basically what the 'AFRODual' at the bottom of this page is - rated at 3000kW in electric mode and 2800kW in diesel mode (from a CAT C175-16 engine). I assume space and weight constraints (and expected use patterns) limited the UK duals to 950hp diesel power.
RME nfotis This concept hasn't been procured, but a 4-axle universal locomotive is now operating in UK: http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/class-88-ukdual-electro-diesel-locomotive-unveiled.html And how much does this thing cost ... producing less than 950 diesel horsepower?
This concept hasn't been procured, but a 4-axle universal locomotive is now operating in UK: http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/class-88-ukdual-electro-diesel-locomotive-unveiled.html
And how much does this thing cost ... producing less than 950 diesel horsepower?
The previous DRS 4-axle diesels had the same horsepower (I am not making it up), so for their purposes it was a one-to-one replacement in diesel mode.
And it offered also electric traction.
The immediate question I have is what the price premium for this specific dual-mode design is over the straight diesel-electric equivalent; that will be at least a guide for what could be done in a North American equivalent.
We haven't seen a working prototype (yet), but on a base cost of 3.5-4 million Euros for either diesel or electric locomotive I would add one more million for the dual power capability (depending on size of orders, which is typically in the ten to twelve in Europe).
Yes, locomotives in Europe are not cheap (but not as pricey as the NJT ALP-45DP). Note that the ALP-45DP is a dual power, but it is very heavy, at 120+ metric tonnes for 4-axle configuration.
RME: Thanks for that clarification.
blue streak 1One mitigating item for the previous post of a electric - diesel combination would be if the off set of emissions for freights would allow for tier 3 locos to continue to be built ?
I think you are mistaking fuel economy for emissions composition. They are not at all related (and in fact some design features that increase economy greatly increase 'pollution', and some features for emissions, notably the hated DPF regeneration, have a significant bad effect on SFC.)
The economies from electric operation would be in reduced gallons of fuel consumed per ton-mile. But the Tier standards don't care about that; they care about the percentage of each gallon that produces a given type of pollution.
If you had legislation that had some kind of tonnage cap on permissible emissions, then you could make the argument that a hybrid electric/Tier 3 compliant diesel freight producing a given number of ton-miles actually produced the same or lower number of kg of, say, NOx than a Tier 4 final compliant diesel consist doing the same work would have. But that is not the way the Tier standards are written or enforced, and moreover the Tier standards apply to transient operating conditions just as they do to steady-state operation (which was as I recall a major problem for all the builders in their Tier 4 testing at some points).
The new announcement of a very large oil find in west Texas may add a new complication for this thread. Enough petroleum to meet US demand for a 3 full years may keep diesel at a historic low ( taking in inflation ).
One mitigating item for the previous post of a electric - diesel combination would be if the off set of emissions for freights would allow for tier 3 locos to continue to be built ?
The complications of dual mode locos seems to be counter productive. Agree that certain routes like the empire corridor definitely require them as the following would reduce revenue cars. If you have a diesel loco and an electric connected together then they can each operate where they are best suited.
For example the Pennsylvanian could use such an arrangement when the train gets to a length needing 2 locos going up horseshoe. If it could use the high tractive effort of say an ACS-64 on the grade then the use of diesel once off both sides of that grade would fall. All would be needed is one diesel on the relative flat grades. Also extend CAT 2 miles west of Harrisburg station then train could rapidly accelerate to track speed. i
RMEA more interesting version would incorporate something like a C175-16 (with accordingly higher diesel horsepower) to better match the capability under wire with the capability otherwise.
RME: the 88s are expected to pull DRS' intermodal trains primarily on electrified corridors, with the diesel used for port areas and their branches. Merely a last mile module on a far larger scale.
I wonder if the EPA could be convinced that a Tier III dual mode would meet Tier IV regulations to help lower the price point?
nfotisThis concept hasn't been procured, but a 4-axle universal locomotive is now operating in UK: http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/class-88-ukdual-electro-diesel-locomotive-unveiled.html
This isn't dual-mode, it's more like the old electro-diesels (like the ones built for the English Southern Railway). A more interesting version would incorporate something like a C175-16 (with accordingly higher diesel horsepower) to better match the capability under wire with the capability otherwise.
The Stadler C-C concept is more attractive, and one thing that I think it reflects is the reduction in size and mass of the HVAC-to-DC circuitry since the age of the Conrail dual-mode proposal in the 1980s ... and another thing it reflects is the reduction of size and mass inherent in converting HVAC to DC-link as opposed to DC suitable for use to drive legacy traction motors directly. The immediate question I have is what the price premium for this specific dual-mode design is over the straight diesel-electric equivalent; that will be at least a guide for what could be done in a North American equivalent.
Vossloh (now Stadler Espana) has proposed a more integrated approach to dual power:
http://www.stadlerrail.es/media/downloads/pdfs/flyer/EURO_DUAL-_EN_July_2012.pdf
This concept hasn't been procured, but a 4-axle universal locomotive is now operating in UK:
http://www.railwaygazette.com/news/traction-rolling-stock/single-view/view/class-88-ukdual-electro-diesel-locomotive-unveiled.html
I have been inside a class 88, due to the very tight UK loading gauge it is very cramped inside this locomotive.Performance is OK as an electric, and equivalent to old UK 4-axle diesels when running in diesel mode.
https://en.wikipedia.org/wiki/British_Rail_Class_88
We expect to see a much more powerful 6-axle dual power locomotive on European rails by next year, if the various sources are reliable.
The design is rather attractive, in my opinion:
This model is being expected to offer under one roof, 7 MW in electric mode and 3 MW in diesel mode.
Another, but similar, approach can be a diesel (possibly two) locomotives and an electrictive. eqch of which can be used independantly as powerful high HP, highTE, high-speed locomotve. nut coupled together with power cables zttached, a dual-purpose unit with double the TE, but the horsepower and speed same as each individual locomotive. Independent use for corridor passenger service and dual-purpose for long freights.
RMEThat's a good idea, particularly if the pantograph/transformer arrangement is capable of sourcing power equivalent to the whole of the combined traction-motor capacity
That's easy to answer: 4400HP equals 3235kW, so the arrangement used on the ACS-64 would be about capable of powering two diesels. Siemens built a series of six-axle locomotives for Denmark rated at 9600kW, also using just one pantograph under a 25kV/50Hz catenary; that would power two diesels and a road slug which would probably a bit shorter than an ACS-64.
carnej1Although the text doesn't give any detail there is an image that shows two diesel electric units coupled back to back with a pantograph equipped B unit or slug..
That's a good idea, particularly if the pantograph/transformer arrangement is capable of sourcing power equivalent to the whole of the combined traction-motor capacity (perhaps more likely on a 'locomotive' comprised of three Bo-Bo chassis). In that arrangement the whole of the 'center' chassis can be occupied by power equipment, with nothing more than hostling controls, the tradeoff then being that the conversion unit always has to trail if not operated 'between cabs'. It appears to have side walkways that would (at least in theory) allow crew to walk between ends without having to descend to the ground.
I wonder what the absolute minimum length of the equivalent for a pair of 4400hp North American road units would be? And how useful as a road slug (under diesel power) it would be -- reminds me of an old GE MATE with dual power?
RME blue streak 1 Instead of building 2 expensive dual modes build two units one an electric motor with a double rated transformer and one a nearly off the shelf diesel with higher capacity traction motors. Connect them up in a tandem arrangement with traction power connected together. Keep in mind these are not the Rolls-Royce kind of 'dual mode' that entities with more money than brains, like New Jersey Transit, have bought. This is the basic idea as given in the Conrail study, updated a bit to reflect widespread AC traction (it need be little more than something that converts the high-tension AC to match the DC link to inverters on the locomotive -- and upgrades the inverters and motors to be able to achieve the wheelrim HP of a comparable straight electric. I do, however, appreciate your point about putting pans, transformers, etc. on each individual locomotive, and that is why I made the point about putting the electrical pickup and transversion gear on a road slug (where there is plenty of room and tolerance for weight) and arrange for the electricity to 'make up' the difference between the constant horsepower of the slug mother and the continuous rating of all the traction motors in the consist. (You could of course design the thing so that all the horsepower above prime-mover idle came from the wires, and run the combination as close to a straight electric; this would be more a political thing for places like the Southern California air-quality-management district than an engineering solution for cost reduction ... but political distortion of costs nonetheless changes engineering solutions. Any slug mother (designed to accept power from an attached source as well as provide it, granted, but that is not too difficult a change to make) will work effectively coupled to the electric slug, and the electric works just as well as any other road slug when away from the wire. You have the cab and MU control on the road slug, and I suppose that if you had a reason you could put enough stuff into it to let it run as a crude single-ended straight electric ... but what would the point of that be, and why would you want to run it separately?
blue streak 1 Instead of building 2 expensive dual modes build two units one an electric motor with a double rated transformer and one a nearly off the shelf diesel with higher capacity traction motors. Connect them up in a tandem arrangement with traction power connected together.
Keep in mind these are not the Rolls-Royce kind of 'dual mode' that entities with more money than brains, like New Jersey Transit, have bought. This is the basic idea as given in the Conrail study, updated a bit to reflect widespread AC traction (it need be little more than something that converts the high-tension AC to match the DC link to inverters on the locomotive -- and upgrades the inverters and motors to be able to achieve the wheelrim HP of a comparable straight electric.
I do, however, appreciate your point about putting pans, transformers, etc. on each individual locomotive, and that is why I made the point about putting the electrical pickup and transversion gear on a road slug (where there is plenty of room and tolerance for weight) and arrange for the electricity to 'make up' the difference between the constant horsepower of the slug mother and the continuous rating of all the traction motors in the consist. (You could of course design the thing so that all the horsepower above prime-mover idle came from the wires, and run the combination as close to a straight electric; this would be more a political thing for places like the Southern California air-quality-management district than an engineering solution for cost reduction ... but political distortion of costs nonetheless changes engineering solutions.
Any slug mother (designed to accept power from an attached source as well as provide it, granted, but that is not too difficult a change to make) will work effectively coupled to the electric slug, and the electric works just as well as any other road slug when away from the wire. You have the cab and MU control on the road slug, and I suppose that if you had a reason you could put enough stuff into it to let it run as a crude single-ended straight electric ... but what would the point of that be, and why would you want to run it separately?
At least one european manufacturer has apparently looked at the pantograph equipped road slug concept:
http://www.railcolor.net/index.php?nav=1409453
Although the text doesn't give any detail there is an image that shows two diesel electric units coupled back to back with a pantograph equipped B unit or slug..
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
CMStPnP PNWRMNM The answer to your question is common sense. Why would any railroad stockholder or manager want to get into another capital intensive, highly regulated business? I see lots more reasons for railroads to run away from electrical power generation than to run to it. Mac You mean like say SP with SPRINT Communications?
PNWRMNM The answer to your question is common sense. Why would any railroad stockholder or manager want to get into another capital intensive, highly regulated business? I see lots more reasons for railroads to run away from electrical power generation than to run to it. Mac
You mean like say SP with SPRINT Communications?
In this case SP decided to commericalize the informatiin backbone that they already had in place for railroad operating purposes.
Yes in principal. In this particular case, SP managed to sell Sprint for a good price and by that time SP had at least 15 years of experience with the technology.
Mac
PNWRMNMThe answer to your question is common sense. Why would any railroad stockholder or manager want to get into another capital intensive, highly regulated business? I see lots more reasons for railroads to run away from electrical power generation than to run to it. Mac
Most railroads and interurbans built their own power plants in order to provide a guaranteed source of electricity for their own use since most public utilities were rather small operations at the time and couldn't reliably provide the power in the amounts needed. As electric generation technology advanced and reliability improved, railroads and interurbans turned to commercial power and dismantled or sold off their own power plants. Between the Public Utilities Holding Company Act and the current state of the electric power market (many states are de-regulated), going into power generation for commercial use may be illegal or a risky investment for a railroad.
CMStPnP Also, what is to stop the railroad from building it's own power plants and selling the excess electricity not used by the railroad to a local utility and/or leasing a portion of it's distribution system for electric transportation by utilities looking to sell excess power across state lines? Honestly, in my view I think railroads could use electrification to open another front of revenue if they were allowed to enter the power generation and distribution field. I am not sure if U.S. Law permits that currently but if it does, there could be opportunities there as the power grid that the railroads built would be a lot newer and more flexible and could transmit power over longer distances more efficiently then the current and older power grid. So there would be a marketing advantage there.
Also, what is to stop the railroad from building it's own power plants and selling the excess electricity not used by the railroad to a local utility and/or leasing a portion of it's distribution system for electric transportation by utilities looking to sell excess power across state lines?
Honestly, in my view I think railroads could use electrification to open another front of revenue if they were allowed to enter the power generation and distribution field. I am not sure if U.S. Law permits that currently but if it does, there could be opportunities there as the power grid that the railroads built would be a lot newer and more flexible and could transmit power over longer distances more efficiently then the current and older power grid. So there would be a marketing advantage there.
The answer to your question is common sense. Why would any railroad stockholder or manager want to get into another capital intensive, highly regulated business? I see lots more reasons for railroads to run away from electrical power generation than to run to it.
Paul Milenkovic Leo_Ames For example, my windows are old and about the best thing that can be said about their energy efficency is that they're better than nothing. New windows would pay for themselves in a few short years. Do you know that replacement windows have an energy payback of "a few short years"? Or is this a sales claim by the people offering to provide new windows? There are reasons for new windows -- the old ones may be unsightly, hard to open and close, require storm windows that have to be laboriously taken down and put up every season, and have cracks that let flies and other bugs get into the house. The old windows may also leak more cold air into your house. But is that where all or even most of the air infiltration is coming from? I read the Princeton, New Jersey study where a government agency modded a couple of duplex town houses for energy efficiency, kind of like David Wardale modding the 3450 steam locomotive. They found that the biggest sources of cold air exchange were 1) the "box sill" where the house rests on top of the foundation wall, and 2) the various light fixture, chimney, and toilet vent pipe penetrations into the ceiling below the unheated attic. Less-than-efficient windows were a minor factor. But the biggest source of infiltration was the wall separating the two halves of the duplex. You shouldn't jump to conclusions that your old windows are driving your heating bills because there are all kinds of people trying to sell you a lot of expensive stuff on claims of "energy efficiency." Electrification is popular in Europe where the governments run the railroads and imported oil is made expensive for the same reasoning that the Japanese pay multiples of the price of rice sold in Arkansas, USA to get that staple from local farmers. It's a kind of mercantilist trade policy along with a desire for a certain kind of self sufficiency. We discussed on another thread reasons why the privately owned U.S. (OK, U.S. and Canadian) railroads aren't standing in line to get wire strung. One of them is the maintenance on the catenary. Another is this "demand pricing" structure where the railroads want to run trains where and when they choose rather than park them in sidings when the power companies raise the price during times of peak demand. If the impetus for electrification is to move to so-called renewable sources of energy (I say so-called because there are substantial resource inputs into the structures and collectors for those fuel-free power sources), which is motivated by the concerns of environmental impacts rather than oil being in any way expensive for in short supply right now, these variable and intermittent source magnify the problem of the power companies wanting to ration electricity to large commercial users with the railroads wanting and needing to run trains on their schedules. Is this like our local grocery store paying a supplemental fee to the power company to have the bragging right of "100 percent wind and solar powered"? Apart from electricity being "fungible", that is, a "dirty" kilowatt from coal being indistinguishable from a "clean" kilowatt from wind, I am willing to accept that you could "allocate" electricity from clean sources to customers who have paid a "clean power" premium. What makes this a fraud is that the "clean" sources are intermediate and variable whereas a food store has to run refrigeration equipment without interruption, that is, unless they want to sell me spoiled food, which a family member has complained that this particular food store has done on more than one occasion. Forget that -- someone "at the U" with "inside knowledge of retailing" suggested to me that a result of this store's expansion within its host mall, it is keeping a lot of their refrigerated food inventory in reefer trucks parked out back, which are very much powered by #2 Diesel fuel supplemented by the required dose of DEF.
Leo_Ames For example, my windows are old and about the best thing that can be said about their energy efficency is that they're better than nothing. New windows would pay for themselves in a few short years.
For example, my windows are old and about the best thing that can be said about their energy efficency is that they're better than nothing. New windows would pay for themselves in a few short years.
Do you know that replacement windows have an energy payback of "a few short years"? Or is this a sales claim by the people offering to provide new windows?
There are reasons for new windows -- the old ones may be unsightly, hard to open and close, require storm windows that have to be laboriously taken down and put up every season, and have cracks that let flies and other bugs get into the house.
The old windows may also leak more cold air into your house. But is that where all or even most of the air infiltration is coming from?
I read the Princeton, New Jersey study where a government agency modded a couple of duplex town houses for energy efficiency, kind of like David Wardale modding the 3450 steam locomotive. They found that the biggest sources of cold air exchange were 1) the "box sill" where the house rests on top of the foundation wall, and 2) the various light fixture, chimney, and toilet vent pipe penetrations into the ceiling below the unheated attic. Less-than-efficient windows were a minor factor. But the biggest source of infiltration was the wall separating the two halves of the duplex. You shouldn't jump to conclusions that your old windows are driving your heating bills because there are all kinds of people trying to sell you a lot of expensive stuff on claims of "energy efficiency."
Electrification is popular in Europe where the governments run the railroads and imported oil is made expensive for the same reasoning that the Japanese pay multiples of the price of rice sold in Arkansas, USA to get that staple from local farmers. It's a kind of mercantilist trade policy along with a desire for a certain kind of self sufficiency.
We discussed on another thread reasons why the privately owned U.S. (OK, U.S. and Canadian) railroads aren't standing in line to get wire strung. One of them is the maintenance on the catenary. Another is this "demand pricing" structure where the railroads want to run trains where and when they choose rather than park them in sidings when the power companies raise the price during times of peak demand.
If the impetus for electrification is to move to so-called renewable sources of energy (I say so-called because there are substantial resource inputs into the structures and collectors for those fuel-free power sources), which is motivated by the concerns of environmental impacts rather than oil being in any way expensive for in short supply right now, these variable and intermittent source magnify the problem of the power companies wanting to ration electricity to large commercial users with the railroads wanting and needing to run trains on their schedules.
Is this like our local grocery store paying a supplemental fee to the power company to have the bragging right of "100 percent wind and solar powered"? Apart from electricity being "fungible", that is, a "dirty" kilowatt from coal being indistinguishable from a "clean" kilowatt from wind, I am willing to accept that you could "allocate" electricity from clean sources to customers who have paid a "clean power" premium.
What makes this a fraud is that the "clean" sources are intermediate and variable whereas a food store has to run refrigeration equipment without interruption, that is, unless they want to sell me spoiled food, which a family member has complained that this particular food store has done on more than one occasion.
Forget that -- someone "at the U" with "inside knowledge of retailing" suggested to me that a result of this store's expansion within its host mall, it is keeping a lot of their refrigerated food inventory in reefer trucks parked out back, which are very much powered by #2 Diesel fuel supplemented by the required dose of DEF.
I think that there is a difference in the way Commerical and Residential Rates and Power usage are managed. For one, Commercial usually has priority in a brownout scenario and residential / office is shutdown first. Second the rates Commerical Pays vs Residential are different and in the case of a railroad would probably be negotiated so there wouldn't be a ebb and flow in electrical rates, rather there would be one fixed rate for the railroad that would apply year round.
I don't think it pays to electrify unless you have established freight corridors like passenger corridors where the trains ran frequently. It will never cut it on a branch line and like Germany and other European Countries the branch and light density lines would need to remain dieselized. Which of course would mean not all the locomotives a railroad would own would be Electric.
GERALD L MCFARLANE JR Checking the list of companies owned or partially owned by Berkshire Hathaway only owns one utility, the former Mid-American Energy Holdings, which is now Berkshire Hathaway Energy, and Mid-American was not a huge player in the utility market, nor are they really located in areas that would be beneficial to the BNSF. Berkshire Hathaway also does not manage any of the properties they own, Warren Buffet only buys well run companies that already have excellent management in place, he allows the existing management to continue to run the company as they see fit(that's how he's been so successful) and that's exactly the reason he bought BNSF.
Checking the list of companies owned or partially owned by Berkshire Hathaway only owns one utility, the former Mid-American Energy Holdings, which is now Berkshire Hathaway Energy, and Mid-American was not a huge player in the utility market, nor are they really located in areas that would be beneficial to the BNSF. Berkshire Hathaway also does not manage any of the properties they own, Warren Buffet only buys well run companies that already have excellent management in place, he allows the existing management to continue to run the company as they see fit(that's how he's been so successful) and that's exactly the reason he bought BNSF.
sandyhookken As most of us know, BNSF is owned by Berkshire Hathaway, which also owns several large electrical utilities, primarily in the West. It's probable that BH management has already looked for synergies between the railroad and electric operations. The fact that nothing regarding electrification of any part of the BNSF has been announced must mean that the finances don't work (yet).
As most of us know, BNSF is owned by Berkshire Hathaway, which also owns several large electrical utilities, primarily in the West. It's probable that BH management has already looked for synergies between the railroad and electric operations. The fact that nothing regarding electrification of any part of the BNSF has been announced must mean that the finances don't work (yet).
blue streak 1Instead of building 2 expensive dual modes build two units one an electric motor with a double rated transformer and one a nearly off the shelf diesel with higher capacity traction motors. Connect them up in a tandem arrangement with traction power connected together.
PNWRMNMDynamic brakes fade quickly as speed increases above 25 MPH. If you want some real pucker factor consider how long it would take to stop a train descending a 2.2% grade at 50 MPH under a 10# reduction with a full service reduction.
Dynamics aren't the things that fade over 23mph, it's composition brake shoes. There is a reason it's illegal now to rely on dynamics to hold a train faster than that speed, as was demonstrated (repeatedly!) on the ex-B&O a couple of years ago. That may make your point far more dramatically; you will not be running any 'helper' downgrade any faster than your brakes can stop if the dynamic fails. (I would expect the same to apply for full regenerative braking into a catenary, even though it can be modulated for maximum retardation net of all wheelslide, so I have no fancy technological solution that gives better safe speed.)
There is no particular 'pucker factor' involved with a train at 50mph on a 2.2% downgrade. You are in the hands of Jesus Christ, or will be more or less shortly, and you will have little to do but reflect on the sin that got you there, because nothing WABTEC or NYAB can build will get you out of it.
Constructing double track is cheaper than the NPV of constant-tension cat strung from poles? I hadn't thought so ... but I have not done modern numbers that would say otherwise.
Building a dual mode loco still has limits on tractive effort
Instead of building 2 expensive dual modes build two units one an electric motor with a double rated transformer and one a nearly off the shelf diesel with higher capacity traction motors. Connect them up in a tandem arrangement with traction power connected together.
This would especially work in yards without CAT. Presently the 4000 HP and higher diesels are power limited on starting and various low speeds due to wheel slip. A dual mode loco by itself would be similarly constrained by power limits. By sharing the diesel's output to the electric motor traction motors the full diesel power can be used for starting.
Once under CAT the electric motor can take over not only with its traction motors but supply the diesel's traction as well. So you then have 12 powered axels with just one CAT powered motor and idle diesel. That way instead of 2 motors pulling 2 - 4 idling diesels you have one motor and one or 2 diesels; Of course if necessary diesels can help where needed. The Motor can remove itself at end of electrification om a short electrified main and pocket track. The two diesels should be sufficient to maintain flatland speeds.
Or the motor can remain on trains that traverse several high grade tracks and engage CAT at each high grade location.
If motor fails then diesel can limp train to a location where replacement power can be added.
The costs of this arrangement are difficult to calculate. Compared to standard diesels and ACS-64s -----
1. Motor -- add cost of a double size transformer, Subtract all passenger specific equipment such as HEP and auxilaries. +/- different wheel ratios.
2. Diesels - Add larger traction motors, another connector for control from either motor or diesel, electrical cables for traction inverters.
Thoughts ? ?
RME The principal interest I have had in the idea of 'assisted helping' on grades started in keeping a one-speed railroad regardless of grade, and keeping a single consist from origin to terminal (without need to reduce length or load for parts of the route due to any restriction other than siding or approach-lead capacity). There are some other considerations for using electrically-assisted max starting torque, for example limiting the time the prime mover has to be run at high power, the time it takes to accelerate the engine (for pollution reasons) to power, or the extent to which it is operated above, say, Run 5 -- these things can have a significant impact on both maintenance and fuel costs relative to the cost of power from 'the grid'. By extension, the faster trains or fleets can negotiate a significant grade, the greater the track capacity. That in part is what the mission of 'snappers' is: not to pull a heavier weight over the grade, but to lessen the time it takes. There is comparatively little value in raising the peak speed of many trains, even intermodal trains, but you can fit more of them into a given piece of railroad ... perhaps many more depending on just how conservative your operating department was in determining combustion-derived HP/ton (or how incompetent they might turn out to be underestimating car factor!). A point associated with this -- at least I thought it was a valuable one -- is that you can cram more trains into the windows of time corresponding to lower industrial or residential demand, when the 'value' of kilowatt-hours is lower (and traditionally power companies offered lower rates). Again, there might be some concern that, say, a helper arrangement over Altamont Pass might be subject to brownout restrictions or even rolling blackouts, if it were not given some sort of 'special priority' in wheeling, or that increases in consumer demand for power (which are likely to outstrip incremental supply increases substantially, even if things like BEVs aren't made to catch on) might make a railroad's power costs rise out of proportion to 'motor fuel' cost -- this is the commonly-given reason for Conrail's abandoning freight electrification. Care would indeed have to be taken to assure proper supply of power (and note that demand might rise dramatically but also fall dramatically within the term of a contract) and also to deal with the chance of changes in politics or government that might change either the cost or relative supply of locally-connected grid power.
The principal interest I have had in the idea of 'assisted helping' on grades started in keeping a one-speed railroad regardless of grade, and keeping a single consist from origin to terminal (without need to reduce length or load for parts of the route due to any restriction other than siding or approach-lead capacity). There are some other considerations for using electrically-assisted max starting torque, for example limiting the time the prime mover has to be run at high power, the time it takes to accelerate the engine (for pollution reasons) to power, or the extent to which it is operated above, say, Run 5 -- these things can have a significant impact on both maintenance and fuel costs relative to the cost of power from 'the grid'.
By extension, the faster trains or fleets can negotiate a significant grade, the greater the track capacity. That in part is what the mission of 'snappers' is: not to pull a heavier weight over the grade, but to lessen the time it takes. There is comparatively little value in raising the peak speed of many trains, even intermodal trains, but you can fit more of them into a given piece of railroad ... perhaps many more depending on just how conservative your operating department was in determining combustion-derived HP/ton (or how incompetent they might turn out to be underestimating car factor!). A point associated with this -- at least I thought it was a valuable one -- is that you can cram more trains into the windows of time corresponding to lower industrial or residential demand, when the 'value' of kilowatt-hours is lower (and traditionally power companies offered lower rates).
Again, there might be some concern that, say, a helper arrangement over Altamont Pass might be subject to brownout restrictions or even rolling blackouts, if it were not given some sort of 'special priority' in wheeling, or that increases in consumer demand for power (which are likely to outstrip incremental supply increases substantially, even if things like BEVs aren't made to catch on) might make a railroad's power costs rise out of proportion to 'motor fuel' cost -- this is the commonly-given reason for Conrail's abandoning freight electrification. Care would indeed have to be taken to assure proper supply of power (and note that demand might rise dramatically but also fall dramatically within the term of a contract) and also to deal with the chance of changes in politics or government that might change either the cost or relative supply of locally-connected grid power.
RME,
The more you explain, the worse this sounds. Remember the railroads are in business to make money and the best way to do that is to invest no more in the fixed plant and equipment than is necessary to do the job.
As to your first point a single speed railroad that has no need to adjust tonnage due to changes in ruling grades. Some would take this as the Holly Grail of railroading.
This is really two points. Lets take tonnage adjustment first. Another way to say that is eliminate helpers. I suggest that diesel locomotives have done much of this already in the sense that most trains are routinely powered to about 1 HPPT, which makes them able to handle anything up to and including 1% ruling grades which is the vast majority of the remaining railroad network.
Mountain grades, typically 2.2%, demand tonnage reduction, helpers or DPU and about 2 to 2.5 HPPT, a big difference. Basic facts like drawbar strength and L/V ratios generated in dynamic braking impose physical limits regardless of whether the power is diesel electric or wire electric. My point is that these fundamental physical factors limit what can be done on mountain grades in terms of train length and tonnage. They always have and the most reasonable expectation is they always will.
What is the value of faster trains on a mountain railroad? You posit more trains per unit time, say trains per day. There is value here only if the line is nearing capacity. Assuming a single track line, another way to increase capacity is to add sidings to reduce the "waiting for the other guy to show up" delay. Simply adding intermediate sidings between the existing ones doubles the capacity of the line, and at a far lower cost than electrification or electric helpers that raise ascending speed from 10 MPH to 15. If that is all it takes to make a difference the obvious expedient is to add more diesels. It is quick, easy, known technology and the railroad is not stuck paying interest on it for 30-50 years as would be the case with electrification.
Another problem with your one speed railroad over mountain grades is that old devil physics. First these lines tend to be crooked and those curves tend to be sharp which limits speed. The second limit is keeping train speed under control on the descent. Dynamic brakes fade quickly as speed increases above 25 MPH. If you want some real pucker factor consider how long it would take to stop a train descending a 2.2% grade at 50 MPH under a 10# reduction with a full service reduction. Speeds in this range on such grades are a formula for runaway trains. Litterally Fatal flaw!
If you need more capacity then add sidings or double track. You can do it incrementally as traffic demands and it will be far more cost effective in raising capacity than going from 10 MPH ascending to 15 MPH ascending with gawd awfull expensive electrics, whether strait or dual mode.
The very idea of brownouts is enough to send any railroad man running away screaming from any electrification proposal. This is an economically fatal flaw and exposes the operation to another type of fuel availability risk, and one the railroad can do nothing about.
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