How about an LNG-fueled 10,000 HP locomotive utilizing two 5000 HP aero derivative gas turbine alternator units feeding rectified power to a common DC bus from which the AC propulsion system would draw its power. A 16,000-gallon tender would be used to carry the LNG. This should provide 1.3 times the working range of an SD80. A small (300-500 HP) spark ignited piston engine, also fueled by LNG, could be used for hostelling and auxiliary power when the main turbines are shut down.
The use of two 5000 HP gas turbines instead of one 10,000 HP unit permits running one turbine at full power when on the level, and thus getting maximum fuel economy, and bringing the second unit on line for train start-up and up grade operations. A gas turbine will go from stop to full power in 90 seconds so this type of operation is both feasible and practical The alternators would be direct drive high speed air bearing units, eliminating losses from gear reductions It would seem that two 3-axle trucks would handle the tractive effort but the tender’s 2-axle trucks might also be powered, which would produce more dynamic braking (a problem with the early gas turbine locomotives).
LNG has a cost of about $3.00/million BTU’s as compared to $25 for diesel#2. However the specific fuel consumption of the turbine is 1.3 times that of the diesel so the adjusted cost
What venture capitalist is going to finance this highly questionable scheme? And would UP want to run it if it was built?
A lot of things based on the existing technology of the time were never taken beyond the ‘imagineering’ stage because they made no economic sense. If you want to see some examples, find a bunch of Popular Mechanix/Popular Science mags from the 1944-45 period.
Back in the 50’s, UP bought 50+ gas turbine locomotives from GE because they would burn Bunker “C” at 4.8 cents/gallon as opposed to 11 cents for diesel #2. The locomotives ran quite well as witnessed by the fact that they kept buying them. The final buy was the “Big Blow” a 10,000 HP unit. Bunker “C” caused acidity and ash problems that reduced turbine blade life but these were manageable.but by this time, EMD had come out with the multiple unit design that offered more flexibility as well as more dynamic braking. In addition, the price difference between Bunker “C” and diesel #2 went down reducing the incentive and the turbine units were retired . The UP application was less than satisfactory , not because of basic problems witth gas turbine propulsion, but rather because of a lack of good control technology, inappropriate operating practices and misapplication of particular industrial gas turbines to railroad use. Never the less, UP operated a significant number of gas turbine units for 16 years, developing the largest body of freight service experience available to the present time.
A valid question is, “Would a 63% fuel savings make UP, or any railroad, think about a modern LNG-powered gas turbine locomotive?”. If up-front money is needed, the FRA and EPA might fund a demonstration but it would go faster without their help. The international Railway Gazette reports that the the Russians have developed a 6000 hp LNG fueled locomotive (GT-001) for service in Siberia. It has successfully hauled 10,000 trailing tonnes (11,025 tons) and more such locomotives are being built. This is not “Popular Mechanics” day dreaming.
I wrote the submission to stir up thinking a bit and it seems to have worked.
I will agree that the design is a novel application of existing technology, but how much of a market is there for what is basically a 10,000 HP gen-set road locomotive? New fuel facilities would also have to be built to handle LNG and this is not going to be cheap, even if such a locomotive is restricted to certain routes to minimize the initial outlay.
If and I emphasize IF – the way to make this work would be to marry a diesel unit to this turbine unit(s) (locomotive). Then when the incremental turbine unit was not needed the Diesel could provide the necessary power to switch and run flat lands. Once the power required exceeded the diesel’s available one or more turbines could be started and provide the extra horsepower. Now the way to really use this setup would be to allow power to go either way to the diesel or turbine. That way adhesion at very low speeds would not limit the diesel and fewer traction motors would be needed on the turbine unit. Present mother - slug technology is already accomplishing this setup.
Railpower Industries(now in bankruptcy and perhaps soon out of business) designed a CNG powered Gas Turbine Electric locomotive they called the CINGL (Compressed Integrated Natural Gas Locomotive) and tried to market it to the North American Railroad industry. They were planning on using industrial/power turbines rather than areoderivatives. One of the big problems they had was that they were unable to reach a partnership with a turbine manufacturer (they approached both Rolls Royce (Allison) and Solar Turbine (a CATERPILLAR subsidiary). Because of this they were not able to fund a demonstrator.
Their main rational for the turbine was that it allowed much more available space on the locomotive for composite CNG tanks (CNG’s lower cost per BTU than LNG was a major selling point). Interestingly their website used to have a line drawing off the locomotive with Union Pacific lettering (long ago deleted). There was also an annual report with a picture of a scale model in CN livery.
The basic model was to use a 5500HP turbine but the claimed that they could develop a 10,000HP version. The most recent proposal would have used a Solar Mercury 50 model gas turbine which is intercooled and recuperative thus offering better part load fuel consumption than an aeroderivative unit.
I can think of no reason you would want to do this. The idea of gas turbine power in the proposed case is to make possible the use of low cost natural gas and to get significant emissions improvment as a bonus. I have nothing against diesel engines bur natural gas will not compression ignite and the diesel’s emissions will always ne high on NOx.
About 20 years ago BN did some dual fuel conversions of EMD locomotives to run on LNG. The conversion was done by Energy Conversions Inc. They had to reduce the compression ratio from 14.5:1 to 12.5:1 to run successfully on LNG. Its still called a diesel cycle in that the diesel fuel injectors are held to idle rack and that in turn ignites the gas fuel which is varied to carry the load. The gas part is otto cycle. Diesels that are converted to run 100% gas must use a spark plug. To get these engines up to rated power there was a separate cooling circuit for the aftercoolers to get the airbox temperatures way down from the normal at the time. Motive Powers switchers that they haven’t had much success marketing have the spark ignited gas version of CAT’s 3516 engine already.
Unfortunately the North American RR industry apparently isn’t interested in the technology given that Railpower presented it and there were no takers… The industry is very, very conservative in it’s mechanical/motive power practices and there are many times that railfans think something is a neat idea but the folks who do it for a living don’t (and IMHO they know their business a bit better than us hobbyists). The same facts have been stated in discussions we’ve had on the forums about other alternative locomotive technology (new build steam locomotives, etc.)… Too bad though as this subject fascinates me…
As far as LNG/CNG fueled diesel engines as pointed out in another post CAT offers spark ignition versions of it’s large engines to the utility/power industry as do several other manufacturers (GE being one)…
Jerry, I have a better idea, instead of towing around a LNG tender behind the locomotive, lets plunk the turbines on the ground at a convenient location alongside the tracks where a Natural Gas pipeline is located. Being on the ground we can use waste heat recovery systems if they make economic sense. Admittedly the wires from the generators to the traction motors will be longer, so it would make sense to boost the voltage to 25 or 50kV and use transformers on the locomotives. The stationing of the turbines and generators on the ground also means that they are no longer are exposed to loading shocks from in-train forces.
BN tried RLM (Refrigerated Liquid Methane ), the reason for using RLM vs. LNG is more predictable combustion properties of the RLM. Since pipeline LNG is a mixture of various hydrocarbon gases (Methane, Ethane, Propane, and Butane), it is possible to develop unequal piston thrust, this isn’t a serious problem with small displacement per cylinder engines, but is a problem with railroad sized engines.
I would like to retire the argument that railroad professionals “know the business a bit better than us hobbyists.” Yes, that is most likely the case, but if that is the answer to anything speculative that a railfan wants to discuss, what is the point of having this forum?
Secondly, Jerry Pier worked on the Amtrak Turboliners, so I think he has more insight into the pros and cons of turbines in railroad applications than some of the railfans who are offering the scolding that he is not a professional railroader.
Thirdly, as to professional railroaders knowing how to run their own business, sometimes you have to bring in people f
I agree that you can’t always assume RRers know best, and I are one!
The problem is that RRs generally can’t afford to extrapolate. The times they do they have been known to get bit in the behind. (HDL and H engines anyone?) And, capital is SO scarce on the RRs, that “extrapolation” type extravaganzas don’t happen often. It’s why ECP hasn’t happened yet…
I find Jerry’s idea intriguing because it combines some more-or-less proven technologies that provide benefits and solutions on several fronts.
An idea I had was to go “small” instead of big. Build, small, mostly cabless, 2000 HP, AC traction, two axle locomotives. Combine with ECP and DPU to do true distributed power - a power unit, a dozen or so cars, another power unit, etc… Reduced buff and draft in the train would translate to lighter, cheaper to build freight cars, which could shorten a car’s lifecycle, getting more state of the art car designs into sevice, quicker.
Actually, #2 diesel (130,00 btu/gal) at $1.40/gal (today’s futures price) comes to under $11 per million btu’s, compared to natural gas (not LNG) at about $3.30 per million btu’s. Then the natural gas needs to be liquified, which takes energy. I don’t know how much that costs, but it’s not free. If you add 10% it gets to about $3.60 per MMbtu, then multiply that by the 1.3 factor you mentioned it’s about $4.70/MMbtu. Still a good deal, but the advantage is closer to $6/MMbtu than $21/MMbtu.
Railroads probably think that if they became huge consumers of natgas the arbitrage process would drive the prices closer together, and eliminate the advantage they would have spent so much to obtain. There would also be a huge investment in the infrastructure required to support this conversion.
I would like to retire the argument that railroad professionals “know the business a bit better than us hobbyists.” Yes, that is most likely the case, but if that is the answer to anything speculative that a railfan wants to discuss, what is the point of having this forum?
Secondly, Jerry Pier worked on the Amtrak Turboliners, so I think he has more insight into the pros and cons of turbines in railroad applications than some of the railfans who are offering the scolding that he is not a professional railroader.
Thirdly, as to professional railroaders knowing how to run their own business, som
Your idea has shades of John Kneiling’s integral train concept from the 60’s and 70’s although he proposed applying the powerplant/propulsion system directly to the cars (not quite like an EMU/DMU as powered cars would be spread out through the length of the train rather than having every car powered)…