Of course they could. All the problems with all three operational steam turbines, the direct drive PRR and the electric drive N&W and C&O are all solvable, and solutions were at hand when they were removed from service. But unless coal gets less expensive and its smoke easier to avoid pollution, and diesel and alternative fuels get more expensive, this would not make economic sense,
While there may be steam turbines in the future, they won't be coal fired. If anything they would be LNG fired with LNG being the current low cost fuel; both to secure and to burn and pass emission requirements.
Never too old to have a happy childhood!
As mentioned, the cost of fuel and servicing tend work against them. A different fuel source is possible and UP used it for many years with their large GTEL locomotives. Fuel costs keep rising and they faded from service.
Another issue is the rather rough ride and vibration in train service(or anything moving). Turbines operate best at high speed, and the clearances are quite tight - damaged blades reduce the efficiency of the power plant - Something that a fixed power plant does not normally see. I am sure this can be engineered as the US Navy has turbine powered warships - But I am sure the cost is quite high. The last US rail turbines I am aware of were the Rohr powered Amtrak turbos - and they are no longer in service either - High fuel costs....
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
A direct-drive steam turbine is hideously inefficient at startup, and at any speed lower than designed operating RPM. According to one report I read, just starting up would reduce the S1's boiler pressure from 300# to 85#, which really stressed the boiler and led to some of the high maintenance costs that eventually sidetracked it.
The normal movement of a steam loco in freight service can only be equaled by a warship firing main battery salvoes (or absorbing damage in combat.) This impacts both the turbine and the boiler, and is one reason why water tube boilers were not very successful for locomotives of any design. Also, coal dust got into the electricals of the C&O and N&W turbines - conductive + abrasive = NOT wonderful!
Of course, steam turbines seem to have a future in rail power - but the steam will be generated in fixed boilers, possibly as the waste heat leg of combined cycle fixed-plant gas turbines fired with natural gas. The locomotives will be very straightforward electrics, probably fed by catenary carrying 60hz AC at commercial voltages.
Chuck
You are correct about direct drive on start-up. Some sort of gear-changing and robust clutch arrangement would be essential, and electric drive is a lot better. The vibration problems probably can be solved by proper spring-mass-and damping isolation mounts, easily done with electric drive, since the alternator and the turbine can be isolated as one unit, with all connections, electrical, fuel, and air, flexible. Modern metallurgy might make the problem less severe.
I think there is more to the preference for a fire tube over a water tube design in a locomotive boiler than simply the shock and vibration environment of a train. I think it has to do more with scale formation on non-condensing steam circuits.
Ships and stationary power plants condense the steam, allowing the use of highly purified water that gets reused. That purified water minimizes scale formation as well as boiler corrosion, allowing the use of water tube boilers at high steam pressure. Scale formation is particularly bad for a water tube boiler because it could block a water tube in a way to cause it to fail from overheating. At very high pressure, boiler operators have to purify the water from dissolved gasses so as to not accelerate boiler corrosion.
Steam locomotives with only a handful of historical exceptions use a non-condensing steam cycle where the water is used only once. As steam locomotives use large amounts of water, that water is maybe "softened" with chemicals to reduce scale formation, but it certainly isn't distilled or purified to the extent possible where you reuse the water in a condensing steam cycle.
The fire-tube "locomotive-type" boiler is more tolerant of scale formation before "bad things happen", although scale affects it too. Because of scale, you are also limited in the maximum boiler pressure.
There was something called the "Schmidt system" to get higher boiler pressure by using a closed heat exchanger loop of purified water at very high pressure, something like the heat exchange loop in a pressurized water type nuclear reactor plant. Because you were transfering heat to your high pressure boiler with this type of heat exchanger rather than directly to the flames, you could mitigate scale formation at higher pressures. Schmidt, I believe, invented the superheater, which was widely used in mainline steam power, and this sounds like his "second act" that didn't catch on with the industry.
Part of why the Schmidt system never caught on may have to do with the British experimental locomotive ironically named "Fury", which killed one crew member and injured another in a breach of a high pressure boiler tube. Steam locomotives are more compact and may place crew members in closer proximity to the dangers of high pressure steam than ships or stationary plants. But even these applications pose dangers from high pressure steam.
The ASME was founded to promote codes for boiler safety, and their Web site had an article regarding an accident on the US Navy ship Iwo Jima during the buildup to the 1990's Gulf War. It was repaired at a foreign-hosted base, and a contractor employee with inadequate training or supervision substituted an ordinary bolt for the special bolt needed on a steam fitting on a 600 PSI circuit. When the ship was put under steam, the bolt broke, and the entire engine room crew perished from burn injuries after being scalded. High pressure steam poses a danger, even in ship or stationary applications and even in this modern age.
There are other disadvantages to high pressure steam. I looked at the "steam tables", and in a non-condensing cycle such as a steam locomotive, the minor efficiency gains of simply boosting steam pressure may not be worth the cost and the safety hazard. To fully take advantage of higher steam pressure, you also need to go to compound expansion because you can't operate single-expansion engines at a short enough cutoff without incurring high cylinder friction and wall cooling losses.
So why don't steam locomotives go "condensing"? Ships and power plants can use water to cool the condensers -- ships are on the water whereas power plants are often sited on a lake or a river. Condensing locomotives had to reject heat to dry air, requiring enormous condensing "tenders" with power robbing cooling fans. Condensers were used on the South African Railways (SAR) 25C class in order to conserve water running through desert country, not to achieve much higher efficiency.
On the other hand, the N&W Jawn Henry used a novel water tube boiler at 600 PSI on a non-condensing cycle. I had heard that the steam turbine in that turbine-electric design was damaged in a hard coupling impact with the locomotive, and I also heard about trouble from coal dust getting into the electrics. But no one ever commented that the boiler on Jawn Henry posed any problems. So maybe if steam continued, somewhat higher pressure boilers using water tubes may have been the next step as people figure out how to properly condition the water to prevent scale.
As to direct-drive turbines, I also heard about the Pennsy steam turbine suffering from boiler stress by the huge drawdown in boiler pressure on startup. But then there was a British direct drive steam turbine designed by Stanier along with a Swedish steam turbine that seemed to work just fine. The Stanier turbine had a multiple switchable nozzle arrangement to economize on steam at low speeds and loads.
As to electric power from an overhead wire being the solution to everything, many parts of the world have indeed taken on this high capital expense that has been resisted in the United States with more abundant native oil (since not keeping up with demand) and coal. Also there are many less wealthy countries than those of Europe and the Far East that may still benefit from a steam locomotive fired by local coal for bio fuels (wood or ag waste or fuel crops on marginal land for food production).
Whereas steam fell to the Diesel in the U.S., outside the U.S. it was displaced by electric railways, but there are many places where electric railways are not practical, keeping the dream of steam power alive.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
daveklepper You are correct about direct drive on start-up. Some sort of gear-changing and robust clutch arrangement would be essential, and electric drive is a lot better. The vibration problems probably can be solved by proper spring-mass-and damping isolation mounts, easily done with electric drive, since the alternator and the turbine can be isolated as one unit, with all connections, electrical, fuel, and air, flexible. Modern metallurgy might make the problem less severe.
DC electric drive is only about 80 percent efficient. Besides incurring the cost of a generator, traction motors, provision for cooling traction generator and traction motors, and an electrical cabinet with all of the switch gear to make the electrical transmission happen.
The complication and efficiency loss of electric drive was one of the knocks on the Diesel, especially the first generation Diesel in competing with steam. This is balanced against the high efficiency of Diesel engines from idle up to full load relative to eveything else.
Steam is much less efficient, and you hang an 80 percent efficient drive on it and you give back all of the efficiency gain from the superheater, which was considered a huge improvement to steam.
"Overmod" talks about something called the "Bowes drive" intended for the never-built Pennsy V1 steam turbine. I can't find anything on the Web about it, but I am guessing it is some kind of integrated or modular electric transmission that may have somewhat higher efficiency. The Toyota Hybrid Synergy Drive on the Prius where the prime mover, a motor-generator, and a generator-motor are all connected to a planetary gear drive of the type used in an automatic transmission might be something like it. That system transmits a large fraction of torque by direct mechanical drive with the electrics being modulated to make up the difference to trade speed for torque as in a fluid torque converter drive, and this setup achieves higher efficiency.
Paul Milenkovic"Overmod" talks about something called the "Bowes drive" intended for the never-built Pennsy V1 steam turbine. I can't find anything on the Web about it, but I am guessing it is some kind of integrated or modular electric transmission that may have somewhat higher efficiency.
A large collection of Bowes material survives at the ISM in Philadelphia; here is an online finding aid . (There is also a .pdf version for people who'd rather have a printed version.)
The original Bowes drive patent is 2465006. An improved version with variable ratios is 2715689, and a version 'sensitive to load speed' is 2747115. (There is also an interesting version optimized as an automobile transmission, 2732508.) I have not had the chance to get back to the Hagley to compare the description of the Bowes drive for the V1 in their collection with the features in these patents. But this will give you a good idea of the principles and the developed technology.
Bowes incidentally worked on the problems of relays subject to severe vibration or shock, and his patent addressing some of the design issues is 2636095. IIRC the problem with relays was at least as detrimental to the TE-1's over-the-road performance as was shock to the main turbine...
As a note: there is a report on diesel torsional vibrations through this design of drive. A steam turbine drive would not have this concern.
With LNG as a relatively cheap fuel, and all the extra problems of steam, it would seem like a gas turbine would be the preferred option. I think the UP used heavy oil, which had its own problems.
MidlandMike With LNG as a relatively cheap fuel, and all the extra problems of steam, it would seem like a gas turbine would be the preferred option. I think the UP used heavy oil, which had its own problems.
Early diesels with dc electric drive had 80% efficiency for the transmission. But modern ac alternator to ac motor transmissions have made a modest improvement to about 85% because the slanted-bar rotor looses far less energy in heat than the dc commutator motor armature coils. Some of the gain is lost through the magnetic power transfer across the clearance gap between the rotating bars and fixed coil pole pieces, but some of the gain is retained. If the motors were body mounted for good vibration isolation ,as required for the turbine as discussed above, clearances could be reduced and the efficiency further improved.
daveklepper If the motors were body mounted for good vibration isolation ,as required for the turbine as discussed above, clearances could be reduced and the efficiency further improved.
If the motors were body mounted for good vibration isolation ,as required for the turbine as discussed above, clearances could be reduced and the efficiency further improved.
Sounds like the system used by EMD in the GA8 and GA12.
M636C MidlandMike With LNG as a relatively cheap fuel, and all the extra problems of steam, it would seem like a gas turbine would be the preferred option. I think the UP used heavy oil, which had its own problems. About one third of the energy in a standard aero-derivative gas turbine is lost as heat in the exhaust.. Around the year 2000, a number of cruise liners were built using exhaust boilers on GE LM2500 turbines and steam turbines to improve their overall fuel efficiency to well above that of diesel powered ships. Of course, there aren't the same vertical clearances in locomotives as in cruise liners but it might be possible to build a two unit locomotive with a gas turbine in one and the boiler and steam turbine in the other. Maybe three units with a gas tank in the third if that were acceptable.... The Russians already have gas turbine locomotives with gas tanks in one powered unit. M636C
Railpower Industries(maker of the Green Goat) designed a 5500 HP Compressed Natural Gas powered gas turbine locomotive which would have used composite gas tanks and been able to operate without a fuel tender (unlike LNG powered locomotives). They had an artist's conception on their website in UP colors and built a large (maybe G scale) display model in CN livery. they never got enough industry interest to justify building a demonstrator.
The locomotive would have used an Industrial Gas Turbine built by a division of Caterpillar. O.C, Cat now owns EMD, so I wonder if they have looked at the Gas Turbine locomotive concept.
However both GE and Cat are developing and testing LNG fuel conversions for their existing Diesel locomotive prime movers and CN and BNSF are testing them. If the converted diesels are technically successful it is hard to imagine the Class 1's looking at turbine power as an option.
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Ships have the big advantage of unlimited sea water coolant for the steam condenser. Rail mounted air cooled condensers just don't have the same efficiency.
MidlandMike M636C MidlandMike With LNG as a relatively cheap fuel, and all the extra problems of steam, it would seem like a gas turbine would be the preferred option. I think the UP used heavy oil, which had its own problems. About one third of the energy in a standard aero-derivative gas turbine is lost as heat in the exhaust.. Around the year 2000, a number of cruise liners were built using exhaust boilers on GE LM2500 turbines and steam turbines to improve their overall fuel efficiency to well above that of diesel powered ships. Of course, there aren't the same vertical clearances in locomotives as in cruise liners but it might be possible to build a two unit locomotive with a gas turbine in one and the boiler and steam turbine in the other. Maybe three units with a gas tank in the third if that were acceptable.... The Russians already have gas turbine locomotives with gas tanks in one powered unit. M636C Ships have the big advantage of unlimited sea water coolant for the steam condenser. Rail mounted air cooled condensers just don't have the same efficiency.
daveklepper Early diesels with dc electric drive had 80% efficiency for the transmission. But modern ac alternator to ac motor transmissions have made a modest improvement to about 85% because the slanted-bar rotor looses far less energy in heat than the dc commutator motor armature coils. Some of the gain is lost through the magnetic power transfer across the clearance gap between the rotating bars and fixed coil pole pieces, but some of the gain is retained. If the motors were body mounted for good vibration isolation ,as required for the turbine as discussed above, clearances could be reduced and the efficiency further improved.
The current AC drive locomotives are 92% - 93% drive efficiency. The last generation AC-DC locomotives were up to 88% drive efficiency. The first generation DC-DC locomotives were around 82% drive efficient. That where the infamous 308 number came from. 308 is 82% of 375 from the Speed X TE / 375 = HP formula. In the current locomotives, a lot of work not only has been done in reducing electrical losses, but mechanical losses between the traction motor and axle. This not only has the effect of improving HP at the rail for a given Nominal Traction HP rating, but also improves emissions because the more efficient a locomotive is in delivering HP to the rail, the less fuel it burns in relationship to the amount of work it can do.
MY EE background told me about the improvement in efficiency for the motors and control and power distribution within the locomotive, but I did not know about improved efficiency for the mechanical coupling between motor and axle. How was this accomplished?
tomikawaTT MidlandMike M636C MidlandMike With LNG as a relatively cheap fuel, and all the extra problems of steam, it would seem like a gas turbine would be the preferred option. I think the UP used heavy oil, which had its own problems. About one third of the energy in a standard aero-derivative gas turbine is lost as heat in the exhaust.. Around the year 2000, a number of cruise liners were built using exhaust boilers on GE LM2500 turbines and steam turbines to improve their overall fuel efficiency to well above that of diesel powered ships. Of course, there aren't the same vertical clearances in locomotives as in cruise liners but it might be possible to build a two unit locomotive with a gas turbine in one and the boiler and steam turbine in the other. Maybe three units with a gas tank in the third if that were acceptable.... The Russians already have gas turbine locomotives with gas tanks in one powered unit. M636C Ships have the big advantage of unlimited sea water coolant for the steam condenser. Rail mounted air cooled condensers just don't have the same efficiency. A couple of comments on all of the above: LNG as fuel - tested (in diesels) and found wanting. Too little density (BTU/cubic foot) and too likely to turn a derailment into a disaster (BLEVE, anyone?) Dual-cycle gas/steam turbine power plants aren't small (except when compared to coal-fired steam fixed plants) and they would be a bear to squeeze into a locomotive. I live about three miles from one, and the cooling tower (no cooling water in the desert!) is easily twice the cubic of ALL of the machinery in the unit that feeds it (two gas turbines, one waste heat boiler, steam turbine, three generators, switch gear...) When I was satisfying my curiosity about the system I found something that said the smallest economical size was in the 10,000 - 15,000 KW range. Also, the fuel is delivered by pipeline, not stored on-site. Chuck
BNSF and GE are spending quite a bit of time and money on converting GEVO units to use LNG fuel at the moment. Time will tell if the industry adopts it......
AFAIK, the FRA has yet to issue definitive rules on LNG tenders, I imagine that could be a "deal breaker"...I know the unions have had some concerns about that issue.
carnej1 AFAIK, the FRA has yet to issue definitive rules on LNG tenders, I imagine that could be a "deal breaker"...I know the unions have had some concerns about that issue.
LNG as a transported commodity is considered HAZMAT - Having a LNG tender coupled to the engine consist??????
BaltACD carnej1 AFAIK, the FRA has yet to issue definitive rules on LNG tenders, I imagine that could be a "deal breaker"...I know the unions have had some concerns about that issue. d LNG as a transported commodity is considered HAZMAT - Having a LNG tender coupled to the engine consist??????
I'm not arguing and I don't have a real opinion on this (I don't work in the Railroad industry)
RAILWAY AGE ran an informative article about the LNG locomotive development programs at the end of last year:
http://www.railwayage.com/index.php/mechanical/locomotives/a-closer-look-at-lng.html
Sorry I can't provide a live link, typing this on a work computer and it's my understanding that the security settings here prevent that ....
IMO,We have gotten too far off topic for discussion of this on the "Steam & Preservation" Forum...
carnej1Sorry I can't provide a live link
Here's the live link to the report
As long as cryomethane was being used as a potential fuel for gas turbines or combined-cycle, its discussion would apply here, and the work of Iden's NGFT group continues to be ... potentially ... applicable to such locomotives were they to be developed. I agree that the subject of LNG-fueled compression-ignition locomotives should be moved to a new thread, probably in 'Locomotives', or one of the older threads on LNG/CNG locomotives be resuscitated for the purpose...
One little note that would also be applicable in a somewhat different sense to turbines:
From the report:
"In the [compression-ignition] engine’s power assemblies (cylinders), diesel fuel, which ignites under high compression, is used to ignite the natural gas. (“All of the technologies current being promoted pass gaseous methane, not LNG, onto the dual-fuel locomotive and into the engine cylinders,” says Iden. “Technology does not currently exist to inject LNG directly into engine cylinders and properly combust it.”) This method provides some operational flexibility, depending upon the LNG/diesel ratio. High pressure direct injection (HPDI, at 5,000 to 8,000 psi), and low pressure (125 psi) fuel delivery methods are being looked at. HPDI fuel delivery requires port or direct injection at the cylinder; this method is purported to save anywhere from 40% to 60% in fuel costs."
I would note that the critical pressure of methane is under 675psi under otherwise standard conditions, so under HPDI the feedstock can be kept in liquid phase through the full required heating, and potentially metered through the same general approach used on the Enginion steam motor "zero emission engine". I also wonder whether laser ignition (which works so well in PDEs burning methane from cryo sources) is not as practical a solution as dual-fuel pilot ignition. (Both, it seems to me, would have application either in a gas-turbine or free-piston gas generator for combined-cycle... either of which might have a steam turbine as the bottoming expander...)
This sounds fascinating. But there is loss of energy in any transfer from one state to another; ie electrical energy to steam.
Why would a locomotive manufacturer make such a system, when a straight electric would be more cost effective and more efficient?
I don't see how a straight electric would be more efficient since the aforementioned loss of energy would take place at the power plant instead of on the locomotive plus there would be additional losses in the movement of electrical energy through the catenary.
Use if fuel in any large power plant is always far more efficient than use on a locomotive. Consant speed operation at the most efficient speed, greater efficiency in cooling, eetc. Doesn't matter whether you compare diesel vs. diesel, steam vs. steam, the larger fixed plant is always more efficeit than the moving small plant. And this difference in efficiency is somewhat greater than the loss of efficiency in transmission, even in the worst cases.
To amplify on what Dave wrote, a combined cycle gas turbine station can reach 60% efficiency. The best diesel engines are running slightly over 50% and those are ship sized units running at constant speed.
In anything moving on earth, the cost to "put that body in motion" is higher than keeping it in motion to a great degree. Maybe its time to think outside the train engine, and climb on board an aircraft carrier. Fixed Steam catapults for Train engines, at stations could save HUGE amounts on other fuels and the various means of creating the steam could be better controlled. Long distance passenger service could benefit the most, but having a boost for freight couldn't hurt. Intermodal maybe?
Since the Jet in NYC landed safely in the Hudson River, a huge amount of research has been done on jet engine "blades" ~vs~ Geese. This involved many tests with frozen turkeys ( no lie) and now there are blades made from carbon Fiber that Stand up to the Turkeys and do NOT vibrate after impact. I do NOT know their heat limits but I have a friend who makes the blades they use in the 787's now. This technology may be something to throw in the mix.
On the CNG and LNG thought. Landfills can and do produce Natural gas. There is a cost to Filter out metals,water, and then you have your average weak natural gas. Natural gas from mining is more pure, but still needs to be purified, water and hydrocarbons gone. Once you have it purified, it takes energy to Compress it into CNG. To make LNG requires even more energy to bring that to a very low temp, (−260 °F) . In Tankers the LNG is at low pressure. LNG has about 2 and a half times MORE energy than CNG, but still only about 62% of Diesel fuel.. Trains running on LNG are a b o m b and would require many many tenders as seen in the CNG tests. BaltACD is correct, its not going to fly. If any of you have been near a port, or in the navy, you know what happens when a LNG tanker comes to port, the CG and or Navy and harbor patrol CLEAR the harbor...MOst the LNG in the US is imported due to cost to make it. Its not as cheap as its been touted. Interesting topic
I'm going to assume that the first part of the last post is an early April fool's joke although there have been proposals to do something similar in concept to what you are suggesting using electromagnetic linear induction motors (which, to tie it together is the same technology that the US Navy is trying to replace Steam catapults with)..
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