In Europe, a lot of tilting trains have been tested, the last one was a version of TGV developped for test in Franch central Mountains. This version was stopped when Alstom bought Fiat Ferroviaria. Since this time, Talgo and Alstom (with Pendolino) are the reference of tilting trains. Siemens can propose also this solution and I believe that high speed connection between Madrid and Lisboa will be tilting train manufactured by Siemens and CAF.
Re Capital Cost vs. Maintenance Cost
I’m not able to generate actual cost ratios for the mild steel vs. light alloy steel as a car body material. I can say, however, that the RTL bodies were virtually rust free when the paint and “Bondo” were sandblasted off and the floors and underframe were solid. As I noted previously, the finish could have been spot repaired at a major cost saving. From a strength standpoint, the trains are good for another 20 years if they ever get back in service. As matter of interest related to another program, I had a qualified person inspect a number of the RTG Trains in France after they were retired. These were also in good condition.
At its birth Amtrak inherited most of the passenger cars the railroads had not already scrapped. Rohr had a contract to restore and refurbish any of these worthy of the effort. This was done at their facility in Mira Loma, CA.
The cars built of mild steel were totally rusted out. Inspectors evaluating them were warned not to set foot on the floor if they did not want to fall through to the track. Restoration was not deemed economic and these cars were generally scrapped with the exception of the trucks and couplers. The Budd stainless steel cars were still very solid and these were restored, refurbished and put back in service as Heritage cars. The only fault with the stainless steel car sides was that if they were dented, the defect could not be repaired other than by replacing a complete panel.
Re Tilt in Europe:
I don’t know where my brain was when I wrote that Talgo was the only tilt system in Europe. I’m very familiar with the Pendolino ETR having been privileged to ride it on a private demonstration run from Arrezo to Florence in 1987. Maximum cant deficiency was 15 inches and speed was in excess of 100 mph. Great ride. The doors were open between cars, permitting a view of the adjacent car’s tilt entering a curve.
My experience in France is somewhat dated but when I was interfacing with ANF in the 70’s and 80’s, SNCF’s philosophy was to run the TGV’s on very good straight track where tilt was not required. On the smaller 125 mph lines on which they ran the RTG’s, cant deficiency of 8 inches was considered acceptable. ANF designed a tilt system but, to the best of my knowledge, never applied it. I’m sure they now offer the Bombardier system
In 1988, the Coalition of Northeastern Governors (CONEG) and Amtrak conducted tests between Boston and New Rochelle to determine whether tilt would permit higher speeds in the Northeast Corridor. An Amfleet train was used as the baseline. Trains tested were the Canadian LRC, Spain’s Talgo, the French RTG and the Rohr Turboliner. Cant deficiencies from 4 inches to 8 inches were tested with the non-tilt trains while the LRC was tested up to 9 inches and the Talgo to 8.4. I rode all of the trains during this program. Not surprisingly, the tilt-trains did better than the non-tilt and the LRC’s active system out-performed the Talgo passive system. The 8” cant deficiency on the non-tilt trains was noticeable but not particularly uncomfortable.
At this stage of the development, the rule was that if the tilt system failed on one car, it would be cut out on all cars. The LRC achieved a 1% failure rate on a per car basis, which is quite good, but when multiplied by 10 for a full train-set the number reaches 10%, meaning that one trip out ten will not be completed with tilt active. Perhaps the rule has been changed for the Acela.
VPayne's description is a little hard to follow. There are two general kinds of passive tilt. Talgo relies on placing airsprings on the tops of tall posts on top of the axle journals -- it is not clear to me if Talgo ports air between the air springs to control the tilt or simply lets the car body roll against air springs with a fixed charge. The UA TurboTrain and Train-X (NYC XPlorer, New Haven Dan'l Webster) used a four-bar linkage remote roll center arrangement.
You can easily place the roll center of the car body any place you chose by simply angling the swing hangers. The problem with this approach is that the swing hangers are short because the space underneath the carbody is limited. As the car rolls, it also jacks up, limiting the percentage of the side force that gets compensated by passive tilt.
What the guided-axle arrangement (Talgo, Train-X, TurboTrain) buys you is that by placing the axle between the train cars (or at in non-revenue space at the end of a train car), those roll links can be much longer and you can get more passive roll compensation. In fact, the TurboTrain and Train-X links are inverted from the swing hanger suspension, and these trains are unstable and would flop over were it not for elastomeric torsion springs.
Hitachi has a patent on an alternate passive tilt arrangement where they use a bolster that has wheels that roll in a circular track, the center of which is the remote roll center. The augment this passive tilt with pneumatic cylinders, and this is the narrow-gauge tilt train (3.5 foot gauge) that tipped over in Australia when a driver failed a speed restriction on a curve.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
The vertical strut you wonder about is close to the Talgo patent.
As I recall but had no quick success Googling, the TGV employed long-travel springs between a bolsterless truck and a body support point above the floor on either side of the gangway between articulated cars. I have no idea how lateral motion between the truck and carbody was controlled - gravity? snubbers? control links? The current Bombardier catalogue features "Flexx" bolsterless trucks and suspension seemingly to avoid maintenance, weight, and complexity of bolsters and swing hangers for everything from trams to locomotives.
The only elastomeric primary journal suspension currently offered by Bombardier is for metro trains. I rode the X2000 when it was on demonstration and was very impressed with the ride and concepts to achieve low unsprung mass. The elastomeric journal springs were replaced by steel coil for the last X2000 version I saw Googling the X2000.
I rather doubt 5-6" underbalance is allowed on any wide-spread basis in Europe. It's been a while, but an SNCF official told me that practice was restricted to all reserved seat, extra-fare trains for standing passenger safety. This practice may have all but disappeared with the completion of high-speed networks diverting the market.
I would be interested to hear from Jerry what he thought of the capital cost to maintenance cost ratio of the light alloy steel bodies used in the Rohr turboliners. Since he was involved in the overhaul of the trainset he should have a pretty good fix on the condition of the equipment at the end of the original service life. I guess my question is why do we feel that we have to do things so different than Europe with regard to the carbody design.
The alternate way of achieving a flat surface was really intriguing but I understand something like this is fairly common in European stock. Experiments like the use of Alpolic composite panels for the finish surface and insulation are also interesting. Just think of all the advances in intercity bus bodies that have been made with structural silicone adhesives, welded tubular frames, and composite panels. Then consider the price point for a motorized bus versus a passenger railcar.
With regard to the unbalanced elevation do any of the other posters know of a modern attempt to reduce the roll angle of a standard carbody to near zero using passive means (modern swinghangers). I have wondered if the airspring bolster could not be fabricated so that it had vertical struts under the airsprings that would allow the airsprings to sit within a pocket above the floor of the car. This bolster would not rotate about the truck vertical axis but rather would be kept in place with a drag link. The truck sideframes would bear on long travel bearings that would rest on this bolster.
The result would be a roll center above the center of gravity that would be entirely passive and somewhat simple. With elastomer journal springs this could pave the way for a high unbalance replacement for the Amfleets that will be needed soon. I suppose Europe has no need for such as they are already allowing 5-6" unbalance with standard coach stock which is why this would have to be a north american innovation.
Finally, I have to applaud Jerry as it is certainly difficult to actually put your neck out on the line when it is your livelihood. The report written by the NY Attorney General was somewhat weak and really represented a lack of understanding of some critical issues that engineer's think about.
The Acela gas turbine may find a home in the Midwest. Illinois and Indiana may have a few 10-20 mile stretches that could be cobbled together to allow up to 150 mph running with at-grade crossing elimination and grade separation and limited curve easement.
The trickiest part would be to avoid passing tracks that would render a 150 mph zone useless without a second main track.
The January, 2009, Trains has a picture of the "Acela" turbine locomotive sitting among weeds in Pueblo. Sadly, this is perhaps the only American passenger locomotive that bears a large American flag.
The comment about Hiawatha's being scheduled for 100 mph operation more than a half century ago using steam locomotives is sad also. Those locomotives were beautiful! No wonder why I frequently lament the absence of pride in our passenger rail system.
"Make no little plans; they have no magic to stir men's blood." Daniel Burnham
Jerry Pier As you are probably aware, tilt is there for passenger comfort and has nothing to do with safety. The Acela has it as does the LRC in Canada. Only the Talgo has it in Europe, the high speed lines are built to avoid curves that might require tilt. The FRA doesn't like cant deficiency above 3 inches but Europe goes well above that on some their feeder lines. I guess it depends on what passengers are used to.
As you are probably aware, tilt is there for passenger comfort and has nothing to do with safety. The Acela has it as does the LRC in Canada. Only the Talgo has it in Europe, the high speed lines are built to avoid curves that might require tilt. The FRA doesn't like cant deficiency above 3 inches but Europe goes well above that on some their feeder lines. I guess it depends on what passengers are used to.
C'mon Jerry you were doing good until you made the statement about only Talgo using tilt in Europe. virtually all European builders have tilt designs running somewhere in Europe. You have the Class 390 Pendolinos and Class 221 Super Voyagers in the UK using Alstom (Fiat) technology. The X2000 trains in Sweden using Bombardier technology, in Germany the Class 611, 612, ICE-T, and ICE-TD DMU and EMUs. In Switzerland the ICN EMUs, and in Italy the various ETR series Pendolino EMUs. And I know I am missing some. The ICE designs in Germany use Siemens technology. I haven't tried to count them but it is likely that Talgo has built or designed one-third or less of all tilting trainsets in Europe.
With regard to the 3" unbalance. I always had in my mind that the Rohr turboliners had some ability to at least tilt less toward the outside of the curve due to their overall smaller profile and the ultimate pick of these trainsets over the UA turbos with passive tilt.
Given that the FRA simply does not seem to want to allow very high unbalance that could be obtained by active tilting equipment is there a sweet spot of say 6" unbalance that would come from a passive system which merely prevented the body from rolling to the outside of the curve? I have read the various articles in interface regarding the L/V ratios at high unbalance and this seems to be the way forward for mixed use lines. Wasn't 4.5" unbalance allowed by the UP for outside bolster trucks. I have found this in a lot of engineering references.
Welcome aboard.
Dave
Lackawanna Route of the Phoebe Snow
Problems of gas turbines are multiple and must be treated globally.
If these goals are obtained, advantages of gas turbines are important:
With gas turbines, french trains have reach more than 310 Km/h and demonstrate capability to operate at high speed
The FRA Program Manager for the Flywheel program is no longer there. I doubt that he had anything to do with the choice of a flywheel development program, he just had to manage it.
The trucks under the RTL Turboliners are an ANF (now Bombardier) design for 125 mph service. They do not hunt at speeds up to 140 mph and have acumulated more than 20 million miles of troublefree service in the Empire Corridor. For higher speeds, I would look to successful European designs
Concerning recuperators, a major constraint on most applications is size and weight. On a locomotive this is not a problem. While my experience with heat exchangers has been with compressed air, I tend to favor a series, tube style, counterflow design with the goal of getting the combustion air temperature as close to that of the exhaust as possible. The AGT1500 did not use this style because of space constraints but the L100, which was developed to replace it (but never produced), used a tube style, a Garrett design I believe. I think the TM1800 uses a tube style as evidenced by its effective recuperation but can't swear to this.
I had totally forgotten the gas turbine work done on trucks. It might be worth another look to take advantage of natural gas a fuel. A down sized L100 gas turbine comes to mind. First cost would be high but with a 24,000 hour TBO and CNG incentives, life cycle costs could be competitive.
Were those direct drive or turbine/electric?
Paul Milenkovic wrote: they would not compare favorably with the one time $7 million cost of recuperating the TF50. I mentioned this to the FRA Program manager early on but was ignored. I suppose the word of a Program Manager carries more weight than what is on their website, but it seems the two things the FRA is interested in funding these days are 1) anything to do with safety -- either structural or having to do with signals or other systems to keep trains safely separated, and 2) they seem to be interested in lightweight, high-power, fuel-efficient propulsion systems with some hint of interest in turbines of the type you are talking about I mention these things because they don't seem to be interested in tilting suspensions, either active or passive pendulum, self-steering trucks or guided axles, trucks and suspensions that suppress wheel hunting at high speeds. At least with the aviation industry there are NASA centers that study advanced technology for passenger airliners instead of simply air traffic control schemes or safety-oriented matters. Safety is important yes, but in the late 60's, early 70's, there still seemed to be interest in basic research on high-speed trains with consideration of the wheel hunting problem, which has a lot of bearing on how much maintenance you have to do with HSR on maintaining wheel and rail profiles and maintaining bushings and wear surfaces on the trucks, along with the amount of wear that the suspension design inflicts on the track and on the train itself.As to this recuperated turbine, what kind of heat exchanger do you have in mind> One kind is a fixed plate-type heat exchanger. The other kind is a rotating drum. I was working for a short time at Ford Motor Research in the mid 1970s, and I saw pieces of the ceramic heat exchanger of the Ford Truck Turbine all over the place.The Ford Truck Turbine apparently was a big project -- one of the buildings on the Dearborn Research campus was called Gas Turbine Lab. My understanding is that they were using metal for the turbine, but they were to use ceramics for the heat exchanger because they thought the mechanical stresses were less critical in something that spun at revolutions-per-minute instead of revolutions-per-second. These heat exchangers were these big cheese wheel sized things that were honeycombed with through holes. My understanding is that exhaust blew through one part of the wheel and compressor air got preheated prior to combustion by passing through another part of the wheel, and the wheel turned to the part that just got heated up by the exhaust gas ended up in the path of the combustion preheat air flow.Another demand of this system is that it had to seal gas pressure between the moving wheel and the nozzles feeding it, especially on the combustion preheat side and less so on the hot exhaust side. On the other hand, those automotive regenerated turbines, such as the Chrysler Turbine Car and the Ford Truck Turbine, operated with maybe one or two stages of radial compressor and at low pressure ratios.Anyway, I remember seeing pieces of fractured regenerator wheels in the hallways as junk, and I had heard that the program came to an early end on account that they sold these Truck Turbines to customers and they kept coming back broken owing to the ceramic wheel not holding up in service.I was told that the Ford Truck Turbine was popular for fire engine pumper trucks -- when you are pumping water, that seems like a condition where you want to run the engine flat out to keep that water coming, and turbines like to operate at full power. But if they break down, that is no good. I imagine some progress in materials has been made these past 30 years or so.As to the story of the competition between United Aircraft and the Turboliner for the Amtrak order, I came across a contemporary article on this in Aviation Week. The Amtrak people interviewed indicated that reliability was a big concern with the UA "TurboTrain 2" as "TurboTrain 1" had been so bad as you mentioned. A helicopter engine with 500 hours service life? What were people thinking? The whole point of a turbine is that it is something that can just run and run compared to pistons, needing major overhaul every 1000 hours or so (or at least in light aircraft), and I don't think a 500 hour TBO would cut it for a light turbine aircraft these days.On the other hand, the UA TurboTrain with its Alan Cripe-designed guided axles and aluminum construction was something like half of the Turboliner and a third or less of a Diesel locomotive train.
they would not compare favorably with the one time $7 million cost of recuperating the TF50. I mentioned this to the FRA Program manager early on but was ignored.
I suppose the word of a Program Manager carries more weight than what is on their website, but it seems the two things the FRA is interested in funding these days are 1) anything to do with safety -- either structural or having to do with signals or other systems to keep trains safely separated, and 2) they seem to be interested in lightweight, high-power, fuel-efficient propulsion systems with some hint of interest in turbines of the type you are talking about
I mention these things because they don't seem to be interested in tilting suspensions, either active or passive pendulum, self-steering trucks or guided axles, trucks and suspensions that suppress wheel hunting at high speeds. At least with the aviation industry there are NASA centers that study advanced technology for passenger airliners instead of simply air traffic control schemes or safety-oriented matters. Safety is important yes, but in the late 60's, early 70's, there still seemed to be interest in basic research on high-speed trains with consideration of the wheel hunting problem, which has a lot of bearing on how much maintenance you have to do with HSR on maintaining wheel and rail profiles and maintaining bushings and wear surfaces on the trucks, along with the amount of wear that the suspension design inflicts on the track and on the train itself.
As to this recuperated turbine, what kind of heat exchanger do you have in mind> One kind is a fixed plate-type heat exchanger. The other kind is a rotating drum. I was working for a short time at Ford Motor Research in the mid 1970s, and I saw pieces of the ceramic heat exchanger of the Ford Truck Turbine all over the place.
The Ford Truck Turbine apparently was a big project -- one of the buildings on the Dearborn Research campus was called Gas Turbine Lab. My understanding is that they were using metal for the turbine, but they were to use ceramics for the heat exchanger because they thought the mechanical stresses were less critical in something that spun at revolutions-per-minute instead of revolutions-per-second. These heat exchangers were these big cheese wheel sized things that were honeycombed with through holes. My understanding is that exhaust blew through one part of the wheel and compressor air got preheated prior to combustion by passing through another part of the wheel, and the wheel turned to the part that just got heated up by the exhaust gas ended up in the path of the combustion preheat air flow.
Another demand of this system is that it had to seal gas pressure between the moving wheel and the nozzles feeding it, especially on the combustion preheat side and less so on the hot exhaust side. On the other hand, those automotive regenerated turbines, such as the Chrysler Turbine Car and the Ford Truck Turbine, operated with maybe one or two stages of radial compressor and at low pressure ratios.
Anyway, I remember seeing pieces of fractured regenerator wheels in the hallways as junk, and I had heard that the program came to an early end on account that they sold these Truck Turbines to customers and they kept coming back broken owing to the ceramic wheel not holding up in service.
I was told that the Ford Truck Turbine was popular for fire engine pumper trucks -- when you are pumping water, that seems like a condition where you want to run the engine flat out to keep that water coming, and turbines like to operate at full power. But if they break down, that is no good. I imagine some progress in materials has been made these past 30 years or so.
As to the story of the competition between United Aircraft and the Turboliner for the Amtrak order, I came across a contemporary article on this in Aviation Week. The Amtrak people interviewed indicated that reliability was a big concern with the UA "TurboTrain 2" as "TurboTrain 1" had been so bad as you mentioned. A helicopter engine with 500 hours service life? What were people thinking? The whole point of a turbine is that it is something that can just run and run compared to pistons, needing major overhaul every 1000 hours or so (or at least in light aircraft), and I don't think a 500 hour TBO would cut it for a light turbine aircraft these days.
On the other hand, the UA TurboTrain with its Alan Cripe-designed guided axles and aluminum construction was something like half of the Turboliner and a third or less of a Diesel locomotive train.
Another experiment with truck turbines was conducted by Boeing, Kenworth, and Garrett truck lines in the late 1950's in the Pacific Northwest. As far as I remember Kenworth suppled two trucks to Boeing who installed the Turbines and an Allison transmission. Garrett supplied the loaded trailers and the driver. The experiment took place on Snoqualmie Pass just after the four laning was fully completed. The fully loaded truck and double trailers was able to top the pass either eastbound or westbound at 70 mph. One thirty day test sequence was performed between Garretts south Seattle terminal and Yakima with the turbine truck completing a round trip daily. The truck was a fuel guzzler and used cheap at the time kerosene. equipped with two 75 gallon tanks it had barely enough fuel to make it from one terminal to the other. The drivers assigned liked it because they were able to cruise the entire trip at the posted speed of seventy over the pass and made for a very short day for those drivers, other trucks were down to fifteen or slower climbing Snoqualmie Pass at the time. I think a big diesel at that time was the 220 Cummins and GM produced one with 210hp. The experiment died for whatever reasons but knowing one of the drivers (neighbor) he was sure disappointed when Garrett did not purchase any. I remember seeing two glass windows on the turbine trucks hood that you could see through from one side to the other showing how small the turbine was compared to a conventional diesel powered truck. He always said the drawback was getting started from the terminal and getting through the stoplights to the highway was very slow going.
In any event the second Kenworth became a Seattle Fire Truck and operated for years, I don't know what the fate of this one was, but I do know the Garrett truck was recycled with a diesel installed and the Allison transmission or torque converter whatever it was remained in place. At the same time the truck turbine experiment was going on their were rumors that Boeing was looking to do a rail experiment but never heard anymore other than some rumors. Anyone know anymore about Boeing and Rail applications of turbines or if it never made it past the rumor stage?
Al - in - Stockton
Concerning gas turbine fuel consumption, see my previous comments on recuperation. The numbers for a recuperated TF50R virtually match a good diesel over the speed range when adjusted for the lighter weight of the locomotive. The Turboliners operated with both turbines in accelration mode but shut down one for constant speed running. They also have 3rd rail capability which was used in the tunnels approaching Penn Station as well as when stopped at the platform. This system, which runs only 7 minutes per trip, costs as much as the the whole turbine-hydraulic system.
The UAC Turbotrains did use multiple small gas turbines but not for reasons of fuel economy. Five Pratt & Whitney 400 HP ST6B turbines were used to provide 2000 HP for traction, A sixth was used for the APU. The turbines were connected by a 3 input gear box in each powercar. This scheme was used for no reason other than it was the only turbine available from UAC who were building the trains. To add insult to injury, they relied on the torque conversion properties of the power section to adjust output, which was a loser from the start. As a consequence, the ST6B seldom reached its 500 hour TBO (marginal for the service anyway.) without a failure. The gear trains were also unreliable with the end result an availability of just 60%. In recognition of these problems, UAC offered a TMT3 version in the bidding competion with the Rohr Turboliner in 1974. The TMT employed an 1120 HP Avco Lycoming gas turbine driving a Voith 411rBu hydraulic transimssion but it was too late and the train was never built.
On the hybrid subject, the FRA flywheel project was doomed from the start by the laws of physics. The flywheel system weighed over 20 tons and would have had to be contained in a trailer car. Never heard anything on projected costs but it's safe to say they would not compare favorably with the one time $7 million cost of recuperating the TF50. I mentioned this to the FRA Program manager early on but was ignorred.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Even if the turboliners were not 30 years old they are equipment not ready for this time. Conceived when fuel was cheap that operating expense has balloned. Since the equipment is only a full power efficient machine there is not anywhere at present that characteristic can be used. If the equipment was able to take power off a third rail when in a station then efficiency would go up.
An example of efficient operation would be: NY Penn station to Albany using Metro North and new third rail to Croton then the turbo to Albany with third rail in Albany station. Then non stop to Schenectady with a third rail there then non stop to Buffalo (another third rail) on the water level route (no up and down profiles). However since there is no third track or PTC yet on that route its speed advantage cannot yet be used (many years in the future). Also some third rail would have to be installed at those stations where it would stop and storage/maintenance tracks. A better location might be a limited stop Chicago - St. Louis if the passenger demand was sufficient. I'm sure you readers may think of other locations. Maybe Washington - Jacksonville.
narig01 wrote: Questions about fuel consumption. What is "BSFC"? Also as mentioned could a turbine be set up in a hybred for passenger rail? The comment that one of the 2 turbines was shut down whilst cruising. (In other words fire up the 2nd turbine when you needed to accelerate from a stop) I vaguely recall that the US Navy was using a combination diesel/gas turbine in ASW frigates & destroyers. Using the diesels when all that was needed was to puter about, but when speed & manueverability was needed(put the pedal to the metal) they could fire up the turbines. Forgive my ignorance on this. And please forgive me if I seem to ramble(It's kind of late) 1. Could you design a turbine powered train for fuel economy? I would think if you designed the power systems around a specific running speed combined with turbine battery electric operation you do better on fuel economy. It is my impression that gas turbines generally were more reliable than internal combustion diesels. (fewer moving parts) , correct me if I'm wrong. 2. If I recall correctly gas turbines do very well in situations were they are run at constant speed(most engines) and at or near the maximum power. By the by what is the fuel consumption of tier 2 diesels compared to gas turbine?(ie the power plant in a SD 70 evo or GEVO (EMC OR GE respectively) It s late am going to post this & go to bed. I'll try to edit this down next chance I get.It is kind of sad to these train sets currently. I'm thinking they may end up down in Mexico like the PA's or so many Baldwin diesels. Many Thx IGN
Questions about fuel consumption. What is "BSFC"?
Also as mentioned could a turbine be set up in a hybred for passenger rail? The comment that one of the 2 turbines was shut down whilst cruising. (In other words fire up the 2nd turbine when you needed to accelerate from a stop) I vaguely recall that the US Navy was using a combination diesel/gas turbine in ASW frigates & destroyers. Using the diesels when all that was needed was to puter about, but when speed & manueverability was needed(put the pedal to the metal) they could fire up the turbines.
Forgive my ignorance on this. And please forgive me if I seem to ramble(It's kind of late)
1. Could you design a turbine powered train for fuel economy? I would think if you designed the power systems around a specific running speed combined with turbine battery electric operation you do better on fuel economy. It is my impression that gas turbines generally were more reliable than internal combustion diesels. (fewer moving parts) , correct me if I'm wrong.
2. If I recall correctly gas turbines do very well in situations were they are run at constant speed(most engines) and at or near the maximum power.
By the by what is the fuel consumption of tier 2 diesels compared to gas turbine?(ie the power plant in a SD 70 evo or GEVO (EMC OR GE respectively)
It s late am going to post this & go to bed. I'll try to edit this down next chance I get.
It is kind of sad to these train sets currently. I'm thinking they may end up down in Mexico like the PA's or so many Baldwin diesels.
Many Thx IGN
Back in the late 1990's the US Department 0f Energy partnered with the FRA to do some serious research on building a hybrid version of the Bombardier JETTRAIN Gas Turbine passenger locomotive with the intention of using a superconducting flywheel energy storage system instead of conventional batteries. At the same time they were funding a similiar research project on using the flywheel technology in Diesel Electric freight applications (BN/BNSF was involved in this). They did build and test a prototype flywheel (in a stationary laboratory setting) but ultimately abandoned the program due to concerns with reliability of the Energy Storage System in mobile applications (the initial plan had been to mount it in a rebuilt bombardier LRC power car shell).
With General Electric making a very serious effort to develop a hybrid version of the Evolution series one wonders if they will look at transit and other passenger applications. Railpower industries had also stated that they wanted to develop a hybrid commuter locomotive, but this was before they experienced the considerable technical issues(i.e fires) with the Green Goats and their website currently does not have anything about commuter applications.
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
BSFC is brake specific fuel consumption. It's a measure of an engines fuel efficiency. In English units it's lbs of fuel per brake horsepower hour. The brake horsepower is the engine output measured at the output shaft on the engine.
You are correct about the part throttle fuel consumption of turbines being lousy. The notion of having several smaller turbines and bringing them on line as needed to get better overall fuel economy was the approach taken in the UA TurboTrain. Having a smaller, single turbine drive a generator to charge batteries would be a good approach for a commuter locomotive, but would be difficult for long distance trains where they can need full output for hours on end. I suppose you could use one large turbine and cycle the turbine on and off during periods of less that full throttle.
The navy uses gas turbines in just about everything but the nuclear aircraft carriers these days. They try hard to capture the waste heat from the turbines by employing boilers in the exhaust gas stream. The steam generated is used for powering other shipborad systems. It helps the ship reduce it's thermal signature, too.
For direct drive, you need a BIG reduction gear set similar to gas turbine engines on Navy ships.
Narig01:
My turbine expertise is in aviation. I do not know how well it would translate to railroading.
Pros:
Turbine engines are much more reliable than reciprocal engines. They make more horsepower per pound of weight. They are fairly economical to keep fuel in. They are not fussy about which combusible liquid you put in them.
Cons:
They are not suitable for direct drive because they make very little low end torque. They work best running wide open for long periods of time. They work very well running generators and auxilary power units. In large helicopters, they often must be started with the rotor system disengaged because of the low end torque issue. In either type of aircraft, when they are driving a propeller or rotor, they are brought up to a given RPM and remain there for all aspects of operation. Acceleration is accomplished by changing the pitch, rather than the speed, of the rotor or propeller.
In a railroad engine, it seems to me like they could be used effectively to run an alternator or generator for turbine/electric or for head end power, but would be a very poor choice for direct drive.
However, I really believe that railroads should be electrified. But that is a discussion for another thread.
Jerry,
Yet another thank you for posting information on the TM-1800. The sfc figure at 50% power is impressive.
That engine would make a sweet prime mover for a commuter locomotive, especially a hybrid design. Th lighter weight of the turbine-generator package would allow for a larger battery.
- Erik
Thanks. This is good information and offers a practical, light weight traction power alternative for fast trains (110-150 mph) where electrification is neither available or practical.
Good and interesting stuff! Thanks, Jerry.
(please "go on and on" anytime!)
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