Why are we talking about things like fuel efficiency and their oddball status? Isn't the topic about restoring one of the Big Blows to operation for special occasions like the steamers?
Uniqueness and fuel cost shouldn't be entering the equation if I'm understanding the topic correctly since it would be only for special events. What matters most are the condition of the survivors (Two, if I'm not mistaken), their completeness such as if they still have their turbine and generators, the ability to maintain one in running condition after restoration such as parts for their Cooper Bessemer engine, its suitability for use, and its potential PR value.
Sadly, we all know it's a moot point even if one of the pair was in excellent condition, the major appliances were able to be reasonably maintained, they could easily burn diesel like the rest of UP's fleet including the two operating steamers, etc. Union Pacific never held these with the fondness that they did their late model steam or their DD40AX's and weren't responsible for saving the two that ended up preserved.
Why would they care now especially with their ambitious plan to restore the 4014?
Firelock76 Putting it simply, a restored gas turbine locomotive won't excite the general public the way a restored steam locomotive will. Railfans yes, but the general public who (no insult intended) couldn't tell a gas turbine from an SD70, no. Exciting the public's what a steam program's all about.
Putting it simply, a restored gas turbine locomotive won't excite the general public the way a restored steam locomotive will. Railfans yes, but the general public who (no insult intended) couldn't tell a gas turbine from an SD70, no.
Exciting the public's what a steam program's all about.
Excellent post although one could argue that the general public wouldn't be able to tell the 4014 apart from the 3985 yet that's happening just the same.
But hard to twist a long forgotten gas turbine locomotive as having any sort of impact like the Big Boy program already has enjoyed these first few months. That tops the list of many reasons why one will never turn a wheel under its own power again.
There's just no significant PR value there compared to the cost.
Firelock76 Railfans yes, but the general public who (no insult intended) couldn't tell a gas turbine from an SD70, no.
efftenxrfe erikem, I realize I restated your concept, full credit to you; my tech flourishes didn't "ruffle" your "feathers," hopefully.
erikem, I realize I restated your concept, full credit to you; my tech flourishes didn't "ruffle" your "feathers," hopefully.
Consider my feathers unruffled...
I was pleased that you thought the idea had merit. A couple of places where it could make sense, one being an area as southern California where air pollution is a major concern, a gas turbine burning natural gas is bound to be cleaner than a diesel. The other would be a line with a long tunnel, e.g. Cascade tunnel or Moffat tunnel, where the turbine would be shut down during passage through the tunnel.
The gas turbine hybrid might be even more efficient than a diesel on a hilly route, where the regenerated power while braking could be put to use later. This was (is?) the impetus behind GE's hybrid locomotive, though the larger battery capacity possible with a gas turbine prime mover might make the concept even more attractive (full power out for maybe 2 hours with the turbine, half power output for one hour with the diesel).
Feasibility? Biggest obstacle is the battery, with the GE battery being my guess as the best choice (strong emphasis on guess).
- Erik
We may be on to something here:
given that a gas turbine's fuel efficiency improves with heavier load, a hybrid locomotive with a battery charging generator powered by a g.t. that would operate at full load when, but not until, the battery needed charging and, I guess, would fire up to supplement the batteries when very high locomotive horsepower was called for, might be possible....feasible?....practical?
The killer issue for gas turbines as prime movers in locomotives is fuel efficiency at low output (high turndown). Diesel engines are the preferred prime movers because of relatively high efficiency at all output levels, especially if the prime mover speed is allowed to vary with power output (true of almost all locomotive applications).
To put things in perspective, the 4500HP GTEL's and the SD70/AC4400's produce are roughly equivalent in power. The GTEL's consumed 450 gallons per hour at full throttle and 200 gallons per hour at idle. The modern diesel consume a bit over 200 gallons per hour at full throttle. OTOH, the GTEL's used 1950 era gas turbine technology, advances in turbine materials allowing higher turbine inlet temperatures and computational fluid dynamics leading to improved compressor design have led to a factor of two or so improvement in efficiency. Some simple cycle as turbines are more efficient at full output than a 1950's era diesel engine.
What may make sense is a gas turbine battery hybrid, where the lighter weight of the gas turbine would allow for a much larger battery than possible with a diesel engine of equivalent power. Ideally the battery should be large enough to allow store at least 1 to 2 hours of the gas turbine's power to allow the turbine to run out at full power (most efficient) and reduce the number of starts (extends the life of the turbine).
Allison was experimenting with steam injection to improve efficiency and reduce NOx using exhaust heat to generate the steam. This could be of help in reducing the exhaust temperatures.
samfp1943 Around this area there seem to have been a few applications in the stand-by Electrical Generation Facilities for Turbine type generator power plants. MAYBE THESE ARE JUST USED TO HELP IN PEAK POWER DEMAND SITUATIONS?
When I worked for Northern Canada Power at Whitehorse Rapids GS back in the 70's we had a couple of gas turbine package units in standby service at Faro, YT (Anvil Mine) on the far end of the 138kv line. They supplemented the existing standby Diesel plant.
I never ran them but according to the Faro operator and others they were noisy, dirty and inefficient. Like wise, they were hard to maintain I was told. IIRC they didn't last long. The diesel on the other hand is still there I believe.
Charlie
Chilliwack, BC
Much better to use its manpower to restoring currently out of service diesels. ie more HP per buck. Also the fuel guzzling turbines do not work well on up and down profiles. Much more miles per gallon on a diesel or maybe a LNG loco. Note what happened to the NY state turbo liners
Overmod Isn't this really two questions: Will UP bring back its old style of GTEL, or will UP use turbine power in the future? The answer to the former has really already been answered. To add to what he said, the economics depended on a very cheap fuel, which ceased to be cheap in the late '50s. If Jerry Pier sees this thread he can comment extensively on this and the other factors involved with these locomotives. There is probably some application for turbine power on UP in future, but it would have to be very different from the historical GTELs (perhaps using a number of smaller ceramic turbines, and including substantial bottoming heat recovery making them in essence small GTCC plants). Whether there are advantages to that, vs. modified positive-displacement piston engines making the same effective hp, remains to be seen; personally, I think the turbines may be a better solution for high horsepower if burning LNG or CNG. But do not expect those locomotives to be Bigger Blows!
Isn't this really two questions: Will UP bring back its old style of GTEL, or will UP use turbine power in the future?
The answer to the former has really already been answered. To add to what he said, the economics depended on a very cheap fuel, which ceased to be cheap in the late '50s. If Jerry Pier sees this thread he can comment extensively on this and the other factors involved with these locomotives.
There is probably some application for turbine power on UP in future, but it would have to be very different from the historical GTELs (perhaps using a number of smaller ceramic turbines, and including substantial bottoming heat recovery making them in essence small GTCC plants). Whether there are advantages to that, vs. modified positive-displacement piston engines making the same effective hp, remains to be seen; personally, I think the turbines may be a better solution for high horsepower if burning LNG or CNG. But do not expect those locomotives to be Bigger Blows!
Comments by Jerry Pier would be a welcome addition here. His unique insite would add much.
With the current regulatory stance by the Federal Government ( essentially, anti- Coal power) in Power production?
Along with the current testing underway on LNG Applications for Railroad locomotives. It would seem that Turbine applications would be an economic benefit(?) possibly, a good alternative to the conversion of Diesel Power to mixed fuels( engines started on diesel and then LNG for operations?) on the Railroad.
Around this area there seem to have been a few applications in the stand-by Electrical Generation Facilities for Turbine type generator power plants. MAYBE THESE ARE JUST USED TO HELP IN PEAK POWER DEMAND SITUATIONS?
There is a large, Electrical Generator Plant near Oologah, OK that receives regular Coal trains from UP, but seem to always have BNSF Power on the head. (There is also a large NG fueled Turbine Power Plant at that same facility).
My guess would be that the older style of UP GTEL locomotives are just curiosities, and museum pieces. But maybe with the smaller, modern compact turbines, would find a place in todays railroad environment?
Is there a Horsepower range in which they would be the best answer to function in?
Isn't this really two questions: Will UP bring back its old style of GTEL, or will UP use turbine power in the future? Note: I am assuming you don't mean whether UP will restore a Big Blow to go with the Big Boy, or to doublehead with the Centennial, or whatever. That question would need to be posted in the Steam and Preservation thread.
Highly unlikely. Even in their prime, the various GTEL's were oddballs on an overwhelmingly diesel (and some steam) roster. Parts availability for the prime movers would be virtually impossible and the support staff would need some A&P-certified mechanics to help keep it running.
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