Other things about turbines that make them less than ideal for RR use…
Consider a comercial airline, the most common application of a turbine engine.
On take off, use full power for approximately 10 minutes…then throttle back to approximatly 85% percent power for 3-5 hours, then trottle back further for the approach, some throttle excursions durring the landing (depends on traffic and how good the pilot anticipates his aircraft…)
turns out that is the most effecient use of a turbine…and used like that, some turbines go thousands of hours before maintainence. (A bore scope inspection of the actual turbinewheels called a hot section is required at about 2,000 hours for commercial aircraft…)
How many trains can set a single power setting for that long? Just like an automobile, grades and curves require power setting adjustments…
And dont forget the main thing that makes a turbine ideal for aircraft (High HP to weight ratio) is not an advantage for the railroads…they would just have to add ballest to increase Tractive effort if you reduced the weight of the prime mover…Dont the modern engines already carry ballast (extra weight)…
THe relative ineffeciencies of turbines in this application, coupled with the high cost (most SMALL aircraft turbines cost around $1M each…) are large factors in not seeing them in RR service.
I recall reading an article in Popular Science in the 70’s about Ford putting small turbines in a Semi tractor…One of the suggestions at that time was to use two turbines, using two for accelerating and climbing grades, and then only using one for most cruise applications. Havent seen those in use, possibly for the same reasons we wont see them again in RR service…a
One of the other autmotive manufacturers (Chrysler, maybe?) played around with turbines in vehicles. I seem to recall the design utilizing multiple turbine stages based on duty (acceleration, cruising, etc.) similar to the Ford semi design you mentioned. I’ll have to see if I can find that article someplace…
…Chrysler…in the 60’s. They put out 50 cars to certain people to evaluate for, I believe it was 90 days and they would be turned in and provided to another person to continue the plan.
I was in one and ready to go for a ride and the engine set there and idled around 18,000 rpm and the fellow got a phone call…and the ride had to be posponed.
Cars resembled a small T-Bird {4-passenger type}, and after the program was finished I believe they had to be destroyed. Believe there is one or two still in existence…{Museum}.
You can pull up a pic of one by using search or Google.
The CR SD80MACs seemed to work fine and gave the road a chance to do some unit reduction on the Boston Line. Apparently a lot of the original bugs with the 20 cylinder engine had been taken care of. I don’t know any difficulty they might have had, but CSX and NS don’t seem to have any big use for them.
Both GE and EMD have started building new 6000hp. locomotives for China, 300 for each builder. The reason that 6000hp. hasn’t caught on in the US is the early reliability problems, coupled with economic reasons. Just as why some railroads haven’t bought AC motored locomotives, so railroads that have bought AC motored locomotives, haven’t found a way to offset the still higher purchase price through operational savings, especially since the early ones had higher operating costs.
6000hp locomotives built for US and Canadian service.
General Electric
Union Pacific
80 units AC6000CW
UP 7500 - 7579
CSXT
118 units
CSX 600 - 699
CSX 5000 - 5017
CSX 699 is operating with a 4400hp. engine, it is scheduled to receive a new 6000hp. engine someday, if someday ever comes. Engine block was destroyed in major failure at the peak of GE HDL engine problems.
GE also owns the prototype, and the former UP 7511, which they replaced with a new locomotive of the same type.
Electromotive Diesel
Union Pacific
Union Pacific (originally owned 61 locomotives)
UP 8500 - 8561
The 21 survivors on UP roster are now UP 8910 - 8931
Canadian Pacific (4 units)
CP 9300 - 9303
EMD Leasing (41 units formerly UP of the same number)
EMLX 8500
EMLX 8522 - 8561
These locomotives were built to be easily converted to 6000hp. at a later date. None have been or are likely to ever be converted due to their age, and other factors (Changing emissions standards etc.).
Union Pacific
EMD SD90MAC 8000 - 8308 (UP calls these SD9043MACs)
GE AC6000CW(U) 7300 - 7405 (UP calls these AC6044CWs)
Canadian Pacific
EMD SD90MAC 9100 - 9160
CEFX Leasing
EMD SD90MAC 100 - 139
At least two of UP’s SD9043MACs have been destroyed
As beaulieu has written look to the Chinese order for 600 units for further development on the 6000 horsepower units. There are several lines in the States where the EMD Leasing units are being tried. This development story isn’t over, just being written in another language.
Talk about Deja-vu. This is the late '60s all over again talking about 3600 horspower in a locomotive. That is the SD45, U36C, U36B, and C636. I heard things like “railroads will never have need for locomotives with more than 3000 horspower”, or “3600 HP is just too slippery”, or “one SD45 is not enough power for a train and two is too much” or "when an SD45 is ol
Another factor to keep in mind is until about the 1980’s, the builders offered a line of several different models for a variety of duties. All that’s being offered now is a 4300-4400 HP C-C model with either AC or DC drive. In the past, many roads would order a mix of models to best suit their motive power needs, now that option is unavailable. Unless you go to NRE or MPI, small power is not available and and SD70M-2 in switching duty is a waste of assets.
Back in the mid '80s, I spoke with the master mechanic of SCL. He told me that until the Fireball Head was developed, the beginning of swirl technology and higher horsepower, that anything over 3,000 HP broke crankshafts. His railroad really, really, really didn’t like replacing broken cranks. It might be recalled that in Formula 1 auto racing, the 3 litre Ford Cosworth began life in 1967 or 68 with 375 HP. By the end of its development, it was putting out about 675. Other engines, both diesel and gas, benefitted from the advances of technoology - and probably the computer - which were coming at faster and faster rates.
The comment about what to do with a 6,000 HP unit and it not being good for anything by long trains is probably true. Someone once told me you buy a house that you can sell, not one you like. I imagine railroad bean counters feel much the same way.
6000 hp locomotives do have a place.The reason the railroads are successful today is speed.More horsepower means more speed.They would love to eliminate all those multiple units to get a 6000 ton train moving at 60-65 mph.That is one thing the modern steam locomotive could do ,was move trains at speed.Very little tractive effort and low horsepower at low speed but when they got into their horsepower range they could move.Unfortunately most railroads misused them.I believe if the railroads could get 10000 reliable horsepower out of one unit they would order bunches of them.Keep in mind that a 6000 hp AC locomotive gets only 5200 hp at the coupler.
Not being a technical person, it seems to me that gettting 6000 hp or more onto the rails is not the problem. See the links to the Siemens site of their Taurus type electric locomotive and Bombardiers site of their Traxx type locomotives. Power is 6400 kW and 5600 kW respectively and on 4 axles. The electrics are a lot lighter than US diesels too.
6000 hp diesel engines were a part of the problem, not many applications of that many horses in non stationary uses up to recently. Most knowledge may be found in Russia I think.
Biggest hurdle probably is the operating mentality and / or needs of the railroads in the USA. They can’t see a good use for them apparently, unlike China.
EMD or GE could come out with an 8 axle, 8000 hp diesel powered by either a 20 cylinder 265H or GEvo, and it would probably be as sucessful as an Airbus A380, which isn’t saying much.
I’m confused about the 5200 HP at the coupler statistic? I know from my reading that the both the GE and EMD primemovers have a gross power rating on the order of 6,250 Horsepower, the “extra horses” taking into account the parasitic load on the engine itself (i.e air compressors and the like). I have also read that they do in fact produce 1,000 HP per axle at the railhead. So is the 5200 HP figure the result of wheel slippage or other factors?
The National Museum of Transport has one (or at least they did in the '90s). It was in operable condition and sounds really cool when fired up. I will have to do some research and see if they still have it. I want to say it was on loan.
If all other things are equal, and the RR is large and application of power and TE doesn’t vary much by train type, then “yes”.
So, why aren’t they popular? Most likely it’s the not-quite-ready-for-primetime prime movers that were initially tried. Both EMD and GE were using designs new to RR service and both had big-time teething problems. They left a sour taste in the Mech Dept’s mouth and shifted the balance of beans back in favor of the 4000+ HP state of the art.
Once the RRs are convinced the bugs are out and the Mech Dept can stomach the thought of owning some more, you’ll probably see some more orders.
Can’t speak for gas turbines in rail service, but in aviation they are far more reliable than any piston engine. Back in the 70s we were taking some out to 3200 (500 knot IAS) hours, then finding almost no wear at overhaul. Of course, a highway diesel is unlikely to swallow a bird…[:-^]
Where the UP turbines were used, in sparsely populated regions, their noise output wasn’t an issue. Imagine the reaction if one went bellowing by in my home town, 2 blocks from the full length of the Strip, then proceeded down through Barstow, over Cajon and into the LA Basin! There would be noise-pollution lawsuits filed in Clark County before the train reached San Diego.
The first generation diesel had an 18 % reduction from the engine rated HP to the HP at the coupler.The modern AC locomotive has a loss of 12 to 13%.This is due to losses through mostly the traction motors and the weight of the locomotive.
A Tom Gerbracht,a retired GE engineer,who helped develop the AC concept stated the 5200 dbhp for the AC 6000.
A 2000 hp engine will have its fuel racks set above that rating to handle parasitic loads and will have a 2000 hp input into the main generator/alternator. There are additional transmission losses between the main alternator and traction motors.
…csmith: Yes, that is a policy museums seem to be active with. Example: The Auburn, {In.}, Museum, which is the old Cord showroom, etc…generally has a Tucker '48 automoble on display but I’ve seen 2 or 3 different colored ones there.
So, someone is moving them around from museum to museum. I’ve seen a green one, a blue one and a maroon one on occasion there. That’s pretty good as only about 51 were built.
Sorry, this has nothing to do with Turbine’s and or RR engines but just answered a post above. {By the way, those cars had a flat six modified Franklin Aircraft engine in them}.