I've read alot about Gensets lately and about how fuel effective they are when compared to other locomotives.
Why can't a normal locomotive lashup be used like a genset?...for example...a train is assigned three GP38-2 (which are basically three engines and three generators) but only one of these GP38-2s runs continously to keep the train moving while the other two only kick in on grades or when the train needs to be started from a dead stop. In effect, your three unit lashup would function as a genset does...only on a larger scale. For some reason the rails don't do this...
Well, I see where you are comming from. But when you think about it, if you put 2 genset locomotives in the same train, you would get one unit reduction. Also the other 2 GP38-2's that the one is pulling while not in use would just add dead weight to the train. Reducing maxamum effiancy.
Now, back to those 2 gensets. If you have 2 loco's one completly fired up, the other only with one genarater running to add just enough power. You now have a fairly efficant set up with minamul dead weight. It's just the thought of unit reduction, and effiacy. I imagine that this happens in real life though. I've heared of engineers shutting down their lead loco(s) to reduce fuel consumption. RWM, wabash1 care to elaborate?
The road to to success is always under construction. _____________________________________________________________________________ When the going gets tough, the tough use duct tape.
If a train is assigned 3 locomotives such as {GP38-2's}, to take a train from point A to point B....I'd believe there is not really very much extra power in the combination assigned....Of course, it would depend on the terrain....If the route would have just one area of grade that all three were needed to accomplish getting up said grade, one might think it possible to idle the other {2}, engines for the "flat" part of the route....if, the single engine could actually pull said train and maintain road speed.
But how many routes would fit that discription....I have no idea.
Quentin
Starting a locomotive isn't as easy as starting your car, although I'm sure it could be done. I'm guessing the issue would be in developing software that could be adapted to the current locomotive consist - they do vary as to the number and types of units in use. Gensets are always together on one chassis so the wiring is permanent.
I'd also opine that in over-the-railroad applications, the needs don't necessarily vary widely the way they do in a yard situation, current home of gensets.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
UlrichI've read alot about Gensets lately and about how fuel effective they are when compared to other locomotives. Why can't a normal locomotive lashup be used like a genset?...for example...a train is assigned three GP38-2 (which are basically three engines and three generators) but only one of these GP38-2s runs continously to keep the train moving while the other two only kick in on grades or when the train needs to be started from a dead stop. In effect, your three unit lashup would function as a genset does...only on a larger scale. For some reason the rails don't do this...
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
Yes, CR and others had Select-a-Power. Often mid train helpers were/are cut out when not needed. But I guess there is a question of when pulling around dead weight when not in use becomes counter productive...but I am sure it is built into the program.
RIDEWITHMEHENRY is the name for our almost monthly day of riding trains and transit in either the NYCity or Philadelphia areas including all commuter lines, Amtrak, subways, light rail and trolleys, bus and ferries when warranted. No fees, just let us know you want to join the ride and pay your fares. Ask to be on our email list or find us on FB as RIDEWITHMEHENRY (all caps) to get descriptions of each outing.
Remember that all three engines in a Genset share the same trucks, electrical system, fuel tank, cab, etc... Three GP38-2s, when one is running, are dragging two locomotives behind it... In addition, the big advantage of a Genset is yard usage, with a lot of idling in one spot and movement in a low notch. Road trains use a bigger percentage of their power.
Many trains now use DPU's. I'm sure you could reduce the rear end power on level track if not needed to save fuel. Does this really save fuel?
If you were moving three locomotives (no cars) from point A to point B, would it be more fuel efficient to run one locomotive and drag the other two or power all three? If all three were under power they would be using a lower knotch to maintain the same speed, right? Regardless of the knotch setting it takes a certain amount of energy to move those three down the line. I bet it's all the same either way if one does all the work or if they share the load.
They did do this quite a bit in the 80s. There were several products on the market. One was Harmon "Select-a-Power" that Conrail bought quite a bit of. There were others that worked similarly. Frisco went for the Prime system. KCS had something home grown, I think. These systems allowed the engineer to set trailing units off line by pushing a button in the lead locomotive.
Did it work? Not really. The trailing units only went to idle, not shutdown and the power producing efficiency of the consist (if turbocharged) wasn't really any different notch to notch. It would be more feasible today if you paired it with the AutoStart systems. I don't know if anybody is doing it, though.
In your example, you would actually be worse off with one GP38 in N8 and one shutdown than with two in N6 because GP38 power generatation efficiency is just lousy in the higher notches.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
BTW, I don't really think gen-set locos are all that great. They are just a stop gap until hybrids are produces. They have way to many moving parts for what they do.
There are a couple other problem with doing this. The traction motor commutators took a beating. The brushes depend on current flowing through them to leave a nice film on the commutator. Without any current, the commutator tends to get machined by the brushes. Changing the brush grade to a softer one means shorter life under load - and maybe you don't make it to the next inspection.
The other problem is no current = no wheelslip detection on some locomotives, so Conrail didn't do idle with Select-a-Power, they did N1. (I'm not sure this helped very much with either problem. I just made people feel better...)
I have read a (a possibly apocryphal tale) that some Conrail engineers who ran trains with the Select-a-Power system would place bets as to who could get a train over the road with the fewest units in the lashup "online" which led to overloading and traction motor damage............
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
oltmannd BTW, I don't really think gen-set locos are all that great. They are just a stop gap until hybrids are produces. They have way to many moving parts for what they do.
But isn't a diesel locomotive just that? A hybrid?i An oil fueled engine produces electricity to propel the vehicle by electic motors mounted on the trucks?
The electric part of a D-E locomotive is generally considered to be the method of transmission of the power. A hybrid connotes a combination of methods of generating the power in the first place - ie, a Diesel motor and batteries, solar cells, shore line (between uses), or perhaps a fuel cell. Some think fusion may make an appearance in the future.
It would be possible to drive the locomotives wheels via a mechanical link (if such a linkage could handle the stresses involved) or perhaps hydraulics - using a big pump at the prime mover and hydraulic motors on the axles (way too many opportunities for leaks). Both methods are fraught with problems.
Using an electrical source the transmission method remains the same regardless of how that electricity is created.
Railpower got into business with hybrids, the Green Goats (GG models) are diesel-battery hybrids but they barely sold. CP's cancellation of a sizable order of Green Goats probably caused other railroads to back off on ordering hybrids. Also consider that part of UP's order for gensets from Railpower originally included a number of hybrids which were changed to gensets before construction.
tree68 [snip] It would be possible to drive the locomotives wheels via a mechanical link (if such a linkage could handle the stresses involved) or perhaps hydraulics - using a big pump at the prime mover and hydraulic motors on the axles (way too many opportunities for leaks). Both methods are fraught with problems. [snip]
The hydraulic drive concept is not merely possible, it was done - with mainline U.S. locomotives, back in the 1960s - though notably unsuccessfully, I think, to be fair. SP imported like 12 or 18 - and DRGW also got a few - Krauss-Maffei [sp Q.] diesel-hydraulics, mainly for tunnel use. Of course, ALCo had to build a few for SP, too. If I recall correctly, none lasted more than 5 or 6 years or so - too much maintenance.
Of course, the smaller 'critter' locomotive class probably has numerous examples of mechanical and hydraulic drives, as well as overseas locomotives - mainly British, who it seems love those oddball designs. Also, I believe that some self-propelled ['locomotive'] cranes have geared drives - and some may have hydraulic drives instead. M-O-W equipment also has mechanical and hydraulic drives - but that's not quite what we're discussing here anymore.
- Paul North.
henry6 oltmannd BTW, I don't really think gen-set locos are all that great. They are just a stop gap until hybrids are produces. They have way to many moving parts for what they do. But isn't a diesel locomotive just that? A hybrid?i An oil fueled engine produces electricity to propel the vehicle by electic motors mounted on the trucks?
...battery storage to store braking energy and use it again to accelerate ala the Green Goat. Maybe when GE gets their loco battery plant up and running....
bubbajustinI've heared of engineers shutting down their lead loco(s) to reduce fuel consumption. RWM, wabash1 care to elaborate?
I did that for a quieter ride.
oltmannd henry6 oltmannd BTW, I don't really think gen-set locos are all that great. They are just a stop gap until hybrids are produces. They have way to many moving parts for what they do. But isn't a diesel locomotive just that? A hybrid?i An oil fueled engine produces electricity to propel the vehicle by electic motors mounted on the trucks? ...battery storage to store braking energy and use it again to accelerate ala the Green Goat. Maybe when GE gets their loco battery plant up and running....
General Electric, of course, has that experimental Hybrid Evolution series loco they have been testing. It uses a more advanced battery technology than the Green Goats..
Gensets seem to save fuel by being broke down a good percentage of the time.
The autostart systems I deal with start the engine when the reverser is moved from center, the independent brakes are below 20 psi, and a few other things. Constant starting and stopping of the engine isn't good for it either.
If assigned 3 GP38s, you will need all, or at least two to get things moving. Many times a crew will isolate the lead engine if not needed for a portion of the trip. Saves a bit of fuel, and the cab is quieter.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
WSOR 3801 Gensets seem to save fuel by being broke down a good percentage of the time. The autostart systems I deal with start the engine when the reverser is moved from center, the independent brakes are below 20 psi, and a few other things. Constant starting and stopping of the engine isn't good for it either. If assigned 3 GP38s, you will need all, or at least two to get things moving. Many times a crew will isolate the lead engine if not needed for a portion of the trip. Saves a bit of fuel, and the cab is quieter.
carnej1 oltmannd henry6 oltmannd BTW, I don't really think gen-set locos are all that great. They are just a stop gap until hybrids are produces. They have way to many moving parts for what they do. But isn't a diesel locomotive just that? A hybrid?i An oil fueled engine produces electricity to propel the vehicle by electic motors mounted on the trucks? ...battery storage to store braking energy and use it again to accelerate ala the Green Goat. Maybe when GE gets their loco battery plant up and running.... General Electric, of course, has that experimental Hybrid Evolution series loco they have been testing. It uses a more advanced battery technology than the Green Goats..
Some sort of sodium based battery. Doesn't charge or discharge quite as fast as lithium ion, but is well suited for locomotives. They are building a plant near Albany NY.
zardozbubbajustinI've heared of engineers shutting down their lead loco(s) to reduce fuel consumption. RWM, wabash1 care to elaborate? I did that for a quieter ride.
As have I. Though on the CNR they don't want you isolating your lead unit.
Our community is FREE to join. To participate you must either login or register for an account.