What does it mean by "de-rated"?

[Anonymous]

I have seen pictures of GE CW44-6 in railpictures.net many times. It follows with "de-rated AC6000CW" What is it?

Karn[:)]

[Randy Stahl]

Lowered horsepower
Randy

[Anonymous]

How? Smaller engine/alternator? Any specific reason to why they don't produce in another model?

Karn[:)]

[Randy Stahl]

I think on these GE's the 6000 hp primemover was either removed or never installed. other wise to derate a locomotive you can do several ways . The easyest way on a modern loco is only a software change. older locomotives require new governer settings .
Randy

[Anonymous]

I just recently read a history of GE locomotives "GE Locomotives, 110 Years of General Electric Motive Power" by Brain Solomon. It says here that GE had developed its new prime mover the 7HDL for the AC6000CW, but some roads namely, the Union Pacific, could not wait for the new engine, so they ordered the AC6000CW platform with a 7FDL engine that will be upgraded later. These were classed as a C44/60AC. So, these engines in fact have a different prime mover, but randy is correct in saying that an engine can be derated by changing the software, which controlles things like injection timing and throttle position, or in older locomotives making changes to the governor, and possibly changing the injectors as well.

[BaltACD]

The CSX CW 44-6AC engines began their life as 6000 HP engines...Account reliabilty problems that occured over several years of operation the engines have been de-rated to 4400 HP the same as the CW 44 AC's.


I don't know the exact mens that were used to derate the engnines, however, I would expect it came from revised fuel management software in the engine management computer, more that making any changes to any particular hardware.

[Anonymous]

If it has not been designed for lowered power at the first place, its potential power under the hood is wasted then. I mean instead of employing only three locos, now they need up to four of the (what should have been) standard power model, assuming they are working in "pure" lash up.

Karn

[Anonymous]

it's the same idea as a semi-truck engine, or any diesel engine nowadays....plug a computer into it hit a few keys and poof, you have 100-150 more or less hp. technology is pretty neat sometimes...

[Anonymous]

I have no technical knowledge and experience, but what you all have explained is very impressed to me. Since you referred to software, I am not sure you were talking about computer-controlled locomotives or a fully manual-controlled one. I mean I am confused whether the software you mentioned was the one in the computer unit you bring to adjust the engine or the software in the locomotive itself. Is this applicable to an older model like SD40-2 or far back to F7 or F9, or it can be applied only to a newer locomotives? Please be apologized if it sounds stupid to ask this question [%-)]. I am thinking about uprating locomotives in my country, Thailand.

Karn[:)]

[UPTRAIN]

I hope UP de-rates the C60ACs, the vibrate so bad parts fall off them and have caught fire, and the traction motors have shorted out and the (name any part on it here) has blown up, you get it I could go on and on and on. The cabs were designed by an idiot that had never rode in a locomotive, but I do have good news!!! I just saved a bunch of money on my car insurence, not really [:D] , they do ride good!!! (I couldn't resist!!! [:P] )

[Hugh Jampton]

QUOTE: Originally posted by rkarn

I have no technical knowledge and experience, but what you all have explained is very impressed to me. Since you referred to software, I am not sure you were talking about computer-controlled locomotives or a fully manual-controlled one. I mean I am confused whether the software you mentioned was the one in the computer unit you bring to adjust the engine or the software in the locomotive itself. Is this applicable to an older model like SD40-2 or far back to F7 or F9, or it can be applied only to a newer locomotives? Please be apologized if it sounds stupid to ask this question [%-)]. I am thinking about uprating locomotives in my country, Thailand.

Karn[:)]

Nowadays the software is in the locomotive itself. In ye olde days engines were de-rated by reducing the boost pressure from the turbo (to get less air in the cylinder) and by altering the fuel injection system to give it less fuel. Less air and less fuel result in less power.
Uprating engines can be dangerous, more power equals more stresses in the engine parts and therefore increased failures.

[UPTRAIN]

Good comment, you may remember the uprated SD50s...[:(]

[Randy Stahl]

Soft ware changes ONLY apply to engines with electronic fuel injection. to change the soft ware in an older mechanical fuel injected engine results in only a waste of fuel. EMD fuel injector on older engines are pretty much all the same. For example an SD-60 with a 710 e3 uses the same cyl head and injector as an SD40, remember all they did on the 710 was to lengthen the stroke. To derate this engine you must modify the governer rack setting, the load regulator will balance in a different spot .
Remember the DD40x each prime mover was rated at 3300 hp, the rpm was raised to 950 throttle 8 rpm. this was accomplished by new gov settings and a new performance control panel, to raise KW output so up rating horsepower does have a precident.
Randy

[Anonymous]

In the trucking industry, with the new computer managed engines it is common to purchase an engine in derated form for fuel economy, relieability, and keep the option of uprating the engine to improve resaleability. If the engine was originally built for the higher horsepower, this is not a problem. Another consideration when uprating is the cooling system. Every system of an engine falls under scrutiny when uprating.

To answer the question from the guy in Tailand, first generation electronic controls were "read only systems" with "EPROM" chips. To change the programing of the computer, chips had to be replaced. Current technology is software driven, by loading a new program into the hard drive, control paramenters can be changed.

In electronic controlled engines, the injectors are directly controlled by a digital signal and no mechanical linkage exists. The injector is still actuated by a rocker arm necessary to develope the needed pressure for injection, as high as 30,000 PSI in the newest engines, but an electronically controlled valve controls whether the fuel is hydraulicly locked or simply squirted out the return port when the plunger is forced down by the rocker arm.

[Anonymous]

The guy from Tailand has an idea that I have been wondering about myself. I am a diesel mechanic with kidney failure, and I'm too young to sell my tools (35). What kind of market is there for upgrading older locomotives to electronic controls? And, can a guy like me do it as an independent contractor? I notice EMD has a new system designed for retrofitting.

[adrianspeeder]

A diesel Mech. eh? Thats cool, I love diesel engines.

My diesel pickup is completely computer controled. Ford moved from mechanical to computer control in 95. Because of the computer control, i was able to buy a performance chip with several features. With a push button control pad, i can derate the engine for more efficiency on the highway when i dont need power. I can get over 20mpg with a big three and a half ton truck (also diesel is about 20 cents cheeper then gas around here).

I can also uprate the engine by 125 hp. (sweet). The block can handle and is happy with this if i watch some things. I put in an Exhaust Gas Temp gauge to keep an eye on that. If my EGTs get over 1200f, I back off. Same thing for the tranny, over 200f, I back off. I put in a huge oil cooler, in addition to the stock cooler, and the oil temps stay really low.

I really love a diesel engine towing.

Adrianspeeder

[jchnhtfd]

Derating is actually rather common. Among all the good thoughts above, one in particular: take a piece of machinery designed to crank out say 6,000 horsepower, derate it (software, governor changes, rack settings, whatever) to produce 4,300 and it will run forever. A nice example from the auto industry is the now departed (and lamented!) Chevy 454 cu. in. V8. In its Corvette tuning it developed upwards of 400 horsepower and lasted pretty well. In its light truck tuning (of which I have an example) it developes 230 hp, but you can't kill it.

Another reason for derating relates, oddly, to a thread from a few days back -- altitude. On turbocharged engines, you can derate the engine by controlling the maximum mainfold pressure to something less than the turbocharger will produce at sea level, but which can be maintained to, say 8,000 feet above sea level. Then you will get the same power from the locomotive at 8,000 feet (assuming everything works right!) that you do at sea level -- and the same emissions/fuel economy etc., which can be a real advantage to the operating department.

[Anonymous]

I saw a turbo once that was so hot it glowed, and after it cooled off it had turned to glass.

[Anonymous]

Please, can anybody answer my question about retrofitting electronic controls? I have always wanted to work for myself.

[Randy Stahl]

There are many companys doing retrofits on older units, E-mail quantum electronics, they have some projects there working on. Tell them you are interested, who knows you might get a break!!!
Randy

[Anonymous]

Thanks, I'll give'm a try