by Mimbrogno
Will, I appreciate the research you have done and the technical knowledge you posses, but I have to disagree with you on the overloading ability of the Baldwin diesels. I completely agree with you that 1625hp is the maximum the diesel engine will ever produce under any operating circumstance, but that doesn't mean that the electrical system can't make a little magic, as it were. There is a little trick that the system pulls. I still don't fully understand it, but I have studied it enough to feel confident that it is what's going on. The diesel engine and the motor's horsepower ratings are in synch at the continuous TE, which is the point where the power into the motors equals the power used by the motors. Above that, and the power put out lowers as compared to the power put in, and below that speed, the power put out increases above the power put in. It's a trick of relative power per instant and time compression. The way the generator is set up is ingenius. It performs as a DC generator, autowinding transformer, and inductor all at the same time. It doesn't just pass the energy from the engine directly through to the motors, it manipulates it a little by shunting the current and forcing up the amperage. The voltage range of the system stays between 595 and ~800 volts. Because of a special link between the generator and exciter, which makes the generator also act as an autowinding transformer, it shunts the excess voltage which would otherwise be produced into additional amperage. For instance, EMD's and Alcos of the time produced up to ~1500 volts DC. Now this high voltage is usefull at high speeds, but it is all but useless at ultra low speeds below CTE. Infact the extra voltage is wasted in extending the magnetic field beyond the induction zone where it does the effective work. The Westinghouse equipment turns that excess voltage into usefull energy, as ultra high amps. Unlike volts, which create the volume of the magnetic fields and how quickly they are established, amps determin the weight or density of the field, and literally how much shear force per area there is.
Now, if you were to measure the electrical output at the motors when the engine is at that power rating (which I think is around 2mph), you would get a measurement of 2650 amps with ~600 to ~650 volts. That translates to around 1.6 megawatts of electricity. Translating Watts into comparable horsepower by the formula of 1/745, you get about 2200hp. This is inspite of the fact that if you were able to get an accurate HP measurement off of the crankshaft at this same rating, you would get the same 1625hp as always. I think it is also somewhat safe to assume that it remains at or below that much because of the load regulator you mentioned earlier.
The effect is relative compression. The engine is a set power supply, which will deliver 1625hp at 9.9mph, but the train isn't going at 9.9mph, it is going at 2mph, and the other 7.9mph worth of power is being shunted onto the motors. I know, it's screwy!!!
The Westinghouse motors and the GE 752s are not as similar as they appear to be. Although they both operate with the same voltage and amperage ranges, and they have virtually identical continuous ratings. The difference is in the mechanical side of the motor. Remember that motors have more than one set of ratings, there are ratings for torque and RPM in addition to voltage, amperage and heat. The power curve of the Westinghouse gear is much sharper and level off much earlier than the curve for the GE gear, with many times more torque at low speeds than the GE, but also with many times less torque at high speeds, and a higher generative effect. The result is that they have different speed ranges. Westinghouse motors are ultra heavy duty low speed motors, GEs are mid-high speed, middle to light weight motors by comparison. (although yes I know they aren't that light in the torque department) This is pointed out by the different gear ratios that GE had to use to equal Westinghouse and vice versa.
You also pointed out that the ratings of the early 600s had to be severaly limited, and that the engine was an inferior one. This I do not dispute, infact I whole heartedly agree with you. The 600's of 1946-1949 were TERRIBLE!! In their defense I will point out that they were relativly new at the time and BLW was still getting many bugts out of them, along with bugs they still carried from the VO. The late 1949-1950 600s on the other hand, are a whole different story. These are the engines that I love so much. I don't have much affection for the VO or the early 600, but the late 600 is the best engine built in those years, in my opinion anyway. I might add that unlike their premature forebearers, the later 600s had an average life of 20-30 years, with a few going on 57-58 with one or two rebuilds. There's one in particular that went for 29 years of continuous hard service, then 25 years of intermitant service with minimal maintance, and still runs today!
Then there is a whole ne set of design improvements I have for the 600, that would make it into a different engine, with capabilities undreamed of by even the most imaginative engineers today. I just need somebody to listen to and believe me, or my own engine shop to build one!
Baldwin engines may have been all but forgotten long ago, but they still offer incredible potential. Baldwins are better, and I'll prove it!!!
Matthew Imbrogno
-Mechanical Volenteer, Arizona Railway Museum.
www.azrymuseum.org.
Now, if you were to measure the electrical output at the motors when the engine is at that power rating (which I think is around 2mph), you would get a measurement of 2650 amps with ~600 to ~650 volts. That translates to around 1.6 megawatts of electricity. Translating Watts into comparable horsepower by the formula of 1/745, you get about 2200hp. This is inspite of the fact that if you were able to get an accurate HP measurement off of the crankshaft at this same rating, you would get the same 1625hp as always. I think it is also somewhat safe to assume that it remains at or below that much because of the load regulator you mentioned earlier.
The effect is relative compression. The engine is a set power supply, which will deliver 1625hp at 9.9mph, but the train isn't going at 9.9mph, it is going at 2mph, and the other 7.9mph worth of power is being shunted onto the motors. I know, it's screwy!!!
The Westinghouse motors and the GE 752s are not as similar as they appear to be. Although they both operate with the same voltage and amperage ranges, and they have virtually identical continuous ratings. The difference is in the mechanical side of the motor. Remember that motors have more than one set of ratings, there are ratings for torque and RPM in addition to voltage, amperage and heat. The power curve of the Westinghouse gear is much sharper and level off much earlier than the curve for the GE gear, with many times more torque at low speeds than the GE, but also with many times less torque at high speeds, and a higher generative effect. The result is that they have different speed ranges. Westinghouse motors are ultra heavy duty low speed motors, GEs are mid-high speed, middle to light weight motors by comparison. (although yes I know they aren't that light in the torque department) This is pointed out by the different gear ratios that GE had to use to equal Westinghouse and vice versa.
You also pointed out that the ratings of the early 600s had to be severaly limited, and that the engine was an inferior one. This I do not dispute, infact I whole heartedly agree with you. The 600's of 1946-1949 were TERRIBLE!! In their defense I will point out that they were relativly new at the time and BLW was still getting many bugts out of them, along with bugs they still carried from the VO. The late 1949-1950 600s on the other hand, are a whole different story. These are the engines that I love so much. I don't have much affection for the VO or the early 600, but the late 600 is the best engine built in those years, in my opinion anyway. I might add that unlike their premature forebearers, the later 600s had an average life of 20-30 years, with a few going on 57-58 with one or two rebuilds. There's one in particular that went for 29 years of continuous hard service, then 25 years of intermitant service with minimal maintance, and still runs today!
Then there is a whole ne set of design improvements I have for the 600, that would make it into a different engine, with capabilities undreamed of by even the most imaginative engineers today. I just need somebody to listen to and believe me, or my own engine shop to build one!
Baldwin engines may have been all but forgotten long ago, but they still offer incredible potential. Baldwins are better, and I'll prove it!!!
Matthew Imbrogno
-Mechanical Volenteer, Arizona Railway Museum.
www.azrymuseum.org.