For those of you that are "challenged" backing up

rhagfo wrote:

Wes Tausend wrote:

2oldman wrote:
Wow. I had no idea voltage was that complicated.

Wes Tausend wrote:
if we knew both the amps and rpm, and there was no slippage, we could theoretically calculate the wattage and convert it back and forth to HP, ftlbs of torque, voltage etc:
1 hp(I) = 745.699872 W {P(hp) = P(W) / 745.699872}

At 4,000 HP, with efficiency of everything at 100%, 4000hp x 746w = 3,000,000 watts/1500a =2,000 volts. Highly theoretical, of course.

I can't imagine the size of cable, or buss bar, that carries that kind of power...let alone the diesel engine size and the generator. I'm so fascinated by big power I hope someone will give me a tour of a modern locomotive.. I've asked, but not yet.

2oldman,

You've definately got the idea now. At higher speeds (40-50 mph), the voltage readout seems to steady out, but even one steady-mph difference changes the ratio between volts and amps... and from memory, every unit is just a bit different. I'm retired now and I can't remember a precise set of matching figures.

Because the Class 1 rail corporations have become so touchy about civilian presence, it became increasingly difficult to invite someone aboard for a tour. The best chance is often on a small short line. These smaller companies are a little more friendly, but most of their equipment is not the newest nor biggest. The very basic electric power transmission principles are exactly the same however, and not unlike the system now found in my wife's hybrid Prius.

I think the root diesel-electric tech evolved out of German hybrid submarines from WWI & II and the need to replace steam. The latest "brushless" AC locomotive US application came out of Siemens and was developed between my home terminal, Mandan, ND and Glendive, MT around 1995. Werner von Siemens founded this vast German company and it was Siemens' engineers that rode and tuned the first 4,000 HP MAC70 experimental locomotives in the US (EMD V16 diesels). Also interesting, Siemens invented one of the first practical electric locomotives of any kind:

von Siemens experimental train, 1879

My company (NP>BN>BNSF), sent us to school in Overland Park (Kansas City), where I became a certified operator in the mid '90's. The school is very thorough in every aspect of railroading and well organized. I'll brag a bit here. In my late 40's, I was worried how well an old man might still learn, since a failure demanded the complete end of my 5 year old job. With this stark incentive, I scored 399 out of 400 in the ABTH/mechanical test and aced out a lot of much younger men. But besides fear, I had a love of machinery, an electrical background and a lot of mechanical experience behind me. Score one for the duffer. :)

Wes
...

How about you two start another thread about the power of Diesel Electric Locomotives, you have done a great job of Hijacking this thread!!!:S