I have a train Question?

Question

Why do railroads intermix EMD and GE diesel engines on their trains?

Answer 1

The simplified explanation is that the railroads will take whatever power is available to fill horsepower requirements, regardless of whether it's EMD or GE.  If a train needs 11,000 horsepower, it may end up with two C40-8's and an SD40-2.  Locomotives from various builders have standardized multiple-unit connections which allows them to be mixed.

This wasn't always the case, and it still isn't on all railroads.  Early diesels from different builders often had different M-U connections and thus weren't compatible with each other at all.

It's also possible that different locomotives that technically are compatible don't really work well together.  I read about a train crew that had trouble starting a train with a GE U33C and an EMD GP38, because the GP38 loaded so much faster that it started slipping before the U33C even got power to the wheels.  In that case, even though they were compatible, they didn't work well together, and there have been cases where railroads keep sets of identical locomotives together for smoother running.

Today's EMD and GE units are quite comparable in terms of power and performance, so there's not much of a problem with running them together.

Answer 2

One manufacturer coulndt supply all the demand, I remember reading that there was quite a waiting list for new GE locomotives.

They are more or less interchangeable as far as controls, whatever happens to be available is what they send out.

From an engineers point of view, there is not a lot of difference until you get on an extremely hard pull then I dont want them mixed, they dont behave exactly the same and it can (and occassionally does) cause  troubles.

And, competition is always good for the consumer, whether it is something as large as a locomotive or as small as a mouse trap, keeps the suppliers on their toes.

Answer 3

Diesel trains don't use diesel engines to run the wheels.   They use diesel engines to run Generators and the generators run huge electric motors to turn the wheels.  They do this because it is extremely economical and energy friendly.  

That's also the concept that "hybrid cars" are based on.  

Kinda makes you wonder why the auto makers didn't come out with this 40 years ago.