This diesel locomotive, weighing 270,000-pounds (122,470-kgs, is designed to tow passenger-train cars and can travel at speeds of up to 110 miles per hour (177 kph) even when fully loaded.

 The two-stroke diesel drive engine can produce 3,200 horsepower, which the electrical generator can turn into about 4,700 amps of electrical current which is used to power the drive mothers. There are four drive motors and they can generate over 64,000 pounds of thrust.

There is separate four-stroke V-12 engine and generator that provides power to the rest of the train. This generator is called the head-end power unit and it can create about 560 kilowatts (kW) of electricity

Because it is a combination of diesel and electric, it is classified as a hybrid vehicle

Why Hybrid? Why Diesel?

The main reason why diesel locomotives are hybrid is because they don't require mechanical transmissions.  They use electricity instead. The reason that diesel fuel is used instead of gasoline, is that it can produce more power. 

The reason your car needs a transmission is that it keeps the engine at it's peak horsepower and torque.

As you can see from the diagram above, the peak horsepower is at a higher rpm than the torque ( the force applied on the ground from the tires).  This means that without a transmission, as the rpm's get higher the torque will go down.  But a transmission uses gears to change the rpm's coming from the engine to the wheels ( example: big gear - small gear ~ small gear goes faster).  With electric motors only torque is created. 

By using a hybrid system the diesel engine can run at a constant speed, while powering the electrical generator.

Steel Wheels
The reason steel wheels are used is to reduce rolling friction.   for example if your car was driving on a freeway, about 25 percent of the engine's power would be used to push the tires down the road. Tires bend and deform a lot as they roll, which uses a lot of energy.

the more weight on the tires the more friction.

to reduce rolling friction trains use steel wheels to reduce the warping of the wheels and the contact area is only the size of a dime. to increase traction sand and water is sprayed on the track.

By using steel wheels on a steel track, the amount of deformation is minimized, which reduces the rolling resistance. In fact, a train is about the most efficient way to move heavy goods.

The downside of using steel wheels is that they don't have much traction. Traction when going around turns is not an issue because train wheels have flanges that keep them on the track. But traction when braking and accelerating is an issue.

This locomotive can generate 64,000 pounds of thrust. But in order for it to use this thrust effectively, the eight wheels on the locomotive have to be able to apply this thrust to the track without slipping. The locomotive uses a neat trick to increase the traction.