Here is a locomotive equipped with anti-friction roller bearings.

And here are some girls. Yes, this is only just the start.

Whenever you're testing the anti-friction bearings, you need less power to start, less power to keep going.

Four young women - together they weigh 410 pounds. A titan of the rails weighing in at 448 US Tons.

Before the anti-friction bearing, you could've powdered the track with husky men, tugging and straining. If they can't, they wouldn't be able to move such hefty machine.

But, look at this.