Eli5: Why train wheels don’t slip on the rails, when both the wheels and the rails are made of metal?
In: 15
Historically, they have, a lot.
That’s a big part of why trains can’t slow down or stop in emergency situations very well.
And why they take so long to build speed.
But modern trains typically have motors driving numerous sets of wheels all throughout the length of train (consist), so some slip while others grab and little by little as the train begins to move the slipping wheels stop slipping and begin to contribute to the momentum.
In the olden days, when there was just one locomotive dragging the entire consist, it was all about overcoming such slippage on the few drive wheels. Sand was often thrown onto the tracks by the crew to aid in traction.
But the modern approach of spreading out the driving forces via the use of electric motors makes it so that the drive wheels get a smaller amount of power and there’s more friction throughout the entire system to remedy slipping.
Latest Answers