Why does putting a carriage on rails make it much easier to pull? As in, how were the first trams such an improvement from omnibuses when the same weight was still being pulled?

Question

Why does putting a carriage on rails make it much easier to pull? As in, how were the first trams such an improvement from omnibuses when the same weight was still being pulled?

In: 520

Answer 1

Compare what it takes to roll a pool ball (hard ball) on a pool table (hard surface) versus rolling a beach tires(squishy) on a beach (soft).

For the least amount of rolling resistance, you want the hardest possible wheel on the hardest possible surface.

Steel on Steel is the way to go.

This is especially true as early wagons had hard wheels with very little surface area. Great on hard surfaces, but in dirt, mud or grass it would sink and take much more effort to pull.