When did railroads switch from iron rails to steel rails? What were the main advantages of upgrading to steel rails?
Original Post
Steel rails were first introduced in 1857, and were soon seen to be such a great improvement over iron rails that iron started to be replaced by steel quite quickly afterwards. Obviously this replacement took time, but I would guess that by the late 1800's there was very little, if any iron rail remaining in general use.
The major benefit of steel rails was increased life. Combine this with the greater strength of steel rail, and you can see why steel became popular very quickly.
