Existing comment:
Original Rail
Spanning a Continent:
The Pacific Railroad Act of 1862 mandated that American-made iron be used to fabricate all rail for the transcontinental railroad. Although steel was more durable, it was not widely available in the United States at the time. It was a costly import item primarily reserved to make specialty products, such as swords and precision instruments, for the Civil War. In contrast to steel, iron was easily accessible in the United States and cost much less. Thus, the demand for iron to use for building the transcontinental railroad helped to boost the domestic economy and iron became the material that spanned a continent, linking out nation east to west.
The Shape of Rail:
The section of rail before you is original to the transcontinental railroad. This type of rail is called "pear head" because a cross-section of it resembles and upside-down tear. Its unique shape was the result of heating and rolling together several bars of wrought iron. Because of this rolling process, iron rail was comprised of many layers which made the rail much weaker than if it had been made out of one solid piece of iron. Despite the pear shape design that was intended to help counter this weakness, the layers of iron made rail vulnerable to splintering under heavy weight. For this reason, iron rail was not very durable and required frequent replacement.
A New Era:
The transcontinental railroad brought a period of unprecedented growth and prosperity in the United States, but the use of iron rail was outdated technology even as it helped to usher in this new era. The outdated iron rail was soon replaced with sturdy steel rail, which became more widely available in the United States by the 1870s. |