Final answer:
The Bessemer process revolutionized the production of steel by significantly reducing the production time for a single rail. The specific time required to produce a single rail using this process is not stated in the provided material, thus, cannot be answered without further information.
Step-by-step explanation:
Henry Bessemer's improved process for making steel was a groundbreaking innovation that significantly reduced the production time for a single rail. The Bessemer process was a method that involved blowing cold air over hot iron to remove impurities, thereby making steel not only stronger but also cheaper to produce. This process dramatically shortened the time needed to produce steel, making it possible to conduct mass production and support the expansion and advancement of various industries, such as railroads and construction. Unfortunately, the provided information does not include the specific time reduction achieved for the production of a single rail. Consequently, this question cannot be answered without additional historical production time data specific to the Bessemer process.