The Bessemer Process

The Bessemer Process
300px-Bessemer_converterImportance of The Bessemer Process:

   Widely impacting the US’s construction of everything from buildings, boats, bridges, and railroads. The Bessemer process is one of the most important discoveries in steel manufacture. Reducing the cost, time, and labor needed to make steel through this valuable process, allowed the transition between construction through wrought iron possible, and allowed the creation of some of the most incredible construction projects in history.


Discovered in 1855 by Sir Henry Bessemer. The Bessemer process was discovered through Sir Henry’s attempts to manufacture steel faster and more cheaply. Particularly for the purpose of manufacturing military weapons, which were at the time made with iron, which is considerably heavier than steel. At the time, steel was only used for generally small items; forks, spoons, and tools. However, the ability to make widespread military use of steel was very appealing because of steel’s strength and reduced weight in comparison to wrought iron.

Reverberatory Furnace

Working with a standard reverberatory furnace, Henry made the accidental discovery of hot air’s effect upon iron, the hot air alone converted the outsides of pig iron into steel. He then completely redesigned his furnace, by creating what’s known as a Bessemer furnace, doing this allowed forced hot air through the molten iron with special air pumps. Generally, one would assume that air would cool the iron rather than burn it hotter. However, oxygen in the forced air ignited impurities of silicon and carbon within the iron. This reaction would then increase the iron’s temperature, and therefore burn out more and more impurities in the iron. Which made the conversion to steel much easier than before.

Below is the process in which a Bessemer furnace works:

Manufacture through the Bessemer process began in a wider scale in 1858, By W and J Galloway using imported pig iron from sweden. The firm of W and J Galloway were the first company to license Sir Henry’s patent of the Bessemer process.


The Bessemer Process impacted industry and labor in so many ways. Allowing steel to be manufactured at much higher rates. Dramatically reducing the cost of manufacture, originally the cost to make steel from iron was roughly £40 per ton, but once the Bessemer process was introducing the price was dropped to between  £6–7 per ton. This brought the price right down to the same ballpark as wrought iron. Prior to this process, iron was the main material for things like bridges and bulding frames, now that steel was accessible it became the main component in these types of construction. With reducing the time it took to create the steel brought the cost of labor down as well.

Although the Bessemer process was replaced by the Basic Oxygen process in 1968. The Bessemer process had an immeasurable impact upon the US economy, manufacturing system, and work force. It allowed steel to become the dominant material for large construction, and made it much more cost effective. Countless millions of tons of steel were manufactured in this manner and countless buildings, bridges, and boats were made with the resulting steel crop, stimulating the US economy in every way possible.