Iron allowed for economic expansion during the Industrial Revolution by serving as a key manufacturing material, and through its value in shaping and constructing various types of infrastructure, namely bridges. The Industrial Revolution saw substantial economic growth in many sectors of the economy, primarily in transportation, mining and construction. Exponential economic growth required fuel in the form of raw materials, which primarily came in the form of iron and later steel.
Although sturdy and solid, iron in the 1700s saw limited use. Iron processing facilities were small and only handled small quantities of iron at a time, making iron production limited in output and expensive. Prior to the Industrial Revolution, the process of iron production involved combining and melting iron with other sources of fuel, primarily charcoal. However, the increased economic activity demanded a greater consumption of resources. As a result, the number of trees available for charcoal production dwindled, leading to experimentation with other heating sources. Eventually, the synthetic material of coke proved a good replacement for charcoal. Coke and iron, when combined, produced smelted iron. Its low melting point and durability gave smelted iron a leading role in engineering, where it helped build infrastructure such as buildings and their components, steam engines and residential items including furnaces.