With a single span of 100 Ft and a height of 52 Ft over high water, the Ironbridge was the first major bridge in the world to be made from Cast Iron. This was only possible because the industrial innovator Abraham Darby had recently made huge improvements to the quality and strength of cast iron. Using coke instead of the traditional charcoal to fuel the smelting process achieved furnace temperatures approaching 1,000ºC higher, which made the iron more homogenous and cohesive and consequently increased its strength considerably. The half ribs and other struts were joined using techniques derived from carpentry, such as dovetail joints, etc, as no other methods were known in the 18th Century. The success of the design and construction gave a great boost to the nascent Industrial Revolution and Ironbridge is now a UNESCO World Heritage Site.