Answer: Abraham Darby I.

Abraham Darby (1678-1717) was the first and best known of a succession of men from the Darby family who carried the same name. 

Born into an English Quaker family who played an important role in the Industrial Revolution, Darby developed an innovative method of iron smelting. Using coke made from local coal to fuel furnaces rather than charcoal, Darby's discovery made the mass production of cast iron economically viable. With this breakthrough in production, the iron trade in Britain accelerated and local industry began to flourish.

Answer: Thomas Farnolls Pritchard

As industry around the gorge grew, so did the need for a strong and durable bridge to transport goods across the river. In 1773, Thomas Farnolls Pritchard - an architect from Shrewsbury - had a bold idea. Combining engineering expertise and new iron-casting techniques, he proposed the world's first iron bridge, which would link the parishes of Madley and Benthall over what was one of the busiest rivers in the country. Pritchard's designs were approved by Act of Parliament.

Answer: 1779

Construction work began on the radical new bridge in 1779 and it opened on New Year's Day 1781. The cost of building the bridge was around £6,000 - significantly more than the £3,200 first estimated.

Image: A view seen behind railings that show the year the bridge was erected. Copyright Getty images.

Answer: None 

Thankfully there were no injuries during the construction process.

Image: The Cast Iron Bridge near Coalbrookdale by William Williams, c.1780 (oil on canvas). With thanks to the Ironbridge Gorge Museum Trust

Answer: 100 feet (30m)

The Iron Bridge is a cast iron, single span bridge of 30m, with five main semicircular ribs. Describing the bridge in 1779, Anglian cleric and theologian John Wesley said, 'It is one arch, a hundred feet broad, fifty-two high and eighteen wide; all of cast-iron, weighing many hundred tons. I doubt whether the Colossus at Rhodes weighed much more." 

Image: The Iron Bridge at night. Photograph by Andy Marshall.

Answer: There are 482 main castings, but with the deck facings and railings the number rises to 1,736.

Image: Ironbridge - Bridge Castings. Photograph by Andy Marshall.

Answer: 378 tons

Although Darby commissioned many paintings and engravings of the finished bridge, a lack of images or eyewitness accounts meant that, for over 200 years, little was known of exactly how Darby managed to erect this structure of almost 400 tons. However, in 1997 a small watercolour sketch by Elias Martin, which illustrated the building of the bridge, was discovered in a Stockholm museum and revealed much about the building process. 

Answer: With carpentry and woodworking style joints.

Darby's workers employed traditional joining techniques used in carpentry, adapting them for cast iron.

Answer: 1934

The bridge remained in full use for over 150 years, by ever-increasing traffic. But in 1934 it was finally closed to vehicles and was designated an Ancient Monument.

Answer: UNESCO World Heritage Status

Universally recognised as the symbol of the Industrial Revolution, the Iron Bridge stands at the heart of the Ironbridge Gorge World Heritage Site.

Image: Ironbridge, Coalbrookdale, Shropshire, September 1979. With thanks to Alamy.