On cars, old, new and future; science & technology; vintage airplanes, computer flight simulation of them; Sherlockiana; our English language; travel; and other stuff
SHROPSHIRE, IN the West Midlands of England, had rich deposits of coal, iron ore and limestone. The shire also has the Gorge, cut through it by the River Severn, at 220 miles the longest river in England. This bifurcation called for a bridge near Coalbrookedale, the town’s name suggesting its attributes.
The result was—and is—Iron Bridge, the world’s first such structure of cast iron and a fitting cradle of the Industrial Age. Iron Bridge was designed by Thomas Farnolls Pritichard, an architect known for his interior designs and funerary monuments.
Iron Bridge’s construction was entrusted to Abraham Darby III, whose grandfather Abraham Darby I had developed a method of producing pig iron in a blast furnace fueled by coke rather than charcoal.
Pause here for a bit of etymology and metallurgy. Pig iron is so named because of its method of tapping a furnace: A channel (the sow) carries molten iron into a series of lateral ingot molds (the piglets).
In a blast furnace, hot air is forced over a mixture of ore and fuel. Chemical reduction of the ore comes from the carbon in the fuel combining with oxygen in the ore, leaving the smelted metal.
Darby I’s use of coke made a lot of economic sense. Deriving coke from coal was quicker and cheaper than making charcoal from wood. Plus, in Midlands England, coal was more plentiful than trees.
The Darbys were four generations of Quakers known for their skills as ironmasters. Darbys II and III seemed to have specialized as well in avoiding any portraiture. There is an Abraham Darby rose (honoring Darby III) introduced by David Austin in 1985. A Pokemon game card labeled Abraham Darby III actually has architect Pritchard’s image.
Iron Bridge’s span across the Gorge is 100 ft., constructed of five cast iron ribs of nearly 1700 individual components. Each was custom-cast to fit its mates, with little uniformity of design.
The original budget of £3250 grew to an estimated £6000, with Darby III eating the overrun. Tolls brought a regular income, said to return shareholders 8 percent/annum on their investment.
Iron Bridge was the sole river structure to survive the Severn flood of 1795. Over the years, repairs were made as pieces came adrift. The structure continued to carry car and truck traffic until 1934, the year it was designated a Scheduled Ancient Monument. Pedestrian tolls were eliminated in 1950.
A major restoration was celebrated with Iron Bridge’s 200th anniversary on January 1, 1981.
Today, there are ten museums in the area celebrating the birthplace of the Industrial Revolution (http://www.ironbridge.org.uk). In addition to those at the time of my visit in the 1990s, the Ironbridge Gorge Museum Trust now includes an Enginuity Museum, the Broseley Pipeworks, Coalport Tar Tunnel and Darby Houses.
Last, in researching this piece for the Trippin’ category of this website, I came upon a book in a genre I enjoy, time-travel.
Heroine Maggie Foster time-travels to Shropshire at the time of Iron Bridge construction. She recognizes the ecological tradeoffs of a dystopian 21st century future and the sooty hardships to come of an Industrial Revolution. How does she handle this knowledge?
I have my copy on order. ds
© Dennis Simanaitis, SimanaitisSays.com, 2014