Simple Solutions That Work! Issue 10

I n 1708, Abraham Darby leased a blast furnace in the village of Coalbrookdale, Shropshire, England, And the rest, as they say is history. Abraham Darby (or Abram, spelling was more fluid in those days) was originally a brass founder and clearly had an enquiring mind. He’d scientifically, within the constraints of the time, studied brass casting to see how it could be improved and is credited with setting up the world’s first metallurgy laboratory. In 1707 he registered a patent for producing pots and pans using sand molds and a reusable pattern. Coalbrookdale offered a number natural advantages when it came to iron making, having both coal and iron ore deposits that were easily accessible and with the river Severn running through the valley. As I’ve said, Abraham had an enquiring mind, and faith in his own abilities, so he applied the techniques he’d developed casting STEVE HARKER Technical Director ACETARC ENGINEERING CO. Ltd ARTICLE TAKEAWAYS: • Don’t be afraid to push the boundaries • Use technology to quantify and improve the process • Remember our shared industrial heritage but keep working towards a technological future HOW TO MEASURE METAL TEMPERATURE IN LADLES 18 brass to casting iron. Shropshire coal was considered to be high quality having a low sulphur content. I don’t know if Abraham knew this or it was a lucky break but I’m sure he worked out that there was something about the coal that helped him to produce consistent high quality iron castings. Most significantly, he moved on to using coke as the fuel. The first to be credited to do so in the western world, enabling larger quantities of metal to be melted at lower cost. Word soon spread with many more coke fired furnaces starting up. The high quality and relatively cheap iron castings that were being produced, and in more complex shapes became the building blocks for the industrial revolution, enabling the steam engines and textile machines we associate with the industrial revolution to be actually made. In 1781 the first cast iron bridge in the world was opened, spanning the 70ft Severn gorge. Abraham Darby III, the original Abraham Darby’s grandson casting the segments in the now much expanded Coalbrookdale foundry. (If you ever visit Coalbrookdale, the original blast furnace, designated as a world heritage site, is now a museum and the cast iron bridge is still in use, at Iron Bridge.) What strikes me is that foundry men like the Darby’s, and many others since, never accepted that something couldn’t be done but just kept pushing the boundaries. To some extent history has filtered out the failures, or at least those that didn’t end in a spectacular or disastrous way but they achieved a great deal with the very limited tools at their disposal. We in the foundry industry can rightly claim our place in history but we also need to look to the future.