Engineering Heroes of the Past

When engineering works, everybody takes it for granted. That's the point. Still, it can't hurt to call to mind on occasion the guys from the past who did astonishing things without the help of computers, Google searches, and every other advancement available in 2008. While checking out one of my favorite obscure websites, The Hyperlinked and Searchable Chambers Book of Days, I discovered that one of the featured folks on the March 5 page is one Robert Stephenson. Stephenson, it seems, built the Britannia tubular bridge over the Menai Straits.   For those of you with no time to check the links (but you should. Chambers' Victorian language alone is worth the price of admission), here's the Cliff"s Notes version. The Menai Straits is a  narrow stretch of shallow tidal water about 14 miles (23 km) long, which separates the island of Anglesey from the mainland of Wales.  Here's Stephenson's engineering challenge: "While the Chester and Holyhead Railway was being constructed, Stephenson pondered how it should cross the Menai. Telford's beautiful suspension bridge being deemed too slight for the purpose, he planned a tube or hollow girder, through which a train might pass as through a tunnel. To make such a tunnel of sheet iron, stiff enough to resist any tendency to bending, was a formidable task. The Menai Strait, at the point selected for the crossing, is about eleven hundred feet wide at high water: in the middle is a rock called the Britannia rock, rising a few feet above high water level. Stephenson resolved to erect a pier of masonry on the rock, so as to break the span of the strait into two portions. To ensure manageable dimensions, it was determined that there should he two tubes, one for the up and one for the down trains. A masonry tower was to support the Caernarvon end of the tubes, and another to support the Anglesea end. There would thus therefore be four separate tubes, forming two when joined end to end." The tunnel was completed in 1850. And it worked. Cool pix of the bridge are available on the Wikipedia link. Okay, so its not process automation, but I'm impressed by a guy with the courage to stick a train in a tunnel spanning the water and keep the thing from crashing into the ocean. Let's hear it for our ancestors.