In 1826 Marc Isambard Brunel and Isambard Kingdom Brunel, a father and son engineering team, sought to build a tunnel under the Thames river in London. Their plan was fairly straight forward. They used screw jacks to push a giant, square, steel plate with holes in it through the mud. The muck oozed through the holes of this “tunneling shield” and laborers scooped it up and hauled it out of the tunnel. As the steel plate inched forward at only 10 inches per day, they laid a square, brick tunnel behind it. At this rate, it took the team 15 years to finish their 400 yard tunnel.
