Tunnel drilling techniques have evolved greatly over the years. Before modern tunneling machines came about. There was much excavation by hand tools. One could imagine that tunnels such as those dug for the tombs of Egypt’s pharaohs that much of the labor was taken on by humans as opposed to large machines. It was not until very much later that the first all inclusive tunneling machine was patented.
The first patent for a machine specifically design to bore tunnels was granted in 1856 to C. Wilson. “Mr Wilson’s idea was to use edged rollers shaped like the discs on a disc harrow. This principle is now employed in shot core drill” (Bancroft,1908). The cutting discs were aligned with the rock face in such a way that the diameter if the discs was parallel to the rock face. This concept is still used today in shot core drills.
Another type of tunneling machine was developed and invented by Russel Sigafoos in 1907. His tunneling machine involved the use of hammering and rotating cutting heads that would chip away at the breast of the rock. Sigafoo’s goal was to deliver a machine that was capable of feeding into the breast of a tunnel as fast as it was capable of cutting into the rock. The machine could be operated by one person.
As time has gone by, tunnel boring machines have become more advanced. Modern day machines are capable of creating tunnel shields as they move forward. This allows the machines to add temporary support to the surrounding rock until the actual tunnel concrete is poured into place. Modern day machines also include more advanced ventilation techniques than earlier machines. Better ventilation allows for smoother operation of the machines in the sense that dust and debris do not clog the inner workings of the machine (the parts not meant to cut rock). Many modern day tunnel boring machines have large heads that rotate in a plane parallel to the rock face.
- Bancroft, Geo J. “A History of the Tunnel Boring Machine.”Mining Science 58 (1908): 65-68. Google Books. Web. 5 Apr. 2016.
- Sigafoos, Russel B. Rotary Tunneling Machine. Russel B. Sigafoos, assignee. Patent US 901392 A. 15 May 1907. Web.
