WorldWide Drilling Resource

A Tunnel Frozen in Time Adapted from Information by Cold Regions Research and Engineering Laboratory (CRREL) and State of the Arctic The Permafrost Tunnel, in Fox, Alaska, was excavated during the winter months of 1963-1969. Although permafrost conditions in the region are sporadic, the area near the junction of Goldstream and Glenn Creeks provided continuous per- mafrost for the excavation of the tunnel, which resides 50 feet below the surface. The tunnel’s original purpose was to serve as a research study focused on testing new mining technologies and construction methods in frozen soils. The site selection allowed engineers to encounter permafrost in the most efficient manner possible. The Alkirk continuous-cycle mining machine was used to bore horizontally into the permafrost. As the machine began excavation, pilot cutters extended into the soil about 7 feet, then packers expanded around the cutters, lodging them in place. The cutters were then slowly retracted, pulling the body of the machine into the face of the excavation, where the cutting disks would grind out the material. Although the machine operated in cycles, it worked continuously, creating a smooth surface behind it and was the forerunner to modern tunnel boring machines. The tunnel is composed of two segments - a main horizontal passage, which passes entirely through frozen silts, and an inclined passage, which extends down one side of the tunnel through silts, a gravel layer, and into bedrock. During the excavation process, it became clear the tunnel would also have usefulness as a natural laboratory for natural science and engineering studies because a cross section of undisturbed, permanently frozen silt, sand, and gravel was preserved within the tunnel’s frozen walls. Scattered throughout this permafrost layer is a diverse collection of plant remains and animal fossils frozen in time, including beatles, mites, flies, moths, butterflies, and the bones and teeth of bison, mammoth, and horses. Over 70 research papers have been written about the tunnel, with topics on mining and geotechnical engineering, surface geophysics, geology, biology, paleontology, paleoclimatology, and Mars permafrost studies. The Permafrost Tunnel will undergo an expansion to further stimu- late research in key permafrost areas. The main research is expected to be focused on improving surface geophysical methods for monitoring permafrost, understanding how permafrost will respond to warming, improving estimates of carbon stocks and release rates, and developing models of permafrost for engineering purposes. The tunnel will more than double in size and directly incorporate research needs. Some design ideas include a detailed 3-D map of complex permafrost features, side rooms for warming experiments, and boardwalks above the tunnel for testing geophysics and remote sensing. In addition to the expansion, new facilities will be built on-site, including laboratories, offices, cold rooms, and a learning center, which will form the Alaska Permafrost Research Center. 36 AUGUST 2018 WorldWide Drilling Resource ® Dealmakers The Lakes Region of New Hampshire is a great place to vacation, and some people have the luxury of living and working there all year long. One such person is Chuck Roth, owner of Roth Artesian Well Co. located in Moultonborough. He recently took delivery of a new Atlas Copco TH60 drill rig from Dave Bijolle, account manager with Epiroc USA. Chuck has been in the drilling business for 48 years. His first rig was a 1948 Bucyrus Erie 24W cable tool machine mounted on a 1950 Brockway truck. Over the years, he has had several different rigs, including two T3Ws and a 2010 TH60. Roth Artesian Well Co. is a full-service company; they not only drill the well, they install the complete pumping system including trenching. They also hydrofracture wells for increased yield. It is a family business with son Scott working since 1984, daughter Shannon for 15 years, and grandson Bradley since high school making up the remaining play- ers on the team. Epiroc USA Send your deals to: michele@worldwidedrillingresource.com Pumps by: Franklin Electric Residential Basic September 11-12 ~ Wilburton, OK phone: 800-348-2420 http://franklinwater.com/more/ training/franklintech-schedule/ Tunneling by: American Society of Civil Engineers Practical Aspects of Tunnel Design September 20-21 ~ Sacramento, CA phone: 703-295-6300 www.asce.org Education Connec. cont’d from page 27. A sketch of the Alkirk continuous-cycle mining machine. Photos courtesy of CRREL. C&G