Giant ‘coffee grinder’ to dig a tunnel under Buffalo riverbed
How do you get from one side of the Buffalo River to the other when a boat or bridge won’t do? You go under it, with a very large coffee grinder.
National Grid on May 1 hosted media and other guests to celebrate a first-of-its kind project on Ohio Street in Buffalo: construction was to begin on a 422-foot tunnel beneath the Buffalo River. The Buffalo River Bore project required National Grid to lower a tunnel boring machine into a steel-reinforced concrete shaft on a parcel of land adjacent to Bison City Rod and Gun Club. The machine is about 14 feet long and weighs about 29 tons. It works like a giant coffee grinder, excavating and grinding chunks of limestone and soil as it is guided forward by operators. All total, 8,000 tons of soil and limestone will be excavated.
After about 20 days, the machine will come out on the other side of the river into a second steel-reinforced concrete shaft that the company built near 95 Ganson St. Both shafts measure 53feet deep and are at least 36feet in diameter. When finished, the concrete tunnel – also reinforced with steel – will house new electrical cables that replace older, outdated equipment, including some that dates to the 1890s.
Construction on the $11 million project began in November, and is expected to be completed in July. All total, equipment was delivered from six countries for the project, which required 8 million lbs. of concrete, enough to build a sidewalk 10 miles long.
The Buffalo River Bore project is part of National Grid’s continuing investment in energy infrastructure and account for growing electric demand by commercial customers in south Buffalo. Carving a six-foot tunnel was considered a better idea than trying to support cables across a section of the river that is 320-feet wide. There’s also an aesthetic benefit, since boaters and Ohio Street residents won’t have to see power lines strung overhead.
“We have made and will continue to make investments along Ohio Street and nearby areas to accommodate electric load growth associated with new and growing commercial space,” said National Grid regional director Ken Kujawa.
National Grid has used similar tunnel boring machines for overseas projects, but the Buffalo River project marks the first time that National Grid has used this technology in the U.S.