Rio Tinto Kemano T2 project near Burns Lake in final stages

The tunnel boring machine (TBM) of the Rio Tinto’s Kemano T2 Project broke through to complete the excavation process back in October of 2021, setting up the next phase in the project for the new year.

The TBM cut 7.6 kilometres through rock over 30 months, completing the route for a 16-kilometre tunnel that was started in the early 1990s. The reason for the project is to create a second tunnel running adjacent to the of the existing tunnel bringing water from the Nechako Reservoir to the Kemano Powerhouse, which powers Rio Tinto’s BC Works smelter in Kitimat.

Now, that the TBM is finished its excavation, it’s time for a complicated extraction process.

“The TBM is 190-metre long and is actually greater in diameter than the finished tunnel it is creating. In most cases, the TBM is removed via the opening that the machine mines itself into, but in this case, tunnel excavation ended at the previously mined intake structure some 100ft below the surface of the water,” said Rio Tinto Kemano T2 Project Manager Alex Jones.

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“The TBM is being removed via the Horetzky landing access [located at about the halfway point of the tunnel], which means the machine, which weighs 1,300 tons, is being disassembled and transported via the tunnel’s rail system. During this operation, other completion activities are undertaken in parallel,” he continued.

According to Jones The next steps for the project is to fill the second tunnel with water.

“The plan is to commence filling the tunnel early in the second half of 2022. That process takes considerable effort and monitoring by the team. Following on from that process, a number of activities remain on the surface. Demobilizing the equipment and the temporary infrastructure along with rehabilitation will be our next priority,” Jones told Lakes District News.

The company said in 2021 that the completion of the Kemano T2 project would happen by the second half of 2022. “We remain on track to meet that schedule,” Jones said.

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