MamaJo is closing in on the 4-mile mark. Currently she’s drilled 20,637 feet with another 3,927 go — just under 3/4 of a mile to go.
Below left is drop shaft 3 (Brown Street) where crews were removing dirt this week and on the right drop shaft 5 where crews were working on the east wall of rebar for the diversion structure. (week of Mar 22-26).
Photo below shows water ingress flow after drilling through packer. The photo gives us a good look at the pipes and tubing installed to build the tunnel that will come out when it’s completed. Pipes and tubes connect electrical, air/oxygen flow, slurry system, etc. As of today (3/26/21) — crews have installed 4,082 – one-foot thick concrete rings to line the tunnel. They have 785 left to install. It takes six concrete slabs to make one ring.