Debris Removal and Placement of a Permanent Concrete Bulkhead to Isolate a Leaking Tunnel in a Mine

This project involved a mine in a remote location that flooded when one of the tunnels intercepted an underground water source. The subsequent flooding left much of the mining support equipment in the flooded tunnels and shaft at a depth of approximately 1,300’.

Hibbard Inshore was hired to supply their Sub-Atlantic Mohican vehicle as well as ROV supervisory services to aid in the retrieval of debris and the preparation of the tunnel to receive a permanent concrete bulkhead to allow the mine shaft and tunnels to be pumped dry so that mining could resume on the site. Once the preparation work was complete, Hibbard Inshore also participated in the placement and filling of the bulkhead.

As part of the preparation work, the Mohican was fitted with cutters to help get steel and ducting out of the way as well as to offer support to vehicles provided by another contractor that had become entangled in the debris due to the high volume of hazards, tight quarters, and low visibility.

The failed part of the mine had let water into the rest of the mine and flooded the entire facility. Debris was removed from the opening into the tunnel before the bulkhead was installed. Debris included sand, vent ducts, utilities, front loader and rock bolts. The bulkhead was a large bag 15 feet x 15 feet x 15 feet. This bag was put into place then pumped full of concrete to create a bulkhead. After this was installed, small shafts were drilled from the surface to pump additional concrete into the tunnel behind the bulkhead. Jay Hibbard was onsite for preparation work with ROVs and was onsite for the ROV installation of the bulkhead.