Workers have found a tangled fragment of steel pipe, plastic and a large rock or concrete piece, during the first 35 hours of inspections inside the cutting face of Highway 99 tunnel machine Bertha.
A state update Tuesday said:
While the inspections are underway, it is too early to speculate on what led to the tunneling stoppage.
Over the weekend, crews inspected a portion of the cutterhead as well as the cutting tools they were able to access. They also cleaned the spokes and removed a bent piece of metal well casing and plastic PVC pipe. Crews also identified a large boulder or piece of concrete material in a cutterhead opening.
This is the first status report since tunnel contractors began sending workers to examine what might be blocking the machine and whether the cutting face is damaged.
In addition, there was a loss of air pressure Sunday that cost the team a bit of time, while the sealed area around the machine was refilled with compressed air, the update said.