Originally Posted by MEASURE TWICE
Lost Tools re-found?
Here is a link about a Central Subway being built is San Francisco. 1.6 Billion Dollars and maybe 8 Million Dollars to add another station to take the tool (Tunnel Drill) out of the ground.
They only go forward. If not able to buy for 8 million land space to remove the drill, the Tunnel Drill will be buried to remain in the ground.
Years may pass and some one finds the drill and says who left this here?
From what I remember about these machines they can back up a short distance, but are not made to back up the distance that they bore the total tunnel. They go to the end that they want to bore and then they many times back them up a little and bore a side tunnel and leave it there to rust away.