Wes,
Generally what will happen here in a Crew situation is the ACB at each end of the circuit will be locked out by everyone working on it.
Then all of the lines will be Grounded on both sides of the work area.
You have 2 padlocks, each with thier own key.
There is no way that there is a Master key.
To close that ACB you have to have all of the locks off of it and the agreement of the Control-room Operator who is in constant contact with the Safety Observer.