"Paul Corfield" wrote in message
...
No - regrettably the Picc Line is a "trunk route" between key depot
locations like Ruislip, Acton and Lillie Bridge and other tube lines
like the Northern and Victoria. The key crossovers and junctions are at
Kings Cross and Finsbury Park.
I can't see how you get the trains rebalanced until the Picc Line is
available again to move stock through the tunnels.

And presumably no engineers' trains can be transferred to the north end of
the Picc or indeed the entire Northern Line while this situation continues.