The problems basically are securing the points and authorizing the train out
of the siding. It could well require the power to be taken off (further
complicated as you might have to involve the sections for both directions
because the siding is in the middle, plus the gaps with the next section to
the north happen to be at 6 points), and would take a lot of time.

Does sound a bit of a mare. Though I'm surprised the siding isn't set
up to
allow this as this isn't the first time the line has been closed from
Hyde park
to arnos grove and I'm sure it won't be the last so it would certainly
add a bit
of extra flexibility to the service not to mention making commuters
lives a bit
easier.

B2003