In message , at 21:11:22 on
Wed, 24 Sep 2014, Paul Corfield remarked:

Introducing the "Night Tube" does raise the issue of what happens if
there is planned engineering work. Do we get "night tube replacement
bus services"?

Or they could do the work on Sun-Thu nights only.

And it would take rather long than if every night was available -

Yes, but we have to assume they've done their sums. In particular why
this new initiative is only possible after a whole year of normal/
current timetabling.

especially Sat to Sun which is the longest break in service because of
the later Sunday start times. The SSR resignalling is already up
against it in terms of time. In order to save face I imagine LU will
want maximum productivity on multiple sites every night of the week
(assuming no clashes).

For serious stuff they could close it all day Sunday (from 4am anyway),
as they do already.

Serious stuff needs 52 hours, sometimes longer. This is why you get
Friday night to Monday morning closures.

These could still take place. I don't think they've announced that
"night tubes" will be any more uninterruptable than the current ones.
--
Roland Perry