Paul Weaver wrote in message ...
As I understand it, the tube has to be closed overnight because of
maintenance work. The NYC subway has 4 tunnel lines so they can be open
all night.

What about a limited service using just one track?

Is there a demand for all night services?

Nice question, Paul, you're using your cdf (common dog f..., er,
common sense).
The standard answer they always give me is that signals won't allow it
- signals aren't set up to protect trains operating this way. Also,
you can't move materials and plant around stations while passengers
are still about (safety issue). Working near crossovers, where workers
could accidently step onto the running line is another issue (also
safety). There are cross-passages between tunnels as well, staff using
them for storing materials could also accidently wander onto the
running line (safety again). And.....

It would be good to see some collective will to overcome these
problems, everyone would benefit. Especially if they could shut down
the one line earlier than they do now, and open it later.


John