from last night's Standard:
http://www.thisislondon.co.uk/standa...eed-repairs.do
(or http://tinyurl.com/lu-block-closures )

Tube closures for three weeks in dramatic tactic to speed repairs

Commuters are facing three-week Tube shutdowns under plans to save
money and avoid years of weekend closures.
Whole sections of the Circle, Hammersmith & City, Metropolitan,
Northern and Piccadilly lines could be closed, the Standard has
learned.
London Underground bosses are planning the “block� suspensions in a
desperate and radical bid to deliver the network's £10 billion upgrade
but they will be a blow to millions of passengers.

--
The article seems to be doing its best to paint it as a Bad Thing, but
it does seem like a sensible plan of action. I daresay most people
could cope with a few weeks of misery if they knew it would lead to a
more reliable service afterwards.

Have similar things not been done in the past? I remember once seeing
a tube map which had one branch of the Northern Line marked as one way.