For anyone who's not seen the posters on Tube stations, the Met line
between Ruislip and Uxbridge will be closed from 19 July to 10 August. The
Piccadilly line will be cut back to Rayner's Lane, as will the Met at
weekends.

Quoted from
http://www.railtechnologymagazine.co...ck-replacement

London Underground (LU) is to replace 6km of track, points and drainage to
improve the infrastructure and service reliability of the Uxbridge branch,
which is served by both the Metropolitan and Piccadilly lines.

LU has decided to do the works in a block closure from 19 July and 10
August, during the school summer holidays, rather than over 14 weekend
closures.

George McInulty, LU’s programme director of infrastructure, said: “The
track replacement work on the Uxbridge branch is a crucial part of the
Metropolitan line upgrade.

“Carrying out a block closure of this section of the network will enable us
to complete the work in just over three weeks as opposed to fourteen
weekend closures. This approach means that there will be no time lost due
to set-up and hand-back of works, which minimises working time and helps to
significantly reduce the cost – saving around £3m of tax and farepayers’
money – and ultimately keeping disruption to customers to an absolute
minimum.�