Engineering work taking place on the 17th February 2008. As you can see there is major work on the District and Piccadilly lines west of Hammersmith. Meaning Heathrow loses its Tube connection to Central London. Making the Hex (Heathrow Express) people very happy! The west legs of the DLR are also closed. As seems to be standard for February the Jubilee north of Wembley Park is closed as well. The central line is also spilt in half with no service between Liverpool Street & Leytonstone. This is because of work for the new westbound (towards London) platform at Stratford. This platform will link the bridge across the DLR International line (which also links the Poplar route and the Jubilee platforms) to aid boarding times into Central London. No Bakerloo line north of Queen's Park and no Overground service on the Watford line between Queen's Park and Wembley Central due to NR engineering on the DC lines.
Please note that this map is not offical but more my own work.