Bridge strengthening works

[Deleted]

Coming up from February 2007 onwards, there will be a series of weekend bridge strengthening works on the stretch of line between Hammersmith and Acton Town. This stretch has two WB and two EB tracks (Picc and District)

Most of the work will be carried out in a way that allows two of the four tracks to be open, rather than a complete shutdown through the area. And in these cases, the Picc will take priority over the District - I think because it serves the airport mainly.

Hence some of the combinations mean that Piccs will be divereted over the local lines between Hammersmith and Acton Town, additionally stopping at the stations in between if the District is suspended as a result. As this uses up run time, the central London weekend 21 TPH service will have to be reduced to 18 TPH as a result.

[Deleted]

Interesting. I would have expected that bridge strengthening works would require the closure of the entire span, not just part of it. Unless Metronet and Tube Lines are willing to do what was done during the Kilburn bridge replacement project in the 70s I am unsure as to how they intend to accomplish this.

[stanmorek]

Sorry I seem to have missed this thread earlier.

Most of the bridge crossings between Acton Town and Hammersmith are actually two seperate bridges, one carrying the westbound and one carrying eastbound tracks. The exceptions I can think of are D70 (4 tracks) at Chiswick Park and D83 (3 tracks) at Ravenscourt Park. The work relates to change over of the longitudinal timbers which is mainly trackwork. As long as two roads are kept open the other two can be worked on over a weekend. At some point though heavy civils work will take place off the abutments.

Also Metronet maintain all four tracks on that section.

For your interest. Bridges D84 and D84A between Ravenscourt Park and Hammersmith were completely replaced in the mid 1990s. D84 carried the Picc E/B, Picc W/B and the District W/B. D84A was a single track bridge for the District E/B.

The new concrete spans were cast on the road below and were jacked up to the underside of the original spans. Over three weekends D84 and D84A were replaced and the Picc line service was maintained with trains diverted over District tracks including wrong way running. A new cross over was installed specially for this prior to the work.

On the first weekend, trains were diverted onto the eastbound tracks while the track and existing bridge spans were removed under the westbound tracks. A new span was jacked up into final position and the new track laid. On the second weekend the single track D84A was replaced under the District W/B in the same way. On the third weekend the remaining Picc E/B was replaced with the service diverted over the District line tracks with a temporary screen erected to protect the W/B.