Crossrail confirmed today that tunnelling had stopped on both bores for the western running tunnels since last week to enable the removal of a build-up of spoil following last month’s hopper collapse.
Following the incident at Westbourne Park near Paddington on 27 September, Crossrail restarted tunnelling the next day. But it was forced to suspend the second of two tunnel boring machines (TBMs), known as Ada, to prevent a build of spoil on site on 2 October. TBMs on Crossrail are expected to progress at around 100m per week.
Last week, Crossrail took the decision to suspend the first TBM, known as Phyllis, to enable engineers remove the spoil in Royal Oak portal. Crossrail has been using excavators to remove spoil from the TBM into the freight wagons while the hopper is out of use.
Crossrail programme director Andy Mitchell rold NCE two weeks ago that one of the challenges was that there is a lack of room to stockpile at the congested site near Paddington. “Stockpiling is a major challenge we face,” he said.
Crossrail area director west Keith Sibley said he hopes to restart tunnelling in the “coming days” once the stockpile has been “sufficiently depleted”.
The cause of the hopper collapse is still unknown and is subject to an investigation by Crossrail and its tunnelling contractor BKF – a Bam Nuttall, Ferrovial, and Kier joint venture.