A design flaw in Crossrail’s energisation system could delay the opening of the flagship project after explosions were heard during tests, City Hall has heard.
Deputy mayor for transport Val Shawcross told members at a London Assembly committee meeting yesterday (Thursday) that a voltage transformer installed in one of the line’s substations contained a design error, leading to a series of failed tests.
Shawcross admitted it was “the worrying stage in the project”, which is 90% compete, adding that the error in equipment installed before Christmas had put pressure on testing schedules.
“The circuitry didn’t just misfunction, it actually made a ‘bang’,” said Shawcross.
Engineers redesigned the component but a new test earlier this week ended in another failure. Further tests yesterday morning were successful, according to Crossrail, although Shawcross admitted the testing schedule was now “compressed”.
Energisation of the scheme was supposed to have taken place in November to allow for further testing.
On Tuesday, Crossrail chairman Sir Terry Morgan told Transport for London that the project was “very close” to breaching its £14.8bn funding envelope, although the Paddington to Abbey Wood section of the line is still expected to open in December 2018.
However, Shawcross stressed Crossrail is still on track to be delivered within budget, adding that construction had been going “very well”. She has previously identified late delivery of Crossrail, wihch is being renamed the Elizabeth line as the “biggest revenue risk” for TfL.
Last week New Civil Engineer reported that current construction costs on the Crossrail project were £172M higher than budgeted, while software faults could mean Crossrail misses its first service delivery deadline of May 2018.
A Crossrail spokesperson said: “During the initial energisation of electrical equipment at Pudding Mill Lane sub-station on 11 November 2017, two voltage transformers failed. Following correction of the faults in the electrical system by the contractors, the sub-station has been successfully switched on. Energisation of the overhead line equipment will now follow, this will allow the infrastructure testing phase to begin. The Elizabeth line remains on course to open as planned in December 2018.”