The boss of Crossrail has insisted “we do have a grip” on the delayed and over-budget project.
Crossrail Ltd chief executive Mark Wild said the railway – which will run between Berkshire and Essex via central London – will open next year with no more money required.
The line was due to open in December 2018, and its budget was set at £15.9 billion in 2007.
But it is more than two years behind schedule and will cost an estimated £18.25 billion.
Mr Wild was appointed in November 2018 after confirmation that Europe’s largest transport scheme had overrun its timetable and budget due to a series of problems.
“When we were invited to take over this job, it was in disarray,” he told the PA news agency.
“The organisation was hollowed out. It didn’t have a plan. There was so much work to do. They didn’t know what the actual scope of the work was.”
Mr Wild described 2019 as a “pretty good year” for the programme, with completed work including tunnelling, tracks, overhead lines and communications systems.
Last month, TfL Rail took over from Great Western Railway in operating stopping trains between London Paddington and Reading, ahead of services becoming part of the Elizabeth Line, which is what Crossrail will be known as when it becomes operational.
But Mr Wild acknowledged that progress on verifying safety aspects of the railway has been “slower than we expected”, which means it will not be ready during the first half of the latest six-month target opening window which runs from October 2020 until March 2021.
He claimed there is a chance that passenger trains will begin running within the second half of the window, although a further update is expected later this month.
Mr Wild said he is “totally committed to doing the job safely and, secondly, doing this as fast as possible”.
Passengers can “rely on us to be working really hard to get it done”, he declared.
“Look to the progress we’ve made, and have confidence that we do have a grip, we have a firm plan.”
Crossrail is being funded by the Department for Transport and Transport for London.
Mr Wild announced in November that up to £650 million more funding could be needed on top of a previous commitment made in December 2018, but insisted that is likely to be the last budget increase.
“We do not expect to need any more money to do this and we expect this railway to open in 2021,” he told PA.
“Barring a very, very unexpected event, we’re going to live within our means.”
Mr Wild, whose career history includes a two-and-a-half-year stint as managing director of London Underground, and being responsible for all public transport in the Australian state of Victoria, described leading Crossrail Ltd as “the job of jobs”.
He said: “I just love it. I feel my accountability to people very deeply. It’s not a comfortable position to be in but it’s such an honour to be doing the job.
“I’m fully committed to handing this to the Queen on the day it opens, which is a special thrill for me.”
The first part of the railway to open will be the central section, with Elizabeth Line trains running between Paddington and Abbey Wood via central London.
All stations on this section are expected to be in operation on the opening day except for Bond Street, which is delayed because of “design and delivery challenges”.
Full services from Reading and Heathrow in the west to Abbey Wood and Shenfield in the east will then commence “as soon as possible”, according to Crossrail Ltd.