Those in charge of the project admitted on Friday that an extension is needed to finish "final infrastructure and extensive testing" to ensure a "safe and reliable railway for customers".
The major scheme, which has been under construction since 2009, will be known as the Elizabeth Line once it starts carrying passengers.


Services were due to begin running in December this year, but its central section - between Paddington and Abbey Wood - will now not be opened until autumn 2019.


The original timetable has been abandoned because more time is required to complete work in the central tunnels and develop software.





The full east-west line will be opened "as soon after the the central tunnels open as possible", the project said.


Simon Wright, chief executive of Crossrail Limited, said: "The Elizabeth Line is one of the most complex and challenging infrastructure projects ever undertaken in the UK and is now in its final stages.


"We have made huge progress with the delivery of this incredible project but we need further time to complete the testing of the new railway.


"We are working around the clock with our supply chain and Transport for London to complete and commission the Elizabeth Line."


There have also been reports Crossrail has struggled to find workers, such as electricians, to help with a last-minute push to finish the project.




BBC      News.