Well that was the easy bit. As reported last month, the first of five stages to deliver Crossrail was reached on 22 June 2017 when the first Class 345 train was introduced into passenger service on the existing tracks between Liverpool Street and Shenfield.
In a candid update to the Transport for London board, Crossrail operations director Howard Smith explained why the launch was delayed from May. He said further releases of software for the Train Control and Management System were required to address issues such as passenger and driver displays. While these did not prevent training and testing, they were deemed unacceptable for passenger service. This need to update the software held up final safety and regulatory sign-offs.