Mr Kirby said that as he prepares to move to a new post at Rolls-Royce, his successor would have the job of managing the transition from planning to construction. "The organisation stands ready to deliver HS2," he said.
As an engineer, "acting as a catalyst for growth in the economy is our reason for existence and what we'll be measured on."
He stressed the importance of local communities and businesses coming together to develop plans to integrate HS2 into the economies of the cities it served, exemplified by Birmingham's plans for Curzon Street, and he praised the way HS2 Ltd was working together with Northern Rail.
It was also vital for the project to focus on people and its community engagement activities would be stepped up as the construction phase began. The organisation would shortly be appointing a community engagement director as part of this.
Of his time at HS2 he said: "What I'm most proud of is the HS2 team and their can-do culture. It's ready to manage the biggest civil engineering project this country has ever seen."
HS2 Ltd would let the £900m enabling works contract later this year, and £9bn of civil engineering contracts next year after Royal Assent of the phase one bill. He stressed the importance of collaboration and, following numerous supply chain event a across Britain and "hundreds of one to one meetings" there were high expectations for the supply chain. "This project will not be business as usual. We must be innovative," he said.
The project remained on schedule. The procurement process for rolling stock would begin next year.
"In taking HS2 from concept to reality we've achieved many great things," he said. The focus should remain on the economic benefit. "HS2 Ltd is an organisation capable of delivering on time and on budget."