Thames Tideway chief executive Andy Mitchell has challenged the construction teams delivering the £4.2bn project to begin construction six months earlier than planned and commission the tunnel two years ahead of schedule.
Speaking exclusively to New Civil Engineer , Mitchell said he put the new timeframe to the joint venture teams as they met as part of the overlying alliance framework agreement on the project.
“There was a prescribed six-month optimised contractor involvement period to discuss thoughts that had come up during the tendering process,” he said. “At the very beginning of that phase, we laid out a challenge to our team to ask if we could do the job significantly faster.”
Mitchell said he thought considerable time savings could be achieved on the project by overlapping packages of work.
“We didn’t see much opportunity to compress the tunnelling duration – the truth is, the long run average rates that were in the tenders and were in our programme were about right and there was no justification for thinking somehow miraculously we’re going to tunnel faster,” he said.
“But by starting tunnelling early and finishing tunnelling early with more overlapping at the beginning and the end, we think we can commission two years early.”
Mitchell denied that the contracting teams would need more money to deal with the abbreviated timeframe.
“If we start earlier, finish earlier and knock anything like that amount of time off, it’s highly likely to be less expensive to build,” he said. “At the end of the day, the tunnel hasn’t got any longer, the scope hasn’t got any bigger; it’s only about sequencing and there are only so many work hours in a job.”
However Mitchell later suggested that there was some flexibility in the new timeframe and that the main purpose of the challenge was to encourage innovation.
“The truth is, even if we start off with a two year earlier programme and we only end up one year early, that’s still a result. If you’re going to have that kind of radical ambition, there’s only one time to call it and that’s at the very beginning. You don’t get two years down the line and say ‘blimey, I wish we’d thought of being a bit more radical.’”
To read the extended interview with Andy Mitchell, click here.