The business case for the #550 million redevelopment of Birmingham New Street Station is the subject of "tough and searching" questions by civil servants, the man behind the ambitious project admitted last night.
Department for Transport officials are investigating the claim that the new station will deliver a cost-benefit ratio of 3.6 to 1 - a figure significantly higher than the Government's 2.1 to 1 benchmark, upon which public sector funding decisions are normally based.
The unexpectedly high cost-benefit ratio is being promoted as justification for the #363 million of public money the New Street Gateway part-ners rely on for the scheme to go ahead.
Martin Chambers, the project director, said the "increasingly interesting" questions being posed by the DfT were not unexpected and he remained confident that all of the points raised would be answered satisfactorily.
However, Mr Chambers told a meeting of the Passenger Focus organisation that none of the money needed for the project to go ahead had yet been approved and the refurbishment of New Street could not be guaranteed.
"The Gateway project is by no means a done deal. We have to recognise that the funding isn't in the bag," he added.
Mr Chambers said: "Quite rightly, the questions are becoming very challenging about all aspects raised by such a staggeringly good cost-benefit ratio.
"They are looking at the design at platform level and at concourse level.
"It is all about testing the benefits that New Street Gateway will deliver. It is not unexpected. You ask for a lot of money and you have to expect some interesting questions."
Government decisions about a series of funding approvals for New Street are expected between January and July next year. Building work will begin in January 2009 and be completed by June 2013, if the business plan is approved by the DfT.
The existing covered building will be replaced by two large public concourses, covered by huge glass atriums.
Mr Chambers said the completed station, which will be able to accommodate 150 per cent more passengers than is possible at the moment, would provide an enjoyable environment in which passengers would want to dwell.
"We are going to bring a sense of arrival back to the city," he added.
Airport-style departure systems will be introduced, with passengers remaining in the concourses until shortly before their train is due to arrive when they will be allowed to descend via lifts and escalators to the platform.
Mr Chambers promised a realistic amount of time would be allowed to ensure passengers could descend to platform level in safety. Passengers would be notified of their train not on a "just in time" basis, but on a timely basis, he said.
"We can't announce train arrivals on the basis that an Olympic sprinter could get there in time. We have to be mindful that you could get a stampede if the timing is not right," Mr Chambers added.
Answering questions about the design of the new station, which has been criticised for lacking originality, Mr Chambers said initial drawings were very much an outline concept.
"We are by no means complete with our designs. It is a question of developing the drawings to make sure they bring an iconic world class station to Birmingham," he added.
