The cost of building the 11km long Midland Metro extension from Wednesbury to Brierley Hill to the north-west of Birmingham has risen by £50M to £449.5M.
The increase was announced in board papers ahead of a West Midlands Combined Authority (WMCA) Investment Board meeting next week.
The authority said the cost has risen due to a “progression of the preliminary design with early contractor and operator input which has resulted in an increase in the overall estimate of scheme outturn costs to £449.5M”.
It is understood this is down to more detailed investigation works on the 23 bridges and viaducts along the route, one of which is listed, with significantly more work necessary to bring them up to the required standards than first anticipated.
The cost of the extension had already risen from the initial figure of £343M to £402M in 2017 to account for £59M of optimism bias which had been left out of the original figure. Optimism bias is a term used to refer to contingency funds made available for cost overruns.
The project is being funded partly through a £207M transforming cities grant made by the WMCA in December 2017 and the Birmingham Connected fund. The additional cost of building the line will not be funded by the taxpayer the WMCA has said. Instead profit from running the metro will cover the additional cost.
“Until recently, the franchise owner [Transport for West Midlands] pocketed the profits from running the line, but now this is in house we get to plough those profits back into the running of the metro,” a WMCA spokesperson said. “This is a new revenue stream for us which we didn’t have before.”
The extension work will be delivered by the Midland Metro Alliance, made up of the West Midlands Combined Authority, the design consortium of Egis, Tony Gee and Pell Frischmann and contractor Colas Rail, with sub-alliance partners Colas, Barhale, Bouygues UK and Auctus Management Group.
The existing 25km line runs from Grand Central New Street Station in Birmingham city centre to Wolverhampton St. George in the north. Six new lines, totalling 32km, are planned and will extend and branch off the existing line.
In September last year work started on the first phase of the 840m long Birmingham Westside extension. Trams on the route will operate on battery power throughout for the first time in the UK.
A Transport and Works Act was granted by the DfT in 2005 with planning permission implemented in 2009. Passenger services on the line expected to begin by 2023.
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