Network Rail confirmed this week that the final cost of rebuilding London’s Blackfriars station will come in at £600M – almost double the original estimate.
Construction cost for Blackfriars station has soared from the £350M figure set when the project was approved in 2008, Network Rail has confirmed.
It said the cost hike was down to an increase in project scope as well as “challenges and complexities” encountered during the construction phase.
The construction problems have also pushed the completion date back from November 2011 to early 2013. NCE reported that the scheme began running into difficulties with delays and managing costs as early as three months into construction.
Blackfriars station is being completely refurbished as a key part of the £5.5bn Thameslink programme, which plans a 50% increase in north-south passenger capacity on the cross-capital route.
Contractor Balfour Beatty is carrying out the work, with design carried out by Jacobs and Tony Gee and Partners.
The complex works have seen Blackfriars national rail station completely rebuilt on top of Victorian Blackfriars rail bridge, which has been reconstructed.
The work called for the complete restoration and expansion of the bridge, extending platforms across its full length, along with construction of a new London Underground ticket hall on the north bank of the Thames and a new Network Rail station on both sides of the river.
It was originally planned to do this for £350M at 2008 prices but scope changes during detailed design brought the total cost to £550M at today’s prices.
Scope changes included building separate Network Rail and London Underground stations on the north bank as well increasing the number of lifts from two to four to cope with expected passenger growth up to 2076, instead of 2032 numbers in the original plans.
The station’s roof was also changed after the project team could not make the original Vierendeel truss work. A deeper roof truss was introduced that allowed for the installation of solar panels (see box).
The remaining £50M price rise is due to challenges encountered during the construction phase, according to Network Rail.
“Some of the challenges we’ve encountered during the build, from severe corrosion on the bridge supports to Victorian structures for which there were no detailed surveys, have slowed us down and cost money to fix,” said a spokesman.
The extra £250M required has been drawn from contingency funds within the Thameslink programme’s £5.5bn budget as well as diverting savings made on other parts of the programme.
The Department for Transport had previously ruled out the idea of providing any extra funding for the Thameslink programme.
Keeping St Paul’s Cathedral in view
Blackfriars project bosses this week revealed that the redesign needed for the roof of Blackfriars station would ordinarily have breached London planning restrictions that prohibit the blocking of sightlines for St Paul’s Cathedral.
The encroachment was only permitted after the project team convinced planners that a small intrusion into the sightlines could be accepted for a roof of “high visual quality”.
Jacobs senior consultant for Blackfriars David Scivier told NCE’s London Rail conference that the greater depth of roof was permitted to intrude into “what were perceived to be” the St Paul’s sightlines “if the quality was deemed high enough”.