No scope for contractor innovation in ‘unbuildable’ bridge

A landmark bridge on the outskirts of Sunderland designed in the heady days of 2005 is to be scrapped and replaced with a simplified design after two bidders were unable to value engineer the complex structure within the £120m budget.

Graham Construction and Vinci’s bids for the tallest bridge in England were “several million pounds” over budget. The job centred on the two independent curving bridge pylons which would have risen 180m and 140m into the air.

Last year, independent bridge experts criticised the scheme in New Civil Engineer, saying that it was overly complicated for the span involved and would not yield any value engineering savings as there was no scope for contractor innovation.

The bridge has been scrapped

The two cable-stay towers located on either side of the 336m deck taper and curve towards each other but have no physical connection. The unusual shape and lack of connection means they have to resist extremely high bending forces and as a result were designed much larger than in a conventional cable stayed structure. As a result, it’s understood that contractors bidding for the project were costing a heavily prescribed construction schedule to keep the structure stable as it was built.

Bridge engineer Simon Bourne told NCE: “In normal bridge schemes, contractors would be given a dozen indicative construction stages and it would be up to the contractor to decide on the best system for them.”

Architect Spence Associates and structural engineer Techniker fought off a host of big names including Frank Gehry, Wilkinson Eyre and Marks Barfield Architects to win the RIBA competition to design it back in 2005.

The scheme was mothballed until 2008, when the council decided to press ahead after a public consultation supported the design. It won planning permission in April 2010.

The Department for Transport committed £82.6m to the scheme in December 2011. Client Sunderland City Council was to contribute £31.9m, with £3.5m from former regional development agency One North East.

Speaking to local newspaper the Sunderland Echo architect Stephen Spence lamented the fact that the project had occupied his time for the best part of a decade and he insisted it had been costed thoroughly and was buildable:  “I know all the arguments, I know about the economy but this was the opportunity to actually get it built and then, in 10 years’ time, people probably would have said ‘This is something we are proud of and we did something that left a mark’.”

Local Conservative group leader Councillor Robert Oliver told the Sunderland Echo that the two tenders that came in were “very substantially over budget, and because they were so far over budget – by several millions of pounds – it was the right thing to look [at the project] again.” Rather than seek further funding, Sunderland City Council will review its plans. It is expected to publish a new OJEU notice later this year.