Balfour Beatty has been handed an eight-week extension to complete the delayed £22m Third Don Crossing in Aberdeen.
Aberdeen City Council confirmed that the extension had been agreed due to series of problems with “weather, re-routing underground and unforeseen circumstances”.
Construction of the bridge started in August 2014 and was originally scheduled to be finished in December 2015.
However, the completion date had to be pushed back to early February 2016, with Balfour Beatty blaming inaccurate piping and cabling maps from Aberdeen City Council for the delay.
Work was then halted following the death of a worker at the site in January, pushing the completion date back further.
It has now emerged that Aberdeen City Council discovered an issue with one of the bridge’s design features.
A council spokeswoman said: “Remedial action has been sought from designers and the design checkers and we’re awaiting final confirmation of how the contract is to proceed at this time.
“The bridge was designed by external consultants Aecom and was checked by Jacobs, both of which are recognised as experienced consultants.”
A spokeswoman for Aecom said: “We consider the design to be correct, but the behaviour of a bridge can be significantly influenced by a complex combination of factors during the construction phase, including the method and sequencing of the construction process.
“We have provided a solution and are working closely with Aberdeen City Council and its other partners to help ensure minimal disruption to the project.”
The contractor and council now hope the bridge will be finished and operational by May.
The project requires the construction of two major bridges, with the first being a 26 m-skew span reinforced concrete bridge and the second a 90 m-span steel box girder bridge over the River Don.
The project also includes 2.4 km of connecting roads on both sides of the River Don.
Balfour Beatty managing director George Hood said: “We continue to support Aberdeen City Council in order to ensure all works are completed as quickly as possible.
“Once complete, the Third Don Crossing will play a significant role in improving local transportation routes. All other works continue to progress at a good rate.”
Aberdeen City Council communities, housing and infrastructure convener Neil Cooney said: “This is Aberdeen’s largest major new bridge infrastructure since the construction of the Queen Elizabeth Bridge 30 years ago and projects of this size are technically complex.
“While we recognise how frustrating these delays are for people, it must be remembered this is a major project that includes two bridges, creating a new road, re-alignment of existing roads, creating cycle paths, and pavements.