The contracting joint venture, Forth Crossing Bridge Constructors (FCBC), has told the client that because of surprisingly windy weather in the Firth of Forth, it will need until May 2017 to complete the bridge, rather than the December 2016 completion date for which it was previously aiming.
Transport Scotland said that as June is actually FCBC’s contractual completion date, so really the bridge won’t be opening late – it will be opening one month early instead of six months early like it had previously been saying.
Transport Scotland said that since September 2015 the downtime due to adverse weather, specifically wind, has been 40% rather than the 25% anticipated by the contractor.
“Until May, FCBC believed that they could mitigate these effects. However, the impact of the weather in April and May with 13 days and 12 days lost to weather was such that they have advised that they can no longer deliver the December 2016 target,” the client organisation said in a statement.
“Whilst FCBC have been able to mitigate the impacts of weather by increasing resources and running a number of activities in parallel they are now entering a stage of bridge construction which is technically very complex.
“In order to mitigate the on-going weather impacts that have arisen over the past few months FCBC has procured additional physical resource, increased staffing by taking on an additional 100 workers, increased working hours, altered construction methodologies where possible and challenged critical construction sequences to identify where any programme efficiencies could be found.
“They have now reached the stage where further additional resources will not bring the delivery date forward due to the complex technical nature of the construction work. In addition, the remaining construction activities can only be carried out sequentially, further limiting the ability to make further gains.
“Specifically the bridge deck and the cable installation process which began in September 2015 is particularly sensitive to wind and this increases as the cables used become longer and are installed at a greater height .
“FCBC have confirmed this creates an unavoidable knock-on effect for subsequent activities, road surfacing and wind barriers which will now take place in wet and cold conditions during autumn and winter 2016/2017.
“This is a project with its own unique weather challenges and the contractor has incorporated their experience to date with weather in their planning process. As a result, they now expect to open the bridge by May 2017, ahead of the contractual completion date.”
The FCBC consortium comprises Hochtief, Dragados, American Bridge and Morrison Construction. It has a £790m construction contract.
The north and south road networks are nearing completion, pouring the concrete deck on the viaducts is under way and nearly 70% of the bridge deck is in place. The final deck lift is now expected in the late autumn, followed by the final closures between the three tower fans and two viaducts.
Scottish government minister Keith Brown said: ““We have always been ambitious about this project and have always worked towards a deliberately ambitious target. However, it is important to recognise that FCBC still fully expects the project to complete within the timeframe of their contract. This project is not late and there will be no impact on the public purse.”
The video below shows footage of the cable installation from the point of view of an FCBC operative.