MANUFACTURING PROBLEMS on four stainless steel support columns have led to a nine month delay on a 1.4M river crossing in Leicester.
The 40m Swan Bridge forms a crucial part of the 190M, five year City Challenge project to regenerate Leicester's West End. Contractor Costain started construction of the two lane crossing in September 1997. It was originally programmed to finish in March 1998, but is now expected to open around Christmas - nine months late.
The delay has been caused by problems in the manufacture of four, 10,000 stainless steel
1-2m high columns which carry the 1m deep concrete bridge deck. The slender columns were specified by consulting engineer Whitby Bird for their appearance and because the bridge loads were very high - around 800t per column.
'If ordinary concrete pillars had been chosen they would have been enormous,' said Leicester City Challenge chief executive Kishor Tailor.
Costain opted to manufacture the 200mm tapered cylindrical columns by casting, as this was thought to produce the best value for money and finish. But delays began when Whitby Bird questioned the pitted surface of the cast columns.
Tests, including X-rays, were carried out to discover whether the columns contained voids. The client eventually rejected them after one was found to contain longitudinal air bubbles.
A dispute over the feasibility of producing void-free columns using the casting process has led to a new batch of columns being milled from forged steel billets, and added several more months of delay.
The hold ups have already led to a dispute with the local community after Leicester Rowing Club had to cancel its annual fund-raising regatta earlier in the year. Temporary works around the columns meant the channel was not wide enough to row two boats side by side.
Now question marks surround changes in the bridge's final structure which permanently reduce the channel's width.
The final navigable width between the columns was to have been 21.7m to match the existing narrow point in the river. But this was challenged by British Waterways which said the columns were not sufficiently protected from collisions. Concrete plinths rising to just above the river level have now had to be constructed on the pile caps to protect the columns, reducing the width to just 17.85m.
Leicester City Challenge is now waiting to see if this constitutes a material change to the planning application. In the meantime it has apologised for the delay to the scheme. 'We are very sorry, but we want to ensure the quality of the structure,' said Tailor.