Thurrock Council needed to widen the A13 from two to three lanes in both directions between the A128 (Orsett Cock roundabout) and the A1014 (The Manorway, Stanford-le-Hope) in Essex. The widened section creates a continuous three lane road in both directions between the M25 and Stanford-le-Hope. By improving the A13, Thurrock Council hopes to boost the local economy, helping businesses to increase productivity and create more jobs. As part of the road widening work, four existing bridges along the A13 needed to be replaced.
Cleveland Bridge was chosen to manufacture and install three of the replacement bridges along the widened section of the A13. The steel construction specialist was chosen for its size and scale, and its ability to trial erect large rigid structures at its manufacturing plant – ultimately saving time and resources on site.
The three bridges were:
• A farm access bridge at Saffron Gardens, measuring 49m long and weighing 230 tonnes
• Two bridges at Orsett required to form a new roundabout. Known as Orsett East and Orsett West, these each measured 40m long and weighed 160 tonnes. At the Orsett Cock junction the new bridges would be built and opened before the old bridges were demolished.
Both Orsett bridges comprised six main girders, configured as three pairs (6 part length pairs) connected by a central diaphragm. The central longer girder pair had diaphragms cantilevering from each side, giving the structure a total width of 6m. That meant it was too wide to be sent to site as a pair, so Cleveland Bridge delivered the central girders individually and bolted them together on site.
Due to limited working space around the Orsett junction, and since the road here was still carrying live traffic, only the central girders were delivered in advance of installation. The other five pairs were delivered on a just in time basis (in sequence) and lifted into position directly from the back of the transport vehicle. The size of the Saffron Gardens bridge posed considerable logistical problems in getting the girders to site. They measured 49m long and weighed 100 tonnes, with a travelling height of 5m. This meant the driver had to use trailer hydraulics to adjust the overall load height at locations with restrictions such as bridges along the route to enable the load to pass underneath.
All bridges were completed on schedule within the route possession period, despite the Covid-19 site restrictions. Both Orsett bridges were installed within just 24 hours.
On the first weekend, Orsett West was handed back to the main contractor on the Saturday night. On the following weekend, Orsett East was handed over on Sunday morning. The Saffron Gardens installation was also completed ahead of the road reopening deadline. This meant that on all three weekends, the road was clear to be reopened early, reducing disruption to road users.
Completing three major bridge installations over three consecutive weekends was no mean feat, and required close coordination between Cleveland Bridge and all parties involved. The scale of the company meant it had the resources to manage such a challenging workload. We were impressed with the efficiency of the installation works, which enabled us to hand back the road for reopening earlier than planned on each weekend.Tsvet Spasov Kier