National Highways is poised to embark on a complex £2.5M repair project for the Severalls Lane Bridge, part of the A12 Colchester Northern Bypass in Essex, following a substantial collision in March 2020. The bridge suffered significant damage when two of its beams were struck by an excavator being transported on a flatbed lorry.
Since the incident, traffic on the bridge has been severely limited to a single 3m wide lane. To ensure safety, a temporary vehicle restraint system is in place, particularly over areas supported by the damaged beams.
The impact caused notable localised damage, particularly to the bridge’s two western-most beams and their transverse bracing. The lower flanges and bracing experienced significant deformation, and there has been a disconnection of bracings from the inner beam due to sheared connecting bolts. A slight kink in the bottom flange at the impact point has also been observed.
National Highways has proposed a repair strategy involving heat straightening of the damaged beams, localised concrete repairs, and bearing replacement. A spokesperson for National Highways elaborated: “This is an extremely complex repair which we want to carry out without significant closures to the A12 and the inconvenience that would cause to many people.”
The organisation plans to implement the repairs with minimal disruption. “We now have an agreed strategy to repair the bridge, and an associated traffic management plan with Essex County Council. This will cause the least amount of disruption to communities and significantly shorten the length of time the bridge will be under repair and unavailable to local people,” the spokesperson added.
“The innovative repair will use heat to straighten the damaged sections. This work requires specialist contractors but will avoid lengthy closures to both the bridge and the A12 that it crosses.” “We are now in the final design phase. Once that is completed, we will look to carry out the repair. This will be in the next 18 months – if not sooner.” “This remains a very challenging repair and we understand the time it is taking can be frustrating, but our approach has always been to avoid the A12 and the bridge itself being closed for a prolonged period of time as this would result in significant levels of traffic being diverted through Colchester.” “The repair work will still require road closures over the bridge and on the A12, but this will be minimal compared to more traditional methods of bridge repair. This will benefit the local community and road users as the works will be completed with minimal disruption.”
The severity of the A12 bridge strike is underlined by the fact that the total costs National Highways is currently estimating it will have to pay out for all other bridge strikes between 2019 and 2022 totals £1.2M, according to a Freedom of Information request sent by NCE.
However, the roads operator still has 27 cases to cost from this period.
Bridge strikes are a major concern beyond Essex. Network Rail has been dealing with numerous such incidents, prompting the launch of the ‘Wise Up, Size Up’ campaign. The campaign aims to minimise these occurrences.
There were 1,572 bridge strikes reported across the railway network in the UK from April 2022 to March 2023 alone.
A Freedom of Information request submitted by NCE revealed that the rail operator hasn’t yet estimated costs for remediating bridge strikes for the last three financial years.
However, for 2019-20 bridge strikes, Network Rail has calculated remediation costs as £6.4M. Network Rail figures for 2018-19 show that it paid just over £5M to fix bridge strikes.
A large proportion of this money is available to be recovered through third party insurance. For 2019-20, Network Rail was able to recover nearly £4.4M of the £6.4M (69%).
A Network Rail spokesperson stating: “Every time a vehicle hits a bridge it can cause serious safety issues for road and rail users. To compound matters, these incidents can delay tens of thousands of passengers while we inspect the bridge and repair any damage – creating cost from public funds which should be used upgrading and improving our network.”
Network Rail is also focused on recovering costs through third-party insurance, successfully recouping a significant portion of the expenses. The spokesperson emphasised the importance of route planning and adherence to height restrictions: “We’ve done a lot of work with transport partners to tackle bridge strikes, and whilst it’s encouraging to see this is paying off there’s a lot more to be done. We urge operators and drivers to properly plan their routes, know the height of their vehicles and be vigilant for road signs showing the height of bridges. Those who don’t risk losing their licences – a measure enforced by the traffic commissioners. Network Rail always looks to recover the repair and delay costs from the driver and the operator.”