Brigsteer and Underbarrow bridges are closed due to structural concerns.
Our decision to close both bridges is a culmination of a thorough established assessment process.
Other organisations have followed the same national standards as we have. The outcomes for different bridges will vary.
Closures of Brigsteer and Underbarrow Road Bridges - July Public Meeting Notes and Actions - news article published Thursday 18 July.
Brigsteer and Underbarrow newsletter updates
We have produced a monthly online newsletter to keep you updated with the latest information on the bridge closures and to show the work we are doing to restore links to communities in Brigsteer and Underbarrow.
- July Brigsteer and Underbarrow newsletter update
- August Brigsteer and Underbarrow newsletter update
- September Brigsteer and Underbarrow newsletter update
Half-joint bridges, explained
Half-joints were introduced into bridge decks as a way of simplifying design and construction operations. A central span rest on L shaped joints.
This form of joint is now known to be particularly vulnerable to deterioration and is difficult to inspect.
Half-joint bridges gone wrong
A recent example of a catastrophic failure of a half-joint bridge was De la Concorde Overpass in Laval, Canada, where the authorities failed to close the road over the bridge to traffic following structural concerns.
As a result 5 people lost their lives and six other people were seriously injured.
Our awareness of the risk
At the beginning of week commencing 3 June 2024, we received the findings of an external expert report we commissioned as a part of our ongoing safety assessments which advised the need to close the bridges in a planned and managed way for precautionary safety assessments.
What we do to maintain the bridges
As part of our commitment to keeping communities safe, proactive assessments are carried out on the 1,075 bridges and structures we are responsible for.
Reinforced concrete half joint bridges, like Brigsteer and Underbarrow, need and get special and detailed assessments that are carried out during an extended period of time to ensure that they benefit from ongoing continuous review in line with national guidance.
In 2022, we started the staged process, set out by National Standards, to assess the half-joint and post-tensioned aspects of these bridges as a result of potential risks highlighted to Highway Authorities.
We have a total of five of this construction type, all have been monitored visually since 2014 and have now received specialist assessments.
Brigsteer and Underbarrow bridges have required closure due to structural concerns, two have required imposed weight restrictions to ensure the safety of road users and the Shenstone Interchange Bridge which also runs over the A591 has been found to require no restrictions.
In Westmorland and Furness, there are five half-joint bridges. All have been inspected biennially since construction.
In 2020 the authority commenced a programme of half-joint assessments following the introduction of National Standard CS 466 ‘Risk management and structural assessment of concrete half-joint deck structures’. A contract was let to assess Brigsteer and Underbarrow in 2022.
The risk management and assessments process includes six parts:
- Initial Review
- Risk assessment for structural assessment
- Structural Review
- Structural Assessment
- Risk assessment for Management
- Management Plan
Following receipt of the structural assessments of half-joints of Brigsteer and Underbarrow bridges, we instructed Jacobs to undertake a review of the bridges in accordance with National Standard CS470 ‘Management of sub-standard highway structures.’ This resulted in the two bridges being classed as ‘Immediate Risk Structures.
Nothing in our past maintenance regime is likely to have prevented the need to close these bridges. The structural concerns relate to the design of the bridge, not their maintenance.
In 2022 we also commenced the process to check the post-tensioning in accordance with National Standard CS 465 ‘Management of post-tensioned bridges.’ To date we have not undertaken intrusive investigations of the post-tensioning, typically this would follow on from a PTSI inspection, as a further commission.
Why we closed the bridges
Having received the information of structural concerns, we had no other choice than to act and remove all applied load from both bridges by closing access to all pedestrians, cyclists and vehicles.
The decision to close both bridges was unavoidable for the safety of all road users.
Having received the information of structural concerns as a part of our specialist assessment report conducted by Jacobs, we had no other choice than to act and remove all applied load from both bridges by closing access to all pedestrians, cyclists and vehicles.
The report found that Brigsteer and Underbarrow bridges have sustained unrestricted highway loading over a period in excess of 50 years.
The CS 470 report recommended that, to reduce the risk posed by the half-joints both Brigsteer and Underbarrow bridges should be closed to all traffic (i.e. eliminate all live loads on the bridge) and that the half-joints should be monitored.
This includes preventing their use by pedestrians, cyclists, equestrians and vehicles.
Taking into account the condition of the bridges and with monitoring in place, the report recommended that the A591 can safely remain open whilst a more sophisticated assessment, with intrusive works, is undertaken.
Specialist structural reports conducted by Jacobs
We commissioned Jacobs consulting engineers to do a structural assessment of the bridges.
Half-joint assessment report Brigsteer road bridge (PDF , 28MB)
Half-joint assessment report Underbarrow road bridge (PDF , 28.2MB)
Half-joint risk management report Brigsteer road bridge (PDF , 6.3MB)
Half-joint risk management report Underbarrow road bridge (PDF , 6.6MB)
Our short term plan
Our two short-term objectives are to:
- Restore links across the A591 at the bridge sites
- Minimise disruption to the A591
We have commissioned a consulting engineer to undertake a peer review (second opinion) on the findings of Jacobs assessment. WSP are experts in half-joint and post-tensioned bridge assessments and have led on the production of the relevant National Standards referred to previously.
They have also been appointed as our specialist project managers and will conduct an options and feasibility study that will confirm the best short-term solution for restoring the link across the bridges.
The study and will include structural assessment, highway layouts and tie-ins, outline designs of temporary works, impact on public utility apparatus, cost plans and programming.
Possible short term solution options are:
- Propping the bridge at half-joint locations
- Demolition and installation of temporary bridges
- Propping the current bridges and installing temporary bridges
- Support the structure from above the bridge
- More sophisticated analysis of the bridges
Timeline
A Traffic Regulation Order is in place on both bridges for 18 months until 2026 and is the standard duration one can be in place. This is not confirmation of the length of closure which has not yet been determined.
WSP completed a Peer Review of Jacob’s assessment report of the half-joints of Brigsteer and Underbarrow bridges that was issued at the end of July.
The Peer Review did not identify any major flaws in Jacob’s assessment or approach. This confirmed that Westmorland and Furness Council acted appropriately in closing both bridges and, as recommended in Jacobs report, that further assessments, or remedial works should be conducted to establish the bridges are safe.
The Peer Review noted a number of conservative assumptions of the data used in the initial assessments and modelling. Although it is considered unlikely that any of these, if treated in isolation, would provide the increased capacity required to reopen these bridges, a combination of them could be significant.
It has therefore been agreed that WSP continue with further assessments of the half-joints, as recommended in the CS470 reports (Management of Sub-standard Highway Structures), to explore the possibility of reopening the bridges under a weight restriction in the short-term.
Length of closure
Preparations are underway to carry out further essential assessments and monitoring that will determine our next steps and the length of closure.
A Traffic Regulation Order is in place on both bridges until 2026 and is the standard duration one can be in place.
This is not confirmation of the length of closure which has not yet been determined.
How long the precautionary safety assessment will take
We focus our efforts on making the situation safe. Over the coming months we will consider:
- implementation of a further comprehensive monitoring regime, including specialist non-destructive testing
- commissioning further analysis of the bridges to seek any possible improvement on the assessed value
- commissioning an options appraisal for the long-term solutions for the bridges
It won’t be a quick process, there is a requirement to ensure the closure is in place as an interim safety measure.
Fixing the bridges
We recognise the importance of the highways to the local community.
Our teams are having active discussions with the bridge experts to understand potential remedial measures that could allow us to at least partially re-open one or both bridges.
Diversion routes
We recognise the diversion routes adds additional time onto journeys.
The routes have been risk assessed and are the most suitable option in the area for the traffic that is diverted from the bridges. It avoids the narrowest lanes in and around Brigsteer village and narrow points between Brigsteer and Levens.
Cyclists are kindly asked to follow the vehicle diversion and there a signed diversion in place for pedestrians.
Enhancements are currently being made to the diversion routes which include erecting new signage, laying new road markings, clearing vegetation on verges to improve visibility and exploring additional traffic calming measures where appropriate.
Diversions for drivers and cyclists
The Underbarrow Bridge diversion route is via the C5048, U853 Queens Road (Kendal), A5284 Windermere Road (Kendal) , B5284, C5059 and C5048. The length of the diversion is 9.5 miles
The Brigsteer Road Bridge diversion the route is via C5062, U782, U583 Queens Road (Kendal), A5284 Windermere Road (Kendal) , B5284, C5059 and C5062. The length of the diversion diversion is 12.7 miles.
Care operators and emergency services have been informed and are still able to access all villages and support residents in need.
Diversions pedestrians
Find diversions for pedestrians on our recommended pedestrian diversion map (PDF , 911KB).
Impact on traffic in Kendal and surrounding areas
At this time no impact on Kendal has been reported to the highways service or noticed by officers regularly out driving and inspecting the diversion route.
Monitoring will continue to take place over the coming months via data tubes which will be installed to record vehicles levels/usage which we can compare with any historical data we have available.
Reporting road defects on the diversion route
We are monitoring the diversion route and will make repairs to actionable defects when they are identified, or are reported to us via our approved reporting channels:
by calling our highways hotline 0300 373 3300
by completing our highways online reporting form
Any necessary repairs will need to carefully consider traffic management to ensure people can still continue their journeys.