Broadmead Road update - Wednesday, 28 August 2024

Broadmead Road Bridge remains closed to traffic. It was closed due to significant structural defects following an inspection of the bridge. We had no choice but to close the bridge to prevent potential loss of life or serious injury. The public's safety is our top priority.

Broadmead Road bridge is 87 years old, and 87 years ago, the stresses on the bridge were less because cars were lighter, and traffic was less.

The official diversionary route is via the A406 to either Chigwell Road or High Road, Woodford. We know the frustration the bridge closure is causing, and understand it's making journey times for local people much longer. We would like to apologise for the inconvenience this is causing for local people. We are doing all we can to resolve the situation.

Actions we've been taking to help resolve this as far as we can

The Council is following a document called CS470 - Management of sub-standard highway structures. The severe condition of the bridge meant we needed to follow the process outlined in this document. It takes us through what is needed to be done to manage sub-standard structures, or when there could be an immediate risk to public safety.

The identified concerns with the condition of the bridge bring it into the scope of this document. The document provides clear guidance to all in its pages on how sub-standard structures are managed and guidance on what to do if we believe there to be an immediate risk.

By closing the bridge, the Council applied what the document describes as an "urgent application of load mitigation interim measures".

This means we had to reduce the load on the bridge by removing all traffic. We took into consideration the safety of people travelling over the bridge, and those using the Central Line that runs underneath the bridge when making this decision. It was not made lightly, but protecting life had to come first.

At this moment in time there is no evidence that the bridge could collapse under its own weight, however additional inspections and monitoring have been put in place to continue to assess the bridge to ensure the public's safety is protected as far as we can.

Whilst we appreciate it may seem that progress is slow, we are working hard and at pace to move through the required steps of this complex process to ensure the safety of residents and the Central Line.

1. Principal Inspection Report & Hammer Tapping

After the closure of the bridge, we acted quickly to arrange, through TfL, a Principal Inspection and Hammer Tapping. A Principal Inspection is a detailed examination of a structure that aims to look at every single element of it including joints, legs, spans and the bridge deck. Hammer tapping allows the structural engineer to test for defects within the concrete, looking for hollow areas which can expose cracks or voids or even delamination. This is a time-consuming process involving hammer tapping the entire structure, but we had to do this to establish the integrity of the bridge and to allow for full analysis to be undertaken.

The findings will be detailed within the Principal Inspection report.

Making the concrete safe during and after testing

As any areas we investigated were exposed and unstable concrete removed, we applied concrete mortar to make safe those areas and reduce any further degradation from the elements.

The status of this work

The Principal Inspection is 99% complete. We require access to one last remaining room underneath the structure to inspect and hammer tap, which we are looking to get the owner to vacate. Then the Council will be able to finalise its report.

Initial findings (ahead of the report)

The initial findings of the report has demonstrated the Council was right in its decision to instruct the closure of the bridge, and in doing so we have ensured the safety of people travelling over, under and near it.

2. Concrete Testing

The Council commissioned concrete testers to get a detailed analysis of the deterioration of the concrete on the bridge. Samples were taken from the legs, spans, and the bridge deck in late Spring and have been sent back to the laboratory for testing. The tests will allow the engineers to determine the level of deterioration that has taken place since the bridge was first constructed, they will also allow us to determine the current structural load capacity of the bridge (ie the weight and whether any activity of traffic over the bridge, that it may be able to bear). This will take time to calculate and check.

Initial findings

The preliminary findings of the concrete testing do indicate structural wear and tear and the defects presented are similar across the bridge. The defects are a combination of natural erosion over time, which is known as carbonation. This can cause the corrosion of concrete. Other deterioration has been noted as a result of the use of de-icing materials when we undertake gritting.

Pedestrians, cyclists and motorcyclists using the footpath

The Council has instructed the amendment of the traffic management of the bridge. Once the traffic order is confirmed and the materials received, work will begin to remove the heras fencing and install planters to allow motorcyclists and cyclists to use the road of the bridge instead of the footpath where pedestrians are. After careful and considered analysis, the engineers have said that allowing cyclists and motorcyclists on the bridge is safe.

3. Next Steps - Options Report

The next step in the process after the concrete samples have been fully tested and load capacity calculated is the options report. This will provide the Council with a set of options on what can be done with the bridge, whether it be replacement options, different repair and protection options or other options the engineers see fit to propose.

We do understand the time-consuming process we're undertaking means journey times are longer for people living and travelling nearby, and we do sincerely apologise for the inconvenience this is causing. The systematic approach we're taking to assessing the structure is essential in ensuring we protect the safety of local people, which we will always put first.