Update Monday 3rd December
Following a series of meetings with Network Rail, Derby City Council has announced new plans to complete the re-opening of Alfreton Rd far sooner than previously believed.
Work to complete the structural repair of the bridge will now commence tonight (Monday 3rd December) and continue through the coming weeks, each week-night until the bridge is repaired.
Alfreton Rd will therefore close completely to motorists between 10.00pm and 6.00am each night to allow work to take place safely. A diversion route will be in place and advanced notices advising motorists that the bridge will be shut prior to each night shift will be displayed.
It is hoped the work will be completed before Christmas, however, this is dependent on several variables, such as inclement weather, changes in track availability, and the progress of repairs, and so an exact date cannot be given for the full re-opening at this stage.
Update Friday 16th November
Alfreton Rd will open to one way in bound traffic on schedule, ready for morning commuters, on Monday 19th November.
Update Friday 9th November
On Monday, an urgent Leader of the Council Cabinet meeting will take place to approve the £700k needed to complete the repair of the Alfreton Rd Bridge.
Also on Monday, Severn Trent Water will begin work to repair the road surface and footpath. The bridge will re-open to traffic these repairs are completed and checked.
It is expected that the bridge will re-open to one-way traffic on Monday 19th November – travelling south-bound into Derby only.
Is the bridge safe?
Our assessment shows that the bridge can only support one lane of traffic until it is fully repaired. Monitoring of the bridge since the burst has shown the bridge to be stable. Our results have been checked and verified by an independent engineer.
Why is nobody working on the bridge now?
Works to expose the damage, replace the water main and install new valves on the bridge were carried out by Severn Trent in the weeks following the burst. After that, works were primarily carried out from underneath the bridge.
Since that time assessment and analysis work has been taking place away from the site, along with the contractual arrangements to carry out the structural repairs.
Works will recommence on the bridge on the 12th November 2018 to repair the damaged road surface and footpath.
Why didn’t you do the repair work when the railway was closed for the Derby Station works?
Much investigation and assessment work was carried out during the time the line closure associated with the Derby Station remodelling project was in place. Working with Network Rail we were able to take advantage of gaps in their works to carry out our investigations but we were not in a position to carry out repairs during that time as our assessment of the effect and extent of the damage was not complete. The line reopened on 6th October 2018 and now that it is back in use we must conduct any work underneath the bridge during the times there are no trains running.
Why will the bridge only reopen one-way south-bound? Why not use traffic lights or a north-bound system?
A range of different options were considered for reopening the bridge but it has been decided that it is not possible to install a signalised system without creating additional delays and safety concerns on the A61. The bridge is too close to the roundabout to provide adequate queuing space on the north side of the bridge. This would lead to inevitable gridlock on the A61 at Pektron roundabout and the A38.
Although there are clear in-bound morning and out-bound evening peaks in traffic, there is enough in-bound traffic at all times that we are unable to set the timing sequence in a way to safely manage the traffic. It is not possible to switch from in-bound to out-bound mid-way through the day for safety reasons.
What further repairs do you have to do to open the bridge fully and how long will they take?
To repair the bridge we need work from underneath at track level and replace the lost bricks and mortar. To do this work we need possession of the railway – i.e. no trains running on the lines. Now that the railway has reopened to full rail traffic, our opportunities to work on the line and carry out repairs are greatly restricted.
Our programme of repairs will be scheduled over a series of Saturday evening possessions of the line between 11.00pm Saturday night and 6.00am Sunday morning when there are no trains running on the lines.
We are working with Network Rail to try and secure access to the tracks as soon as, and as frequently as they can allow in order to expedite matters.
The date for a complete reopening is dependent on the availability of rail access and the rate of progress of our repairs and other factors that may affect the works such as inclement weather or cancellation of railway possessions. We will announce a date once we are in a position to do so.
Update: Friday 26th October
Derby City Council and independent engineers have approved the partial re-opening of Alfreton Road. We are working with Severn Trent to complete the ‘above bridge’ repairs to the road surface and to install traffic management as soon as possible and will announce the re-opening date shortly.
Due to the damage caused by the burst water main, the bridge can only be re-opened with restrictions and so a decision has been taken, on the advice of our Traffic and Network Management team, to allow inbound traffic only.
Access to carry out repairs to the bridge itself from the railway line is only possible on Saturday nights and so will be carried out over a period of weeks and only then can the road be fully re-opened.
We are currently working with Severn Trent Water to complete ‘above bridge’ carriageway repairs, followed by the installation of traffic management, as soon as possible. We will announce the date for one- way reopening shortly.
Access to carry out repairs to the bridge itself from the railway line is only possible on Saturday nights and will be carried out over a period of weeks. Once these repairs have been made, the bridge can fully reopen.
As we will be working trackside, we need approval from Network Rail. A date for the commencement of this work is subject to their agreement. Normally Network Rail’s approval process is 18 weeks, however we are currently working with Network Rail to see if this period can be reduced.”
It is now two months since the water main burst on Alfreton Road and understandably people are asking what is being done to get the road open again. Behind the scenes there has been much work taking place on what has proved to be an enormously complex situation.
We wanted to update you on what has happened so far, and where we are now.
On Thursday 9th August, a 15 inch Severn Trent Water (STW) water main burst, flooding the road and railway track nearby.
This was an extremely serious event; it caused major damage to the road surface, creating a large void beneath the surface of the road. Water also ran through the structure of the Grade II listed bridge, and onto the railway lines.
The first issue was the burst main, so following an initial inspection, a full site meeting took place with all the utilities companies who have services going through the bridge to inspect their damaged equipment.
At this stage, it was established that there were serious concerns with the structural integrity of the bridge and that a detailed investigation was required.
Working with STW work was carried out to remove damaged pipe-work, and prepare for work on the road, and the reinstatement of the burst water main.
Due to the Derby Resignalling Project , Network Rail is completing a huge amount of work in the area making access more difficult than usual, however we have worked closely together on this issue and were able to carry out our first detailed inspection of the bridge from the track level on Tuesday 28th August.
The initial results showed that the bridge had a large volume of water inside the structure. This came from the road when it initially flooded, but was running through the bridge for several days. As the water leaked out, this dragged with it brickwork and debris from the bridge.
From this, it was clear that damage was not just to the road, but to the internal structure also, and further testing and inspection would be required, in order to understand the full scope and scale of damage to the bridge.
In early September, access to the railway was agreed with Network Rail, and a second, more intrusive inspection of the bridge was carried out taking samples to establish the condition of the brickwork and fill material.
Results of this showed that the structure as a whole was sounder than original inspections indicated, however geotechnical investigations (to the soil, rock and brick of the bridge) began to give us a better picture of what damage had been done.
Due to the water leaking from the bridge, a number of holes, or voids, were created inside the bridge, and so in mid-September, a Ground Penetrating Radar (GPR) survey was carried out to try to map the location of voids.
While this was happening, STW completed their work to install new valves on either side of the bridge and sleeve new plastic pipe through the remainder of the cast iron pipe in order to reconnect the water supply and by the start of October, STW completed repair work to their damaged pipe.
As we enter October, we have produced a series of drawings, informed by our various investigations of structure, materials and voids illustrating the repair work required.
Results of our investigations are crucial in understanding what we need to do to restore the bridge back to a full strength and address any further deterioration. We are consulting closely with conservation officers to ensure the bridge is properly restored.
In order to make the bridge safe, the process is likely to involve injecting grout into the bridge to fill in the holes, repoint the masonry, and replace any missing bricks to return the structure to full strength.
We continue to work with Network Rail on access agreements to the railway and we are working together to get these repairs completed as quickly as possible.
The investigation reports also allow us to carry out detailed calculations of the load bearing of the bridge as it currently stands. This work is on-going and the results are expected by the end of next week (w/c Monday 8th October). Once the calculations are complete it may be possible to determine if the road can safely be re-opened in some way before the full bridge repairs are complete.
At present, a Road Closure Notice is in place until the end of November.
Cllr Matthew Holmes, Deputy Leader said:
“We appreciate that this situation has been incredibly frustrating for residents and businesses in the area but our priority has to be to ensure the bridge is repaired safely for the long term good of the city’s infrastructure, and to prevent a potential catastrophe.
“We thank everyone for their patience and we continue to do our best to get the road re-opened as soon as possible, given the constraints we face.”