Active collaboration
As a part of the Environmental Agency’s flood alleviation scheme, a start on the project was made at the beginning of August 2023, with most of the project work carried out by specialist subcontractor Beaver Bridges and with Jackson taking a management role.
Jackson Senior Project Manager, Darren Blank said the Jackson team established “a good collaborative relationship” with Beaver Bridges’ Operations team and their Project Manager, who also attended all client meetings.
Together they worked through design changes – mostly relating to the bearing shelves on the bridge abutments and the work required on the central pier, which had degraded more than had previously been thought.
Environmental considerations
Large structures were not permitted in the river channel under the bridge due to fears this could increase flood risks by forming a potential dam. This meant that the team could not use a splash deck to capture any debris that might fall when the structure was being dismantled.
Instead, a plastic sheet was fixed into the underside of the old bridge (a floating capture system) via teams accessing the area by rope. To lighten the weight of the old span decks, squares were cut out of the bottom and taken out. The debris caught in the plastic sheeting was removed using vacuum excavation equipment.
Removing old footbridge decks
A 24hr bridge closure was required to accommodate removal of the old decks and Beaver Bridges used a 250t crane to extract the footbridge in three sections. The old decks were then transported for recycling.
Senior Project Manager Darren Blank said: “The removal of the old bridge was very challenging in itself. Both lifting and flood risk constraints forced us to utilise more difficult techniques to allow removal. This also had to be completed without environmental incident and the utmost time and care was taken to ensure this.”
The bridge had to be reopened to traffic by 8am the next day, adding to the pressure.
Positioning the new footbridge
There was an ever present danger to the workforce of flash floods and river level monitoring equipment was placed on the bridge and consulted regularly, alongside weather forecasts. Just six weeks after the old structure was removed, the 250t crane returned and was back in position and the two new concrete slabs arrived on flatbed trucks, ready to be dropped in one at a time. The North span (composite bridge, steel beam, concrete deck) delivered by crane, was fitted in complete. The South span section, however, was first cast with concrete before being lowered in. By midnight both sections of the footbridge were safely in position.
Community interaction
Jackson worked closely with the local community and businesses. Letters were sent to approximately 100 addresses in the immediate area, giving residents and business owners a brief overview of the work that was to be carried out. A further letter was sent to local residents informing them of an overnight road closure.
Café business Jo’s Kitchen and Mytholmroyd Community Centre were both high interest stakeholders. Jo’s Café had access from their front door to the footbridge and the community centre car park housed the site cabins. Jackson communicated face-to face with these business owners and Jo Ward, owner of the Café was invited to cut the ribbon at the bridge opening.
Proximity to a heritage structure
The adjacent New Road bridge to which the footbridge abuts, is Grade II listed. Parts of the structure date back to 1684, which meant Jackson had to liaise with Historic England throughout the project. Heritage officials were invited to inspect the structure after the old footbridge was removed to see if there was anything of interest. The mortar (lime) used on the project was pre-approved, as were the colour and types of stone used on the cladding.
Darren Blank said: “Working with a listed structure was major consideration - we liaised with the heritage reps and ensured that it was both protected and in places, remediated with full compliance with their spec. Mortar was pre-approved and samples were created to ensure they could sign off on the materials well ahead of use.”
Dogleg ramp
Adjustments to the bridge abutments meant that a single ramp access point to the footbridge from the main road, would have been too steep for pedestrians and wheelchair users.
The Highways team therefore devised a dogleg design with a gentler slope. Poor weather held up application of a resin bound aggregate to the surface. The resin needs two to three days of good weather to set or the resin goes milky – adversely affecting the look of the structure. A temporary tent over this section kept the rain off and enabled the job to be completed.
Local considerations
The local wildlife was also accommodated. The river channel is a bat corridor and the bridge itself provides roosting spots. A pre-approved bat roost (see grey box - right of image) was installed under the bridge to provide further roosting space.
The new Mytholmroyd footbridge was officially opened on Wednesday 20th March 2024 by local businessperson, Jo Ward. People came along to celebrate the bridge opening and congregated on the structure for a picture to mark the occasion. First elected Mayor of West Yorkshire, Tracy Brabin said: “It’s great to see the new footbridge open as part of a wide range of projects to improve walking and cycling facilities in Calderdale."
