Stobart Developments and Burmeister & Wain Scandinavian Contractor (BWSC) were responsible for building the largest combined heat and power (CHP) site in the North West of England. Located in Widnes, Cheshire, the Stobart Group is the landowner, investor and fuel supplier for the plant.

Stobart Energy will supply the scheme with 146,000 tonnes of waste wood each year, worth £108 million over a 16-year contract. It will also use heat from the plant for a neighbouring wood drying facility, which will dry 140,000 tonnes of virgin wood material a year for sale into the wood chip and pellet market. The plant will provide enough renewable electricity to power more than 35,000 homes each year.

Due to some of the challenges on site, Stobart Developments turned to RMD Kwikform to provide a range of formwork and shoring solutions to construct a multitude of superstructure and substructure works.

As many of the construction works were being undertaken simultaneously, coordination and collaboration was essential. Kevin Smith, project manager at Stobart Developments, said: “This is a very important project; it will be the largest biomass waste wood to energy producing plant in the North West of England. Due to the close proximity of various works on site, such as the construction of the fuel store, service building and turbine building, we needed a solution that would enable the site team to work productively and safely.

“We chose to work with RMD Kwikform as we could reuse the kit and maximise its usage for various elements of the project, which has helped us to coordinate deliveries and reduce storage space, saving us time and money.”

Stobart Developments worked with RMD Kwikform from the very inception of the project, designing multiple solutions to construct the various buildings on site. RMD Kwikform’s Maxima panel formwork was supplied for retaining and upper walls, Minima panels for the sub-structure works, and Alshor and Alstair for access and soffit support.

The largest element of the project was the large-scale fuel store, with 6.7 metre-high and 22 metre-long retaining walls. Using Maxima Panels, the super-structure concrete walls were cast in a four stage pour sequence, with the shutters being reused twice for each wall, allowing the site team to construct the reinforced concrete slab after each sequence.

Alongside a multitude of ongoing works, one of the key challenges was the boiler building. The 125-tonne boiler is positioned inside a steel structure, and Stobart Developments and RMD Kwikform had to overcome interface challenges with regards to how the site team executed the concrete works. With other subcontractors working on one side of the building, Stobart Developments constructed the other three sides concurrently using RMD Kwikform’s kit.

The basic substructure works on the project consisted of burning down piles, and then introducing pile caps on top of the tubular steel piles, utilising Maxima and Minima panel formwork. Following on from this were the ground-beams, ground floor slabs, associated pits, and then superstructure concrete walls.

Kevin continues: “We had over 70 people on site, solely from Stobart Developments, along with many other people from other subcontractors; it was vital that we got the sequence and logistics right to manage this project efficiently. We worked very closely with RMD Kwikform in designing and redesigning solutions in line with changes on site; the team’s technical expertise and equipment versatility is accountable for the success of this project to date.”