Westfield EfW

In June 2022, careys commenced the delivery of the £21.5m westfield EfW project for Hitachi Zosen inova ( HZI ). It will run for 55 weeks and see Careys workforce peaking between 60 and 130 operatives on site.

Renewable Energy Developer, Brockwell Energy, says the facility will be a "cost efficient residual waste disposal option" for fife council and other Scottish local authorities that have not yet secured this kind of disposal route for waste . The state of-the-art plant will assist in meeting the Scottish Government`s environmental and legislative targets in advance of the landfill ban implemented in 2025.

Scope of works

Our scope on the project includes:

• Earthworks (bunker excavation, reduced level excavations and capping to lay down, compound and car park)
• RC Raft Slab Construction to Waste Bunker, Boiler House, FGT, Ash Bunker, Turbine Hall
• RC Foundations and Ground Slabs in Tipping Hall, ACC, Transformer, and other buildings
• Large RC Bunker Wall Construction (the remote location of the site means concrete delivery during the slipform operations for the bunker posed a challenge for the team, but this will be overcome through the use of an on-site concrete batching plant).
• Attenuation Ponds
• Underground and Cast in Slab Drainage and Tanks
• Underground and Cast in Slab Service
• Earthing
• Hard Landscaping
• Fencing

Slipform

The waste bunker at Westfield was constructed in November 2022 using a traditional 3 deck slipform rig supplied by UK slipform. The waste bunker consists of 5 number chute openings. It is 26m long, 20m wide and 33m high. The structure started at 10m below ground, rising to +23m on 3 sides with one section of wall rising a further 3.6m to +26.6m.

A tower crane was positioned centrally inside the bunker on a cruciform base with 180T of ballast to feed the slipform rig. We also had a 90T crawler crane located at the top of the bunker excavation to feed the tower as required.

The overall volume of concrete placed was 2,794m3. All concrete was produced by an onsite batching plant which was set up specifically for the slipforming operation. Concrete was placed to the rig using two static concrete pumps located at the top of the bunker excavation, which pumped the concrete to two placing booms situated on top of 20m free standing stacks within the bunker.