State-of- the-art energy-from- waste plant
The Buckinghamshire Waste Management Facility is a major new EfW (Energy from Waste) plant located at Greatmoor, nine miles from the town of Aylesbury.
The plant is being constructed by principal contractor Sir Robert McAlpine, working on behalf of plant process provider Hitachi Zosen Inova AG. Caunton has supplied and erected 2,000 tonnes of structural steelwork for the project.
When operational the plant will benefit both the environment and the country by reducing reliance on landfill, increasing the recycling of waste and generating 22MW of electricity – enough to power 36,000 homes.
The tallest part of the structure, excluding the emissions stack, is almost 53m high, and the plant consists of several process areas; tipping hall, waste bunker hall, boiler hall, flue gas treatment area, turbine hall and admin offices. Cranes are installed in several locations and Caunton was responsible for the supply and erection of the structures supporting these.
An architectural feature of the project is the ACC canopy, which passes over the top of low-level plant. The two sides of the canopy are an extension of the feature cladding bands that arch across the entire length of the plant on both sides.
Fully modelled by the client HZI, the project model was given to the construction team in Navisworks format for the purposes of visualisation, coordination and sequencing of the works. Caunton used the model to extract information and coordinate construction interfaces.
The level of detail in the model was high enough to visualise all aspects of the project and proved extremely useful when planning our site activities around those carried out by other trade and plant installation contractors.
Tekla model constructed to LOD 400
Our Tekla structural model was constructed to a similar high level of detail, (LOD 400 in BIM terms), sufficient to extract all necessary manufacturing data for our NC machines, fabrication drawings for our production assembly teams and all installation information used by our site teams. This process is routine on all of our projects, whether or not they are to be carried out to a formal BIM protocol.
Logistics of working at heights of up to 53m presented challenges for our installation teams and some parts of the structure could only be accessed by our erectors working from man baskets, rather than the usual method of MEWPs. This was also partly due to restrictions of already installed plant structures and equipment.
Arched box girder trusses, 1.8m wide x 1.5m high, form the feature ACC canopy. The trusses were manufactured in sections of between 13m and 16m long, and some of them had to be erected over the top of a low-level structure and equipment that had already been installed.
The box girders are fully clad and it was decided that in light of the extremely difficult access for the cladding contractor they would be mostly clad at ground level and then lifted into position by Caunton. Final installation of cladding at the connection interfaces was then done in-situ by the cladder.
All structural steel was supplied in hot dip galvanized finish to reduce maintenance needs during the life of the project.
The majority of our works were completed on programme, over a six-month period, with a return visit approximately four months later to install the ACC canopy steel.