WATSON STEEL STRUCTURES LTD
BAM NUTTALL LTD
LAKESIDE ENERGY FROM WASTE LTD
Lakeside Energy from Waste plant is a state-of-the-art facility to convert household waste into electrical energy. The new plant consists of three processes:-
- A clinical waste incinerator which provides a safe means of disposing of waste from the healthcare centre
- A material recycling facility to separate out any materials from commercial and household waste which can be re-used – up to 40,000 tonnes per year of waste is planned to be re-cycled
- The remaining waste (approx 400,000 tonnes per year) is incinerated, and the energy released is converted into electricity – the facility will produce 32 mega-watts of power
Adopting a steel solution enabled a building of over 40m high to be constructed whilst maximising the internal space. This was achieved by using a series of long span beams and trusses for roof construction and unrestrained central columns up to 42m in length. The overall delivery programme required many sections of the plant process equipment to be installed prior to the roof structure installation. The frame was required to be erected in four main stages within the overall programme, thus each part frame needed to be independently framed for overall stability under temporary loading conditions.
The weight and component size of the process plant contained within the building dictated that the shell had to be constructed from the inside out – hence the main components of the generating process and all the associated pipe works and support steel had to be installed first while crane access was available from above. The shell had then to be erected over the top of this, which meant that all crane and man access had to be from outside of the building shell. The steel was designed in long span sections to minimise the number and weight of connections that needed to be accessed. The bracing was concentrated around the perimeter where access by MEWP was possible and columns were spliced to minimise length when being lifted over existing structures.
The sides of the building are curved on plan, translating an ovoid shape on the ground, and the roof is a curve which changes in pitch, steepening towards the chimney. The combination of these factors resulted in eaves that transcribe a spiral along the building, which made accuracy of fabrication and erection paramount. The geometry of the Y shaped columns is different at each location and these were required to be welded in-situ due to transportation limitations, requiring a high degree of accuracy of fabrication and considerable skill by the welders and engineering staff on site.
The building contains several free standing columns of up to 42m in height. These are formed from two UB sections welded into both symmetric and asymmetric cruciform sections – the straightness of these sections was vital.
In order to minimise the visual impact of the external plant on the roof, two large downstand recesses (18m by 10m by 2m deep) were framed into the overall roof profile. The chimney flues extend vertically by 75 metres and therefore are the most visual part of the building. The architect cleverly extended the roof structure around the chimney by incorporating a dipped curved edge, which represents the tip of the ‘aeroplane wing’.
This striking building combines the functional requirements of an industrial process with excellent architecture and demonstrates that industrial buildings can be both attractive and efficient.
A large multi facetted waste plant and offices have been accommodated in a dramatic, racy envelope. The heavy long-span steel roof structure is practical and economic, and erection so close to the Heathrow flight paths was a major challenge.
An important project demonstrating how unpopular, but increasingly common, waste incineration/energy plants can be handled prominently and effectively.