Old technologies adapted for ventilation chimney at Chester Zoo
Laing O’Rourke have completed work on a new tropical animal house at Chester Zoo. One of the many challenges they faced was to ensure that the necessary heat required for a tropical animal house was at a constant temperature throughout the new structure and that any excess heat generated could be stored, recycled and, if necessary, vented.
To achieve this aim, Laing O’Rourke worked collaboratively with the CPM Group.
CPM engineers suggested in order to maintain structural integrity for the two chimneys required, standard DN2100mm chamber ring sections could be strapped together employing galvanised steel straps for rigidity, much needed as the two chimneys were over 7000mm high and 11000mm in height respectively.
CPM engineers were also tasked with ensuring that maintenance could be safely affected once the ventilation chimneys were in place. To this end, special cuts were made into the lower units of the chimney stacks to allow not only access, but also the delivery of component parts for a winding steel staircase structure to be erected inside the chimney.
Once the basic structures were in place, Laing O’Rourke and subcontractor Kago-Hammerschmidt, by fixing a composite, sculpted mesh frame to the ring sections and applied spray concrete (Shotcrete). This concrete surface was coloured and detailed by hand to create a tree trunk facade to the chimneys which blended into the surrounding jungle environment. The entire cladding system was supported by brackets post fixed into the ring sections.