Horseshoe Point
National Grid's ongoing investment programme included the modernisation of cable-tunnel cooling fans near Grain power station. Having secured the £1m+ contract with main contractor BBEA, Allaway Acoustics designed, built, and installed two very large acoustic enclosures, each more than 8m tall and housing two 8.5-tonne fans. Also included in our contract were the massive-section high-pressure ductwork systems and supporting steelwork, plus all the control and pressure relief dampers. At full duty, each system is capable of delivering 58m3/s of air at 7,500Pa on a full “run & standby” basis.
Extensive development work was undertaken to refine the design prior to manufacture, in conjunction with design co-ordinators Tunnel Ventilation Systems. This process included pressure-testing a trial duct section to 35,000Pa (five times the rated system pressure).
The enclosures were pre-assembled in sections at our Thetford factory, and were then craned into place and bolted together. The largest of these sections weighed more than 20 tonnes. The contract was undertaken on a package basis with all necessary subcontractors under our control, working within the stringent NG/BBEA safety framework appropriate for a live substation.
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