Structural Works for Bio-mass Eco Store Project

The new Biomass Eco-Store Project at Drax Power Station involves the construction of facilities to import bio-mass fuel (shredded wood and plant material) by rail into Drax Power Station and to unload, store and feed the bio-mass into the Power Station burners to generate electricity for the National Grid.

We were contracted to construct the works substructure and external works on which the mechanical conveyor feeds and storage buildings were to be erected. The substructure works were to be located in deep excavations adjacent to a rail line, working within a high risk environment (Power Station) and involved the delivery of a large volume of work within a short period of time and with high cost and programme impacts with other trade disciplines and contractor work packages.

The substructure itself consists of four tunnels, each 200 meters long and made up of 109 complete arch precast concrete units sat on a concrete ground slab sloping from a depth of 15 metres to ground level. In addition insitu concrete shafts and base foundations were required to accept the above ground storage buildings and the mechanical and electrical feeders and conveyor equipment which stores and then transports the biomass from above ground into the tunnels and then onto the power plant furnaces.

The sectional completion time for the substructure delivery was just 36 weeks. On award of the contract we looked to mitigate the programme risks associated with transporting 436 precast units each weighing 17 tonnes from the nominated manufacturer to site and through the high security arrangements at the Power Station.

It was agreed that we would set up a precast yard on the Power Station and Manufacture quality assured units for the proposed works themselves. The 17 tonne units, once manufactured and cured, were transported across site by heavy duty forklift truck and craned into position by 250t and 350 t cranes required due to the lift radius into the deep excavations. Lifts were further restricted due to the rail line bordering one side of the tunnel runs and the overhead lines on the other.

Works on the tunnel and substructure construction were completed both to programme and budget

Structural Works for Bio-mass Eco Store Project

Client: Drax Power Station, Shepherd Construction
Location: Drax Power Station
Contract Value: £7.5m
Contract Period: 14 months