Dairyland Steam Power Station Chimney
PROJECT OUTLINE
After experiencing difficulties with a demolition contractor performing the removal of a power plant at their site in Alma, Wisconsin, Dairyland Power Cooperative (DPC) retained the services of American Demolition & Nuclear Decommissioning (ADND) to inspect the remaining 700’ tall, thin shell, reinforced concrete windscreen, and free-standing radial brick flue, as well as put the project out to bid and select the contractors to get the structure on the ground without interrupting service to the switchyard, which remained active immediately behind the chimney.
PROJECT PLANNING
ADND selected the preparation and demolition proposal put forward by CDI due to their detailed inspection of the structure, identification of structural faults and other considerations that had to be dealt with during preparations before bringing the structure to grade.
The chimney had to be perfectly felled in between active high-tension lines along the east side of the site and railroad main lines that parallel the fall area to the west. That level of control required CDI to design a reinforced concrete plug system to be placed in existing openings in the chimney to create a symmetrical base about which the chimney could be rotated and felled per plan.
ADND contracted installation of the concrete plugs per CDI’s design and contracted with other local firms to perform saw-cutting of precise hinges to control the fall and columns to be blasted by CDI to initiate the felling sequence.
THE DETONATION
CDI drilled elements in the chimney for placement and detonation of 310 lb of explosives to fell the structure exactly on the center line which was staked out by CDI leading up to the project.
There was no fly of debris, interruption of service through the switchyard to the rear of the chimney or interruption of high-tension line service adjacent to the fall area. Rail service on the opposite side of the fall area was halted for less than an hour before service was restored.
Click HERE to watch the Dairyland Chimney implosion.
