Minnesota, USA-based Rachel Contracting is bringing down a massive 65,000 sq m (700,000 sq ft) complex with a range of machinery including a newly-designed tool from Genesis Attachments.
The former West Publishing headquarters, built in 1886, and the Ramsey County Adult Detention Center (ADC), built in 1979, were mainstays of the St Paul riverfront landscape.
The complex had outlived its usefulness when West relocated to a suburb, and the jail was quickly deemed inadequate. Repeated efforts to sell the property were hindered by the daunting thought of demolishing the existing structures, which rise up to 10 storeys from the base of a riverside bluff. Eventually, Ramsey County committed to undertaking the demolition, using Rachel Contracting for the job.
The eight-story ADC is the first structure slated to come down. Work on it started in August 2015 with interior demolition, according to Mark Kraemer, Rachel’s vice president of field operations.
The height of the structures, more than 27 m (88 ft) in most areas, coupled with their proximity to active pedestrian, vehicle and train traffic, eliminated the use of any of the more traditional demolition techniques such as implosion or a wrecking ball.
The alternative, a high reach excavator outfitted with a GDT Razer 290 from Genesis Attachments, fitted the bill perfectly, said Mark.
“We have the GDT mounted on a Volvo EC700C HR, a 89 t base machine with the high reach package,” he said. “That configuration affords us just over 27 m of reach, more than enough for even the uppermost reaches of the ADC structure. Our options were definitely limited by our surroundings. An active Amtrak rail line runs as close as 7 m (23 ft) to one side of the jail, and one corner of the structure is just feet from the heavily-travelled Wabasha Street Bridge.
“Through a combination of the attachment’s rotation and its design, the GDT Razer is able to easily access every area we need to get at.”